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Diffstat (limited to 'include/linux/fs.h')
| -rw-r--r-- | include/linux/fs.h | 3689 |
1 files changed, 3689 insertions, 0 deletions
diff --git a/include/linux/fs.h b/include/linux/fs.h new file mode 100644 index 000000000..f9d1e05e8 --- /dev/null +++ b/include/linux/fs.h @@ -0,0 +1,3689 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _LINUX_FS_H +#define _LINUX_FS_H + +#include <linux/fs/super.h> +#include <linux/vfsdebug.h> +#include <linux/linkage.h> +#include <linux/wait_bit.h> +#include <linux/kdev_t.h> +#include <linux/dcache.h> +#include <linux/path.h> +#include <linux/stat.h> +#include <linux/cache.h> +#include <linux/list.h> +#include <linux/llist.h> +#include <linux/radix-tree.h> +#include <linux/xarray.h> +#include <linux/rbtree.h> +#include <linux/init.h> +#include <linux/pid.h> +#include <linux/bug.h> +#include <linux/mutex.h> +#include <linux/rwsem.h> +#include <linux/mm_types.h> +#include <linux/capability.h> +#include <linux/semaphore.h> +#include <linux/fcntl.h> +#include <linux/rculist_bl.h> +#include <linux/atomic.h> +#include <linux/shrinker.h> +#include <linux/migrate_mode.h> +#include <linux/uidgid.h> +#include <linux/lockdep.h> +#include <linux/percpu-rwsem.h> +#include <linux/workqueue.h> +#include <linux/delayed_call.h> +#include <linux/uuid.h> +#include <linux/errseq.h> +#include <linux/ioprio.h> +#include <linux/build_bug.h> +#include <linux/stddef.h> +#include <linux/mount.h> +#include <linux/cred.h> +#include <linux/mnt_idmapping.h> +#include <linux/slab.h> +#include <linux/maple_tree.h> +#include <linux/rw_hint.h> +#include <linux/file_ref.h> +#include <linux/unicode.h> + +#include <asm/byteorder.h> +#include <uapi/linux/fs.h> + +struct bdi_writeback; +struct bio; +struct io_comp_batch; +struct fiemap_extent_info; +struct kiocb; +struct kobject; +struct pipe_inode_info; +struct poll_table_struct; +struct kstatfs; +struct vm_area_struct; +struct vfsmount; +struct cred; +struct swap_info_struct; +struct seq_file; +struct iov_iter; +struct fsnotify_mark_connector; +struct fs_context; +struct fs_parameter_spec; +struct file_kattr; +struct iomap_ops; +struct delegated_inode; + +extern void __init inode_init(void); +extern void __init inode_init_early(void); +extern void __init files_init(void); +extern void __init files_maxfiles_init(void); + +extern unsigned long get_max_files(void); +extern unsigned int sysctl_nr_open; + +typedef __kernel_rwf_t rwf_t; + +struct buffer_head; +typedef int (get_block_t)(struct inode *inode, sector_t iblock, + struct buffer_head *bh_result, int create); +typedef int (dio_iodone_t)(struct kiocb *iocb, loff_t offset, + ssize_t bytes, void *private); + +#define MAY_EXEC 0x00000001 +#define MAY_WRITE 0x00000002 +#define MAY_READ 0x00000004 +#define MAY_APPEND 0x00000008 +#define MAY_ACCESS 0x00000010 +#define MAY_OPEN 0x00000020 +#define MAY_CHDIR 0x00000040 +/* called from RCU mode, don't block */ +#define MAY_NOT_BLOCK 0x00000080 + +/* + * flags in file.f_mode. Note that FMODE_READ and FMODE_WRITE must correspond + * to O_WRONLY and O_RDWR via the strange trick in do_dentry_open() + */ + +/* file is open for reading */ +#define FMODE_READ ((__force fmode_t)(1 << 0)) +/* file is open for writing */ +#define FMODE_WRITE ((__force fmode_t)(1 << 1)) +/* file is seekable */ +#define FMODE_LSEEK ((__force fmode_t)(1 << 2)) +/* file can be accessed using pread */ +#define FMODE_PREAD ((__force fmode_t)(1 << 3)) +/* file can be accessed using pwrite */ +#define FMODE_PWRITE ((__force fmode_t)(1 << 4)) +/* File is opened for execution with sys_execve / sys_uselib */ +#define FMODE_EXEC ((__force fmode_t)(1 << 5)) +/* File writes are restricted (block device specific) */ +#define FMODE_WRITE_RESTRICTED ((__force fmode_t)(1 << 6)) +/* File supports atomic writes */ +#define FMODE_CAN_ATOMIC_WRITE ((__force fmode_t)(1 << 7)) + +/* FMODE_* bit 8 */ + +/* 32bit hashes as llseek() offset (for directories) */ +#define FMODE_32BITHASH ((__force fmode_t)(1 << 9)) +/* 64bit hashes as llseek() offset (for directories) */ +#define FMODE_64BITHASH ((__force fmode_t)(1 << 10)) + +/* + * Don't update ctime and mtime. + * + * Currently a special hack for the XFS open_by_handle ioctl, but we'll + * hopefully graduate it to a proper O_CMTIME flag supported by open(2) soon. + */ +#define FMODE_NOCMTIME ((__force fmode_t)(1 << 11)) + +/* Expect random access pattern */ +#define FMODE_RANDOM ((__force fmode_t)(1 << 12)) + +/* Supports IOCB_HAS_METADATA */ +#define FMODE_HAS_METADATA ((__force fmode_t)(1 << 13)) + +/* File is opened with O_PATH; almost nothing can be done with it */ +#define FMODE_PATH ((__force fmode_t)(1 << 14)) + +/* File needs atomic accesses to f_pos */ +#define FMODE_ATOMIC_POS ((__force fmode_t)(1 << 15)) +/* Write access to underlying fs */ +#define FMODE_WRITER ((__force fmode_t)(1 << 16)) +/* Has read method(s) */ +#define FMODE_CAN_READ ((__force fmode_t)(1 << 17)) +/* Has write method(s) */ +#define FMODE_CAN_WRITE ((__force fmode_t)(1 << 18)) + +#define FMODE_OPENED ((__force fmode_t)(1 << 19)) +#define FMODE_CREATED ((__force fmode_t)(1 << 20)) + +/* File is stream-like */ +#define FMODE_STREAM ((__force fmode_t)(1 << 21)) + +/* File supports DIRECT IO */ +#define FMODE_CAN_ODIRECT ((__force fmode_t)(1 << 22)) + +#define FMODE_NOREUSE ((__force fmode_t)(1 << 23)) + +/* File is embedded in backing_file object */ +#define FMODE_BACKING ((__force fmode_t)(1 << 24)) + +/* + * Together with FMODE_NONOTIFY_PERM defines which fsnotify events shouldn't be + * generated (see below) + */ +#define FMODE_NONOTIFY ((__force fmode_t)(1 << 25)) + +/* + * Together with FMODE_NONOTIFY defines which fsnotify events shouldn't be + * generated (see below) + */ +#define FMODE_NONOTIFY_PERM ((__force fmode_t)(1 << 26)) + +/* File is capable of returning -EAGAIN if I/O will block */ +#define FMODE_NOWAIT ((__force fmode_t)(1 << 27)) + +/* File represents mount that needs unmounting */ +#define FMODE_NEED_UNMOUNT ((__force fmode_t)(1 << 28)) + +/* File does not contribute to nr_files count */ +#define FMODE_NOACCOUNT ((__force fmode_t)(1 << 29)) + +/* + * The two FMODE_NONOTIFY* define which fsnotify events should not be generated + * for an open file. These are the possible values of + * (f->f_mode & FMODE_FSNOTIFY_MASK) and their meaning: + * + * FMODE_NONOTIFY - suppress all (incl. non-permission) events. + * FMODE_NONOTIFY_PERM - suppress permission (incl. pre-content) events. + * FMODE_NONOTIFY | FMODE_NONOTIFY_PERM - suppress only FAN_ACCESS_PERM. + */ +#define FMODE_FSNOTIFY_MASK \ + (FMODE_NONOTIFY | FMODE_NONOTIFY_PERM) + +#define FMODE_FSNOTIFY_NONE(mode) \ + ((mode & FMODE_FSNOTIFY_MASK) == FMODE_NONOTIFY) +#ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS +#define FMODE_FSNOTIFY_HSM(mode) \ + ((mode & FMODE_FSNOTIFY_MASK) == 0 || \ + (mode & FMODE_FSNOTIFY_MASK) == (FMODE_NONOTIFY | FMODE_NONOTIFY_PERM)) +#define FMODE_FSNOTIFY_ACCESS_PERM(mode) \ + ((mode & FMODE_FSNOTIFY_MASK) == 0) +#else +#define FMODE_FSNOTIFY_ACCESS_PERM(mode) 0 +#define FMODE_FSNOTIFY_HSM(mode) 0 +#endif + +/* + * Attribute flags. These should be or-ed together to figure out what + * has been changed! + */ +#define ATTR_MODE (1 << 0) +#define ATTR_UID (1 << 1) +#define ATTR_GID (1 << 2) +#define ATTR_SIZE (1 << 3) +#define ATTR_ATIME (1 << 4) +#define ATTR_MTIME (1 << 5) +#define ATTR_CTIME (1 << 6) +#define ATTR_ATIME_SET (1 << 7) +#define ATTR_MTIME_SET (1 << 8) +#define ATTR_FORCE (1 << 9) /* Not a change, but a change it */ +#define ATTR_CTIME_SET (1 << 10) +#define ATTR_KILL_SUID (1 << 11) +#define ATTR_KILL_SGID (1 << 12) +#define ATTR_FILE (1 << 13) +#define ATTR_KILL_PRIV (1 << 14) +#define ATTR_OPEN (1 << 15) /* Truncating from open(O_TRUNC) */ +#define ATTR_TIMES_SET (1 << 16) +#define ATTR_TOUCH (1 << 17) +#define ATTR_DELEG (1 << 18) /* Delegated attrs. Don't break write delegations */ + +/* + * Whiteout is represented by a char device. The following constants define the + * mode and device number to use. + */ +#define WHITEOUT_MODE 0 +#define WHITEOUT_DEV 0 + +/* + * This is the Inode Attributes structure, used for notify_change(). It + * uses the above definitions as flags, to know which values have changed. + * Also, in this manner, a Filesystem can look at only the values it cares + * about. Basically, these are the attributes that the VFS layer can + * request to change from the FS layer. + * + * Derek Atkins <warlord@MIT.EDU> 94-10-20 + */ +struct iattr { + unsigned int ia_valid; + umode_t ia_mode; + /* + * The two anonymous unions wrap structures with the same member. + * + * Filesystems raising FS_ALLOW_IDMAP need to use ia_vfs{g,u}id which + * are a dedicated type requiring the filesystem to use the dedicated + * helpers. Other filesystem can continue to use ia_{g,u}id until they + * have been ported. + * + * They always contain the same value. In other words FS_ALLOW_IDMAP + * pass down the same value on idmapped mounts as they would on regular + * mounts. + */ + union { + kuid_t ia_uid; + vfsuid_t ia_vfsuid; + }; + union { + kgid_t ia_gid; + vfsgid_t ia_vfsgid; + }; + loff_t ia_size; + struct timespec64 ia_atime; + struct timespec64 ia_mtime; + struct timespec64 ia_ctime; + + /* + * Not an attribute, but an auxiliary info for filesystems wanting to + * implement an ftruncate() like method. NOTE: filesystem should + * check for (ia_valid & ATTR_FILE), and not for (ia_file != NULL). + */ + struct file *ia_file; +}; + +/* + * Maximum number of layers of fs stack. Needs to be limited to + * prevent kernel stack overflow + */ +#define FILESYSTEM_MAX_STACK_DEPTH 2 + +/** + * enum positive_aop_returns - aop return codes with specific semantics + * + * @AOP_WRITEPAGE_ACTIVATE: Informs the caller that page writeback has + * completed, that the page is still locked, and + * should be considered active. The VM uses this hint + * to return the page to the active list -- it won't + * be a candidate for writeback again in the near + * future. Other callers must be careful to unlock + * the page if they get this return. Returned by + * writepage(); + * + * @AOP_TRUNCATED_PAGE: The AOP method that was handed a locked page has + * unlocked it and the page might have been truncated. + * The caller should back up to acquiring a new page and + * trying again. The aop will be taking reasonable + * precautions not to livelock. If the caller held a page + * reference, it should drop it before retrying. Returned + * by read_folio(). + * + * address_space_operation functions return these large constants to indicate + * special semantics to the caller. These are much larger than the bytes in a + * page to allow for functions that return the number of bytes operated on in a + * given page. + */ + +enum positive_aop_returns { + AOP_WRITEPAGE_ACTIVATE = 0x80000, + AOP_TRUNCATED_PAGE = 0x80001, +}; + +/* + * oh the beauties of C type declarations. + */ +struct page; +struct address_space; +struct writeback_control; +struct readahead_control; + +/* Match RWF_* bits to IOCB bits */ +#define IOCB_HIPRI (__force int) RWF_HIPRI +#define IOCB_DSYNC (__force int) RWF_DSYNC +#define IOCB_SYNC (__force int) RWF_SYNC +#define IOCB_NOWAIT (__force int) RWF_NOWAIT +#define IOCB_APPEND (__force int) RWF_APPEND +#define IOCB_ATOMIC (__force int) RWF_ATOMIC +#define IOCB_DONTCACHE (__force int) RWF_DONTCACHE +#define IOCB_NOSIGNAL (__force int) RWF_NOSIGNAL + +/* non-RWF related bits - start at 16 */ +#define IOCB_EVENTFD (1 << 16) +#define IOCB_DIRECT (1 << 17) +#define IOCB_WRITE (1 << 18) +/* iocb->ki_waitq is valid */ +#define IOCB_WAITQ (1 << 19) +#define IOCB_NOIO (1 << 20) +/* can use bio alloc cache */ +#define IOCB_ALLOC_CACHE (1 << 21) +/* kiocb is a read or write operation submitted by fs/aio.c. */ +#define IOCB_AIO_RW (1 << 22) +#define IOCB_HAS_METADATA (1 << 23) + +/* for use in trace events */ +#define TRACE_IOCB_STRINGS \ + { IOCB_HIPRI, "HIPRI" }, \ + { IOCB_DSYNC, "DSYNC" }, \ + { IOCB_SYNC, "SYNC" }, \ + { IOCB_NOWAIT, "NOWAIT" }, \ + { IOCB_APPEND, "APPEND" }, \ + { IOCB_ATOMIC, "ATOMIC" }, \ + { IOCB_DONTCACHE, "DONTCACHE" }, \ + { IOCB_EVENTFD, "EVENTFD"}, \ + { IOCB_DIRECT, "DIRECT" }, \ + { IOCB_WRITE, "WRITE" }, \ + { IOCB_WAITQ, "WAITQ" }, \ + { IOCB_NOIO, "NOIO" }, \ + { IOCB_ALLOC_CACHE, "ALLOC_CACHE" }, \ + { IOCB_AIO_RW, "AIO_RW" }, \ + { IOCB_HAS_METADATA, "AIO_HAS_METADATA" } + +struct kiocb { + struct file *ki_filp; + loff_t ki_pos; + void (*ki_complete)(struct kiocb *iocb, long ret); + void *private; + int ki_flags; + u16 ki_ioprio; /* See linux/ioprio.h */ + u8 ki_write_stream; + + /* + * Only used for async buffered reads, where it denotes the page + * waitqueue associated with completing the read. + * Valid IFF IOCB_WAITQ is set. + */ + struct wait_page_queue *ki_waitq; +}; + +static inline bool is_sync_kiocb(struct kiocb *kiocb) +{ + return kiocb->ki_complete == NULL; +} + +struct address_space_operations { + int (*read_folio)(struct file *, struct folio *); + + /* Write back some dirty pages from this mapping. */ + int (*writepages)(struct address_space *, struct writeback_control *); + + /* Mark a folio dirty. Return true if this dirtied it */ + bool (*dirty_folio)(struct address_space *, struct folio *); + + void (*readahead)(struct readahead_control *); + + int (*write_begin)(const struct kiocb *, struct address_space *mapping, + loff_t pos, unsigned len, + struct folio **foliop, void **fsdata); + int (*write_end)(const struct kiocb *, struct address_space *mapping, + loff_t pos, unsigned len, unsigned copied, + struct folio *folio, void *fsdata); + + /* Unfortunately this kludge is needed for FIBMAP. Don't use it */ + sector_t (*bmap)(struct address_space *, sector_t); + void (*invalidate_folio) (struct folio *, size_t offset, size_t len); + bool (*release_folio)(struct folio *, gfp_t); + void (*free_folio)(struct folio *folio); + ssize_t (*direct_IO)(struct kiocb *, struct iov_iter *iter); + /* + * migrate the contents of a folio to the specified target. If + * migrate_mode is MIGRATE_ASYNC, it must not block. + */ + int (*migrate_folio)(struct address_space *, struct folio *dst, + struct folio *src, enum migrate_mode); + int (*launder_folio)(struct folio *); + bool (*is_partially_uptodate) (struct folio *, size_t from, + size_t count); + void (*is_dirty_writeback) (struct folio *, bool *dirty, bool *wb); + int (*error_remove_folio)(struct address_space *, struct folio *); + + /* swapfile support */ + int (*swap_activate)(struct swap_info_struct *sis, struct file *file, + sector_t *span); + void (*swap_deactivate)(struct file *file); +}; + +extern const struct address_space_operations empty_aops; + +/* Structure for tracking metadata buffer heads associated with the mapping */ +struct mapping_metadata_bhs { + struct address_space *mapping; /* Mapping bhs are associated with */ + spinlock_t lock; /* Lock protecting bh list */ + struct list_head list; /* The list of bhs (b_assoc_buffers) */ +}; + +/** + * struct address_space - Contents of a cacheable, mappable object. + * @host: Owner, either the inode or the block_device. + * @i_pages: Cached pages. + * @invalidate_lock: Guards coherency between page cache contents and + * file offset->disk block mappings in the filesystem during invalidates. + * It is also used to block modification of page cache contents through + * memory mappings. + * @gfp_mask: Memory allocation flags to use for allocating pages. + * @i_mmap_writable: Number of VM_SHARED, VM_MAYWRITE mappings. + * @i_mmap: Tree of private and shared mappings. + * @i_mmap_rwsem: Protects @i_mmap and @i_mmap_writable. + * @nrpages: Number of page entries, protected by the i_pages lock. + * @writeback_index: Writeback starts here. + * @a_ops: Methods. + * @flags: Error bits and flags (AS_*). + * @wb_err: The most recent error which has occurred. + * @i_private_lock: For use by the owner of the address_space. + */ +struct address_space { + struct inode *host; + struct xarray i_pages; + struct rw_semaphore invalidate_lock; + gfp_t gfp_mask; + atomic_t i_mmap_writable; + struct rb_root_cached i_mmap; + unsigned long nrpages; + pgoff_t writeback_index; + const struct address_space_operations *a_ops; + unsigned long flags; + errseq_t wb_err; + spinlock_t i_private_lock; + struct rw_semaphore i_mmap_rwsem; +} __attribute__((aligned(sizeof(long)))) __randomize_layout; + /* + * On most architectures that alignment is already the case; but + * must be enforced here for CRIS, to let the least significant bit + * of struct folio's "mapping" pointer be used for FOLIO_MAPPING_ANON. + */ + +/* XArray tags, for tagging dirty and writeback pages in the pagecache. */ +#define PAGECACHE_TAG_DIRTY XA_MARK_0 +#define PAGECACHE_TAG_WRITEBACK XA_MARK_1 +#define PAGECACHE_TAG_TOWRITE XA_MARK_2 + +/* + * Returns true if any of the pages in the mapping are marked with the tag. + */ +static inline bool mapping_tagged(const struct address_space *mapping, xa_mark_t tag) +{ + return xa_marked(&mapping->i_pages, tag); +} + +static inline void i_mmap_lock_write(struct address_space *mapping) +{ + down_write(&mapping->i_mmap_rwsem); +} + +static inline int i_mmap_trylock_write(struct address_space *mapping) +{ + return down_write_trylock(&mapping->i_mmap_rwsem); +} + +static inline void i_mmap_unlock_write(struct address_space *mapping) +{ + up_write(&mapping->i_mmap_rwsem); +} + +static inline int i_mmap_trylock_read(struct address_space *mapping) +{ + return down_read_trylock(&mapping->i_mmap_rwsem); +} + +static inline void i_mmap_lock_read(struct address_space *mapping) +{ + down_read(&mapping->i_mmap_rwsem); +} + +static inline void i_mmap_unlock_read(struct address_space *mapping) +{ + up_read(&mapping->i_mmap_rwsem); +} + +static inline void i_mmap_assert_locked(struct address_space *mapping) +{ + lockdep_assert_held(&mapping->i_mmap_rwsem); +} + +static inline void i_mmap_assert_write_locked(struct address_space *mapping) +{ + lockdep_assert_held_write(&mapping->i_mmap_rwsem); +} + +/* + * Might pages of this file be mapped into userspace? + */ +static inline int mapping_mapped(const struct address_space *mapping) +{ + return !RB_EMPTY_ROOT(&mapping->i_mmap.rb_root); +} + +/* + * Might pages of this file have been modified in userspace? + * Note that i_mmap_writable counts all VM_SHARED, VM_MAYWRITE vmas: do_mmap + * marks vma as VM_SHARED if it is shared, and the file was opened for + * writing i.e. vma may be mprotected writable even if now readonly. + * + * If i_mmap_writable is negative, no new writable mappings are allowed. You + * can only deny writable mappings, if none exists right now. + */ +static inline int mapping_writably_mapped(const struct address_space *mapping) +{ + return atomic_read(&mapping->i_mmap_writable) > 0; +} + +static inline int mapping_map_writable(struct address_space *mapping) +{ + return atomic_inc_unless_negative(&mapping->i_mmap_writable) ? + 0 : -EPERM; +} + +static inline void mapping_unmap_writable(struct address_space *mapping) +{ + atomic_dec(&mapping->i_mmap_writable); +} + +static inline int mapping_deny_writable(struct address_space *mapping) +{ + return atomic_dec_unless_positive(&mapping->i_mmap_writable) ? + 0 : -EBUSY; +} + +static inline void mapping_allow_writable(struct address_space *mapping) +{ + atomic_inc(&mapping->i_mmap_writable); +} + +/* + * Use sequence counter to get consistent i_size on 32-bit processors. + */ +#if BITS_PER_LONG==32 && defined(CONFIG_SMP) +#include <linux/seqlock.h> +#define __NEED_I_SIZE_ORDERED +#define i_size_ordered_init(inode) seqcount_init(&inode->i_size_seqcount) +#else +#define i_size_ordered_init(inode) do { } while (0) +#endif + +struct posix_acl; +#define ACL_NOT_CACHED ((void *)(-1)) +/* + * ACL_DONT_CACHE is for stacked filesystems, that rely on underlying fs to + * cache the ACL. This also means that ->get_inode_acl() can be called in RCU + * mode with the LOOKUP_RCU flag. + */ +#define ACL_DONT_CACHE ((void *)(-3)) + +static inline struct posix_acl * +uncached_acl_sentinel(struct task_struct *task) +{ + return (void *)task + 1; +} + +static inline bool +is_uncached_acl(struct posix_acl *acl) +{ + return (long)acl & 1; +} + +#define IOP_FASTPERM 0x0001 +#define IOP_LOOKUP 0x0002 +#define IOP_NOFOLLOW 0x0004 +#define IOP_XATTR 0x0008 +#define IOP_DEFAULT_READLINK 0x0010 +#define IOP_MGTIME 0x0020 +#define IOP_CACHED_LINK 0x0040 +#define IOP_FASTPERM_MAY_EXEC 0x0080 +#define IOP_FLCTX 0x0100 + +/* + * Inode state bits. Protected by inode->i_lock + * + * Four bits determine the dirty state of the inode: I_DIRTY_SYNC, + * I_DIRTY_DATASYNC, I_DIRTY_PAGES, and I_DIRTY_TIME. + * + * Four bits define the lifetime of an inode. Initially, inodes are I_NEW, + * until that flag is cleared. I_WILL_FREE, I_FREEING and I_CLEAR are set at + * various stages of removing an inode. + * + * Two bits are used for locking and completion notification, I_NEW and I_SYNC. + * + * I_DIRTY_SYNC Inode is dirty, but doesn't have to be written on + * fdatasync() (unless I_DIRTY_DATASYNC is also set). + * Timestamp updates are the usual cause. + * I_DIRTY_DATASYNC Data-related inode changes pending. We keep track of + * these changes separately from I_DIRTY_SYNC so that we + * don't have to write inode on fdatasync() when only + * e.g. the timestamps have changed. + * I_DIRTY_PAGES Inode has dirty pages. Inode itself may be clean. + * I_DIRTY_TIME The inode itself has dirty timestamps, and the + * lazytime mount option is enabled. We keep track of this + * separately from I_DIRTY_SYNC in order to implement + * lazytime. This gets cleared if I_DIRTY_INODE + * (I_DIRTY_SYNC and/or I_DIRTY_DATASYNC) gets set. But + * I_DIRTY_TIME can still be set if I_DIRTY_SYNC is already + * in place because writeback might already be in progress + * and we don't want to lose the time update + * I_NEW Serves as both a mutex and completion notification. + * New inodes set I_NEW. If two processes both create + * the same inode, one of them will release its inode and + * wait for I_NEW to be released before returning. + * Inodes in I_WILL_FREE, I_FREEING or I_CLEAR state can + * also cause waiting on I_NEW, without I_NEW actually + * being set. find_inode() uses this to prevent returning + * nearly-dead inodes. + * I_WILL_FREE Must be set when calling write_inode_now() if i_count + * is zero. I_FREEING must be set when I_WILL_FREE is + * cleared. + * I_FREEING Set when inode is about to be freed but still has dirty + * pages or buffers attached or the inode itself is still + * dirty. + * I_CLEAR Added by clear_inode(). In this state the inode is + * clean and can be destroyed. Inode keeps I_FREEING. + * + * Inodes that are I_WILL_FREE, I_FREEING or I_CLEAR are + * prohibited for many purposes. iget() must wait for + * the inode to be completely released, then create it + * anew. Other functions will just ignore such inodes, + * if appropriate. I_NEW is used for waiting. + * + * I_SYNC Writeback of inode is running. The bit is set during + * data writeback, and cleared with a wakeup on the bit + * address once it is done. The bit is also used to pin + * the inode in memory for flusher thread. + * + * I_REFERENCED Marks the inode as recently references on the LRU list. + * + * I_WB_SWITCH Cgroup bdi_writeback switching in progress. Used to + * synchronize competing switching instances and to tell + * wb stat updates to grab the i_pages lock. See + * inode_switch_wbs_work_fn() for details. + * + * I_OVL_INUSE Used by overlayfs to get exclusive ownership on upper + * and work dirs among overlayfs mounts. + * + * I_CREATING New object's inode in the middle of setting up. + * + * I_DONTCACHE Evict inode as soon as it is not used anymore. + * + * I_SYNC_QUEUED Inode is queued in b_io or b_more_io writeback lists. + * Used to detect that mark_inode_dirty() should not move + * inode between dirty lists. + * + * I_PINNING_FSCACHE_WB Inode is pinning an fscache object for writeback. + * + * I_LRU_ISOLATING Inode is pinned being isolated from LRU without holding + * i_count. + * + * Q: What is the difference between I_WILL_FREE and I_FREEING? + * + * __I_{SYNC,NEW,LRU_ISOLATING} are used to derive unique addresses to wait + * upon. There's one free address left. + */ + +enum inode_state_bits { + __I_NEW = 0U, + __I_SYNC = 1U, + __I_LRU_ISOLATING = 2U + /* reserved wait address bit 3 */ +}; + +enum inode_state_flags_enum { + I_NEW = (1U << __I_NEW), + I_SYNC = (1U << __I_SYNC), + I_LRU_ISOLATING = (1U << __I_LRU_ISOLATING), + /* reserved flag bit 3 */ + I_DIRTY_SYNC = (1U << 4), + I_DIRTY_DATASYNC = (1U << 5), + I_DIRTY_PAGES = (1U << 6), + I_WILL_FREE = (1U << 7), + I_FREEING = (1U << 8), + I_CLEAR = (1U << 9), + I_REFERENCED = (1U << 10), + I_LINKABLE = (1U << 11), + I_DIRTY_TIME = (1U << 12), + I_WB_SWITCH = (1U << 13), + I_OVL_INUSE = (1U << 14), + I_CREATING = (1U << 15), + I_DONTCACHE = (1U << 16), + I_SYNC_QUEUED = (1U << 17), + I_PINNING_NETFS_WB = (1U << 18), + I_METADATA_WRITEBACK = (1U << 19), +}; + +#define I_DIRTY_INODE (I_DIRTY_SYNC | I_DIRTY_DATASYNC) +#define I_DIRTY (I_DIRTY_INODE | I_DIRTY_PAGES) +#define I_DIRTY_ALL (I_DIRTY | I_DIRTY_TIME) + +/* + * Use inode_state_read() & friends to access. + */ +struct inode_state_flags { + enum inode_state_flags_enum __state; +}; + +/* + * Keep mostly read-only and often accessed (especially for + * the RCU path lookup and 'stat' data) fields at the beginning + * of the 'struct inode' + */ +struct inode { + umode_t i_mode; + unsigned short i_opflags; + unsigned int i_flags; +#ifdef CONFIG_FS_POSIX_ACL + struct posix_acl *i_acl; + struct posix_acl *i_default_acl; +#endif + kuid_t i_uid; + kgid_t i_gid; + + const struct inode_operations *i_op; + struct super_block *i_sb; + struct address_space *i_mapping; + +#ifdef CONFIG_SECURITY + void *i_security; +#endif + + /* Stat data, not accessed from path walking */ + u64 i_ino; + /* + * Filesystems may only read i_nlink directly. They shall use the + * following functions for modification: + * + * (set|clear|inc|drop)_nlink + * inode_(inc|dec)_link_count + */ + union { + const unsigned int i_nlink; + unsigned int __i_nlink; + }; + dev_t i_rdev; + loff_t i_size; + time64_t i_atime_sec; + time64_t i_mtime_sec; + time64_t i_ctime_sec; + u32 i_atime_nsec; + u32 i_mtime_nsec; + u32 i_ctime_nsec; + u32 i_generation; + spinlock_t i_lock; /* i_blocks, i_bytes, maybe i_size */ + unsigned short i_bytes; + u8 i_blkbits; + enum rw_hint i_write_hint; + blkcnt_t i_blocks; + +#ifdef __NEED_I_SIZE_ORDERED + seqcount_t i_size_seqcount; +#endif + + /* Misc */ + struct inode_state_flags i_state; + /* 32-bit hole */ + struct rw_semaphore i_rwsem; + + unsigned long dirtied_when; /* jiffies of first dirtying */ + unsigned long dirtied_time_when; + + struct hlist_node i_hash; + struct list_head i_io_list; /* backing dev IO list */ +#ifdef CONFIG_CGROUP_WRITEBACK + struct bdi_writeback *i_wb; /* the associated cgroup wb */ + + /* foreign inode detection, see wbc_detach_inode() */ + int i_wb_frn_winner; + u16 i_wb_frn_avg_time; + u16 i_wb_frn_history; +#endif + struct list_head i_lru; /* inode LRU list */ + struct list_head i_sb_list; + struct list_head i_wb_list; /* backing dev writeback list */ + union { + struct hlist_head i_dentry; + struct rcu_head i_rcu; + }; + atomic64_t i_version; + atomic64_t i_sequence; /* see futex */ + atomic_t i_count; + atomic_t i_dio_count; + atomic_t i_writecount; +#if defined(CONFIG_IMA) || defined(CONFIG_FILE_LOCKING) + atomic_t i_readcount; /* struct files open RO */ +#endif + union { + const struct file_operations *i_fop; /* former ->i_op->default_file_ops */ + void (*free_inode)(struct inode *); + }; + struct file_lock_context *i_flctx; + struct address_space i_data; + union { + struct list_head i_devices; + int i_linklen; + }; + union { + struct pipe_inode_info *i_pipe; + struct cdev *i_cdev; + char *i_link; + unsigned i_dir_seq; + }; + + +#ifdef CONFIG_FSNOTIFY + __u32 i_fsnotify_mask; /* all events this inode cares about */ + /* 32-bit hole reserved for expanding i_fsnotify_mask */ + struct fsnotify_mark_connector __rcu *i_fsnotify_marks; +#endif + + void *i_private; /* fs or device private pointer */ +} __randomize_layout; + +/* + * i_state handling + * + * We hide all of it behind helpers so that we can validate consumers. + */ +static inline enum inode_state_flags_enum inode_state_read_once(struct inode *inode) +{ + return READ_ONCE(inode->i_state.__state); +} + +static inline enum inode_state_flags_enum inode_state_read(struct inode *inode) +{ + lockdep_assert_held(&inode->i_lock); + return inode->i_state.__state; +} + +static inline void inode_state_set_raw(struct inode *inode, + enum inode_state_flags_enum flags) +{ + WRITE_ONCE(inode->i_state.__state, inode->i_state.__state | flags); +} + +static inline void inode_state_set(struct inode *inode, + enum inode_state_flags_enum flags) +{ + lockdep_assert_held(&inode->i_lock); + inode_state_set_raw(inode, flags); +} + +static inline void inode_state_clear_raw(struct inode *inode, + enum inode_state_flags_enum flags) +{ + WRITE_ONCE(inode->i_state.__state, inode->i_state.__state & ~flags); +} + +static inline void inode_state_clear(struct inode *inode, + enum inode_state_flags_enum flags) +{ + lockdep_assert_held(&inode->i_lock); + inode_state_clear_raw(inode, flags); +} + +static inline void inode_state_assign_raw(struct inode *inode, + enum inode_state_flags_enum flags) +{ + WRITE_ONCE(inode->i_state.__state, flags); +} + +static inline void inode_state_assign(struct inode *inode, + enum inode_state_flags_enum flags) +{ + lockdep_assert_held(&inode->i_lock); + inode_state_assign_raw(inode, flags); +} + +static inline void inode_state_replace_raw(struct inode *inode, + enum inode_state_flags_enum clearflags, + enum inode_state_flags_enum setflags) +{ + enum inode_state_flags_enum flags; + flags = inode->i_state.__state; + flags &= ~clearflags; + flags |= setflags; + inode_state_assign_raw(inode, flags); +} + +static inline void inode_state_replace(struct inode *inode, + enum inode_state_flags_enum clearflags, + enum inode_state_flags_enum setflags) +{ + lockdep_assert_held(&inode->i_lock); + inode_state_replace_raw(inode, clearflags, setflags); +} + +static inline void inode_set_cached_link(struct inode *inode, char *link, int linklen) +{ + VFS_WARN_ON_INODE(strlen(link) != linklen, inode); + VFS_WARN_ON_INODE(inode->i_opflags & IOP_CACHED_LINK, inode); + inode->i_link = link; + inode->i_linklen = linklen; + inode->i_opflags |= IOP_CACHED_LINK; +} + +/* + * Get bit address from inode->i_state to use with wait_var_event() + * infrastructre. + */ +#define inode_state_wait_address(inode, bit) ((char *)&(inode)->i_state + (bit)) + +struct wait_queue_head *inode_bit_waitqueue(struct wait_bit_queue_entry *wqe, + struct inode *inode, u32 bit); + +static inline void inode_wake_up_bit(struct inode *inode, u32 bit) +{ + /* Caller is responsible for correct memory barriers. */ + wake_up_var(inode_state_wait_address(inode, bit)); +} + +struct timespec64 timestamp_truncate(struct timespec64 t, struct inode *inode); + +static inline unsigned int i_blocksize(const struct inode *node) +{ + return (1 << node->i_blkbits); +} + +static inline int inode_unhashed(struct inode *inode) +{ + return hlist_unhashed(&inode->i_hash); +} + +/* + * __mark_inode_dirty expects inodes to be hashed. Since we don't + * want special inodes in the fileset inode space, we make them + * appear hashed, but do not put on any lists. hlist_del() + * will work fine and require no locking. + */ +static inline void inode_fake_hash(struct inode *inode) +{ + hlist_add_fake(&inode->i_hash); +} + +void wait_on_new_inode(struct inode *inode); + +/* + * inode->i_rwsem nesting subclasses for the lock validator: + * + * 0: the object of the current VFS operation + * 1: parent + * 2: child/target + * 3: xattr + * 4: second non-directory + * 5: second parent (when locking independent directories in rename) + * + * I_MUTEX_NONDIR2 is for certain operations (such as rename) which lock two + * non-directories at once. + * + * The locking order between these classes is + * parent[2] -> child -> grandchild -> normal -> xattr -> second non-directory + */ +enum inode_i_mutex_lock_class +{ + I_MUTEX_NORMAL, + I_MUTEX_PARENT, + I_MUTEX_CHILD, + I_MUTEX_XATTR, + I_MUTEX_NONDIR2, + I_MUTEX_PARENT2, +}; + +static inline void inode_lock(struct inode *inode) +{ + down_write(&inode->i_rwsem); +} + +static inline __must_check int inode_lock_killable(struct inode *inode) +{ + return down_write_killable(&inode->i_rwsem); +} + +static inline void inode_unlock(struct inode *inode) +{ + up_write(&inode->i_rwsem); +} + +static inline void inode_lock_shared(struct inode *inode) +{ + down_read(&inode->i_rwsem); +} + +static inline __must_check int inode_lock_shared_killable(struct inode *inode) +{ + return down_read_killable(&inode->i_rwsem); +} + +static inline void inode_unlock_shared(struct inode *inode) +{ + up_read(&inode->i_rwsem); +} + +static inline int inode_trylock(struct inode *inode) +{ + return down_write_trylock(&inode->i_rwsem); +} + +static inline int inode_trylock_shared(struct inode *inode) +{ + return down_read_trylock(&inode->i_rwsem); +} + +static inline int inode_is_locked(struct inode *inode) +{ + return rwsem_is_locked(&inode->i_rwsem); +} + +static inline void inode_lock_nested(struct inode *inode, unsigned subclass) +{ + down_write_nested(&inode->i_rwsem, subclass); +} + +static inline void inode_lock_shared_nested(struct inode *inode, unsigned subclass) +{ + down_read_nested(&inode->i_rwsem, subclass); +} + +static inline void filemap_invalidate_lock(struct address_space *mapping) +{ + down_write(&mapping->invalidate_lock); +} + +static inline void filemap_invalidate_unlock(struct address_space *mapping) +{ + up_write(&mapping->invalidate_lock); +} + +static inline void filemap_invalidate_lock_shared(struct address_space *mapping) +{ + down_read(&mapping->invalidate_lock); +} + +static inline int filemap_invalidate_trylock_shared( + struct address_space *mapping) +{ + return down_read_trylock(&mapping->invalidate_lock); +} + +static inline void filemap_invalidate_unlock_shared( + struct address_space *mapping) +{ + up_read(&mapping->invalidate_lock); +} + +void lock_two_nondirectories(struct inode *, struct inode*); +void unlock_two_nondirectories(struct inode *, struct inode*); + +void filemap_invalidate_lock_two(struct address_space *mapping1, + struct address_space *mapping2); +void filemap_invalidate_unlock_two(struct address_space *mapping1, + struct address_space *mapping2); + + +/* + * NOTE: in a 32bit arch with a preemptable kernel and + * an UP compile the i_size_read/write must be atomic + * with respect to the local cpu (unlike with preempt disabled), + * but they don't need to be atomic with respect to other cpus like in + * true SMP (so they need either to either locally disable irq around + * the read or for example on x86 they can be still implemented as a + * cmpxchg8b without the need of the lock prefix). For SMP compiles + * and 64bit archs it makes no difference if preempt is enabled or not. + */ +static inline loff_t i_size_read(const struct inode *inode) +{ +#if BITS_PER_LONG==32 && defined(CONFIG_SMP) + loff_t i_size; + unsigned int seq; + + do { + seq = read_seqcount_begin(&inode->i_size_seqcount); + i_size = inode->i_size; + } while (read_seqcount_retry(&inode->i_size_seqcount, seq)); + return i_size; +#elif BITS_PER_LONG==32 && defined(CONFIG_PREEMPTION) + loff_t i_size; + + preempt_disable(); + i_size = inode->i_size; + preempt_enable(); + return i_size; +#else + /* Pairs with smp_store_release() in i_size_write() */ + return smp_load_acquire(&inode->i_size); +#endif +} + +/* + * NOTE: unlike i_size_read(), i_size_write() does need locking around it + * (normally i_rwsem), otherwise on 32bit/SMP an update of i_size_seqcount + * can be lost, resulting in subsequent i_size_read() calls spinning forever. + */ +static inline void i_size_write(struct inode *inode, loff_t i_size) +{ +#if BITS_PER_LONG==32 && defined(CONFIG_SMP) + preempt_disable(); + write_seqcount_begin(&inode->i_size_seqcount); + inode->i_size = i_size; + write_seqcount_end(&inode->i_size_seqcount); + preempt_enable(); +#elif BITS_PER_LONG==32 && defined(CONFIG_PREEMPTION) + preempt_disable(); + inode->i_size = i_size; + preempt_enable(); +#else + /* + * Pairs with smp_load_acquire() in i_size_read() to ensure + * changes related to inode size (such as page contents) are + * visible before we see the changed inode size. + */ + smp_store_release(&inode->i_size, i_size); +#endif +} + +static inline unsigned iminor(const struct inode *inode) +{ + return MINOR(inode->i_rdev); +} + +static inline unsigned imajor(const struct inode *inode) +{ + return MAJOR(inode->i_rdev); +} + +struct fown_struct { + struct file *file; /* backpointer for security modules */ + rwlock_t lock; /* protects pid, uid, euid fields */ + struct pid *pid; /* pid or -pgrp where SIGIO should be sent */ + enum pid_type pid_type; /* Kind of process group SIGIO should be sent to */ + kuid_t uid, euid; /* uid/euid of process setting the owner */ + int signum; /* posix.1b rt signal to be delivered on IO */ +}; + +/** + * struct file_ra_state - Track a file's readahead state. + * @start: Where the most recent readahead started. + * @size: Number of pages read in the most recent readahead. + * @async_size: Numer of pages that were/are not needed immediately + * and so were/are genuinely "ahead". Start next readahead when + * the first of these pages is accessed. + * @ra_pages: Maximum size of a readahead request, copied from the bdi. + * @order: Preferred folio order used for most recent readahead. + * @mmap_miss: How many mmap accesses missed in the page cache. + * @prev_pos: The last byte in the most recent read request. + * + * When this structure is passed to ->readahead(), the "most recent" + * readahead means the current readahead. + */ +struct file_ra_state { + pgoff_t start; + unsigned int size; + unsigned int async_size; + unsigned int ra_pages; + unsigned short order; + unsigned short mmap_miss; + loff_t prev_pos; +}; + +/* + * Check if @index falls in the readahead windows. + */ +static inline int ra_has_index(struct file_ra_state *ra, pgoff_t index) +{ + return (index >= ra->start && + index < ra->start + ra->size); +} + +/** + * struct file - Represents a file + * @f_lock: Protects f_ep, f_flags. Must not be taken from IRQ context. + * @f_mode: FMODE_* flags often used in hotpaths + * @f_op: file operations + * @f_mapping: Contents of a cacheable, mappable object. + * @private_data: filesystem or driver specific data + * @f_inode: cached inode + * @f_flags: file flags + * @f_iocb_flags: iocb flags + * @f_cred: stashed credentials of creator/opener + * @f_owner: file owner + * @f_path: path of the file + * @__f_path: writable alias for @f_path; *ONLY* for core VFS and only before + * the file gets open + * @f_pos_lock: lock protecting file position + * @f_pipe: specific to pipes + * @f_pos: file position + * @f_security: LSM security context of this file + * @f_wb_err: writeback error + * @f_sb_err: per sb writeback errors + * @f_ep: link of all epoll hooks for this file + * @f_task_work: task work entry point + * @f_llist: work queue entrypoint + * @f_ra: file's readahead state + * @f_freeptr: Pointer used by SLAB_TYPESAFE_BY_RCU file cache (don't touch.) + * @f_ref: reference count + */ +struct file { + spinlock_t f_lock; + fmode_t f_mode; + const struct file_operations *f_op; + struct address_space *f_mapping; + void *private_data; + struct inode *f_inode; + unsigned int f_flags; + unsigned int f_iocb_flags; + const struct cred *f_cred; + struct fown_struct *f_owner; + /* --- cacheline 1 boundary (64 bytes) --- */ + union { + const struct path f_path; + struct path __f_path; + }; + union { + /* regular files (with FMODE_ATOMIC_POS) and directories */ + struct mutex f_pos_lock; + /* pipes */ + u64 f_pipe; + }; + loff_t f_pos; +#ifdef CONFIG_SECURITY + void *f_security; +#endif + /* --- cacheline 2 boundary (128 bytes) --- */ + errseq_t f_wb_err; + errseq_t f_sb_err; +#ifdef CONFIG_EPOLL + struct hlist_head *f_ep; +#endif + union { + struct callback_head f_task_work; + struct llist_node f_llist; + struct file_ra_state f_ra; + freeptr_t f_freeptr; + }; + file_ref_t f_ref; + /* --- cacheline 3 boundary (192 bytes) --- */ +} __randomize_layout + __attribute__((aligned(4))); /* lest something weird decides that 2 is OK */ + +struct file_handle { + __u32 handle_bytes; + int handle_type; + /* file identifier */ + unsigned char f_handle[] __counted_by(handle_bytes); +}; + +static inline struct file *get_file(struct file *f) +{ + file_ref_inc(&f->f_ref); + return f; +} + +struct file *get_file_rcu(struct file __rcu **f); +struct file *get_file_active(struct file **f); + +#define file_count(f) file_ref_read(&(f)->f_ref) + +#define MAX_NON_LFS ((1UL<<31) - 1) + +/* Page cache limit. The filesystems should put that into their s_maxbytes + limits, otherwise bad things can happen in VM. */ +#if BITS_PER_LONG==32 +#define MAX_LFS_FILESIZE ((loff_t)ULONG_MAX << PAGE_SHIFT) +#elif BITS_PER_LONG==64 +#define MAX_LFS_FILESIZE ((loff_t)LLONG_MAX) +#endif + +/* legacy typedef, should eventually be removed */ +typedef void *fl_owner_t; + +struct file_lock; +struct file_lease; + +/* The following constant reflects the upper bound of the file/locking space */ +#ifndef OFFSET_MAX +#define OFFSET_MAX type_max(loff_t) +#define OFFT_OFFSET_MAX type_max(off_t) +#endif + +int file_f_owner_allocate(struct file *file); +static inline struct fown_struct *file_f_owner(const struct file *file) +{ + return READ_ONCE(file->f_owner); +} + +extern void send_sigio(struct fown_struct *fown, int fd, int band); + +static inline struct inode *file_inode(const struct file *f) +{ + return f->f_inode; +} + +/* + * file_dentry() is a relic from the days that overlayfs was using files with a + * "fake" path, meaning, f_path on overlayfs and f_inode on underlying fs. + * In those days, file_dentry() was needed to get the underlying fs dentry that + * matches f_inode. + * Files with "fake" path should not exist nowadays, so use an assertion to make + * sure that file_dentry() was not papering over filesystem bugs. + */ +static inline struct dentry *file_dentry(const struct file *file) +{ + struct dentry *dentry = file->f_path.dentry; + + WARN_ON_ONCE(d_inode(dentry) != file_inode(file)); + return dentry; +} + +struct fasync_struct { + rwlock_t fa_lock; + int magic; + int fa_fd; + struct fasync_struct *fa_next; /* singly linked list */ + struct file *fa_file; + struct rcu_head fa_rcu; +}; + +#define FASYNC_MAGIC 0x4601 + +/* SMP safe fasync helpers: */ +extern int fasync_helper(int, struct file *, int, struct fasync_struct **); +extern struct fasync_struct *fasync_insert_entry(int, struct file *, struct fasync_struct **, struct fasync_struct *); +extern int fasync_remove_entry(struct file *, struct fasync_struct **); +extern struct fasync_struct *fasync_alloc(void); +extern void fasync_free(struct fasync_struct *); + +/* can be called from interrupts */ +extern void kill_fasync(struct fasync_struct **, int, int); + +extern void __f_setown(struct file *filp, struct pid *, enum pid_type, int force); +extern int f_setown(struct file *filp, int who, int force); +extern void f_delown(struct file *filp); +extern pid_t f_getown(struct file *filp); +extern int send_sigurg(struct file *file); + +/* + * Umount options + */ + +#define MNT_FORCE 0x00000001 /* Attempt to forcibily umount */ +#define MNT_DETACH 0x00000002 /* Just detach from the tree */ +#define MNT_EXPIRE 0x00000004 /* Mark for expiry */ +#define UMOUNT_NOFOLLOW 0x00000008 /* Don't follow symlink on umount */ +#define UMOUNT_UNUSED 0x80000000 /* Flag guaranteed to be unused */ + +static inline struct user_namespace *i_user_ns(const struct inode *inode) +{ + return inode->i_sb->s_user_ns; +} + +/* Helper functions so that in most cases filesystems will + * not need to deal directly with kuid_t and kgid_t and can + * instead deal with the raw numeric values that are stored + * in the filesystem. + */ +static inline uid_t i_uid_read(const struct inode *inode) +{ + return from_kuid(i_user_ns(inode), inode->i_uid); +} + +static inline gid_t i_gid_read(const struct inode *inode) +{ + return from_kgid(i_user_ns(inode), inode->i_gid); +} + +static inline void i_uid_write(struct inode *inode, uid_t uid) +{ + inode->i_uid = make_kuid(i_user_ns(inode), uid); +} + +static inline void i_gid_write(struct inode *inode, gid_t gid) +{ + inode->i_gid = make_kgid(i_user_ns(inode), gid); +} + +/** + * i_uid_into_vfsuid - map an inode's i_uid down according to an idmapping + * @idmap: idmap of the mount the inode was found from + * @inode: inode to map + * + * Return: whe inode's i_uid mapped down according to @idmap. + * If the inode's i_uid has no mapping INVALID_VFSUID is returned. + */ +static inline vfsuid_t i_uid_into_vfsuid(struct mnt_idmap *idmap, + const struct inode *inode) +{ + return make_vfsuid(idmap, i_user_ns(inode), inode->i_uid); +} + +/** + * i_uid_needs_update - check whether inode's i_uid needs to be updated + * @idmap: idmap of the mount the inode was found from + * @attr: the new attributes of @inode + * @inode: the inode to update + * + * Check whether the $inode's i_uid field needs to be updated taking idmapped + * mounts into account if the filesystem supports it. + * + * Return: true if @inode's i_uid field needs to be updated, false if not. + */ +static inline bool i_uid_needs_update(struct mnt_idmap *idmap, + const struct iattr *attr, + const struct inode *inode) +{ + return ((attr->ia_valid & ATTR_UID) && + !vfsuid_eq(attr->ia_vfsuid, + i_uid_into_vfsuid(idmap, inode))); +} + +/** + * i_uid_update - update @inode's i_uid field + * @idmap: idmap of the mount the inode was found from + * @attr: the new attributes of @inode + * @inode: the inode to update + * + * Safely update @inode's i_uid field translating the vfsuid of any idmapped + * mount into the filesystem kuid. + */ +static inline void i_uid_update(struct mnt_idmap *idmap, + const struct iattr *attr, + struct inode *inode) +{ + if (attr->ia_valid & ATTR_UID) + inode->i_uid = from_vfsuid(idmap, i_user_ns(inode), + attr->ia_vfsuid); +} + +/** + * i_gid_into_vfsgid - map an inode's i_gid down according to an idmapping + * @idmap: idmap of the mount the inode was found from + * @inode: inode to map + * + * Return: the inode's i_gid mapped down according to @idmap. + * If the inode's i_gid has no mapping INVALID_VFSGID is returned. + */ +static inline vfsgid_t i_gid_into_vfsgid(struct mnt_idmap *idmap, + const struct inode *inode) +{ + return make_vfsgid(idmap, i_user_ns(inode), inode->i_gid); +} + +/** + * i_gid_needs_update - check whether inode's i_gid needs to be updated + * @idmap: idmap of the mount the inode was found from + * @attr: the new attributes of @inode + * @inode: the inode to update + * + * Check whether the $inode's i_gid field needs to be updated taking idmapped + * mounts into account if the filesystem supports it. + * + * Return: true if @inode's i_gid field needs to be updated, false if not. + */ +static inline bool i_gid_needs_update(struct mnt_idmap *idmap, + const struct iattr *attr, + const struct inode *inode) +{ + return ((attr->ia_valid & ATTR_GID) && + !vfsgid_eq(attr->ia_vfsgid, + i_gid_into_vfsgid(idmap, inode))); +} + +/** + * i_gid_update - update @inode's i_gid field + * @idmap: idmap of the mount the inode was found from + * @attr: the new attributes of @inode + * @inode: the inode to update + * + * Safely update @inode's i_gid field translating the vfsgid of any idmapped + * mount into the filesystem kgid. + */ +static inline void i_gid_update(struct mnt_idmap *idmap, + const struct iattr *attr, + struct inode *inode) +{ + if (attr->ia_valid & ATTR_GID) + inode->i_gid = from_vfsgid(idmap, i_user_ns(inode), + attr->ia_vfsgid); +} + +/** + * inode_fsuid_set - initialize inode's i_uid field with callers fsuid + * @inode: inode to initialize + * @idmap: idmap of the mount the inode was found from + * + * Initialize the i_uid field of @inode. If the inode was found/created via + * an idmapped mount map the caller's fsuid according to @idmap. + */ +static inline void inode_fsuid_set(struct inode *inode, + struct mnt_idmap *idmap) +{ + inode->i_uid = mapped_fsuid(idmap, i_user_ns(inode)); +} + +/** + * inode_fsgid_set - initialize inode's i_gid field with callers fsgid + * @inode: inode to initialize + * @idmap: idmap of the mount the inode was found from + * + * Initialize the i_gid field of @inode. If the inode was found/created via + * an idmapped mount map the caller's fsgid according to @idmap. + */ +static inline void inode_fsgid_set(struct inode *inode, + struct mnt_idmap *idmap) +{ + inode->i_gid = mapped_fsgid(idmap, i_user_ns(inode)); +} + +/** + * fsuidgid_has_mapping() - check whether caller's fsuid/fsgid is mapped + * @sb: the superblock we want a mapping in + * @idmap: idmap of the relevant mount + * + * Check whether the caller's fsuid and fsgid have a valid mapping in the + * s_user_ns of the superblock @sb. If the caller is on an idmapped mount map + * the caller's fsuid and fsgid according to the @idmap first. + * + * Return: true if fsuid and fsgid is mapped, false if not. + */ +static inline bool fsuidgid_has_mapping(struct super_block *sb, + struct mnt_idmap *idmap) +{ + struct user_namespace *fs_userns = sb->s_user_ns; + kuid_t kuid; + kgid_t kgid; + + kuid = mapped_fsuid(idmap, fs_userns); + if (!uid_valid(kuid)) + return false; + kgid = mapped_fsgid(idmap, fs_userns); + if (!gid_valid(kgid)) + return false; + return kuid_has_mapping(fs_userns, kuid) && + kgid_has_mapping(fs_userns, kgid); +} + +struct timespec64 current_time(struct inode *inode); +struct timespec64 inode_set_ctime_current(struct inode *inode); +struct timespec64 inode_set_ctime_deleg(struct inode *inode, + struct timespec64 update); + +static inline time64_t inode_get_atime_sec(const struct inode *inode) +{ + return READ_ONCE(inode->i_atime_sec); +} + +static inline long inode_get_atime_nsec(const struct inode *inode) +{ + return READ_ONCE(inode->i_atime_nsec); +} + +static inline struct timespec64 inode_get_atime(const struct inode *inode) +{ + struct timespec64 ts = { .tv_sec = inode_get_atime_sec(inode), + .tv_nsec = inode_get_atime_nsec(inode) }; + + return ts; +} + +static inline struct timespec64 inode_set_atime_to_ts(struct inode *inode, + struct timespec64 ts) +{ + WRITE_ONCE(inode->i_atime_sec, ts.tv_sec); + WRITE_ONCE(inode->i_atime_nsec, ts.tv_nsec); + return ts; +} + +static inline struct timespec64 inode_set_atime(struct inode *inode, + time64_t sec, long nsec) +{ + struct timespec64 ts = { .tv_sec = sec, + .tv_nsec = nsec }; + + return inode_set_atime_to_ts(inode, ts); +} + +static inline time64_t inode_get_mtime_sec(const struct inode *inode) +{ + return READ_ONCE(inode->i_mtime_sec); +} + +static inline long inode_get_mtime_nsec(const struct inode *inode) +{ + return READ_ONCE(inode->i_mtime_nsec); +} + +static inline struct timespec64 inode_get_mtime(const struct inode *inode) +{ + struct timespec64 ts = { .tv_sec = inode_get_mtime_sec(inode), + .tv_nsec = inode_get_mtime_nsec(inode) }; + return ts; +} + +static inline struct timespec64 inode_set_mtime_to_ts(struct inode *inode, + struct timespec64 ts) +{ + WRITE_ONCE(inode->i_mtime_sec, ts.tv_sec); + WRITE_ONCE(inode->i_mtime_nsec, ts.tv_nsec); + return ts; +} + +static inline struct timespec64 inode_set_mtime(struct inode *inode, + time64_t sec, long nsec) +{ + struct timespec64 ts = { .tv_sec = sec, + .tv_nsec = nsec }; + return inode_set_mtime_to_ts(inode, ts); +} + +/* + * Multigrain timestamps + * + * Conditionally use fine-grained ctime and mtime timestamps when there + * are users actively observing them via getattr. The primary use-case + * for this is NFS clients that use the ctime to distinguish between + * different states of the file, and that are often fooled by multiple + * operations that occur in the same coarse-grained timer tick. + */ +#define I_CTIME_QUERIED ((u32)BIT(31)) + +static inline time64_t inode_get_ctime_sec(const struct inode *inode) +{ + return READ_ONCE(inode->i_ctime_sec); +} + +static inline long inode_get_ctime_nsec(const struct inode *inode) +{ + return READ_ONCE(inode->i_ctime_nsec) & ~I_CTIME_QUERIED; +} + +static inline struct timespec64 inode_get_ctime(const struct inode *inode) +{ + struct timespec64 ts = { .tv_sec = inode_get_ctime_sec(inode), + .tv_nsec = inode_get_ctime_nsec(inode) }; + + return ts; +} + +struct timespec64 inode_set_ctime_to_ts(struct inode *inode, struct timespec64 ts); + +/** + * inode_set_ctime - set the ctime in the inode + * @inode: inode in which to set the ctime + * @sec: tv_sec value to set + * @nsec: tv_nsec value to set + * + * Set the ctime in @inode to { @sec, @nsec } + */ +static inline struct timespec64 inode_set_ctime(struct inode *inode, + time64_t sec, long nsec) +{ + struct timespec64 ts = { .tv_sec = sec, + .tv_nsec = nsec }; + + return inode_set_ctime_to_ts(inode, ts); +} + +struct timespec64 simple_inode_init_ts(struct inode *inode); + +static inline int inode_time_dirty_flag(struct inode *inode) +{ + if (inode->i_sb->s_flags & SB_LAZYTIME) + return I_DIRTY_TIME; + return I_DIRTY_SYNC; +} + +/* + * Snapshotting support. + */ + +/** + * file_write_started - check if SB_FREEZE_WRITE is held + * @file: the file we write to + * + * May be false positive with !CONFIG_LOCKDEP/LOCK_STATE_UNKNOWN. + * May be false positive with !S_ISREG, because file_start_write() has + * no effect on !S_ISREG. + */ +static inline bool file_write_started(const struct file *file) +{ + if (!S_ISREG(file_inode(file)->i_mode)) + return true; + return sb_write_started(file_inode(file)->i_sb); +} + +/** + * file_write_not_started - check if SB_FREEZE_WRITE is not held + * @file: the file we write to + * + * May be false positive with !CONFIG_LOCKDEP/LOCK_STATE_UNKNOWN. + * May be false positive with !S_ISREG, because file_start_write() has + * no effect on !S_ISREG. + */ +static inline bool file_write_not_started(const struct file *file) +{ + if (!S_ISREG(file_inode(file)->i_mode)) + return true; + return sb_write_not_started(file_inode(file)->i_sb); +} + +bool inode_owner_or_capable(struct mnt_idmap *idmap, + const struct inode *inode); + +/* + * VFS helper functions.. + */ +int vfs_create(struct mnt_idmap *, struct dentry *, umode_t, + struct delegated_inode *); +struct dentry *vfs_mkdir(struct mnt_idmap *, struct inode *, + struct dentry *, umode_t, struct delegated_inode *); +int vfs_mknod(struct mnt_idmap *, struct inode *, struct dentry *, + umode_t, dev_t, struct delegated_inode *); +int vfs_symlink(struct mnt_idmap *, struct inode *, + struct dentry *, const char *, struct delegated_inode *); +int vfs_link(struct dentry *, struct mnt_idmap *, struct inode *, + struct dentry *, struct delegated_inode *); +int vfs_rmdir(struct mnt_idmap *, struct inode *, struct dentry *, + struct delegated_inode *); +int vfs_unlink(struct mnt_idmap *, struct inode *, struct dentry *, + struct delegated_inode *); + +/** + * struct renamedata - contains all information required for renaming + * @mnt_idmap: idmap of the mount in which the rename is happening. + * @old_parent: parent of source + * @old_dentry: source + * @new_parent: parent of destination + * @new_dentry: destination + * @delegated_inode: returns an inode needing a delegation break + * @flags: rename flags + */ +struct renamedata { + struct mnt_idmap *mnt_idmap; + struct dentry *old_parent; + struct dentry *old_dentry; + struct dentry *new_parent; + struct dentry *new_dentry; + struct delegated_inode *delegated_inode; + unsigned int flags; +} __randomize_layout; + +int vfs_rename(struct renamedata *); + +static inline int vfs_whiteout(struct mnt_idmap *idmap, + struct inode *dir, struct dentry *dentry) +{ + return vfs_mknod(idmap, dir, dentry, S_IFCHR | WHITEOUT_MODE, + WHITEOUT_DEV, NULL); +} + +struct file *kernel_tmpfile_open(struct mnt_idmap *idmap, + const struct path *parentpath, + umode_t mode, int open_flag, + const struct cred *cred); +struct file *kernel_file_open(const struct path *path, int flags, + const struct cred *cred); + +int vfs_mkobj(struct dentry *, umode_t, + int (*f)(struct dentry *, umode_t, void *), + void *); + +int vfs_fchown(struct file *file, uid_t user, gid_t group); +int vfs_fchmod(struct file *file, umode_t mode); +int vfs_utimes(const struct path *path, struct timespec64 *times); + +#ifdef CONFIG_COMPAT +extern long compat_ptr_ioctl(struct file *file, unsigned int cmd, + unsigned long arg); +#else +#define compat_ptr_ioctl NULL +#endif + +/* + * VFS file helper functions. + */ +void inode_init_owner(struct mnt_idmap *idmap, struct inode *inode, + const struct inode *dir, umode_t mode); +extern bool may_open_dev(const struct path *path); +umode_t mode_strip_sgid(struct mnt_idmap *idmap, + const struct inode *dir, umode_t mode); +bool in_group_or_capable(struct mnt_idmap *idmap, + const struct inode *inode, vfsgid_t vfsgid); + +/* + * This is the "filldir" function type, used by readdir() to let + * the kernel specify what kind of dirent layout it wants to have. + * This allows the kernel to read directories into kernel space or + * to have different dirent layouts depending on the binary type. + * Return 'true' to keep going and 'false' if there are no more entries. + */ +struct dir_context; +typedef bool (*filldir_t)(struct dir_context *, const char *, int, loff_t, u64, + unsigned); + +struct dir_context { + filldir_t actor; + loff_t pos; + /* + * Filesystems MUST NOT MODIFY count, but may use as a hint: + * 0 unknown + * > 0 space in buffer (assume at least one entry) + * INT_MAX unlimited + */ + int count; + /* @actor supports these flags in d_type high bits */ + unsigned int dt_flags_mask; +}; + +/* If OR-ed with d_type, pending signals are not checked */ +#define FILLDIR_FLAG_NOINTR 0x1000 + +/* + * These flags let !MMU mmap() govern direct device mapping vs immediate + * copying more easily for MAP_PRIVATE, especially for ROM filesystems. + * + * NOMMU_MAP_COPY: Copy can be mapped (MAP_PRIVATE) + * NOMMU_MAP_DIRECT: Can be mapped directly (MAP_SHARED) + * NOMMU_MAP_READ: Can be mapped for reading + * NOMMU_MAP_WRITE: Can be mapped for writing + * NOMMU_MAP_EXEC: Can be mapped for execution + */ +#define NOMMU_MAP_COPY 0x00000001 +#define NOMMU_MAP_DIRECT 0x00000008 +#define NOMMU_MAP_READ VM_MAYREAD +#define NOMMU_MAP_WRITE VM_MAYWRITE +#define NOMMU_MAP_EXEC VM_MAYEXEC + +#define NOMMU_VMFLAGS \ + (NOMMU_MAP_READ | NOMMU_MAP_WRITE | NOMMU_MAP_EXEC) + +/* + * These flags control the behavior of the remap_file_range function pointer. + * If it is called with len == 0 that means "remap to end of source file". + * See Documentation/filesystems/vfs.rst for more details about this call. + * + * REMAP_FILE_DEDUP: only remap if contents identical (i.e. deduplicate) + * REMAP_FILE_CAN_SHORTEN: caller can handle a shortened request + */ +#define REMAP_FILE_DEDUP (1 << 0) +#define REMAP_FILE_CAN_SHORTEN (1 << 1) + +/* + * These flags signal that the caller is ok with altering various aspects of + * the behavior of the remap operation. The changes must be made by the + * implementation; the vfs remap helper functions can take advantage of them. + * Flags in this category exist to preserve the quirky behavior of the hoisted + * btrfs clone/dedupe ioctls. + */ +#define REMAP_FILE_ADVISORY (REMAP_FILE_CAN_SHORTEN) + +/* + * These flags control the behavior of vfs_copy_file_range(). + * They are not available to the user via syscall. + * + * COPY_FILE_SPLICE: call splice direct instead of fs clone/copy ops + */ +#define COPY_FILE_SPLICE (1 << 0) + +struct io_uring_cmd; +struct offset_ctx; + +struct file_operations { + struct module *owner; + fop_flags_t fop_flags; + loff_t (*llseek) (struct file *, loff_t, int); + ssize_t (*read) (struct file *, char __user *, size_t, loff_t *); + ssize_t (*write) (struct file *, const char __user *, size_t, loff_t *); + ssize_t (*read_iter) (struct kiocb *, struct iov_iter *); + ssize_t (*write_iter) (struct kiocb *, struct iov_iter *); + int (*iopoll)(struct kiocb *kiocb, struct io_comp_batch *, + unsigned int flags); + int (*iterate_shared) (struct file *, struct dir_context *); + __poll_t (*poll) (struct file *, struct poll_table_struct *); + long (*unlocked_ioctl) (struct file *, unsigned int, unsigned long); + long (*compat_ioctl) (struct file *, unsigned int, unsigned long); + int (*mmap) (struct file *, struct vm_area_struct *); + int (*open) (struct inode *, struct file *); + int (*flush) (struct file *, fl_owner_t id); + int (*release) (struct inode *, struct file *); + int (*fsync) (struct file *, loff_t, loff_t, int datasync); + int (*fasync) (int, struct file *, int); + int (*lock) (struct file *, int, struct file_lock *); + unsigned long (*get_unmapped_area)(struct file *, unsigned long, unsigned long, unsigned long, unsigned long); + int (*check_flags)(int); + int (*flock) (struct file *, int, struct file_lock *); + ssize_t (*splice_write)(struct pipe_inode_info *, struct file *, loff_t *, size_t, unsigned int); + ssize_t (*splice_read)(struct file *, loff_t *, struct pipe_inode_info *, size_t, unsigned int); + void (*splice_eof)(struct file *file); + int (*setlease)(struct file *, int, struct file_lease **, void **); + long (*fallocate)(struct file *file, int mode, loff_t offset, + loff_t len); + void (*show_fdinfo)(struct seq_file *m, struct file *f); +#ifndef CONFIG_MMU + unsigned (*mmap_capabilities)(struct file *); +#endif + ssize_t (*copy_file_range)(struct file *, loff_t, struct file *, + loff_t, size_t, unsigned int); + loff_t (*remap_file_range)(struct file *file_in, loff_t pos_in, + struct file *file_out, loff_t pos_out, + loff_t len, unsigned int remap_flags); + int (*fadvise)(struct file *, loff_t, loff_t, int); + int (*uring_cmd)(struct io_uring_cmd *ioucmd, unsigned int issue_flags); + int (*uring_cmd_iopoll)(struct io_uring_cmd *, struct io_comp_batch *, + unsigned int poll_flags); + int (*mmap_prepare)(struct vm_area_desc *); +} __randomize_layout; + +/* Supports async buffered reads */ +#define FOP_BUFFER_RASYNC ((__force fop_flags_t)(1 << 0)) +/* Supports async buffered writes */ +#define FOP_BUFFER_WASYNC ((__force fop_flags_t)(1 << 1)) +/* Supports synchronous page faults for mappings */ +#define FOP_MMAP_SYNC ((__force fop_flags_t)(1 << 2)) +/* Supports non-exclusive O_DIRECT writes from multiple threads */ +#define FOP_DIO_PARALLEL_WRITE ((__force fop_flags_t)(1 << 3)) +/* Contains huge pages */ +#define FOP_HUGE_PAGES ((__force fop_flags_t)(1 << 4)) +/* Treat loff_t as unsigned (e.g., /dev/mem) */ +#define FOP_UNSIGNED_OFFSET ((__force fop_flags_t)(1 << 5)) +/* Supports asynchronous lock callbacks */ +#define FOP_ASYNC_LOCK ((__force fop_flags_t)(1 << 6)) +/* File system supports uncached read/write buffered IO */ +#define FOP_DONTCACHE ((__force fop_flags_t)(1 << 7)) + +/* Wrap a directory iterator that needs exclusive inode access */ +int wrap_directory_iterator(struct file *, struct dir_context *, + int (*) (struct file *, struct dir_context *)); +#define WRAP_DIR_ITER(x) \ + static int shared_##x(struct file *file , struct dir_context *ctx) \ + { return wrap_directory_iterator(file, ctx, x); } + +enum fs_update_time { + FS_UPD_ATIME, + FS_UPD_CMTIME, +}; + +struct inode_operations { + struct dentry * (*lookup) (struct inode *,struct dentry *, unsigned int); + const char * (*get_link) (struct dentry *, struct inode *, struct delayed_call *); + int (*permission) (struct mnt_idmap *, struct inode *, int); + struct posix_acl * (*get_inode_acl)(struct inode *, int, bool); + + int (*readlink) (struct dentry *, char __user *,int); + + int (*create) (struct mnt_idmap *, struct inode *,struct dentry *, + umode_t); + int (*link) (struct dentry *,struct inode *,struct dentry *); + int (*unlink) (struct inode *,struct dentry *); + int (*symlink) (struct mnt_idmap *, struct inode *,struct dentry *, + const char *); + struct dentry *(*mkdir) (struct mnt_idmap *, struct inode *, + struct dentry *, umode_t); + int (*rmdir) (struct inode *,struct dentry *); + int (*mknod) (struct mnt_idmap *, struct inode *,struct dentry *, + umode_t,dev_t); + int (*rename) (struct mnt_idmap *, struct inode *, struct dentry *, + struct inode *, struct dentry *, unsigned int); + int (*setattr) (struct mnt_idmap *, struct dentry *, struct iattr *); + int (*getattr) (struct mnt_idmap *, const struct path *, + struct kstat *, u32, unsigned int); + ssize_t (*listxattr) (struct dentry *, char *, size_t); + int (*fiemap)(struct inode *, struct fiemap_extent_info *, u64 start, + u64 len); + int (*update_time)(struct inode *inode, enum fs_update_time type, + unsigned int flags); + void (*sync_lazytime)(struct inode *inode); + int (*atomic_open)(struct inode *, struct dentry *, + struct file *, unsigned open_flag, + umode_t create_mode); + int (*tmpfile) (struct mnt_idmap *, struct inode *, + struct file *, umode_t); + struct posix_acl *(*get_acl)(struct mnt_idmap *, struct dentry *, + int); + int (*set_acl)(struct mnt_idmap *, struct dentry *, + struct posix_acl *, int); + int (*fileattr_set)(struct mnt_idmap *idmap, + struct dentry *dentry, struct file_kattr *fa); + int (*fileattr_get)(struct dentry *dentry, struct file_kattr *fa); + struct offset_ctx *(*get_offset_ctx)(struct inode *inode); +} ____cacheline_aligned; + +/* Did the driver provide valid mmap hook configuration? */ +static inline bool can_mmap_file(struct file *file) +{ + bool has_mmap = file->f_op->mmap; + bool has_mmap_prepare = file->f_op->mmap_prepare; + + /* Hooks are mutually exclusive. */ + if (WARN_ON_ONCE(has_mmap && has_mmap_prepare)) + return false; + if (!has_mmap && !has_mmap_prepare) + return false; + + return true; +} + +void compat_set_desc_from_vma(struct vm_area_desc *desc, const struct file *file, + const struct vm_area_struct *vma); +int __compat_vma_mmap(struct vm_area_desc *desc, struct vm_area_struct *vma); +int compat_vma_mmap(struct file *file, struct vm_area_struct *vma); + +static inline int vfs_mmap(struct file *file, struct vm_area_struct *vma) +{ + if (file->f_op->mmap_prepare) + return compat_vma_mmap(file, vma); + + return file->f_op->mmap(file, vma); +} + +static inline int vfs_mmap_prepare(struct file *file, struct vm_area_desc *desc) +{ + return file->f_op->mmap_prepare(desc); +} + +extern ssize_t vfs_read(struct file *, char __user *, size_t, loff_t *); +extern ssize_t vfs_write(struct file *, const char __user *, size_t, loff_t *); +extern ssize_t vfs_copy_file_range(struct file *, loff_t , struct file *, + loff_t, size_t, unsigned int); +int remap_verify_area(struct file *file, loff_t pos, loff_t len, bool write); +int __generic_remap_file_range_prep(struct file *file_in, loff_t pos_in, + struct file *file_out, loff_t pos_out, + loff_t *len, unsigned int remap_flags, + const struct iomap_ops *dax_read_ops); +int generic_remap_file_range_prep(struct file *file_in, loff_t pos_in, + struct file *file_out, loff_t pos_out, + loff_t *count, unsigned int remap_flags); +extern loff_t vfs_clone_file_range(struct file *file_in, loff_t pos_in, + struct file *file_out, loff_t pos_out, + loff_t len, unsigned int remap_flags); +extern int vfs_dedupe_file_range(struct file *file, + struct file_dedupe_range *same); +extern loff_t vfs_dedupe_file_range_one(struct file *src_file, loff_t src_pos, + struct file *dst_file, loff_t dst_pos, + loff_t len, unsigned int remap_flags); + +/* + * Inode flags - they have no relation to superblock flags now + */ +#define S_SYNC (1 << 0) /* Writes are synced at once */ +#define S_NOATIME (1 << 1) /* Do not update access times */ +#define S_APPEND (1 << 2) /* Append-only file */ +#define S_IMMUTABLE (1 << 3) /* Immutable file */ +#define S_DEAD (1 << 4) /* removed, but still open directory */ +#define S_NOQUOTA (1 << 5) /* Inode is not counted to quota */ +#define S_DIRSYNC (1 << 6) /* Directory modifications are synchronous */ +#define S_NOCMTIME (1 << 7) /* Do not update file c/mtime */ +#define S_SWAPFILE (1 << 8) /* Do not truncate: swapon got its bmaps */ +#define S_PRIVATE (1 << 9) /* Inode is fs-internal */ +#define S_IMA (1 << 10) /* Inode has an associated IMA struct */ +#define S_AUTOMOUNT (1 << 11) /* Automount/referral quasi-directory */ +#define S_NOSEC (1 << 12) /* no suid or xattr security attributes */ +#ifdef CONFIG_FS_DAX +#define S_DAX (1 << 13) /* Direct Access, avoiding the page cache */ +#else +#define S_DAX 0 /* Make all the DAX code disappear */ +#endif +#define S_ENCRYPTED (1 << 14) /* Encrypted file (using fs/crypto/) */ +#define S_CASEFOLD (1 << 15) /* Casefolded file */ +#define S_VERITY (1 << 16) /* Verity file (using fs/verity/) */ +#define S_KERNEL_FILE (1 << 17) /* File is in use by the kernel (eg. fs/cachefiles) */ +#define S_ANON_INODE (1 << 19) /* Inode is an anonymous inode */ + +/* + * Note that nosuid etc flags are inode-specific: setting some file-system + * flags just means all the inodes inherit those flags by default. It might be + * possible to override it selectively if you really wanted to with some + * ioctl() that is not currently implemented. + * + * Exception: SB_RDONLY is always applied to the entire file system. + * + * Unfortunately, it is possible to change a filesystems flags with it mounted + * with files in use. This means that all of the inodes will not have their + * i_flags updated. Hence, i_flags no longer inherit the superblock mount + * flags, so these have to be checked separately. -- rmk@arm.uk.linux.org + */ +#define __IS_FLG(inode, flg) ((inode)->i_sb->s_flags & (flg)) + +#define IS_RDONLY(inode) sb_rdonly((inode)->i_sb) +#define IS_SYNC(inode) (__IS_FLG(inode, SB_SYNCHRONOUS) || \ + ((inode)->i_flags & S_SYNC)) +#define IS_DIRSYNC(inode) (__IS_FLG(inode, SB_SYNCHRONOUS|SB_DIRSYNC) || \ + ((inode)->i_flags & (S_SYNC|S_DIRSYNC))) +#define IS_MANDLOCK(inode) __IS_FLG(inode, SB_MANDLOCK) +#define IS_NOATIME(inode) __IS_FLG(inode, SB_RDONLY|SB_NOATIME) +#define IS_I_VERSION(inode) __IS_FLG(inode, SB_I_VERSION) + +#define IS_NOQUOTA(inode) ((inode)->i_flags & S_NOQUOTA) +#define IS_APPEND(inode) ((inode)->i_flags & S_APPEND) +#define IS_IMMUTABLE(inode) ((inode)->i_flags & S_IMMUTABLE) + +#ifdef CONFIG_FS_POSIX_ACL +#define IS_POSIXACL(inode) __IS_FLG(inode, SB_POSIXACL) +#else +#define IS_POSIXACL(inode) 0 +#endif + +#define IS_DEADDIR(inode) ((inode)->i_flags & S_DEAD) +#define IS_NOCMTIME(inode) ((inode)->i_flags & S_NOCMTIME) + +#ifdef CONFIG_SWAP +#define IS_SWAPFILE(inode) ((inode)->i_flags & S_SWAPFILE) +#else +#define IS_SWAPFILE(inode) ((void)(inode), 0U) +#endif + +#define IS_PRIVATE(inode) ((inode)->i_flags & S_PRIVATE) +#define IS_IMA(inode) ((inode)->i_flags & S_IMA) +#define IS_AUTOMOUNT(inode) ((inode)->i_flags & S_AUTOMOUNT) +#define IS_NOSEC(inode) ((inode)->i_flags & S_NOSEC) +#define IS_DAX(inode) ((inode)->i_flags & S_DAX) +#define IS_ENCRYPTED(inode) ((inode)->i_flags & S_ENCRYPTED) +#define IS_CASEFOLDED(inode) ((inode)->i_flags & S_CASEFOLD) +#define IS_VERITY(inode) ((inode)->i_flags & S_VERITY) + +#define IS_WHITEOUT(inode) (S_ISCHR(inode->i_mode) && \ + (inode)->i_rdev == WHITEOUT_DEV) +#define IS_ANON_FILE(inode) ((inode)->i_flags & S_ANON_INODE) + +static inline bool HAS_UNMAPPED_ID(struct mnt_idmap *idmap, + struct inode *inode) +{ + return !vfsuid_valid(i_uid_into_vfsuid(idmap, inode)) || + !vfsgid_valid(i_gid_into_vfsgid(idmap, inode)); +} + +static inline void init_sync_kiocb(struct kiocb *kiocb, struct file *filp) +{ + *kiocb = (struct kiocb) { + .ki_filp = filp, + .ki_flags = filp->f_iocb_flags, + .ki_ioprio = get_current_ioprio(), + }; +} + +static inline void kiocb_clone(struct kiocb *kiocb, struct kiocb *kiocb_src, + struct file *filp) +{ + *kiocb = (struct kiocb) { + .ki_filp = filp, + .ki_flags = kiocb_src->ki_flags, + .ki_ioprio = kiocb_src->ki_ioprio, + .ki_pos = kiocb_src->ki_pos, + }; +} + +extern void __mark_inode_dirty(struct inode *, int); +static inline void mark_inode_dirty(struct inode *inode) +{ + __mark_inode_dirty(inode, I_DIRTY); +} + +static inline void mark_inode_dirty_sync(struct inode *inode) +{ + __mark_inode_dirty(inode, I_DIRTY_SYNC); +} + +static inline void set_inode_metadata_writeback(struct inode *inode) +{ + spin_lock(&inode->i_lock); + inode_state_set(inode, I_METADATA_WRITEBACK); + spin_unlock(&inode->i_lock); +} + +/* + * returns the refcount on the inode. it can change arbitrarily. + */ +static inline int icount_read_once(const struct inode *inode) +{ + return atomic_read(&inode->i_count); +} + +/* + * returns the refcount on the inode. The lock guarantees no 0->1 or 1->0 transitions + * of the count are going to take place, otherwise it changes arbitrarily. + */ +static inline int icount_read(const struct inode *inode) +{ + lockdep_assert_held(&inode->i_lock); + return atomic_read(&inode->i_count); +} + +/* + * Returns true if the given inode itself only has dirty timestamps (its pages + * may still be dirty) and isn't currently being allocated or freed. + * Filesystems should call this if when writing an inode when lazytime is + * enabled, they want to opportunistically write the timestamps of other inodes + * located very nearby on-disk, e.g. in the same inode block. This returns true + * if the given inode is in need of such an opportunistic update. Requires + * i_lock, or at least later re-checking under i_lock. + */ +static inline bool inode_is_dirtytime_only(struct inode *inode) +{ + return (inode_state_read_once(inode) & + (I_DIRTY_TIME | I_NEW | I_FREEING | I_WILL_FREE)) == I_DIRTY_TIME; +} + +extern void inc_nlink(struct inode *inode); +extern void drop_nlink(struct inode *inode); +extern void clear_nlink(struct inode *inode); +extern void set_nlink(struct inode *inode, unsigned int nlink); + +static inline void inode_inc_link_count(struct inode *inode) +{ + inc_nlink(inode); + mark_inode_dirty(inode); +} + +static inline void inode_dec_link_count(struct inode *inode) +{ + drop_nlink(inode); + mark_inode_dirty(inode); +} + +extern bool atime_needs_update(const struct path *, struct inode *); +extern void touch_atime(const struct path *); + +static inline void file_accessed(struct file *file) +{ + if (!(file->f_flags & O_NOATIME)) + touch_atime(&file->f_path); +} + +extern int file_modified(struct file *file); +int kiocb_modified(struct kiocb *iocb); + +int sync_inode_metadata(struct inode *inode, int wait); + +struct file_system_type { + const char *name; + int fs_flags; +#define FS_REQUIRES_DEV 1 +#define FS_BINARY_MOUNTDATA 2 +#define FS_HAS_SUBTYPE 4 +#define FS_USERNS_MOUNT 8 /* Can be mounted by userns root */ +#define FS_DISALLOW_NOTIFY_PERM 16 /* Disable fanotify permission events */ +#define FS_ALLOW_IDMAP 32 /* FS has been updated to handle vfs idmappings. */ +#define FS_MGTIME 64 /* FS uses multigrain timestamps */ +#define FS_LBS 128 /* FS supports LBS */ +#define FS_POWER_FREEZE 256 /* Always freeze on suspend/hibernate */ +#define FS_USERNS_MOUNT_RESTRICTED 512 /* Restrict mount in userns if not already visible */ +#define FS_USERNS_DELEGATABLE 1024 /* Can be mounted inside userns from outside */ +#define FS_RENAME_DOES_D_MOVE 32768 /* FS will handle d_move() during rename() internally. */ + int (*init_fs_context)(struct fs_context *); + const struct fs_parameter_spec *parameters; + void (*kill_sb) (struct super_block *); + struct module *owner; + struct hlist_node list; + struct hlist_head fs_supers; + + struct lock_class_key s_lock_key; + struct lock_class_key s_umount_key; + struct lock_class_key s_vfs_rename_key; + struct lock_class_key s_writers_key[SB_FREEZE_LEVELS]; + + struct lock_class_key i_lock_key; + struct lock_class_key i_mutex_key; + struct lock_class_key invalidate_lock_key; + struct lock_class_key i_mutex_dir_key; +}; + +#define MODULE_ALIAS_FS(NAME) MODULE_ALIAS("fs-" NAME) + +/** + * is_mgtime: is this inode using multigrain timestamps + * @inode: inode to test for multigrain timestamps + * + * Return true if the inode uses multigrain timestamps, false otherwise. + */ +static inline bool is_mgtime(const struct inode *inode) +{ + return inode->i_opflags & IOP_MGTIME; +} + +extern struct dentry *mount_subtree(struct vfsmount *mnt, const char *path); +void retire_super(struct super_block *sb); +void generic_shutdown_super(struct super_block *sb); +void kill_block_super(struct super_block *sb); +void kill_anon_super(struct super_block *sb); +void deactivate_super(struct super_block *sb); +void deactivate_locked_super(struct super_block *sb); +int set_anon_super(struct super_block *s, void *data); +int set_anon_super_fc(struct super_block *s, struct fs_context *fc); +int get_anon_bdev(dev_t *); +void free_anon_bdev(dev_t); +struct super_block *sget_fc(struct fs_context *fc, + int (*test)(struct super_block *, struct fs_context *), + int (*set)(struct super_block *, struct fs_context *)); +struct super_block *sget_dev(struct fs_context *fc, dev_t dev); + +/* Alas, no aliases. Too much hassle with bringing module.h everywhere */ +#define fops_get(fops) ({ \ + const struct file_operations *_fops = (fops); \ + (((_fops) && try_module_get((_fops)->owner) ? (_fops) : NULL)); \ +}) + +#define fops_put(fops) ({ \ + const struct file_operations *_fops = (fops); \ + if (_fops) \ + module_put((_fops)->owner); \ +}) + +/* + * This one is to be used *ONLY* from ->open() instances. + * fops must be non-NULL, pinned down *and* module dependencies + * should be sufficient to pin the caller down as well. + */ +#define replace_fops(f, fops) \ + do { \ + struct file *__file = (f); \ + fops_put(__file->f_op); \ + BUG_ON(!(__file->f_op = (fops))); \ + } while(0) + +extern int register_filesystem(struct file_system_type *); +extern int unregister_filesystem(struct file_system_type *); +extern int vfs_statfs(const struct path *, struct kstatfs *); +extern int user_statfs(const char __user *, struct kstatfs *); +extern int fd_statfs(int, struct kstatfs *); +extern __printf(2, 3) +int super_setup_bdi_name(struct super_block *sb, char *fmt, ...); +extern int super_setup_bdi(struct super_block *sb); + +static inline void super_set_uuid(struct super_block *sb, const u8 *uuid, unsigned len) +{ + if (WARN_ON(len > sizeof(sb->s_uuid))) + len = sizeof(sb->s_uuid); + sb->s_uuid_len = len; + memcpy(&sb->s_uuid, uuid, len); +} + +/* set sb sysfs name based on sb->s_bdev */ +static inline void super_set_sysfs_name_bdev(struct super_block *sb) +{ + snprintf(sb->s_sysfs_name, sizeof(sb->s_sysfs_name), "%pg", sb->s_bdev); +} + +/* set sb sysfs name based on sb->s_uuid */ +static inline void super_set_sysfs_name_uuid(struct super_block *sb) +{ + WARN_ON(sb->s_uuid_len != sizeof(sb->s_uuid)); + snprintf(sb->s_sysfs_name, sizeof(sb->s_sysfs_name), "%pU", sb->s_uuid.b); +} + +/* set sb sysfs name based on sb->s_id */ +static inline void super_set_sysfs_name_id(struct super_block *sb) +{ + strscpy(sb->s_sysfs_name, sb->s_id, sizeof(sb->s_sysfs_name)); +} + +/* try to use something standard before you use this */ +__printf(2, 3) +static inline void super_set_sysfs_name_generic(struct super_block *sb, const char *fmt, ...) +{ + va_list args; + + va_start(args, fmt); + vsnprintf(sb->s_sysfs_name, sizeof(sb->s_sysfs_name), fmt, args); + va_end(args); +} + +extern void ihold(struct inode * inode); +extern void iput(struct inode *); +void iput_not_last(struct inode *); + +/** + * iput_if_not_last - drop an inode reference only if it is not the last one + * @inode: inode to put + * + * Returns true if the reference was dropped, false if this was the last + * reference and the caller must arrange for final iput() in a safe context. + */ +static inline bool __must_check iput_if_not_last(struct inode *inode) +{ + VFS_BUG_ON_INODE(inode_state_read_once(inode) & (I_FREEING | I_CLEAR), inode); + VFS_BUG_ON_INODE(icount_read_once(inode) < 1, inode); + return atomic_add_unless(&inode->i_count, -1, 1); +} + +int inode_update_time(struct inode *inode, enum fs_update_time type, + unsigned int flags); +int generic_update_time(struct inode *inode, enum fs_update_time type, + unsigned int flags); + +/* /sys/fs */ +extern struct kobject *fs_kobj; + +#define MAX_RW_COUNT (INT_MAX & PAGE_MASK) + +/* fs/open.c */ +struct audit_names; + +struct __filename_head { + const char *name; /* pointer to actual string */ + int refcnt; + struct audit_names *aname; +}; +#define EMBEDDED_NAME_MAX (192 - sizeof(struct __filename_head)) +struct filename { + struct __filename_head; + const char iname[EMBEDDED_NAME_MAX]; +}; +static_assert(offsetof(struct filename, iname) % sizeof(long) == 0); +static_assert(sizeof(struct filename) % 64 == 0); + +static inline struct mnt_idmap *file_mnt_idmap(const struct file *file) +{ + return mnt_idmap(file->f_path.mnt); +} + +static inline bool file_owner_or_capable(const struct file *file) +{ + return inode_owner_or_capable(file_mnt_idmap(file), file_inode(file)); +} + +/** + * is_idmapped_mnt - check whether a mount is mapped + * @mnt: the mount to check + * + * If @mnt has an non @nop_mnt_idmap attached to it then @mnt is mapped. + * + * Return: true if mount is mapped, false if not. + */ +static inline bool is_idmapped_mnt(const struct vfsmount *mnt) +{ + return mnt_idmap(mnt) != &nop_mnt_idmap; +} + +int vfs_truncate(const struct path *, loff_t); +int do_truncate(struct mnt_idmap *, struct dentry *, loff_t start, + unsigned int time_attrs, struct file *filp); +extern int vfs_fallocate(struct file *file, int mode, loff_t offset, + loff_t len); +int do_sys_open(int dfd, const char __user *filename, int flags, + umode_t mode); +extern struct file *file_open_name(struct filename *, int, umode_t); +extern struct file *filp_open(const char *, int, umode_t); +extern struct file *file_open_root(const struct path *, + const char *, int, umode_t); +static inline struct file *file_open_root_mnt(struct vfsmount *mnt, + const char *name, int flags, umode_t mode) +{ + return file_open_root(&(struct path){.mnt = mnt, .dentry = mnt->mnt_root}, + name, flags, mode); +} +struct file *dentry_open(const struct path *path, int flags, + const struct cred *creds); +struct file *dentry_open_nonotify(const struct path *path, int flags, + const struct cred *cred); +struct file *dentry_create(struct path *path, int flags, umode_t mode, + const struct cred *cred); +const struct path *backing_file_user_path(const struct file *f); + +#ifdef CONFIG_SECURITY +void *backing_file_security(const struct file *f); +void backing_file_set_security(struct file *f, void *security); +#else +static inline void *backing_file_security(const struct file *f) +{ + return NULL; +} +static inline void backing_file_set_security(struct file *f, void *security) +{ +} +#endif /* CONFIG_SECURITY */ + +/* + * When mmapping a file on a stackable filesystem (e.g., overlayfs), the file + * stored in ->vm_file is a backing file whose f_inode is on the underlying + * filesystem. When the mapped file path and inode number are displayed to + * user (e.g. via /proc/<pid>/maps), these helpers should be used to get the + * path and inode number to display to the user, which is the path of the fd + * that user has requested to map and the inode number that would be returned + * by fstat() on that same fd. + */ +/* Get the path to display in /proc/<pid>/maps */ +static inline const struct path *file_user_path(const struct file *f) +{ + if (unlikely(f->f_mode & FMODE_BACKING)) + return backing_file_user_path(f); + return &f->f_path; +} +/* Get the inode whose inode number to display in /proc/<pid>/maps */ +static inline const struct inode *file_user_inode(const struct file *f) +{ + if (unlikely(f->f_mode & FMODE_BACKING)) + return d_inode(backing_file_user_path(f)->dentry); + return file_inode(f); +} + +static inline struct file *file_clone_open(struct file *file) +{ + return dentry_open(&file->f_path, file->f_flags, file->f_cred); +} +extern int filp_close(struct file *, fl_owner_t id); + +extern struct filename *getname_flags(const char __user *, int); +extern struct filename *getname_uflags(const char __user *, int); +static inline struct filename *getname(const char __user *name) +{ + return getname_flags(name, 0); +} +extern struct filename *getname_kernel(const char *); +extern struct filename *__getname_maybe_null(const char __user *); +static inline struct filename *getname_maybe_null(const char __user *name, int flags) +{ + if (!(flags & AT_EMPTY_PATH)) + return getname(name); + + if (!name) + return NULL; + return __getname_maybe_null(name); +} +extern void putname(struct filename *name); +DEFINE_FREE(putname, struct filename *, if (!IS_ERR_OR_NULL(_T)) putname(_T)) + +struct delayed_filename { + struct filename *__incomplete_filename; // don't touch +}; +#define INIT_DELAYED_FILENAME(ptr) \ + ((void)(*(ptr) = (struct delayed_filename){})) +int delayed_getname(struct delayed_filename *, const char __user *); +int delayed_getname_uflags(struct delayed_filename *v, const char __user *, int); +void dismiss_delayed_filename(struct delayed_filename *); +int putname_to_delayed(struct delayed_filename *, struct filename *); +struct filename *complete_getname(struct delayed_filename *); + +DEFINE_CLASS(filename, struct filename *, putname(_T), getname(p), const char __user *p) +EXTEND_CLASS(filename, _kernel, getname_kernel(p), const char *p) +EXTEND_CLASS(filename, _flags, getname_flags(p, f), const char __user *p, unsigned int f) +EXTEND_CLASS(filename, _uflags, getname_uflags(p, f), const char __user *p, unsigned int f) +EXTEND_CLASS(filename, _maybe_null, getname_maybe_null(p, f), const char __user *p, unsigned int f) +EXTEND_CLASS(filename, _complete_delayed, complete_getname(p), struct delayed_filename *p) + +extern int finish_open(struct file *file, struct dentry *dentry, + int (*open)(struct inode *, struct file *)); +extern int finish_no_open(struct file *file, struct dentry *dentry); + +/* Helper for the simple case when original dentry is used */ +static inline int finish_open_simple(struct file *file, int error) +{ + if (error) + return error; + + return finish_open(file, file->f_path.dentry, NULL); +} + +/* fs/dcache.c */ +extern void __init vfs_caches_init_early(void); +extern void __init vfs_caches_init(void); + +#define __getname() kmalloc(PATH_MAX, GFP_KERNEL) +#define __putname(name) kfree(name) + +void emergency_thaw_all(void); +extern int sync_filesystem(struct super_block *); +extern const struct file_operations def_blk_fops; +extern const struct file_operations def_chr_fops; + +/* fs/char_dev.c */ +#define CHRDEV_MAJOR_MAX 512 +/* Marks the bottom of the first segment of free char majors */ +#define CHRDEV_MAJOR_DYN_END 234 +/* Marks the top and bottom of the second segment of free char majors */ +#define CHRDEV_MAJOR_DYN_EXT_START 511 +#define CHRDEV_MAJOR_DYN_EXT_END 384 + +extern int alloc_chrdev_region(dev_t *, unsigned, unsigned, const char *); +extern int register_chrdev_region(dev_t, unsigned, const char *); +extern int __register_chrdev(unsigned int major, unsigned int baseminor, + unsigned int count, const char *name, + const struct file_operations *fops); +extern void __unregister_chrdev(unsigned int major, unsigned int baseminor, + unsigned int count, const char *name); +extern void unregister_chrdev_region(dev_t, unsigned); +extern void chrdev_show(struct seq_file *,off_t); + +static inline int register_chrdev(unsigned int major, const char *name, + const struct file_operations *fops) +{ + return __register_chrdev(major, 0, 256, name, fops); +} + +static inline void unregister_chrdev(unsigned int major, const char *name) +{ + __unregister_chrdev(major, 0, 256, name); +} + +extern void init_special_inode(struct inode *, umode_t, dev_t); + +/* Invalid inode operations -- fs/bad_inode.c */ +extern void make_bad_inode(struct inode *); +extern bool is_bad_inode(struct inode *); + +extern int __must_check file_fdatawait_range(struct file *file, loff_t lstart, + loff_t lend); +extern int __must_check file_check_and_advance_wb_err(struct file *file); +extern int __must_check file_write_and_wait_range(struct file *file, + loff_t start, loff_t end); +int filemap_flush_range(struct address_space *mapping, loff_t start, + loff_t end); +void filemap_dontcache_kick_writeback(struct address_space *mapping); + +static inline int file_write_and_wait(struct file *file) +{ + return file_write_and_wait_range(file, 0, LLONG_MAX); +} + +extern int vfs_fsync_range(struct file *file, loff_t start, loff_t end, + int datasync); +extern int vfs_fsync(struct file *file, int datasync); + +extern int sync_file_range(struct file *file, loff_t offset, loff_t nbytes, + unsigned int flags); + +static inline bool iocb_is_dsync(const struct kiocb *iocb) +{ + return (iocb->ki_flags & IOCB_DSYNC) || + IS_SYNC(iocb->ki_filp->f_mapping->host); +} + +/* + * Sync the bytes written if this was a synchronous write. Expect ki_pos + * to already be updated for the write, and will return either the amount + * of bytes passed in, or an error if syncing the file failed. + */ +static inline ssize_t generic_write_sync(struct kiocb *iocb, ssize_t count) +{ + if (iocb_is_dsync(iocb)) { + int ret = vfs_fsync_range(iocb->ki_filp, + iocb->ki_pos - count, iocb->ki_pos - 1, + (iocb->ki_flags & IOCB_SYNC) ? 0 : 1); + if (ret) + return ret; + } else if (iocb->ki_flags & IOCB_DONTCACHE) { + filemap_dontcache_kick_writeback(iocb->ki_filp->f_mapping); + } + + return count; +} + +extern void emergency_sync(void); +extern void emergency_remount(void); + +#ifdef CONFIG_BLOCK +extern int bmap(struct inode *inode, sector_t *block); +#else +static inline int bmap(struct inode *inode, sector_t *block) +{ + return -EINVAL; +} +#endif + +int notify_change(struct mnt_idmap *, struct dentry *, + struct iattr *, struct delegated_inode *); +int inode_permission(struct mnt_idmap *, struct inode *, int); +int generic_permission(struct mnt_idmap *, struct inode *, int); +static inline int file_permission(struct file *file, int mask) +{ + return inode_permission(file_mnt_idmap(file), + file_inode(file), mask); +} +static inline int path_permission(const struct path *path, int mask) +{ + return inode_permission(mnt_idmap(path->mnt), + d_inode(path->dentry), mask); +} +int __check_sticky(struct mnt_idmap *idmap, struct inode *dir, + struct inode *inode); + +int may_delete_dentry(struct mnt_idmap *idmap, struct inode *dir, + struct dentry *victim, bool isdir); +int may_create_dentry(struct mnt_idmap *idmap, + struct inode *dir, struct dentry *child); + +static inline bool execute_ok(struct inode *inode) +{ + return (inode->i_mode & S_IXUGO) || S_ISDIR(inode->i_mode); +} + +static inline bool inode_wrong_type(const struct inode *inode, umode_t mode) +{ + return (inode->i_mode ^ mode) & S_IFMT; +} + +/** + * file_start_write - get write access to a superblock for regular file io + * @file: the file we want to write to + * + * This is a variant of sb_start_write() which is a noop on non-regular file. + * Should be matched with a call to file_end_write(). + */ +static inline void file_start_write(struct file *file) +{ + if (!S_ISREG(file_inode(file)->i_mode)) + return; + sb_start_write(file_inode(file)->i_sb); +} + +static inline bool file_start_write_trylock(struct file *file) +{ + if (!S_ISREG(file_inode(file)->i_mode)) + return true; + return sb_start_write_trylock(file_inode(file)->i_sb); +} + +/** + * file_end_write - drop write access to a superblock of a regular file + * @file: the file we wrote to + * + * Should be matched with a call to file_start_write(). + */ +static inline void file_end_write(struct file *file) +{ + if (!S_ISREG(file_inode(file)->i_mode)) + return; + sb_end_write(file_inode(file)->i_sb); +} + +/** + * kiocb_start_write - get write access to a superblock for async file io + * @iocb: the io context we want to submit the write with + * + * This is a variant of sb_start_write() for async io submission. + * Should be matched with a call to kiocb_end_write(). + */ +static inline void kiocb_start_write(struct kiocb *iocb) +{ + struct inode *inode = file_inode(iocb->ki_filp); + + sb_start_write(inode->i_sb); + /* + * Fool lockdep by telling it the lock got released so that it + * doesn't complain about the held lock when we return to userspace. + */ + __sb_writers_release(inode->i_sb, SB_FREEZE_WRITE); +} + +/** + * kiocb_end_write - drop write access to a superblock after async file io + * @iocb: the io context we sumbitted the write with + * + * Should be matched with a call to kiocb_start_write(). + */ +static inline void kiocb_end_write(struct kiocb *iocb) +{ + struct inode *inode = file_inode(iocb->ki_filp); + + /* + * Tell lockdep we inherited freeze protection from submission thread. + */ + __sb_writers_acquired(inode->i_sb, SB_FREEZE_WRITE); + sb_end_write(inode->i_sb); +} + +/* + * This is used for regular files where some users -- especially the + * currently executed binary in a process, previously handled via + * VM_DENYWRITE -- cannot handle concurrent write (and maybe mmap + * read-write shared) accesses. + * + * get_write_access() gets write permission for a file. + * put_write_access() releases this write permission. + * deny_write_access() denies write access to a file. + * allow_write_access() re-enables write access to a file. + * + * The i_writecount field of an inode can have the following values: + * 0: no write access, no denied write access + * < 0: (-i_writecount) users that denied write access to the file. + * > 0: (i_writecount) users that have write access to the file. + * + * Normally we operate on that counter with atomic_{inc,dec} and it's safe + * except for the cases where we don't hold i_writecount yet. Then we need to + * use {get,deny}_write_access() - these functions check the sign and refuse + * to do the change if sign is wrong. + */ +static inline int get_write_access(struct inode *inode) +{ + return atomic_inc_unless_negative(&inode->i_writecount) ? 0 : -ETXTBSY; +} +static inline int deny_write_access(struct file *file) +{ + struct inode *inode = file_inode(file); + return atomic_dec_unless_positive(&inode->i_writecount) ? 0 : -ETXTBSY; +} +static inline void put_write_access(struct inode * inode) +{ + atomic_dec(&inode->i_writecount); +} +static inline void allow_write_access(struct file *file) +{ + if (file) + atomic_inc(&file_inode(file)->i_writecount); +} + +/* + * Do not prevent write to executable file when watched by pre-content events. + * + * Note that FMODE_FSNOTIFY_HSM mode is set depending on pre-content watches at + * the time of file open and remains constant for entire lifetime of the file, + * so if pre-content watches are added post execution or removed before the end + * of the execution, it will not cause i_writecount reference leak. + */ +static inline int exe_file_deny_write_access(struct file *exe_file) +{ + if (unlikely(FMODE_FSNOTIFY_HSM(exe_file->f_mode))) + return 0; + return deny_write_access(exe_file); +} +static inline void exe_file_allow_write_access(struct file *exe_file) +{ + if (unlikely(!exe_file || FMODE_FSNOTIFY_HSM(exe_file->f_mode))) + return; + allow_write_access(exe_file); +} + +static inline void file_set_fsnotify_mode(struct file *file, fmode_t mode) +{ + file->f_mode &= ~FMODE_FSNOTIFY_MASK; + file->f_mode |= mode; +} + +static inline bool inode_is_open_for_write(const struct inode *inode) +{ + return atomic_read(&inode->i_writecount) > 0; +} + +#if defined(CONFIG_IMA) || defined(CONFIG_FILE_LOCKING) +static inline void i_readcount_dec(struct inode *inode) +{ + BUG_ON(atomic_dec_return(&inode->i_readcount) < 0); +} +static inline void i_readcount_inc(struct inode *inode) +{ + atomic_inc(&inode->i_readcount); +} +#else +static inline void i_readcount_dec(struct inode *inode) +{ + return; +} +static inline void i_readcount_inc(struct inode *inode) +{ + return; +} +#endif +extern int do_pipe_flags(int *, int); + +extern ssize_t kernel_read(struct file *, void *, size_t, loff_t *); +ssize_t __kernel_read(struct file *file, void *buf, size_t count, loff_t *pos); +extern ssize_t kernel_write(struct file *, const void *, size_t, loff_t *); +extern ssize_t __kernel_write(struct file *, const void *, size_t, loff_t *); +extern struct file * open_exec(const char *); + +/* fs/dcache.c -- generic fs support functions */ +extern bool is_subdir(struct dentry *, struct dentry *); +extern bool path_is_under(const struct path *, const struct path *); +u64 vfsmount_to_propagation_flags(struct vfsmount *mnt); + +extern char *file_path(struct file *, char *, int); + +static inline bool name_is_dot(const char *name, size_t len) +{ + return unlikely(len == 1 && name[0] == '.'); +} + +static inline bool name_is_dotdot(const char *name, size_t len) +{ + return unlikely(len == 2 && name[0] == '.' && name[1] == '.'); +} + +/** + * name_is_dot_dotdot - returns true only if @name is "." or ".." + * @name: file name to check + * @len: length of file name, in bytes + */ +static inline bool name_is_dot_dotdot(const char *name, size_t len) +{ + return len && unlikely(name[0] == '.') && + (len == 1 || (len == 2 && name[1] == '.')); +} + +/** + * name_contains_dotdot - check if a file name contains ".." path components + * @name: File path string to check + * Search for ".." surrounded by either '/' or start/end of string. + */ +static inline bool name_contains_dotdot(const char *name) +{ + size_t name_len; + + name_len = strlen(name); + return strcmp(name, "..") == 0 || + strncmp(name, "../", 3) == 0 || + strstr(name, "/../") != NULL || + (name_len >= 3 && strcmp(name + name_len - 3, "/..") == 0); +} + +#include <linux/err.h> + +/* needed for stackable file system support */ +loff_t default_llseek(struct file *file, loff_t offset, int whence); + +loff_t vfs_llseek(struct file *file, loff_t offset, int whence); + +int inode_init_always_gfp(struct super_block *sb, struct inode *inode, gfp_t gfp); +static inline int inode_init_always(struct super_block *sb, struct inode *inode) +{ + return inode_init_always_gfp(sb, inode, GFP_NOFS); +} + +void inode_init_once(struct inode *inode); +void address_space_init_once(struct address_space *mapping); +struct inode *igrab(struct inode *inode); +ino_t iunique(struct super_block *sb, ino_t max_reserved); +int inode_needs_sync(struct inode *inode); +int inode_just_drop(struct inode *inode); +static inline int inode_generic_drop(struct inode *inode) +{ + return !inode->i_nlink || inode_unhashed(inode); +} +void d_mark_dontcache(struct inode *inode); + +struct inode *ilookup5_nowait(struct super_block *sb, u64 hashval, + int (*test)(struct inode *, void *), void *data, + bool *isnew); +struct inode *ilookup5(struct super_block *sb, u64 hashval, + int (*test)(struct inode *, void *), void *data); +struct inode *ilookup(struct super_block *sb, u64 ino); + +struct inode *inode_insert5(struct inode *inode, u64 hashval, + int (*test)(struct inode *, void *), + int (*set)(struct inode *, void *), void *data); +struct inode *iget5_locked(struct super_block *sb, u64 hashval, + int (*test)(struct inode *, void *), + int (*set)(struct inode *, void *), void *data); +struct inode *iget5_locked_rcu(struct super_block *sb, u64 hashval, + int (*test)(struct inode *, void *), + int (*set)(struct inode *, void *), void *data); +struct inode *iget_locked(struct super_block *sb, u64 ino); +struct inode *find_inode_nowait(struct super_block *sb, u64 hashval, + int (*match)(struct inode *, u64, void *), + void *data); +struct inode *find_inode_rcu(struct super_block *sb, u64 hashval, + int (*test)(struct inode *, void *), void *data); +struct inode *find_inode_by_ino_rcu(struct super_block *sb, u64 ino); +int insert_inode_locked4(struct inode *inode, u64 hashval, + int (*test)(struct inode *, void *), void *data); +int insert_inode_locked(struct inode *inode); +#ifdef CONFIG_DEBUG_LOCK_ALLOC +void lockdep_annotate_inode_mutex_key(struct inode *inode); +#else +static inline void lockdep_annotate_inode_mutex_key(struct inode *inode) { }; +#endif +void unlock_new_inode(struct inode *inode); +void discard_new_inode(struct inode *inode); +unsigned int get_next_ino(void); +void evict_inodes(struct super_block *sb); +void dump_mapping(const struct address_space *); + +/* + * Userspace may rely on the inode number being non-zero. For example, glibc + * simply ignores files with zero i_ino in unlink() and other places. + * + * As an additional complication, if userspace was compiled with + * _FILE_OFFSET_BITS=32 on a 64-bit kernel we'll only end up reading out the + * lower 32 bits, so we need to check that those aren't zero explicitly. With + * _FILE_OFFSET_BITS=64, this may cause some harmless false-negatives, but + * better safe than sorry. + */ +static inline bool is_zero_ino(ino_t ino) +{ + return (u32)ino == 0; +} + +static inline void __iget(struct inode *inode) +{ + lockdep_assert_held(&inode->i_lock); + atomic_inc(&inode->i_count); +} + +extern void iget_failed(struct inode *); +extern void clear_inode(struct inode *); +extern void __destroy_inode(struct inode *); +struct inode *alloc_inode(struct super_block *sb); +static inline struct inode *new_inode_pseudo(struct super_block *sb) +{ + return alloc_inode(sb); +} +extern struct inode *new_inode(struct super_block *sb); +extern void free_inode_nonrcu(struct inode *inode); +extern int setattr_should_drop_suidgid(struct mnt_idmap *, struct inode *); +extern int file_remove_privs(struct file *); +int setattr_should_drop_sgid(struct mnt_idmap *idmap, + const struct inode *inode); + +/* + * This must be used for allocating filesystems specific inodes to set + * up the inode reclaim context correctly. + */ +#define alloc_inode_sb(_sb, _cache, _gfp) kmem_cache_alloc_lru(_cache, &_sb->s_inode_lru, _gfp) + +void __insert_inode_hash(struct inode *inode, u64 hashval); +static inline void insert_inode_hash(struct inode *inode) +{ + __insert_inode_hash(inode, inode->i_ino); +} + +void __remove_inode_hash(struct inode *inode); +static inline void remove_inode_hash(struct inode *inode) +{ + if (!inode_unhashed(inode) && !hlist_fake(&inode->i_hash)) + __remove_inode_hash(inode); +} + +void inode_sb_list_add(struct inode *inode); +void inode_lru_list_add(struct inode *inode); + +int generic_file_mmap(struct file *, struct vm_area_struct *); +int generic_file_mmap_prepare(struct vm_area_desc *desc); +int generic_file_readonly_mmap(struct file *, struct vm_area_struct *); +int generic_file_readonly_mmap_prepare(struct vm_area_desc *desc); +extern ssize_t generic_write_checks(struct kiocb *, struct iov_iter *); +int generic_write_checks_count(struct kiocb *iocb, loff_t *count); +extern int generic_write_check_limits(struct file *file, loff_t pos, + loff_t *count); +extern int generic_file_rw_checks(struct file *file_in, struct file *file_out); +ssize_t filemap_read(struct kiocb *iocb, struct iov_iter *to, + ssize_t already_read); +extern ssize_t generic_file_read_iter(struct kiocb *, struct iov_iter *); +extern ssize_t __generic_file_write_iter(struct kiocb *, struct iov_iter *); +extern ssize_t generic_file_write_iter(struct kiocb *, struct iov_iter *); +extern ssize_t generic_file_direct_write(struct kiocb *, struct iov_iter *); +ssize_t generic_perform_write(struct kiocb *, struct iov_iter *); +ssize_t direct_write_fallback(struct kiocb *iocb, struct iov_iter *iter, + ssize_t direct_written, ssize_t buffered_written); + +ssize_t vfs_iter_read(struct file *file, struct iov_iter *iter, loff_t *ppos, + rwf_t flags); +ssize_t vfs_iter_write(struct file *file, struct iov_iter *iter, loff_t *ppos, + rwf_t flags); +ssize_t vfs_iocb_iter_read(struct file *file, struct kiocb *iocb, + struct iov_iter *iter); +ssize_t vfs_iocb_iter_write(struct file *file, struct kiocb *iocb, + struct iov_iter *iter); + +/* fs/splice.c */ +ssize_t filemap_splice_read(struct file *in, loff_t *ppos, + struct pipe_inode_info *pipe, + size_t len, unsigned int flags); +ssize_t copy_splice_read(struct file *in, loff_t *ppos, + struct pipe_inode_info *pipe, + size_t len, unsigned int flags); +extern ssize_t iter_file_splice_write(struct pipe_inode_info *, + struct file *, loff_t *, size_t, unsigned int); + + +extern void +file_ra_state_init(struct file_ra_state *ra, struct address_space *mapping); +extern loff_t noop_llseek(struct file *file, loff_t offset, int whence); +extern loff_t vfs_setpos(struct file *file, loff_t offset, loff_t maxsize); +extern loff_t generic_file_llseek(struct file *file, loff_t offset, int whence); +extern loff_t generic_file_llseek_size(struct file *file, loff_t offset, + int whence, loff_t maxsize, loff_t eof); +loff_t generic_llseek_cookie(struct file *file, loff_t offset, int whence, + u64 *cookie); +extern loff_t fixed_size_llseek(struct file *file, loff_t offset, + int whence, loff_t size); +extern loff_t no_seek_end_llseek_size(struct file *, loff_t, int, loff_t); +extern loff_t no_seek_end_llseek(struct file *, loff_t, int); +int rw_verify_area(int, struct file *, const loff_t *, size_t); +extern int generic_file_open(struct inode * inode, struct file * filp); +extern int nonseekable_open(struct inode * inode, struct file * filp); +extern int stream_open(struct inode * inode, struct file * filp); + +#ifdef CONFIG_BLOCK +typedef void (dio_submit_t)(struct bio *bio, struct inode *inode, + loff_t file_offset); + +enum { + /* need locking between buffered and direct access */ + DIO_LOCKING = 0x01, + + /* filesystem does not support filling holes */ + DIO_SKIP_HOLES = 0x02, +}; + +ssize_t __blockdev_direct_IO(struct kiocb *iocb, struct inode *inode, + struct block_device *bdev, struct iov_iter *iter, + get_block_t get_block, + dio_iodone_t end_io, + int flags); + +static inline ssize_t blockdev_direct_IO(struct kiocb *iocb, + struct inode *inode, + struct iov_iter *iter, + get_block_t get_block) +{ + return __blockdev_direct_IO(iocb, inode, inode->i_sb->s_bdev, iter, + get_block, NULL, DIO_LOCKING | DIO_SKIP_HOLES); +} +#endif + +bool inode_dio_finished(const struct inode *inode); +void inode_dio_wait(struct inode *inode); +void inode_dio_wait_interruptible(struct inode *inode); + +/** + * inode_dio_begin - signal start of a direct I/O requests + * @inode: inode the direct I/O happens on + * + * This is called once we've finished processing a direct I/O request, + * and is used to wake up callers waiting for direct I/O to be quiesced. + */ +static inline void inode_dio_begin(struct inode *inode) +{ + atomic_inc(&inode->i_dio_count); +} + +/** + * inode_dio_end - signal finish of a direct I/O requests + * @inode: inode the direct I/O happens on + * + * This is called once we've finished processing a direct I/O request, + * and is used to wake up callers waiting for direct I/O to be quiesced. + */ +static inline void inode_dio_end(struct inode *inode) +{ + if (atomic_dec_and_test(&inode->i_dio_count)) + wake_up_var(&inode->i_dio_count); +} + +extern void inode_set_flags(struct inode *inode, unsigned int flags, + unsigned int mask); + +extern const struct file_operations generic_ro_fops; + +#define special_file(m) (S_ISCHR(m)||S_ISBLK(m)||S_ISFIFO(m)||S_ISSOCK(m)) + +extern int readlink_copy(char __user *, int, const char *, int); +extern int page_readlink(struct dentry *, char __user *, int); +extern const char *page_get_link_raw(struct dentry *, struct inode *, + struct delayed_call *); +extern const char *page_get_link(struct dentry *, struct inode *, + struct delayed_call *); +extern void page_put_link(void *); +extern int page_symlink(struct inode *inode, const char *symname, int len); +extern const struct inode_operations page_symlink_inode_operations; +extern void kfree_link(void *); +void fill_mg_cmtime(struct kstat *stat, u32 request_mask, struct inode *inode); +void generic_fillattr(struct mnt_idmap *, u32, struct inode *, struct kstat *); +void generic_fill_statx_attr(struct inode *inode, struct kstat *stat); +void generic_fill_statx_atomic_writes(struct kstat *stat, + unsigned int unit_min, + unsigned int unit_max, + unsigned int unit_max_opt); +extern int vfs_getattr_nosec(const struct path *, struct kstat *, u32, unsigned int); +extern int vfs_getattr(const struct path *, struct kstat *, u32, unsigned int); +void __inode_add_bytes(struct inode *inode, loff_t bytes); +void inode_add_bytes(struct inode *inode, loff_t bytes); +void __inode_sub_bytes(struct inode *inode, loff_t bytes); +void inode_sub_bytes(struct inode *inode, loff_t bytes); +static inline loff_t __inode_get_bytes(struct inode *inode) +{ + return (((loff_t)inode->i_blocks) << 9) + inode->i_bytes; +} +loff_t inode_get_bytes(struct inode *inode); +void inode_set_bytes(struct inode *inode, loff_t bytes); +const char *simple_get_link(struct dentry *, struct inode *, + struct delayed_call *); +extern const struct inode_operations simple_symlink_inode_operations; + +extern int iterate_dir(struct file *, struct dir_context *); + +int vfs_fstatat(int dfd, const char __user *filename, struct kstat *stat, + int flags); +int vfs_fstat(int fd, struct kstat *stat); + +static inline int vfs_stat(const char __user *filename, struct kstat *stat) +{ + return vfs_fstatat(AT_FDCWD, filename, stat, 0); +} +static inline int vfs_lstat(const char __user *name, struct kstat *stat) +{ + return vfs_fstatat(AT_FDCWD, name, stat, AT_SYMLINK_NOFOLLOW); +} + +extern const char *vfs_get_link(struct dentry *, struct delayed_call *); +extern int vfs_readlink(struct dentry *, char __user *, int); + +extern struct file_system_type *get_filesystem(struct file_system_type *fs); +extern void put_filesystem(struct file_system_type *fs); +extern struct file_system_type *get_fs_type(const char *name); +extern void drop_super(struct super_block *sb); +extern void drop_super_exclusive(struct super_block *sb); +extern void iterate_supers(void (*f)(struct super_block *, void *), void *arg); +extern void iterate_supers_type(struct file_system_type *, + void (*)(struct super_block *, void *), void *); +void filesystems_freeze(bool freeze_all); +void filesystems_thaw(void); + +void end_dirop(struct dentry *de); + +extern int dcache_dir_open(struct inode *, struct file *); +extern int dcache_dir_close(struct inode *, struct file *); +extern loff_t dcache_dir_lseek(struct file *, loff_t, int); +extern int dcache_readdir(struct file *, struct dir_context *); +extern int simple_setattr(struct mnt_idmap *, struct dentry *, + struct iattr *); +extern int simple_getattr(struct mnt_idmap *, const struct path *, + struct kstat *, u32, unsigned int); +extern int simple_statfs(struct dentry *, struct kstatfs *); +extern int simple_open(struct inode *inode, struct file *file); +extern int simple_link(struct dentry *, struct inode *, struct dentry *); +extern int simple_unlink(struct inode *, struct dentry *); +extern int simple_rmdir(struct inode *, struct dentry *); +extern void __simple_unlink(struct inode *, struct dentry *); +extern void __simple_rmdir(struct inode *, struct dentry *); +void simple_rename_timestamp(struct inode *old_dir, struct dentry *old_dentry, + struct inode *new_dir, struct dentry *new_dentry); +extern int simple_rename_exchange(struct inode *old_dir, struct dentry *old_dentry, + struct inode *new_dir, struct dentry *new_dentry); +extern int simple_rename(struct mnt_idmap *, struct inode *, + struct dentry *, struct inode *, struct dentry *, + unsigned int); +extern void simple_recursive_removal(struct dentry *, + void (*callback)(struct dentry *)); +extern void simple_remove_by_name(struct dentry *, const char *, + void (*callback)(struct dentry *)); +extern void locked_recursive_removal(struct dentry *, + void (*callback)(struct dentry *)); +extern int noop_fsync(struct file *, loff_t, loff_t, int); +extern ssize_t noop_direct_IO(struct kiocb *iocb, struct iov_iter *iter); +extern int simple_empty(struct dentry *); +extern int simple_write_begin(const struct kiocb *iocb, + struct address_space *mapping, + loff_t pos, unsigned len, + struct folio **foliop, void **fsdata); +extern const struct address_space_operations ram_aops; +extern int always_delete_dentry(const struct dentry *); +extern struct inode *alloc_anon_inode(struct super_block *); +struct inode *anon_inode_make_secure_inode(struct super_block *sb, const char *name, + const struct inode *context_inode); + +extern struct dentry *simple_lookup(struct inode *, struct dentry *, unsigned int flags); +extern ssize_t generic_read_dir(struct file *, char __user *, size_t, loff_t *); +extern const struct file_operations simple_dir_operations; +extern const struct inode_operations simple_dir_inode_operations; +extern void make_empty_dir_inode(struct inode *inode); +extern bool is_empty_dir_inode(struct inode *inode); +struct tree_descr { const char *name; const struct file_operations *ops; int mode; }; +struct dentry *d_alloc_name(struct dentry *, const char *); +extern int simple_fill_super(struct super_block *, unsigned long, + const struct tree_descr *); +extern int simple_pin_fs(struct file_system_type *, struct vfsmount **mount, int *count); +extern void simple_release_fs(struct vfsmount **mount, int *count); +struct dentry *simple_start_creating(struct dentry *, const char *); +void simple_done_creating(struct dentry *); + +extern ssize_t simple_read_from_buffer(void __user *to, size_t count, + loff_t *ppos, const void *from, size_t available); +extern ssize_t simple_write_to_buffer(void *to, size_t available, loff_t *ppos, + const void __user *from, size_t count); + +struct offset_ctx { + struct maple_tree mt; + unsigned long next_offset; +}; + +void simple_offset_init(struct offset_ctx *octx); +int simple_offset_add(struct offset_ctx *octx, struct dentry *dentry); +void simple_offset_remove(struct offset_ctx *octx, struct dentry *dentry); +void simple_offset_rename(struct inode *old_dir, struct dentry *old_dentry, + struct inode *new_dir, struct dentry *new_dentry); +int simple_offset_rename_exchange(struct inode *old_dir, + struct dentry *old_dentry, + struct inode *new_dir, + struct dentry *new_dentry); +void simple_offset_destroy(struct offset_ctx *octx); + +extern const struct file_operations simple_offset_dir_operations; + +extern int simple_fsync_noflush(struct file *, loff_t, loff_t, int); +extern int simple_fsync(struct file *, loff_t, loff_t, int); + +extern int generic_check_addressable(unsigned, u64); + +extern void generic_set_sb_d_ops(struct super_block *sb); +extern int generic_ci_match(const struct inode *parent, + const struct qstr *name, + const struct qstr *folded_name, + const u8 *de_name, u32 de_name_len); + +#if IS_ENABLED(CONFIG_UNICODE) +int generic_ci_d_hash(const struct dentry *dentry, struct qstr *str); +int generic_ci_d_compare(const struct dentry *dentry, unsigned int len, + const char *str, const struct qstr *name); + +/** + * generic_ci_validate_strict_name - Check if a given name is suitable + * for a directory + * + * This functions checks if the proposed filename is valid for the + * parent directory. That means that only valid UTF-8 filenames will be + * accepted for casefold directories from filesystems created with the + * strict encoding flag. That also means that any name will be + * accepted for directories that doesn't have casefold enabled, or + * aren't being strict with the encoding. + * + * @dir: inode of the directory where the new file will be created + * @name: name of the new file + * + * Return: + * * True: if the filename is suitable for this directory. It can be + * true if a given name is not suitable for a strict encoding + * directory, but the directory being used isn't strict + * * False if the filename isn't suitable for this directory. This only + * happens when a directory is casefolded and the filesystem is strict + * about its encoding. + */ +static inline bool generic_ci_validate_strict_name(struct inode *dir, + const struct qstr *name) +{ + if (!IS_CASEFOLDED(dir) || !sb_has_strict_encoding(dir->i_sb)) + return true; + + /* + * A casefold dir must have a encoding set, unless the filesystem + * is corrupted + */ + if (WARN_ON_ONCE(!dir->i_sb->s_encoding)) + return true; + + return !utf8_validate(dir->i_sb->s_encoding, name); +} +#else +static inline bool generic_ci_validate_strict_name(struct inode *dir, + const struct qstr *name) +{ + return true; +} +#endif + +int may_setattr(struct mnt_idmap *idmap, struct inode *inode, + unsigned int ia_valid); +int setattr_prepare(struct mnt_idmap *, struct dentry *, struct iattr *); +extern int inode_newsize_ok(const struct inode *, loff_t offset); +void setattr_copy(struct mnt_idmap *, struct inode *inode, + const struct iattr *attr); + +extern int file_update_time(struct file *file); + +static inline bool file_is_dax(const struct file *file) +{ + return file && IS_DAX(file->f_mapping->host); +} + +static inline bool vma_is_dax(const struct vm_area_struct *vma) +{ + return file_is_dax(vma->vm_file); +} + +static inline bool vma_is_fsdax(struct vm_area_struct *vma) +{ + struct inode *inode; + + if (!IS_ENABLED(CONFIG_FS_DAX) || !vma->vm_file) + return false; + if (!vma_is_dax(vma)) + return false; + inode = file_inode(vma->vm_file); + if (S_ISCHR(inode->i_mode)) + return false; /* device-dax */ + return true; +} + +static inline int iocb_flags(struct file *file) +{ + int res = 0; + if (file->f_flags & O_APPEND) + res |= IOCB_APPEND; + if (file->f_flags & O_DIRECT) + res |= IOCB_DIRECT; + if (file->f_flags & O_DSYNC) + res |= IOCB_DSYNC; + if (file->f_flags & __O_SYNC) + res |= IOCB_SYNC; + return res; +} + +static inline int kiocb_set_rw_flags(struct kiocb *ki, rwf_t flags, + int rw_type) +{ + int kiocb_flags = 0; + + /* make sure there's no overlap between RWF and private IOCB flags */ + BUILD_BUG_ON((__force int) RWF_SUPPORTED & IOCB_EVENTFD); + + if (!flags) + return 0; + if (unlikely(flags & ~RWF_SUPPORTED)) + return -EOPNOTSUPP; + if (unlikely((flags & RWF_APPEND) && (flags & RWF_NOAPPEND))) + return -EINVAL; + + if (flags & RWF_NOWAIT) { + if (!(ki->ki_filp->f_mode & FMODE_NOWAIT)) + return -EOPNOTSUPP; + } + if (flags & RWF_ATOMIC) { + if (rw_type != WRITE) + return -EOPNOTSUPP; + if (!(ki->ki_filp->f_mode & FMODE_CAN_ATOMIC_WRITE)) + return -EOPNOTSUPP; + } + if (flags & RWF_DONTCACHE) { + /* file system must support it */ + if (!(ki->ki_filp->f_op->fop_flags & FOP_DONTCACHE)) + return -EOPNOTSUPP; + /* DAX mappings not supported */ + if (IS_DAX(ki->ki_filp->f_mapping->host)) + return -EOPNOTSUPP; + } + kiocb_flags |= (__force int) (flags & RWF_SUPPORTED); + if (flags & RWF_SYNC) + kiocb_flags |= IOCB_DSYNC; + + if ((flags & RWF_NOAPPEND) && (ki->ki_flags & IOCB_APPEND)) { + if (IS_APPEND(file_inode(ki->ki_filp))) + return -EPERM; + ki->ki_flags &= ~IOCB_APPEND; + } + + ki->ki_flags |= kiocb_flags; + return 0; +} + +/* Transaction based IO helpers */ + +/* + * An argresp is stored in an allocated page and holds the + * size of the argument or response, along with its content + */ +struct simple_transaction_argresp { + ssize_t size; + char data[]; +}; + +#define SIMPLE_TRANSACTION_LIMIT (PAGE_SIZE - sizeof(struct simple_transaction_argresp)) + +char *simple_transaction_get(struct file *file, const char __user *buf, + size_t size); +ssize_t simple_transaction_read(struct file *file, char __user *buf, + size_t size, loff_t *pos); +int simple_transaction_release(struct inode *inode, struct file *file); + +void simple_transaction_set(struct file *file, size_t n); + +/* + * simple attribute files + * + * These attributes behave similar to those in sysfs: + * + * Writing to an attribute immediately sets a value, an open file can be + * written to multiple times. + * + * Reading from an attribute creates a buffer from the value that might get + * read with multiple read calls. When the attribute has been read + * completely, no further read calls are possible until the file is opened + * again. + * + * All attributes contain a text representation of a numeric value + * that are accessed with the get() and set() functions. + */ +#define DEFINE_SIMPLE_ATTRIBUTE_XSIGNED(__fops, __get, __set, __fmt, __is_signed) \ +static int __fops ## _open(struct inode *inode, struct file *file) \ +{ \ + __simple_attr_check_format(__fmt, 0ull); \ + return simple_attr_open(inode, file, __get, __set, __fmt); \ +} \ +static const struct file_operations __fops = { \ + .owner = THIS_MODULE, \ + .open = __fops ## _open, \ + .release = simple_attr_release, \ + .read = simple_attr_read, \ + .write = (__is_signed) ? simple_attr_write_signed : simple_attr_write, \ + .llseek = generic_file_llseek, \ +} + +#define DEFINE_SIMPLE_ATTRIBUTE(__fops, __get, __set, __fmt) \ + DEFINE_SIMPLE_ATTRIBUTE_XSIGNED(__fops, __get, __set, __fmt, false) + +#define DEFINE_SIMPLE_ATTRIBUTE_SIGNED(__fops, __get, __set, __fmt) \ + DEFINE_SIMPLE_ATTRIBUTE_XSIGNED(__fops, __get, __set, __fmt, true) + +static inline __printf(1, 2) +void __simple_attr_check_format(const char *fmt, ...) +{ + /* don't do anything, just let the compiler check the arguments; */ +} + +int simple_attr_open(struct inode *inode, struct file *file, + int (*get)(void *, u64 *), int (*set)(void *, u64), + const char *fmt); +int simple_attr_release(struct inode *inode, struct file *file); +ssize_t simple_attr_read(struct file *file, char __user *buf, + size_t len, loff_t *ppos); +ssize_t simple_attr_write(struct file *file, const char __user *buf, + size_t len, loff_t *ppos); +ssize_t simple_attr_write_signed(struct file *file, const char __user *buf, + size_t len, loff_t *ppos); + +int __init list_bdev_fs_names(char *buf, size_t size); + +#define __FMODE_EXEC ((__force int) FMODE_EXEC) + +#define ACC_MODE(x) ("\004\002\006\006"[(x)&O_ACCMODE]) +#define OPEN_FMODE(flag) ((__force fmode_t)((flag + 1) & O_ACCMODE)) + +static inline bool is_sxid(umode_t mode) +{ + return mode & (S_ISUID | S_ISGID); +} + +static inline int check_sticky(struct mnt_idmap *idmap, + struct inode *dir, struct inode *inode) +{ + if (!(dir->i_mode & S_ISVTX)) + return 0; + + return __check_sticky(idmap, dir, inode); +} + +static inline void inode_has_no_xattr(struct inode *inode) +{ + if (!is_sxid(inode->i_mode) && (inode->i_sb->s_flags & SB_NOSEC)) + inode->i_flags |= S_NOSEC; +} + +static inline bool is_root_inode(struct inode *inode) +{ + return inode == inode->i_sb->s_root->d_inode; +} + +static inline bool dir_emit(struct dir_context *ctx, + const char *name, int namelen, + u64 ino, unsigned type) +{ + unsigned int dt_mask = S_DT_MASK | ctx->dt_flags_mask; + + return ctx->actor(ctx, name, namelen, ctx->pos, ino, type & dt_mask); +} +static inline bool dir_emit_dot(struct file *file, struct dir_context *ctx) +{ + return ctx->actor(ctx, ".", 1, ctx->pos, + file->f_path.dentry->d_inode->i_ino, DT_DIR); +} +static inline bool dir_emit_dotdot(struct file *file, struct dir_context *ctx) +{ + return ctx->actor(ctx, "..", 2, ctx->pos, + d_parent_ino(file->f_path.dentry), DT_DIR); +} +static inline bool dir_emit_dots(struct file *file, struct dir_context *ctx) +{ + if (ctx->pos == 0) { + if (!dir_emit_dot(file, ctx)) + return false; + ctx->pos = 1; + } + if (ctx->pos == 1) { + if (!dir_emit_dotdot(file, ctx)) + return false; + ctx->pos = 2; + } + return true; +} +static inline bool dir_relax(struct inode *inode) +{ + inode_unlock(inode); + inode_lock(inode); + return !IS_DEADDIR(inode); +} + +static inline bool dir_relax_shared(struct inode *inode) +{ + inode_unlock_shared(inode); + inode_lock_shared(inode); + return !IS_DEADDIR(inode); +} + +extern bool path_noexec(const struct path *path); +extern void inode_nohighmem(struct inode *inode); + +/* mm/fadvise.c */ +extern int vfs_fadvise(struct file *file, loff_t offset, loff_t len, + int advice); +extern int generic_fadvise(struct file *file, loff_t offset, loff_t len, + int advice); + +static inline bool vfs_empty_path(int dfd, const char __user *path) +{ + char c; + + if (dfd < 0) + return false; + + /* We now allow NULL to be used for empty path. */ + if (!path) + return true; + + if (unlikely(get_user(c, path))) + return false; + + return !c; +} + +int generic_atomic_write_valid(struct kiocb *iocb, struct iov_iter *iter); + +static inline bool extensible_ioctl_valid(unsigned int cmd_a, + unsigned int cmd_b, size_t min_size) +{ + if (_IOC_DIR(cmd_a) != _IOC_DIR(cmd_b)) + return false; + if (_IOC_TYPE(cmd_a) != _IOC_TYPE(cmd_b)) + return false; + if (_IOC_NR(cmd_a) != _IOC_NR(cmd_b)) + return false; + if (_IOC_SIZE(cmd_a) < min_size) + return false; + return true; +} + +#endif /* _LINUX_FS_H */ |