diff options
Diffstat (limited to 'fs/xfs/xfs_file.c')
| -rw-r--r-- | fs/xfs/xfs_file.c | 2212 |
1 files changed, 2212 insertions, 0 deletions
diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c new file mode 100644 index 000000000..7bff07e31 --- /dev/null +++ b/fs/xfs/xfs_file.c @@ -0,0 +1,2212 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (c) 2000-2005 Silicon Graphics, Inc. + * All Rights Reserved. + */ +#include "xfs_platform.h" +#include "xfs_fs.h" +#include "xfs_shared.h" +#include "xfs_format.h" +#include "xfs_log_format.h" +#include "xfs_trans_resv.h" +#include "xfs_mount.h" +#include "xfs_inode.h" +#include "xfs_trans.h" +#include "xfs_inode_item.h" +#include "xfs_bmap.h" +#include "xfs_bmap_util.h" +#include "xfs_dir2.h" +#include "xfs_dir2_priv.h" +#include "xfs_ioctl.h" +#include "xfs_trace.h" +#include "xfs_log.h" +#include "xfs_icache.h" +#include "xfs_pnfs.h" +#include "xfs_iomap.h" +#include "xfs_reflink.h" +#include "xfs_file.h" +#include "xfs_aops.h" +#include "xfs_zone_alloc.h" +#include "xfs_error.h" +#include "xfs_errortag.h" + +#include <linux/dax.h> +#include <linux/falloc.h> +#include <linux/backing-dev.h> +#include <linux/mman.h> +#include <linux/fadvise.h> +#include <linux/mount.h> +#include <linux/filelock.h> + +static const struct vm_operations_struct xfs_file_vm_ops; + +/* + * Decide if the given file range is aligned to the size of the fundamental + * allocation unit for the file. + */ +bool +xfs_is_falloc_aligned( + struct xfs_inode *ip, + loff_t pos, + long long int len) +{ + unsigned int alloc_unit = xfs_inode_alloc_unitsize(ip); + + if (!is_power_of_2(alloc_unit)) + return isaligned_64(pos, alloc_unit) && + isaligned_64(len, alloc_unit); + + return !((pos | len) & (alloc_unit - 1)); +} + +/* + * Fsync operations on directories are much simpler than on regular files, + * as there is no file data to flush, and thus also no need for explicit + * cache flush operations, and there are no non-transaction metadata updates + * on directories either. + */ +STATIC int +xfs_dir_fsync( + struct file *file, + loff_t start, + loff_t end, + int datasync) +{ + struct xfs_inode *ip = XFS_I(file->f_mapping->host); + + trace_xfs_dir_fsync(ip); + return xfs_log_force_inode(ip); +} + +/* + * All metadata updates are logged, which means that we just have to push the + * journal to the required sequence number than holds the updates. We track + * datasync commits separately to full sync commits, and hence only need to + * select the correct sequence number for the log force here. + * + * We don't have to serialise against concurrent modifications, as we do not + * have to wait for modifications that have not yet completed. We define a + * transaction commit as completing when the commit sequence number is updated, + * hence if the sequence number has not updated, the sync operation has been + * run before the commit completed and we don't have to wait for it. + * + * If we have concurrent fsync/fdatasync() calls, the sequence numbers remain + * set on the log item until - at least - the journal flush completes. In + * reality, they are only cleared when the inode is fully unpinned (i.e. + * persistent in the journal and not dirty in the CIL), and so we rely on + * xfs_log_force_seq() either skipping sequences that have been persisted or + * waiting on sequences that are still in flight to correctly order concurrent + * sync operations. + */ +static int +xfs_fsync_flush_log( + struct xfs_inode *ip, + bool datasync, + int *log_flushed) +{ + struct xfs_inode_log_item *iip = ip->i_itemp; + xfs_csn_t seq = 0; + + spin_lock(&iip->ili_lock); + if (datasync) + seq = iip->ili_datasync_seq; + else + seq = iip->ili_commit_seq; + spin_unlock(&iip->ili_lock); + + if (!seq) + return 0; + + return xfs_log_force_seq(ip->i_mount, seq, XFS_LOG_SYNC, + log_flushed); +} + +STATIC int +xfs_file_fsync( + struct file *file, + loff_t start, + loff_t end, + int datasync) +{ + struct xfs_inode *ip = XFS_I(file->f_mapping->host); + struct xfs_mount *mp = ip->i_mount; + int error, err2; + int log_flushed = 0; + + trace_xfs_file_fsync(ip); + + error = file_write_and_wait_range(file, start, end); + if (error) + return error; + + if (xfs_is_shutdown(mp)) + return -EIO; + + xfs_iflags_clear(ip, XFS_ITRUNCATED); + + /* + * If we have an RT and/or log subvolume we need to make sure to flush + * the write cache the device used for file data first. This is to + * ensure newly written file data make it to disk before logging the new + * inode size in case of an extending write. + */ + if (XFS_IS_REALTIME_INODE(ip) && mp->m_rtdev_targp != mp->m_ddev_targp) + error = blkdev_issue_flush(mp->m_rtdev_targp->bt_bdev); + else if (mp->m_logdev_targp != mp->m_ddev_targp) + error = blkdev_issue_flush(mp->m_ddev_targp->bt_bdev); + + /* + * If the inode has a inode log item attached, it may need the journal + * flushed to persist any changes the log item might be tracking. + */ + if (ip->i_itemp) { + err2 = xfs_fsync_flush_log(ip, datasync, &log_flushed); + if (err2 && !error) + error = err2; + } + + /* + * If the log force was a no-op, we may still need to flush the + * file data target cache here. This can happen for fdatasync/O_DSYNC + * when no metadata needed to be committed. + * + * Use the inode's actual file data target rather than assuming the + * main data device. Realtime inodes with a separate realtime device + * are flushed before the log force, so this fallback only applies + * when the file data target is the same as the log target. + */ + if (!log_flushed) { + struct xfs_buftarg *file_targp = xfs_inode_buftarg(ip); + + if (mp->m_logdev_targp == file_targp) { + err2 = blkdev_issue_flush(file_targp->bt_bdev); + if (err2 && !error) + error = err2; + } + } + + return error; +} + +static int +xfs_ilock_iocb( + struct kiocb *iocb, + unsigned int lock_mode) +{ + struct xfs_inode *ip = XFS_I(file_inode(iocb->ki_filp)); + + if (iocb->ki_flags & IOCB_NOWAIT) { + if (!xfs_ilock_nowait(ip, lock_mode)) + return -EAGAIN; + } else { + xfs_ilock(ip, lock_mode); + } + + return 0; +} + +static int +xfs_ilock_iocb_for_write( + struct kiocb *iocb, + unsigned int *lock_mode) +{ + ssize_t ret; + struct xfs_inode *ip = XFS_I(file_inode(iocb->ki_filp)); + + ret = xfs_ilock_iocb(iocb, *lock_mode); + if (ret) + return ret; + + /* + * If a reflink remap is in progress we always need to take the iolock + * exclusively to wait for it to finish. + */ + if (*lock_mode == XFS_IOLOCK_SHARED && + xfs_iflags_test(ip, XFS_IREMAPPING)) { + xfs_iunlock(ip, *lock_mode); + *lock_mode = XFS_IOLOCK_EXCL; + return xfs_ilock_iocb(iocb, *lock_mode); + } + + return 0; +} + +/* + * Bounce buffering dio reads need a user context to copy back the data. + * Use an ioend to provide that. + */ +static void +xfs_dio_read_bounce_submit_io( + const struct iomap_iter *iter, + struct bio *bio, + loff_t file_offset) +{ + iomap_init_ioend(iter->inode, bio, file_offset, IOMAP_IOEND_DIRECT); + bio->bi_end_io = xfs_end_bio; + submit_bio(bio); +} + +static const struct iomap_dio_ops xfs_dio_read_bounce_ops = { + .submit_io = xfs_dio_read_bounce_submit_io, + .bio_set = &iomap_ioend_bioset, +}; + +STATIC ssize_t +xfs_file_dio_read( + struct kiocb *iocb, + struct iov_iter *to) +{ + struct xfs_inode *ip = XFS_I(file_inode(iocb->ki_filp)); + ssize_t ret; + + trace_xfs_file_direct_read(iocb, to); + + if (!iov_iter_count(to)) + return 0; /* skip atime */ + + file_accessed(iocb->ki_filp); + + ret = xfs_ilock_iocb(iocb, XFS_IOLOCK_SHARED); + if (ret) + return ret; + if (mapping_stable_writes(iocb->ki_filp->f_mapping)) { + ret = iomap_dio_rw(iocb, to, &xfs_read_iomap_ops, + &xfs_dio_read_bounce_ops, IOMAP_DIO_BOUNCE, + NULL, 0); + } else { + ret = iomap_dio_read_simple(iocb, to, xfs_read_iomap_begin); + if (ret == -ENOTBLK) + ret = iomap_dio_rw(iocb, to, &xfs_read_iomap_ops, NULL, + 0, NULL, 0); + } + xfs_iunlock(ip, XFS_IOLOCK_SHARED); + + return ret; +} + +static noinline ssize_t +xfs_file_dax_read( + struct kiocb *iocb, + struct iov_iter *to) +{ + struct xfs_inode *ip = XFS_I(iocb->ki_filp->f_mapping->host); + ssize_t ret = 0; + + trace_xfs_file_dax_read(iocb, to); + + if (!iov_iter_count(to)) + return 0; /* skip atime */ + + ret = xfs_ilock_iocb(iocb, XFS_IOLOCK_SHARED); + if (ret) + return ret; + ret = dax_iomap_rw(iocb, to, &xfs_read_iomap_ops); + xfs_iunlock(ip, XFS_IOLOCK_SHARED); + + file_accessed(iocb->ki_filp); + return ret; +} + +STATIC ssize_t +xfs_file_buffered_read( + struct kiocb *iocb, + struct iov_iter *to) +{ + struct xfs_inode *ip = XFS_I(file_inode(iocb->ki_filp)); + ssize_t ret; + + trace_xfs_file_buffered_read(iocb, to); + + ret = xfs_ilock_iocb(iocb, XFS_IOLOCK_SHARED); + if (ret) + return ret; + ret = generic_file_read_iter(iocb, to); + xfs_iunlock(ip, XFS_IOLOCK_SHARED); + + return ret; +} + +STATIC ssize_t +xfs_file_read_iter( + struct kiocb *iocb, + struct iov_iter *to) +{ + struct inode *inode = file_inode(iocb->ki_filp); + struct xfs_mount *mp = XFS_I(inode)->i_mount; + ssize_t ret = 0; + + XFS_STATS_INC(mp, xs_read_calls); + + if (xfs_is_shutdown(mp)) + return -EIO; + + if (IS_DAX(inode)) + ret = xfs_file_dax_read(iocb, to); + else if (iocb->ki_flags & IOCB_DIRECT) + ret = xfs_file_dio_read(iocb, to); + else + ret = xfs_file_buffered_read(iocb, to); + + if (ret > 0) + XFS_STATS_ADD(mp, xs_read_bytes, ret); + return ret; +} + +STATIC ssize_t +xfs_file_splice_read( + struct file *in, + loff_t *ppos, + struct pipe_inode_info *pipe, + size_t len, + unsigned int flags) +{ + struct inode *inode = file_inode(in); + struct xfs_inode *ip = XFS_I(inode); + struct xfs_mount *mp = ip->i_mount; + ssize_t ret = 0; + + XFS_STATS_INC(mp, xs_read_calls); + + if (xfs_is_shutdown(mp)) + return -EIO; + + trace_xfs_file_splice_read(ip, *ppos, len); + + xfs_ilock(ip, XFS_IOLOCK_SHARED); + ret = filemap_splice_read(in, ppos, pipe, len, flags); + xfs_iunlock(ip, XFS_IOLOCK_SHARED); + if (ret > 0) + XFS_STATS_ADD(mp, xs_read_bytes, ret); + return ret; +} + +/* + * Take care of zeroing post-EOF blocks when they might exist. + * + * Returns 0 if successfully, a negative error for a failure, or 1 if this + * function dropped the iolock and reacquired it exclusively and the caller + * needs to restart the write sanity checks. + */ +static ssize_t +xfs_file_write_zero_eof( + struct kiocb *iocb, + struct iov_iter *from, + unsigned int *iolock, + size_t count, + bool *drained_dio, + struct xfs_zone_alloc_ctx *ac) +{ + struct xfs_inode *ip = XFS_I(iocb->ki_filp->f_mapping->host); + loff_t isize; + int error; + + /* + * We need to serialise against EOF updates that occur in IO completions + * here. We want to make sure that nobody is changing the size while + * we do this check until we have placed an IO barrier (i.e. hold + * XFS_IOLOCK_EXCL) that prevents new IO from being dispatched. The + * spinlock effectively forms a memory barrier once we have + * XFS_IOLOCK_EXCL so we are guaranteed to see the latest EOF value and + * hence be able to correctly determine if we need to run zeroing. + */ + spin_lock(&ip->i_flags_lock); + isize = i_size_read(VFS_I(ip)); + if (iocb->ki_pos <= isize) { + spin_unlock(&ip->i_flags_lock); + return 0; + } + spin_unlock(&ip->i_flags_lock); + + if (iocb->ki_flags & IOCB_NOWAIT) + return -EAGAIN; + + if (!*drained_dio) { + /* + * If zeroing is needed and we are currently holding the iolock + * shared, we need to update it to exclusive which implies + * having to redo all checks before. + */ + if (*iolock == XFS_IOLOCK_SHARED) { + xfs_iunlock(ip, *iolock); + *iolock = XFS_IOLOCK_EXCL; + xfs_ilock(ip, *iolock); + iov_iter_reexpand(from, count); + } + + /* + * We now have an IO submission barrier in place, but AIO can do + * EOF updates during IO completion and hence we now need to + * wait for all of them to drain. Non-AIO DIO will have drained + * before we are given the XFS_IOLOCK_EXCL, and so for most + * cases this wait is a no-op. + */ + inode_dio_wait(VFS_I(ip)); + *drained_dio = true; + return 1; + } + + trace_xfs_zero_eof(ip, isize, iocb->ki_pos - isize); + + xfs_ilock(ip, XFS_MMAPLOCK_EXCL); + error = xfs_zero_range(ip, isize, iocb->ki_pos - isize, ac, NULL); + xfs_iunlock(ip, XFS_MMAPLOCK_EXCL); + + return error; +} + +/* + * Common pre-write limit and setup checks. + * + * Called with the iolock held either shared and exclusive according to + * @iolock, and returns with it held. Might upgrade the iolock to exclusive + * if called for a direct write beyond i_size. + */ +STATIC ssize_t +xfs_file_write_checks( + struct kiocb *iocb, + struct iov_iter *from, + unsigned int *iolock, + struct xfs_zone_alloc_ctx *ac) +{ + struct inode *inode = iocb->ki_filp->f_mapping->host; + size_t count = iov_iter_count(from); + bool drained_dio = false; + ssize_t error; + +restart: + error = generic_write_checks(iocb, from); + if (error <= 0) + return error; + + if (iocb->ki_flags & IOCB_NOWAIT) { + error = break_layout(inode, false); + if (error == -EWOULDBLOCK) + error = -EAGAIN; + } else { + error = xfs_break_layouts(inode, iolock, BREAK_WRITE); + } + + if (error) + return error; + + /* + * For changing security info in file_remove_privs() we need i_rwsem + * exclusively. + */ + if (*iolock == XFS_IOLOCK_SHARED && !IS_NOSEC(inode)) { + xfs_iunlock(XFS_I(inode), *iolock); + *iolock = XFS_IOLOCK_EXCL; + error = xfs_ilock_iocb(iocb, *iolock); + if (error) { + *iolock = 0; + return error; + } + goto restart; + } + + /* + * If the offset is beyond the size of the file, we need to zero all + * blocks that fall between the existing EOF and the start of this + * write. + * + * We can do an unlocked check for i_size here safely as I/O completion + * can only extend EOF. Truncate is locked out at this point, so the + * EOF can not move backwards, only forwards. Hence we only need to take + * the slow path when we are at or beyond the current EOF. + */ + if (iocb->ki_pos > i_size_read(inode)) { + error = xfs_file_write_zero_eof(iocb, from, iolock, count, + &drained_dio, ac); + if (error == 1) + goto restart; + if (error) + return error; + } + + return kiocb_modified(iocb); +} + +static ssize_t +xfs_zoned_write_space_reserve( + struct xfs_mount *mp, + struct kiocb *iocb, + struct iov_iter *from, + unsigned int flags, + struct xfs_zone_alloc_ctx *ac) +{ + loff_t count = iov_iter_count(from); + int error; + + if (iocb->ki_flags & IOCB_NOWAIT) + flags |= XFS_ZR_NOWAIT; + + /* + * Check the rlimit and LFS boundary first so that we don't over-reserve + * by possibly a lot. + * + * The generic write path will redo this check later, and it might have + * changed by then. If it got expanded we'll stick to our earlier + * smaller limit, and if it is decreased the new smaller limit will be + * used and our extra space reservation will be returned after finishing + * the write. + */ + error = generic_write_check_limits(iocb->ki_filp, iocb->ki_pos, &count); + if (error) + return error; + + /* + * Sloppily round up count to file system blocks. + * + * This will often reserve an extra block, but that avoids having to look + * at the start offset, which isn't stable for O_APPEND until taking the + * iolock. Also we need to reserve a block each for zeroing the old + * EOF block and the new start block if they are unaligned. + * + * Any remaining block will be returned after the write. + */ + return xfs_zoned_space_reserve(mp, XFS_B_TO_FSB(mp, count) + 1 + 2, + flags, ac); +} + +/* + * We need to lock the test/set EOF update as we can be racing with + * other IO completions here to update the EOF. Failing to serialise + * here can result in EOF moving backwards and Bad Things Happen when + * that occurs. + * + * As IO completion only ever extends EOF, we can do an unlocked check + * here to avoid taking the spinlock. If we land within the current EOF, + * then we do not need to do an extending update at all, and we don't + * need to take the lock to check this. If we race with an update moving + * EOF, then we'll either still be beyond EOF and need to take the lock, + * or we'll be within EOF and we don't need to take it at all. + */ +static int +xfs_dio_endio_set_isize( + struct inode *inode, + loff_t offset, + ssize_t size) +{ + struct xfs_inode *ip = XFS_I(inode); + + if (offset + size <= i_size_read(inode)) + return 0; + + spin_lock(&ip->i_flags_lock); + if (offset + size <= i_size_read(inode)) { + spin_unlock(&ip->i_flags_lock); + return 0; + } + + i_size_write(inode, offset + size); + spin_unlock(&ip->i_flags_lock); + + return xfs_setfilesize(ip, offset, size); +} + +static int +xfs_zoned_dio_write_end_io( + struct kiocb *iocb, + ssize_t size, + int error, + unsigned flags) +{ + struct inode *inode = file_inode(iocb->ki_filp); + struct xfs_inode *ip = XFS_I(inode); + unsigned int nofs_flag; + + ASSERT(!(flags & (IOMAP_DIO_UNWRITTEN | IOMAP_DIO_COW))); + + trace_xfs_end_io_direct_write(ip, iocb->ki_pos, size); + + if (xfs_is_shutdown(ip->i_mount)) + return -EIO; + + if (error || !size) + return error; + + XFS_STATS_ADD(ip->i_mount, xs_write_bytes, size); + + nofs_flag = memalloc_nofs_save(); + error = xfs_dio_endio_set_isize(inode, iocb->ki_pos, size); + memalloc_nofs_restore(nofs_flag); + + return error; +} + +static int +xfs_dio_write_end_io( + struct kiocb *iocb, + ssize_t size, + int error, + unsigned flags) +{ + struct inode *inode = file_inode(iocb->ki_filp); + struct xfs_inode *ip = XFS_I(inode); + loff_t offset = iocb->ki_pos; + unsigned int nofs_flag; + + ASSERT(!xfs_is_zoned_inode(ip)); + + trace_xfs_end_io_direct_write(ip, offset, size); + + if (xfs_is_shutdown(ip->i_mount)) + return -EIO; + + if (error) + return error; + if (!size) + return 0; + + /* + * Capture amount written on completion as we can't reliably account + * for it on submission. + */ + XFS_STATS_ADD(ip->i_mount, xs_write_bytes, size); + + /* + * We can allocate memory here while doing writeback on behalf of + * memory reclaim. To avoid memory allocation deadlocks set the + * task-wide nofs context for the following operations. + */ + nofs_flag = memalloc_nofs_save(); + + if (flags & IOMAP_DIO_COW) { + if (iocb->ki_flags & IOCB_ATOMIC) + error = xfs_reflink_end_atomic_cow(ip, offset, size); + else + error = xfs_reflink_end_cow(ip, offset, size); + if (error) + goto out; + } + + /* + * Unwritten conversion updates the in-core isize after extent + * conversion but before updating the on-disk size. Updating isize any + * earlier allows a racing dio read to find unwritten extents before + * they are converted. + */ + if (flags & IOMAP_DIO_UNWRITTEN) { + error = xfs_iomap_write_unwritten(ip, offset, size, true); + goto out; + } + + /* + * We need to update the in-core inode size here so that we don't end up + * with the on-disk inode size being outside the in-core inode size. We + * have no other method of updating EOF for AIO, so always do it here + * if necessary. + */ + error = xfs_dio_endio_set_isize(inode, offset, size); + +out: + memalloc_nofs_restore(nofs_flag); + return error; +} + +static const struct iomap_dio_ops xfs_dio_write_ops = { + .end_io = xfs_dio_write_end_io, +}; + +static void +xfs_dio_zoned_submit_io( + const struct iomap_iter *iter, + struct bio *bio, + loff_t file_offset) +{ + struct xfs_mount *mp = XFS_I(iter->inode)->i_mount; + struct xfs_zone_alloc_ctx *ac = iter->private; + xfs_filblks_t count_fsb; + struct iomap_ioend *ioend; + + count_fsb = XFS_B_TO_FSB(mp, bio->bi_iter.bi_size); + if (count_fsb > ac->reserved_blocks) { + xfs_err(mp, +"allocation (%lld) larger than reservation (%lld).", + count_fsb, ac->reserved_blocks); + xfs_force_shutdown(mp, SHUTDOWN_CORRUPT_INCORE); + bio_io_error(bio); + return; + } + ac->reserved_blocks -= count_fsb; + + bio->bi_end_io = xfs_end_bio; + ioend = iomap_init_ioend(iter->inode, bio, file_offset, + IOMAP_IOEND_DIRECT); + xfs_zone_alloc_and_submit(ioend, &ac->open_zone); +} + +static const struct iomap_dio_ops xfs_dio_zoned_write_ops = { + .bio_set = &iomap_ioend_bioset, + .submit_io = xfs_dio_zoned_submit_io, + .end_io = xfs_zoned_dio_write_end_io, +}; + +/* + * Handle block aligned direct I/O writes. + */ +static noinline ssize_t +xfs_file_dio_write_aligned( + struct xfs_inode *ip, + struct kiocb *iocb, + struct iov_iter *from, + const struct iomap_ops *ops, + const struct iomap_dio_ops *dops, + struct xfs_zone_alloc_ctx *ac) +{ + unsigned int iolock = XFS_IOLOCK_SHARED; + unsigned int dio_flags = 0; + ssize_t ret; + + /* + * For always COW inodes, each bio must be aligned to the file system + * block size and not just the device sector size because we need to + * allocate a block-aligned amount of space for each write. + */ + if (xfs_is_always_cow_inode(ip)) + dio_flags |= IOMAP_DIO_FSBLOCK_ALIGNED; + + ret = xfs_ilock_iocb_for_write(iocb, &iolock); + if (ret) + return ret; + ret = xfs_file_write_checks(iocb, from, &iolock, ac); + if (ret) + goto out_unlock; + + /* + * We don't need to hold the IOLOCK exclusively across the IO, so demote + * the iolock back to shared if we had to take the exclusive lock in + * xfs_file_write_checks() for other reasons. + */ + if (iolock == XFS_IOLOCK_EXCL) { + xfs_ilock_demote(ip, XFS_IOLOCK_EXCL); + iolock = XFS_IOLOCK_SHARED; + } + if (mapping_stable_writes(iocb->ki_filp->f_mapping)) + dio_flags |= IOMAP_DIO_BOUNCE; + trace_xfs_file_direct_write(iocb, from); + ret = iomap_dio_rw(iocb, from, ops, dops, dio_flags, ac, 0); +out_unlock: + xfs_iunlock(ip, iolock); + return ret; +} + +/* + * Handle block aligned direct I/O writes to zoned devices. + */ +static noinline ssize_t +xfs_file_dio_write_zoned( + struct xfs_inode *ip, + struct kiocb *iocb, + struct iov_iter *from) +{ + struct xfs_zone_alloc_ctx ac = { }; + ssize_t ret; + + ret = xfs_zoned_write_space_reserve(ip->i_mount, iocb, from, 0, &ac); + if (ret < 0) + return ret; + ret = xfs_file_dio_write_aligned(ip, iocb, from, + &xfs_zoned_direct_write_iomap_ops, + &xfs_dio_zoned_write_ops, &ac); + xfs_zoned_space_unreserve(ip->i_mount, &ac); + return ret; +} + +/* + * Handle block atomic writes + * + * Two methods of atomic writes are supported: + * - REQ_ATOMIC-based, which would typically use some form of HW offload in the + * disk + * - COW-based, which uses a COW fork as a staging extent for data updates + * before atomically updating extent mappings for the range being written + * + */ +static noinline ssize_t +xfs_file_dio_write_atomic( + struct xfs_inode *ip, + struct kiocb *iocb, + struct iov_iter *from) +{ + unsigned int iolock = XFS_IOLOCK_SHARED; + ssize_t ret, ocount = iov_iter_count(from); + unsigned int dio_flags = 0; + const struct iomap_ops *dops; + + /* + * HW offload should be faster, so try that first if it is already + * known that the write length is not too large. + */ + if (ocount > xfs_inode_buftarg(ip)->bt_awu_max) + dops = &xfs_atomic_write_cow_iomap_ops; + else + dops = &xfs_direct_write_iomap_ops; + +retry: + ret = xfs_ilock_iocb_for_write(iocb, &iolock); + if (ret) + return ret; + + ret = xfs_file_write_checks(iocb, from, &iolock, NULL); + if (ret) + goto out_unlock; + + /* Demote similar to xfs_file_dio_write_aligned() */ + if (iolock == XFS_IOLOCK_EXCL) { + xfs_ilock_demote(ip, XFS_IOLOCK_EXCL); + iolock = XFS_IOLOCK_SHARED; + } + + trace_xfs_file_direct_write(iocb, from); + if (mapping_stable_writes(iocb->ki_filp->f_mapping)) + dio_flags |= IOMAP_DIO_BOUNCE; + ret = iomap_dio_rw(iocb, from, dops, &xfs_dio_write_ops, dio_flags, + NULL, 0); + + /* + * The retry mechanism is based on the ->iomap_next method returning + * -ENOPROTOOPT, which would be when the REQ_ATOMIC-based write is not + * possible. The REQ_ATOMIC-based method is typically not possible if + * the write spans multiple extents or the disk blocks are misaligned. + */ + if (ret == -ENOPROTOOPT && dops == &xfs_direct_write_iomap_ops) { + xfs_iunlock(ip, iolock); + dops = &xfs_atomic_write_cow_iomap_ops; + goto retry; + } + +out_unlock: + if (iolock) + xfs_iunlock(ip, iolock); + return ret; +} + +/* + * Handle block unaligned direct I/O writes + * + * In most cases direct I/O writes will be done holding IOLOCK_SHARED, allowing + * them to be done in parallel with reads and other direct I/O writes. However, + * if the I/O is not aligned to filesystem blocks, the direct I/O layer may need + * to do sub-block zeroing and that requires serialisation against other direct + * I/O to the same block. In this case we need to serialise the submission of + * the unaligned I/O so that we don't get racing block zeroing in the dio layer. + * In the case where sub-block zeroing is not required, we can do concurrent + * sub-block dios to the same block successfully. + * + * Optimistically submit the I/O using the shared lock first, but use the + * IOMAP_DIO_OVERWRITE_ONLY flag to tell the lower layers to return -EAGAIN + * if block allocation or partial block zeroing would be required. In that case + * we try again with the exclusive lock. + */ +static noinline ssize_t +xfs_file_dio_write_unaligned( + struct xfs_inode *ip, + struct kiocb *iocb, + struct iov_iter *from) +{ + size_t isize = i_size_read(VFS_I(ip)); + size_t count = iov_iter_count(from); + unsigned int iolock = XFS_IOLOCK_SHARED; + unsigned int flags = IOMAP_DIO_OVERWRITE_ONLY; + ssize_t ret; + + /* + * Extending writes need exclusivity because of the sub-block zeroing + * that the DIO code always does for partial tail blocks beyond EOF, so + * don't even bother trying the fast path in this case. + */ + if (iocb->ki_pos > isize || iocb->ki_pos + count >= isize) { + if (iocb->ki_flags & IOCB_NOWAIT) + return -EAGAIN; +retry_exclusive: + iolock = XFS_IOLOCK_EXCL; + flags = IOMAP_DIO_FORCE_WAIT; + } + + ret = xfs_ilock_iocb_for_write(iocb, &iolock); + if (ret) + return ret; + + /* + * We can't properly handle unaligned direct I/O to reflink files yet, + * as we can't unshare a partial block. + */ + if (xfs_is_cow_inode(ip)) { + trace_xfs_reflink_bounce_dio_write(iocb, from); + ret = -ENOTBLK; + goto out_unlock; + } + + ret = xfs_file_write_checks(iocb, from, &iolock, NULL); + if (ret) + goto out_unlock; + + /* + * If we are doing exclusive unaligned I/O, this must be the only I/O + * in-flight. Otherwise we risk data corruption due to unwritten extent + * conversions from the AIO end_io handler. Wait for all other I/O to + * drain first. + */ + if (flags & IOMAP_DIO_FORCE_WAIT) + inode_dio_wait(VFS_I(ip)); + + if (mapping_stable_writes(iocb->ki_filp->f_mapping)) + flags |= IOMAP_DIO_BOUNCE; + + trace_xfs_file_direct_write(iocb, from); + ret = iomap_dio_rw(iocb, from, &xfs_direct_write_iomap_ops, + &xfs_dio_write_ops, flags, NULL, 0); + + /* + * Retry unaligned I/O with exclusive blocking semantics if the DIO + * layer rejected it for mapping or locking reasons. If we are doing + * nonblocking user I/O, propagate the error. + */ + if (ret == -EAGAIN && !(iocb->ki_flags & IOCB_NOWAIT)) { + ASSERT(flags & IOMAP_DIO_OVERWRITE_ONLY); + xfs_iunlock(ip, iolock); + goto retry_exclusive; + } + +out_unlock: + if (iolock) + xfs_iunlock(ip, iolock); + return ret; +} + +static ssize_t +xfs_file_dio_write( + struct kiocb *iocb, + struct iov_iter *from) +{ + struct xfs_inode *ip = XFS_I(file_inode(iocb->ki_filp)); + struct xfs_buftarg *target = xfs_inode_buftarg(ip); + size_t count = iov_iter_count(from); + + /* direct I/O must be aligned to device logical sector size */ + if ((iocb->ki_pos | count) & target->bt_logical_sectormask) + return -EINVAL; + + if ((iocb->ki_pos | count) & ip->i_mount->m_blockmask) + return xfs_file_dio_write_unaligned(ip, iocb, from); + if (xfs_is_zoned_inode(ip)) + return xfs_file_dio_write_zoned(ip, iocb, from); + if (iocb->ki_flags & IOCB_ATOMIC) + return xfs_file_dio_write_atomic(ip, iocb, from); + return xfs_file_dio_write_aligned(ip, iocb, from, + &xfs_direct_write_iomap_ops, &xfs_dio_write_ops, NULL); +} + +static noinline ssize_t +xfs_file_dax_write( + struct kiocb *iocb, + struct iov_iter *from) +{ + struct inode *inode = iocb->ki_filp->f_mapping->host; + struct xfs_inode *ip = XFS_I(inode); + unsigned int iolock = XFS_IOLOCK_EXCL; + ssize_t ret, error = 0; + loff_t pos; + + ret = xfs_ilock_iocb(iocb, iolock); + if (ret) + return ret; + ret = xfs_file_write_checks(iocb, from, &iolock, NULL); + if (ret) + goto out; + + pos = iocb->ki_pos; + + trace_xfs_file_dax_write(iocb, from); + ret = dax_iomap_rw(iocb, from, &xfs_dax_write_iomap_ops); + if (ret > 0 && iocb->ki_pos > i_size_read(inode)) { + i_size_write(inode, iocb->ki_pos); + error = xfs_setfilesize(ip, pos, ret); + } +out: + if (iolock) + xfs_iunlock(ip, iolock); + if (error) + return error; + + if (ret > 0) { + XFS_STATS_ADD(ip->i_mount, xs_write_bytes, ret); + + /* Handle various SYNC-type writes */ + ret = generic_write_sync(iocb, ret); + } + return ret; +} + +STATIC ssize_t +xfs_file_buffered_write( + struct kiocb *iocb, + struct iov_iter *from) +{ + struct inode *inode = iocb->ki_filp->f_mapping->host; + struct xfs_inode *ip = XFS_I(inode); + ssize_t ret; + bool cleared_space = false; + unsigned int iolock; + +write_retry: + iolock = XFS_IOLOCK_EXCL; + ret = xfs_ilock_iocb(iocb, iolock); + if (ret) + return ret; + + ret = xfs_file_write_checks(iocb, from, &iolock, NULL); + if (ret) + goto out; + + trace_xfs_file_buffered_write(iocb, from); + ret = iomap_file_buffered_write(iocb, from, + &xfs_buffered_write_iomap_ops, &xfs_iomap_write_ops, + NULL); + + /* + * If we hit a space limit, try to free up some lingering preallocated + * space before returning an error. In the case of ENOSPC, first try to + * write back all dirty inodes to free up some of the excess reserved + * metadata space. This reduces the chances that the eofblocks scan + * waits on dirty mappings. Since xfs_flush_inodes() is serialized, this + * also behaves as a filter to prevent too many eofblocks scans from + * running at the same time. Use a synchronous scan to increase the + * effectiveness of the scan. + */ + if (ret == -EDQUOT && !cleared_space) { + xfs_iunlock(ip, iolock); + xfs_blockgc_free_quota(ip, XFS_ICWALK_FLAG_SYNC); + cleared_space = true; + goto write_retry; + } else if (ret == -ENOSPC && !cleared_space) { + struct xfs_icwalk icw = {0}; + + cleared_space = true; + xfs_flush_inodes(ip->i_mount); + + xfs_iunlock(ip, iolock); + icw.icw_flags = XFS_ICWALK_FLAG_SYNC; + xfs_blockgc_free_space(ip->i_mount, &icw); + goto write_retry; + } + +out: + if (iolock) + xfs_iunlock(ip, iolock); + + if (ret > 0) { + XFS_STATS_ADD(ip->i_mount, xs_write_bytes, ret); + /* Handle various SYNC-type writes */ + ret = generic_write_sync(iocb, ret); + } + return ret; +} + +STATIC ssize_t +xfs_file_buffered_write_zoned( + struct kiocb *iocb, + struct iov_iter *from) +{ + struct xfs_inode *ip = XFS_I(iocb->ki_filp->f_mapping->host); + struct xfs_mount *mp = ip->i_mount; + unsigned int iolock = XFS_IOLOCK_EXCL; + bool cleared_space = false; + struct xfs_zone_alloc_ctx ac = { }; + ssize_t ret; + + ret = xfs_zoned_write_space_reserve(mp, iocb, from, XFS_ZR_GREEDY, &ac); + if (ret < 0) + return ret; + + ret = xfs_ilock_iocb(iocb, iolock); + if (ret) + goto out_unreserve; + + ret = xfs_file_write_checks(iocb, from, &iolock, &ac); + if (ret) + goto out_unlock; + + /* + * Truncate the iter to the length that we were actually able to + * allocate blocks for. This needs to happen after + * xfs_file_write_checks, because that assigns ki_pos for O_APPEND + * writes. + */ + iov_iter_truncate(from, + XFS_FSB_TO_B(mp, ac.reserved_blocks) - + (iocb->ki_pos & mp->m_blockmask)); + if (!iov_iter_count(from)) + goto out_unlock; + +retry: + trace_xfs_file_buffered_write(iocb, from); + ret = iomap_file_buffered_write(iocb, from, + &xfs_buffered_write_iomap_ops, &xfs_iomap_write_ops, + &ac); + if (ret == -ENOSPC && !cleared_space) { + /* + * Kick off writeback to convert delalloc space and release the + * usually too pessimistic indirect block reservations. + */ + xfs_flush_inodes(mp); + cleared_space = true; + goto retry; + } + +out_unlock: + xfs_iunlock(ip, iolock); +out_unreserve: + xfs_zoned_space_unreserve(ip->i_mount, &ac); + if (ret > 0) { + XFS_STATS_ADD(mp, xs_write_bytes, ret); + ret = generic_write_sync(iocb, ret); + } + return ret; +} + +STATIC ssize_t +xfs_file_write_iter( + struct kiocb *iocb, + struct iov_iter *from) +{ + struct inode *inode = iocb->ki_filp->f_mapping->host; + struct xfs_inode *ip = XFS_I(inode); + ssize_t ret; + size_t ocount = iov_iter_count(from); + + XFS_STATS_INC(ip->i_mount, xs_write_calls); + + if (ocount == 0) + return 0; + + if (xfs_is_shutdown(ip->i_mount)) + return -EIO; + + if (iocb->ki_flags & IOCB_ATOMIC) { + if (ocount < xfs_get_atomic_write_min(ip)) + return -EINVAL; + + if (ocount > xfs_get_atomic_write_max(ip)) + return -EINVAL; + + ret = generic_atomic_write_valid(iocb, from); + if (ret) + return ret; + } + + if (IS_DAX(inode)) + return xfs_file_dax_write(iocb, from); + + if (iocb->ki_flags & IOCB_DIRECT) { + /* + * Allow a directio write to fall back to a buffered + * write *only* in the case that we're doing a reflink + * CoW. In all other directio scenarios we do not + * allow an operation to fall back to buffered mode. + */ + ret = xfs_file_dio_write(iocb, from); + if (ret != -ENOTBLK) + return ret; + } + + if (xfs_is_zoned_inode(ip)) + return xfs_file_buffered_write_zoned(iocb, from); + return xfs_file_buffered_write(iocb, from); +} + +/* Does this file, inode, or mount want synchronous writes? */ +static inline bool xfs_file_sync_writes(struct file *filp) +{ + struct xfs_inode *ip = XFS_I(file_inode(filp)); + + if (xfs_has_wsync(ip->i_mount)) + return true; + if (filp->f_flags & (__O_SYNC | O_DSYNC)) + return true; + if (IS_SYNC(file_inode(filp))) + return true; + + return false; +} + +static int +xfs_falloc_newsize( + struct file *file, + int mode, + loff_t offset, + loff_t len, + loff_t *new_size) +{ + struct inode *inode = file_inode(file); + + if ((mode & FALLOC_FL_KEEP_SIZE) || offset + len <= i_size_read(inode)) + return 0; + *new_size = offset + len; + return inode_newsize_ok(inode, *new_size); +} + +static int +xfs_falloc_setsize( + struct file *file, + loff_t new_size) +{ + struct iattr iattr = { + .ia_valid = ATTR_SIZE, + .ia_size = new_size, + }; + + if (!new_size) + return 0; + return xfs_vn_setattr_size(file_mnt_idmap(file), file_dentry(file), + &iattr); +} + +static int +xfs_falloc_collapse_range( + struct file *file, + loff_t offset, + loff_t len, + struct xfs_zone_alloc_ctx *ac) +{ + struct inode *inode = file_inode(file); + loff_t new_size = i_size_read(inode) - len; + int error; + + if (!xfs_is_falloc_aligned(XFS_I(inode), offset, len)) + return -EINVAL; + + /* + * There is no need to overlap collapse range with EOF, in which case it + * is effectively a truncate operation + */ + if (offset + len >= i_size_read(inode)) + return -EINVAL; + + error = xfs_collapse_file_space(XFS_I(inode), offset, len, ac); + if (error) + return error; + return xfs_falloc_setsize(file, new_size); +} + +static int +xfs_falloc_insert_range( + struct file *file, + loff_t offset, + loff_t len) +{ + struct inode *inode = file_inode(file); + loff_t isize = i_size_read(inode); + int error; + + if (!xfs_is_falloc_aligned(XFS_I(inode), offset, len)) + return -EINVAL; + + /* + * New inode size must not exceed ->s_maxbytes, accounting for + * possible signed overflow. + */ + if (inode->i_sb->s_maxbytes - isize < len) + return -EFBIG; + + /* Offset should be less than i_size */ + if (offset >= isize) + return -EINVAL; + + /* + * Let writeback clean up EOF folio state before we bump i_size. The + * insert flushes before it starts shifting and under certain + * circumstances we can write back blocks that should technically be + * considered post-eof (and thus should not be submitted for writeback). + * + * For example, a large, dirty folio that spans EOF and is backed by + * post-eof COW fork preallocation can cause block remap into the data + * fork. This shifts back out beyond EOF, but creates an expectedly + * written post-eof block. The insert is going to flush, unmap and + * cancel prealloc across this whole range, so flush EOF now before we + * bump i_size to provide consistent behavior. + */ + error = filemap_write_and_wait_range(inode->i_mapping, isize, isize); + if (error) + return error; + + error = xfs_falloc_setsize(file, isize + len); + if (error) + return error; + + /* + * Perform hole insertion now that the file size has been updated so + * that if we crash during the operation we don't leave shifted extents + * past EOF and hence losing access to the data that is contained within + * them. + */ + return xfs_insert_file_space(XFS_I(inode), offset, len); +} + +/* + * For various operations we need to zero up to one block at each end of + * the affected range. For zoned file systems this will require a space + * allocation, for which we need a reservation ahead of time. + */ +#define XFS_ZONED_ZERO_EDGE_SPACE_RES 2 + +/* + * Zero range implements a full zeroing mechanism but is only used in limited + * situations. It is more efficient to allocate unwritten extents than to + * perform zeroing here, so use an errortag to randomly force zeroing on DEBUG + * kernels for added test coverage. + * + * On zoned file systems, the error is already injected by + * xfs_file_zoned_fallocate, which then reserves the additional space needed. + * We only check for this extra space reservation here. + */ +static inline bool +xfs_falloc_force_zero( + struct xfs_inode *ip, + struct xfs_zone_alloc_ctx *ac) +{ + if (xfs_is_zoned_inode(ip)) { + if (ac->reserved_blocks > XFS_ZONED_ZERO_EDGE_SPACE_RES) { + ASSERT(IS_ENABLED(CONFIG_XFS_DEBUG)); + return true; + } + return false; + } + return XFS_TEST_ERROR(ip->i_mount, XFS_ERRTAG_FORCE_ZERO_RANGE); +} + +static int +xfs_falloc_write_zeroes( + struct file *file, + int mode, + loff_t offset, + loff_t len, + struct xfs_zone_alloc_ctx *ac) +{ + struct inode *inode = file_inode(file); + struct xfs_inode *ip = XFS_I(inode); + loff_t new_size = 0; + int error; + + /* + * XXX: There is an issue with bigrtalloc inodes where there can be blocks + * that are written after the EOF block. This breaks the promise of no + * written blocks past EOF. Return EOPNOTSUPP until it is fixed. + */ + if (xfs_is_always_cow_inode(ip) || xfs_inode_has_bigrtalloc(ip) || + !bdev_write_zeroes_unmap_sectors(xfs_inode_buftarg(ip)->bt_bdev)) + return -EOPNOTSUPP; + + error = xfs_falloc_newsize(file, mode, offset, len, &new_size); + if (error) + return error; + + /* + * + * |----------|----------|----------|----------|----------| + * ^ ^ ^ ^ ^ ^ + * | | | | | | + * | offset | | end | + * | | | | + * offset_rd offset_ru end_rd end_ru + * + * xfs_free_file_space() punches the aligned interior offset_ru -> end_rd + * to holes and byte-zeroes the in-range parts of the partial edge blocks, + * offset -> offset_ru and end_rd -> end. xfs_zero_range() only touches + * already-written blocks here; it skips holes and unwritten extents, so + * unallocated/unwritten edge blocks are left for the allocation below. + */ + error = xfs_free_file_space(ip, offset, len, ac); + if (error) + return error; + + /* + * Publish the new size while the punched range is still a hole, then + * fill it with written zeroes. Like the other fallocate modes we use + * xfs_falloc_setsize(), but it must run *before* we convert the range + * to written extents: xfs_setattr_size() zeroes [old EOF, new size) via + * xfs_zero_range(), which skips holes, so there is nothing to re-zero. + * It will also writeback partial EOF block before the on-disk size is + * logged. + * Note: extending the size before allocating means a failure below + * leaves the file larger with unallocated holes in the new range. + * That is safe as holes within i_size read back as zeroes and expose + * no stale data while the error is propagated to the caller. + */ + error = xfs_falloc_setsize(file, new_size); + if (error) + return error; + + /* + * Allocate written, zeroed extents across the range. xfs_alloc_file_space() + * rounds outward to block granularity: + * - holes (the punched interior and any unallocated edge block) are + * allocated and zeroed; + * - unwritten extents (including unwritten edge blocks) are converted to + * written and zeroed; + * - Already written edge blocks are skipped. The out-of-range bytes of + * a written edge block keep their data (offset_rd -> offset and + * end -> end_rd); their in-range bytes (offset -> offset_ru and + * end_ru -> end were already zeroed by xfs_free_file_space(). + */ + return xfs_alloc_file_space(ip, offset, len, + XFS_ALLOC_FILE_SPACE_WRITE_ZEROES); +} + +/* + * Punch a hole and prealloc the range. We use a hole punch rather than + * unwritten extent conversion for two reasons: + * + * 1.) Hole punch handles partial block zeroing for us. + * 2.) If prealloc returns ENOSPC, the file range is still zero-valued by + * virtue of the hole punch. + */ +static int +xfs_falloc_zero_range( + struct file *file, + int mode, + loff_t offset, + loff_t len, + struct xfs_zone_alloc_ctx *ac) +{ + struct inode *inode = file_inode(file); + struct xfs_inode *ip = XFS_I(inode); + unsigned int blksize = i_blocksize(inode); + loff_t new_size = 0; + int error; + + trace_xfs_zero_file_space(ip); + + error = xfs_falloc_newsize(file, mode, offset, len, &new_size); + if (error) + return error; + + if (xfs_falloc_force_zero(ip, ac)) { + error = xfs_zero_range(ip, offset, len, ac, NULL); + } else { + error = xfs_free_file_space(ip, offset, len, ac); + if (error) + return error; + + len = round_up(offset + len, blksize) - + round_down(offset, blksize); + offset = round_down(offset, blksize); + error = xfs_alloc_file_space(ip, offset, len, + XFS_ALLOC_FILE_SPACE_PREALLOC); + } + if (error) + return error; + return xfs_falloc_setsize(file, new_size); +} + +static int +xfs_falloc_unshare_range( + struct file *file, + int mode, + loff_t offset, + loff_t len) +{ + struct inode *inode = file_inode(file); + loff_t new_size = 0; + int error; + + error = xfs_falloc_newsize(file, mode, offset, len, &new_size); + if (error) + return error; + + error = xfs_reflink_unshare(XFS_I(inode), offset, len); + if (error) + return error; + + error = xfs_alloc_file_space(XFS_I(inode), offset, len, + XFS_ALLOC_FILE_SPACE_PREALLOC); + if (error) + return error; + return xfs_falloc_setsize(file, new_size); +} + +static int +xfs_falloc_allocate_range( + struct file *file, + int mode, + loff_t offset, + loff_t len) +{ + struct inode *inode = file_inode(file); + loff_t new_size = 0; + int error; + + /* + * If always_cow mode we can't use preallocations and thus should not + * create them. + */ + if (xfs_is_always_cow_inode(XFS_I(inode))) + return -EOPNOTSUPP; + + error = xfs_falloc_newsize(file, mode, offset, len, &new_size); + if (error) + return error; + + error = xfs_alloc_file_space(XFS_I(inode), offset, len, + XFS_ALLOC_FILE_SPACE_PREALLOC); + if (error) + return error; + return xfs_falloc_setsize(file, new_size); +} + +#define XFS_FALLOC_FL_SUPPORTED \ + (FALLOC_FL_ALLOCATE_RANGE | FALLOC_FL_KEEP_SIZE | \ + FALLOC_FL_PUNCH_HOLE | FALLOC_FL_COLLAPSE_RANGE | \ + FALLOC_FL_ZERO_RANGE | FALLOC_FL_INSERT_RANGE | \ + FALLOC_FL_UNSHARE_RANGE | FALLOC_FL_WRITE_ZEROES) + +STATIC long +__xfs_file_fallocate( + struct file *file, + int mode, + loff_t offset, + loff_t len, + struct xfs_zone_alloc_ctx *ac) +{ + struct inode *inode = file_inode(file); + struct xfs_inode *ip = XFS_I(inode); + long error; + uint iolock = XFS_IOLOCK_EXCL | XFS_MMAPLOCK_EXCL; + + xfs_ilock(ip, iolock); + error = xfs_break_layouts(inode, &iolock, BREAK_UNMAP); + if (error) + goto out_unlock; + + /* + * Must wait for all AIO to complete before we continue as AIO can + * change the file size on completion without holding any locks we + * currently hold. We must do this first because AIO can update both + * the on disk and in memory inode sizes, and the operations that follow + * require the in-memory size to be fully up-to-date. + */ + inode_dio_wait(inode); + + error = file_modified(file); + if (error) + goto out_unlock; + + switch (mode & FALLOC_FL_MODE_MASK) { + case FALLOC_FL_PUNCH_HOLE: + error = xfs_free_file_space(ip, offset, len, ac); + break; + case FALLOC_FL_COLLAPSE_RANGE: + error = xfs_falloc_collapse_range(file, offset, len, ac); + break; + case FALLOC_FL_INSERT_RANGE: + error = xfs_falloc_insert_range(file, offset, len); + break; + case FALLOC_FL_ZERO_RANGE: + error = xfs_falloc_zero_range(file, mode, offset, len, ac); + break; + case FALLOC_FL_UNSHARE_RANGE: + error = xfs_falloc_unshare_range(file, mode, offset, len); + break; + case FALLOC_FL_ALLOCATE_RANGE: + error = xfs_falloc_allocate_range(file, mode, offset, len); + break; + case FALLOC_FL_WRITE_ZEROES: + error = xfs_falloc_write_zeroes(file, mode, offset, len, ac); + break; + default: + error = -EOPNOTSUPP; + break; + } + + if (!error && xfs_file_sync_writes(file)) + error = xfs_log_force_inode(ip); + +out_unlock: + xfs_iunlock(ip, iolock); + return error; +} + +static long +xfs_file_zoned_fallocate( + struct file *file, + int mode, + loff_t offset, + loff_t len) +{ + struct xfs_zone_alloc_ctx ac = { }; + struct xfs_inode *ip = XFS_I(file_inode(file)); + struct xfs_mount *mp = ip->i_mount; + xfs_filblks_t count_fsb; + int error; + + /* + * If full zeroing is forced by the error injection knob, we need a + * space reservation that covers the entire range. See the comment in + * xfs_zoned_write_space_reserve for the rationale for the calculation. + * Otherwise just reserve space for the two boundary blocks. + */ + count_fsb = XFS_ZONED_ZERO_EDGE_SPACE_RES; + if ((mode & FALLOC_FL_MODE_MASK) == FALLOC_FL_ZERO_RANGE && + XFS_TEST_ERROR(mp, XFS_ERRTAG_FORCE_ZERO_RANGE)) + count_fsb += XFS_B_TO_FSB(mp, len) + 1; + + error = xfs_zoned_space_reserve(mp, count_fsb, XFS_ZR_RESERVED, &ac); + if (error) + return error; + error = __xfs_file_fallocate(file, mode, offset, len, &ac); + xfs_zoned_space_unreserve(mp, &ac); + return error; +} + +static long +xfs_file_fallocate( + struct file *file, + int mode, + loff_t offset, + loff_t len) +{ + struct inode *inode = file_inode(file); + + if (!S_ISREG(inode->i_mode)) + return -EINVAL; + if (mode & ~XFS_FALLOC_FL_SUPPORTED) + return -EOPNOTSUPP; + + /* + * For zoned file systems, zeroing the first and last block of a hole + * punch requires allocating a new block to rewrite the remaining data + * and new zeroes out of place. Get a reservations for those before + * taking the iolock. Dip into the reserved pool because we are + * expected to be able to punch a hole even on a completely full + * file system. + */ + if (xfs_is_zoned_inode(XFS_I(inode)) && + (mode & (FALLOC_FL_PUNCH_HOLE | FALLOC_FL_ZERO_RANGE | + FALLOC_FL_COLLAPSE_RANGE))) + return xfs_file_zoned_fallocate(file, mode, offset, len); + return __xfs_file_fallocate(file, mode, offset, len, NULL); +} + +STATIC int +xfs_file_fadvise( + struct file *file, + loff_t start, + loff_t end, + int advice) +{ + struct xfs_inode *ip = XFS_I(file_inode(file)); + int ret; + int lockflags = 0; + + /* + * Operations creating pages in page cache need protection from hole + * punching and similar ops + */ + if (advice == POSIX_FADV_WILLNEED) { + lockflags = XFS_IOLOCK_SHARED; + xfs_ilock(ip, lockflags); + } + ret = generic_fadvise(file, start, end, advice); + if (lockflags) + xfs_iunlock(ip, lockflags); + return ret; +} + +STATIC loff_t +xfs_file_remap_range( + struct file *file_in, + loff_t pos_in, + struct file *file_out, + loff_t pos_out, + loff_t len, + unsigned int remap_flags) +{ + struct inode *inode_in = file_inode(file_in); + struct xfs_inode *src = XFS_I(inode_in); + struct inode *inode_out = file_inode(file_out); + struct xfs_inode *dest = XFS_I(inode_out); + struct xfs_mount *mp = src->i_mount; + loff_t remapped = 0; + xfs_extlen_t cowextsize; + int ret; + + if (remap_flags & ~(REMAP_FILE_DEDUP | REMAP_FILE_ADVISORY)) + return -EINVAL; + + if (!xfs_has_reflink(mp)) + return -EOPNOTSUPP; + + if (xfs_is_shutdown(mp)) + return -EIO; + + /* Prepare and then clone file data. */ + ret = xfs_reflink_remap_prep(file_in, pos_in, file_out, pos_out, + &len, remap_flags); + if (ret || len == 0) + return ret; + + trace_xfs_reflink_remap_range(src, pos_in, len, dest, pos_out); + + ret = xfs_reflink_remap_blocks(src, pos_in, dest, pos_out, len, + &remapped); + if (ret) + goto out_unlock; + + /* + * Carry the cowextsize hint from src to dest if we're sharing the + * entire source file to the entire destination file, the source file + * has a cowextsize hint, and the destination file does not. + */ + cowextsize = 0; + if (pos_in == 0 && len == i_size_read(inode_in) && + (src->i_diflags2 & XFS_DIFLAG2_COWEXTSIZE) && + pos_out == 0 && len >= i_size_read(inode_out) && + !(dest->i_diflags2 & XFS_DIFLAG2_COWEXTSIZE)) + cowextsize = src->i_cowextsize; + + ret = xfs_reflink_update_dest(dest, pos_out + len, cowextsize, + remap_flags); + if (ret) + goto out_unlock; + + if (xfs_file_sync_writes(file_in) || xfs_file_sync_writes(file_out)) + xfs_log_force_inode(dest); +out_unlock: + xfs_iunlock2_remapping(src, dest); + if (ret) + trace_xfs_reflink_remap_range_error(dest, ret, _RET_IP_); + /* + * If the caller did not set CAN_SHORTEN, then it is not prepared to + * handle partial results -- either the whole remap succeeds, or we + * must say why it did not. In this case, any error should be returned + * to the caller. + */ + if (ret && remapped < len && !(remap_flags & REMAP_FILE_CAN_SHORTEN)) + return ret; + return remapped > 0 ? remapped : ret; +} + +STATIC int +xfs_file_open( + struct inode *inode, + struct file *file) +{ + if (xfs_is_shutdown(XFS_M(inode->i_sb))) + return -EIO; + file->f_mode |= FMODE_NOWAIT | FMODE_CAN_ODIRECT; + if (xfs_get_atomic_write_min(XFS_I(inode)) > 0) + file->f_mode |= FMODE_CAN_ATOMIC_WRITE; + return generic_file_open(inode, file); +} + +STATIC int +xfs_dir_open( + struct inode *inode, + struct file *file) +{ + struct xfs_inode *ip = XFS_I(inode); + unsigned int mode; + int error; + + if (xfs_is_shutdown(ip->i_mount)) + return -EIO; + error = generic_file_open(inode, file); + if (error) + return error; + + /* + * If there are any blocks, read-ahead block 0 as we're almost + * certain to have the next operation be a read there. + */ + mode = xfs_ilock_data_map_shared(ip); + if (ip->i_df.if_nextents > 0) + error = xfs_dir3_data_readahead(ip, 0, 0); + xfs_iunlock(ip, mode); + return error; +} + +/* + * Don't bother propagating errors. We're just doing cleanup, and the caller + * ignores the return value anyway. + */ +STATIC int +xfs_file_release( + struct inode *inode, + struct file *file) +{ + struct xfs_inode *ip = XFS_I(inode); + struct xfs_mount *mp = ip->i_mount; + + /* + * If this is a read-only mount or the file system has been shut down, + * don't generate I/O. + */ + if (xfs_is_readonly(mp) || xfs_is_shutdown(mp)) + return 0; + + /* + * If we previously truncated this file and removed old data in the + * process, we want to initiate "early" writeout on the last close. + * This is an attempt to combat the notorious NULL files problem which + * is particularly noticeable from a truncate down, buffered (re-)write + * (delalloc), followed by a crash. What we are effectively doing here + * is significantly reducing the time window where we'd otherwise be + * exposed to that problem. + */ + if (xfs_iflags_test_and_clear(ip, XFS_ITRUNCATED)) { + xfs_iflags_clear(ip, XFS_EOFBLOCKS_RELEASED); + if (ip->i_delayed_blks > 0) + filemap_flush(inode->i_mapping); + } + + /* + * XFS aggressively preallocates post-EOF space to generate contiguous + * allocations for writers that append to the end of the file. + * + * To support workloads that close and reopen the file frequently, these + * preallocations usually persist after a close unless it is the first + * close for the inode. This is a tradeoff to generate tightly packed + * data layouts for unpacking tarballs or similar archives that write + * one file after another without going back to it while keeping the + * preallocation for files that have recurring open/write/close cycles. + * + * This heuristic is skipped for inodes with the append-only flag as + * that flag is rather pointless for inodes written only once. + * + * There is no point in freeing blocks here for open but unlinked files + * as they will be taken care of by the inactivation path soon. + * + * When releasing a read-only context, don't flush data or trim post-EOF + * blocks. This avoids open/read/close workloads from removing EOF + * blocks that other writers depend upon to reduce fragmentation. + * + * Inodes on the zoned RT device never have preallocations, so skip + * taking the locks below. + */ + if (!inode->i_nlink || + !(file->f_mode & FMODE_WRITE) || + (ip->i_diflags & XFS_DIFLAG_APPEND) || + xfs_is_zoned_inode(ip)) + return 0; + + /* + * If we can't get the iolock just skip truncating the blocks past EOF + * because we could deadlock with the mmap_lock otherwise. We'll get + * another chance to drop them once the last reference to the inode is + * dropped, so we'll never leak blocks permanently. + */ + if (!xfs_iflags_test(ip, XFS_EOFBLOCKS_RELEASED) && + xfs_ilock_nowait(ip, XFS_IOLOCK_EXCL)) { + if (xfs_can_free_eofblocks(ip) && + !xfs_iflags_test_and_set(ip, XFS_EOFBLOCKS_RELEASED)) + xfs_free_eofblocks(ip); + xfs_iunlock(ip, XFS_IOLOCK_EXCL); + } + + return 0; +} + +STATIC int +xfs_file_readdir( + struct file *file, + struct dir_context *ctx) +{ + struct inode *inode = file_inode(file); + xfs_inode_t *ip = XFS_I(inode); + size_t bufsize; + + /* + * The Linux API doesn't pass down the total size of the buffer + * we read into down to the filesystem. With the filldir concept + * it's not needed for correct information, but the XFS dir2 leaf + * code wants an estimate of the buffer size to calculate it's + * readahead window and size the buffers used for mapping to + * physical blocks. + * + * Try to give it an estimate that's good enough, maybe at some + * point we can change the ->readdir prototype to include the + * buffer size. For now we use the current glibc buffer size. + */ + bufsize = (size_t)min_t(loff_t, XFS_READDIR_BUFSIZE, ip->i_disk_size); + + return xfs_readdir(NULL, ip, ctx, bufsize); +} + +STATIC loff_t +xfs_file_llseek( + struct file *file, + loff_t offset, + int whence) +{ + struct inode *inode = file->f_mapping->host; + + if (xfs_is_shutdown(XFS_I(inode)->i_mount)) + return -EIO; + + switch (whence) { + default: + return generic_file_llseek(file, offset, whence); + case SEEK_HOLE: + offset = iomap_seek_hole(inode, offset, &xfs_seek_iomap_ops); + break; + case SEEK_DATA: + offset = iomap_seek_data(inode, offset, &xfs_seek_iomap_ops); + break; + } + + if (offset < 0) + return offset; + return vfs_setpos(file, offset, inode->i_sb->s_maxbytes); +} + +static inline vm_fault_t +xfs_dax_fault_locked( + struct vm_fault *vmf, + unsigned int order, + bool write_fault) +{ + vm_fault_t ret; + unsigned long pfn; + + if (!IS_ENABLED(CONFIG_FS_DAX)) { + ASSERT(0); + return VM_FAULT_SIGBUS; + } + ret = dax_iomap_fault(vmf, order, &pfn, NULL, + (write_fault && !vmf->cow_page) ? + &xfs_dax_write_iomap_ops : + &xfs_read_iomap_ops); + if (ret & VM_FAULT_NEEDDSYNC) + ret = dax_finish_sync_fault(vmf, order, pfn); + return ret; +} + +static vm_fault_t +xfs_dax_read_fault( + struct vm_fault *vmf, + unsigned int order) +{ + struct xfs_inode *ip = XFS_I(file_inode(vmf->vma->vm_file)); + vm_fault_t ret; + + trace_xfs_read_fault(ip, order); + + xfs_ilock(ip, XFS_MMAPLOCK_SHARED); + ret = xfs_dax_fault_locked(vmf, order, false); + xfs_iunlock(ip, XFS_MMAPLOCK_SHARED); + + return ret; +} + +/* + * Locking for serialisation of IO during page faults. This results in a lock + * ordering of: + * + * mmap_lock (MM) + * sb_start_pagefault(vfs, freeze) + * invalidate_lock (vfs/XFS_MMAPLOCK - truncate serialisation) + * page_lock (MM) + * i_lock (XFS - extent map serialisation) + */ +static vm_fault_t +__xfs_write_fault( + struct vm_fault *vmf, + unsigned int order, + struct xfs_zone_alloc_ctx *ac) +{ + struct inode *inode = file_inode(vmf->vma->vm_file); + struct xfs_inode *ip = XFS_I(inode); + unsigned int lock_mode = XFS_MMAPLOCK_SHARED; + vm_fault_t ret; + + trace_xfs_write_fault(ip, order); + + sb_start_pagefault(inode->i_sb); + file_update_time(vmf->vma->vm_file); + + /* + * Normally we only need the shared mmaplock, but if a reflink remap is + * in progress we take the exclusive lock to wait for the remap to + * finish before taking a write fault. + */ + xfs_ilock(ip, XFS_MMAPLOCK_SHARED); + if (xfs_iflags_test(ip, XFS_IREMAPPING)) { + xfs_iunlock(ip, XFS_MMAPLOCK_SHARED); + xfs_ilock(ip, XFS_MMAPLOCK_EXCL); + lock_mode = XFS_MMAPLOCK_EXCL; + } + + if (IS_DAX(inode)) + ret = xfs_dax_fault_locked(vmf, order, true); + else + ret = iomap_page_mkwrite(vmf, &xfs_buffered_write_iomap_ops, + ac); + xfs_iunlock(ip, lock_mode); + + sb_end_pagefault(inode->i_sb); + return ret; +} + +static vm_fault_t +xfs_write_fault_zoned( + struct vm_fault *vmf, + unsigned int order) +{ + struct xfs_inode *ip = XFS_I(file_inode(vmf->vma->vm_file)); + unsigned int len = folio_size(page_folio(vmf->page)); + struct xfs_zone_alloc_ctx ac = { }; + int error; + vm_fault_t ret; + + /* + * This could over-allocate as it doesn't check for truncation. + * + * But as the overallocation is limited to less than a folio and will be + * release instantly that's just fine. + */ + error = xfs_zoned_space_reserve(ip->i_mount, + XFS_B_TO_FSB(ip->i_mount, len), 0, &ac); + if (error < 0) + return vmf_fs_error(error); + ret = __xfs_write_fault(vmf, order, &ac); + xfs_zoned_space_unreserve(ip->i_mount, &ac); + return ret; +} + +static vm_fault_t +xfs_write_fault( + struct vm_fault *vmf, + unsigned int order) +{ + if (xfs_is_zoned_inode(XFS_I(file_inode(vmf->vma->vm_file)))) + return xfs_write_fault_zoned(vmf, order); + return __xfs_write_fault(vmf, order, NULL); +} + +static inline bool +xfs_is_write_fault( + struct vm_fault *vmf) +{ + return (vmf->flags & FAULT_FLAG_WRITE) && + (vmf->vma->vm_flags & VM_SHARED); +} + +static vm_fault_t +xfs_filemap_fault( + struct vm_fault *vmf) +{ + struct inode *inode = file_inode(vmf->vma->vm_file); + + /* DAX can shortcut the normal fault path on write faults! */ + if (IS_DAX(inode)) { + if (xfs_is_write_fault(vmf)) + return xfs_write_fault(vmf, 0); + return xfs_dax_read_fault(vmf, 0); + } + + trace_xfs_read_fault(XFS_I(inode), 0); + return filemap_fault(vmf); +} + +static vm_fault_t +xfs_filemap_huge_fault( + struct vm_fault *vmf, + unsigned int order) +{ + if (!IS_DAX(file_inode(vmf->vma->vm_file))) + return VM_FAULT_FALLBACK; + + /* DAX can shortcut the normal fault path on write faults! */ + if (xfs_is_write_fault(vmf)) + return xfs_write_fault(vmf, order); + return xfs_dax_read_fault(vmf, order); +} + +static vm_fault_t +xfs_filemap_page_mkwrite( + struct vm_fault *vmf) +{ + return xfs_write_fault(vmf, 0); +} + +/* + * pfn_mkwrite was originally intended to ensure we capture time stamp updates + * on write faults. In reality, it needs to serialise against truncate and + * prepare memory for writing so handle is as standard write fault. + */ +static vm_fault_t +xfs_filemap_pfn_mkwrite( + struct vm_fault *vmf) +{ + return xfs_write_fault(vmf, 0); +} + +static const struct vm_operations_struct xfs_file_vm_ops = { + .fault = xfs_filemap_fault, + .huge_fault = xfs_filemap_huge_fault, + .map_pages = filemap_map_pages, + .page_mkwrite = xfs_filemap_page_mkwrite, + .pfn_mkwrite = xfs_filemap_pfn_mkwrite, +}; + +STATIC int +xfs_file_mmap_prepare( + struct vm_area_desc *desc) +{ + struct file *file = desc->file; + struct inode *inode = file_inode(file); + struct xfs_buftarg *target = xfs_inode_buftarg(XFS_I(inode)); + + /* + * We don't support synchronous mappings for non-DAX files and + * for DAX files if underneath dax_device is not synchronous. + */ + if (!daxdev_mapping_supported(desc, file_inode(file), + target->bt_daxdev)) + return -EOPNOTSUPP; + + file_accessed(file); + desc->vm_ops = &xfs_file_vm_ops; + if (IS_DAX(inode)) + vma_desc_set_flags(desc, VMA_HUGEPAGE_BIT); + return 0; +} + +const struct file_operations xfs_file_operations = { + .llseek = xfs_file_llseek, + .read_iter = xfs_file_read_iter, + .write_iter = xfs_file_write_iter, + .splice_read = xfs_file_splice_read, + .splice_write = iter_file_splice_write, + .iopoll = iocb_bio_iopoll, + .unlocked_ioctl = xfs_file_ioctl, +#ifdef CONFIG_COMPAT + .compat_ioctl = xfs_file_compat_ioctl, +#endif + .mmap_prepare = xfs_file_mmap_prepare, + .open = xfs_file_open, + .release = xfs_file_release, + .fsync = xfs_file_fsync, + .get_unmapped_area = thp_get_unmapped_area, + .fallocate = xfs_file_fallocate, + .fadvise = xfs_file_fadvise, + .remap_file_range = xfs_file_remap_range, + .fop_flags = FOP_MMAP_SYNC | FOP_BUFFER_RASYNC | + FOP_BUFFER_WASYNC | FOP_DIO_PARALLEL_WRITE | + FOP_DONTCACHE, + .setlease = generic_setlease, +}; + +const struct file_operations xfs_dir_file_operations = { + .open = xfs_dir_open, + .read = generic_read_dir, + .iterate_shared = xfs_file_readdir, + .llseek = generic_file_llseek, + .unlocked_ioctl = xfs_file_ioctl, +#ifdef CONFIG_COMPAT + .compat_ioctl = xfs_file_compat_ioctl, +#endif + .fsync = xfs_dir_fsync, + .setlease = generic_setlease, +}; |