diff options
Diffstat (limited to 'fs/ufs/dir.c')
| -rw-r--r-- | fs/ufs/dir.c | 658 |
1 files changed, 658 insertions, 0 deletions
diff --git a/fs/ufs/dir.c b/fs/ufs/dir.c new file mode 100644 index 000000000..e62fe5667 --- /dev/null +++ b/fs/ufs/dir.c @@ -0,0 +1,658 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * linux/fs/ufs/ufs_dir.c + * + * Copyright (C) 1996 + * Adrian Rodriguez (adrian@franklins-tower.rutgers.edu) + * Laboratory for Computer Science Research Computing Facility + * Rutgers, The State University of New Jersey + * + * swab support by Francois-Rene Rideau <fare@tunes.org> 19970406 + * + * 4.4BSD (FreeBSD) support added on February 1st 1998 by + * Niels Kristian Bech Jensen <nkbj@image.dk> partially based + * on code by Martin von Loewis <martin@mira.isdn.cs.tu-berlin.de>. + * + * Migration to usage of "page cache" on May 2006 by + * Evgeniy Dushistov <dushistov@mail.ru> based on ext2 code base. + */ + +#include <linux/time.h> +#include <linux/fs.h> +#include <linux/filelock.h> +#include <linux/swap.h> +#include <linux/iversion.h> + +#include "ufs_fs.h" +#include "ufs.h" +#include "swab.h" +#include "util.h" + +/* + * NOTE! unlike strncmp, ufs_match returns 1 for success, 0 for failure. + * + * len <= UFS_MAXNAMLEN and de != NULL are guaranteed by caller. + */ +static inline int ufs_match(struct super_block *sb, int len, + const unsigned char *name, struct ufs_dir_entry *de) +{ + if (len != ufs_get_de_namlen(sb, de)) + return 0; + if (!de->d_ino) + return 0; + return !memcmp(name, de->d_name, len); +} + +static void ufs_commit_chunk(struct folio *folio, loff_t pos, unsigned len) +{ + struct address_space *mapping = folio->mapping; + struct inode *dir = mapping->host; + + inode_inc_iversion(dir); + block_write_end(pos, len, len, folio); + if (pos+len > dir->i_size) { + i_size_write(dir, pos+len); + mark_inode_dirty(dir); + } + folio_unlock(folio); +} + +static int ufs_handle_dirsync(struct inode *dir) +{ + int err; + + err = filemap_write_and_wait(dir->i_mapping); + if (!err) + err = sync_inode_metadata(dir, 1); + return err; +} + +ino_t ufs_inode_by_name(struct inode *dir, const struct qstr *qstr) +{ + ino_t res = 0; + struct ufs_dir_entry *de; + struct folio *folio; + + de = ufs_find_entry(dir, qstr, &folio); + if (de) { + res = fs32_to_cpu(dir->i_sb, de->d_ino); + folio_release_kmap(folio, de); + } + return res; +} + + +int ufs_set_link(struct inode *dir, struct ufs_dir_entry *de, + struct folio *folio, struct inode *inode, + bool update_times) +{ + loff_t pos = folio_pos(folio) + offset_in_folio(folio, de); + unsigned len = fs16_to_cpu(dir->i_sb, de->d_reclen); + int err; + + folio_lock(folio); + err = ufs_prepare_chunk(folio, pos, len); + if (unlikely(err)) { + folio_unlock(folio); + return err; + } + + de->d_ino = cpu_to_fs32(dir->i_sb, inode->i_ino); + ufs_set_de_type(dir->i_sb, de, inode->i_mode); + + ufs_commit_chunk(folio, pos, len); + if (update_times) + inode_set_mtime_to_ts(dir, inode_set_ctime_current(dir)); + mark_inode_dirty(dir); + return ufs_handle_dirsync(dir); +} + +static bool ufs_check_folio(struct folio *folio, char *kaddr) +{ + struct inode *dir = folio->mapping->host; + struct super_block *sb = dir->i_sb; + unsigned offs, rec_len; + unsigned limit = folio_size(folio); + const unsigned chunk_mask = UFS_SB(sb)->s_uspi->s_dirblksize - 1; + struct ufs_dir_entry *p; + char *error; + + if (dir->i_size < folio_pos(folio) + limit) { + limit = offset_in_folio(folio, dir->i_size); + if (limit & chunk_mask) + goto Ebadsize; + if (!limit) + goto out; + } + for (offs = 0; offs <= limit - UFS_DIR_REC_LEN(1); offs += rec_len) { + p = (struct ufs_dir_entry *)(kaddr + offs); + rec_len = fs16_to_cpu(sb, p->d_reclen); + + if (rec_len < UFS_DIR_REC_LEN(1)) + goto Eshort; + if (rec_len & 3) + goto Ealign; + if (rec_len < UFS_DIR_REC_LEN(ufs_get_de_namlen(sb, p))) + goto Enamelen; + if (((offs + rec_len - 1) ^ offs) & ~chunk_mask) + goto Espan; + if (fs32_to_cpu(sb, p->d_ino) > (UFS_SB(sb)->s_uspi->s_ipg * + UFS_SB(sb)->s_uspi->s_ncg)) + goto Einumber; + } + if (offs != limit) + goto Eend; +out: + folio_set_checked(folio); + return true; + + /* Too bad, we had an error */ + +Ebadsize: + ufs_error(sb, __func__, + "size of directory #%llu is not a multiple of chunk size", + dir->i_ino + ); + goto fail; +Eshort: + error = "rec_len is smaller than minimal"; + goto bad_entry; +Ealign: + error = "unaligned directory entry"; + goto bad_entry; +Enamelen: + error = "rec_len is too small for name_len"; + goto bad_entry; +Espan: + error = "directory entry across blocks"; + goto bad_entry; +Einumber: + error = "inode out of bounds"; +bad_entry: + ufs_error(sb, __func__, "bad entry in directory #%llu: %s - " + "offset=%llu, rec_len=%d, name_len=%d", + dir->i_ino, error, folio_pos(folio) + offs, + rec_len, ufs_get_de_namlen(sb, p)); + goto fail; +Eend: + p = (struct ufs_dir_entry *)(kaddr + offs); + ufs_error(sb, __func__, + "entry in directory #%llu spans the page boundary" + "offset=%llu", + dir->i_ino, folio_pos(folio) + offs); +fail: + return false; +} + +static void *ufs_get_folio(struct inode *dir, unsigned long n, + struct folio **foliop) +{ + struct address_space *mapping = dir->i_mapping; + struct folio *folio = read_mapping_folio(mapping, n, NULL); + void *kaddr; + + if (IS_ERR(folio)) + return ERR_CAST(folio); + kaddr = kmap_local_folio(folio, 0); + if (unlikely(!folio_test_checked(folio))) { + if (!ufs_check_folio(folio, kaddr)) + goto fail; + } + *foliop = folio; + return kaddr; + +fail: + folio_release_kmap(folio, kaddr); + return ERR_PTR(-EIO); +} + +/* + * Return the offset into page `page_nr' of the last valid + * byte in that page, plus one. + */ +static unsigned +ufs_last_byte(struct inode *inode, unsigned long page_nr) +{ + unsigned last_byte = inode->i_size; + + last_byte -= page_nr << PAGE_SHIFT; + if (last_byte > PAGE_SIZE) + last_byte = PAGE_SIZE; + return last_byte; +} + +static inline struct ufs_dir_entry * +ufs_next_entry(struct super_block *sb, struct ufs_dir_entry *p) +{ + return (struct ufs_dir_entry *)((char *)p + + fs16_to_cpu(sb, p->d_reclen)); +} + +struct ufs_dir_entry *ufs_dotdot(struct inode *dir, struct folio **foliop) +{ + struct ufs_dir_entry *de = ufs_get_folio(dir, 0, foliop); + + if (!IS_ERR(de)) + return ufs_next_entry(dir->i_sb, de); + + return NULL; +} + +/* + * ufs_find_entry() + * + * finds an entry in the specified directory with the wanted name. It + * returns the page in which the entry was found, and the entry itself + * (as a parameter - res_dir). Page is returned mapped and unlocked. + * Entry is guaranteed to be valid. + */ +struct ufs_dir_entry *ufs_find_entry(struct inode *dir, const struct qstr *qstr, + struct folio **foliop) +{ + struct super_block *sb = dir->i_sb; + const unsigned char *name = qstr->name; + int namelen = qstr->len; + unsigned reclen = UFS_DIR_REC_LEN(namelen); + unsigned long start, n; + unsigned long npages = dir_pages(dir); + struct ufs_inode_info *ui = UFS_I(dir); + struct ufs_dir_entry *de; + + UFSD("ENTER, dir_ino %llu, name %s, namlen %u\n", dir->i_ino, name, namelen); + + if (npages == 0 || namelen > UFS_MAXNAMLEN) + goto out; + + start = ui->i_dir_start_lookup; + + if (start >= npages) + start = 0; + n = start; + do { + char *kaddr = ufs_get_folio(dir, n, foliop); + + if (!IS_ERR(kaddr)) { + de = (struct ufs_dir_entry *)kaddr; + kaddr += ufs_last_byte(dir, n) - reclen; + while ((char *) de <= kaddr) { + if (ufs_match(sb, namelen, name, de)) + goto found; + de = ufs_next_entry(sb, de); + } + folio_release_kmap(*foliop, kaddr); + } + if (++n >= npages) + n = 0; + } while (n != start); +out: + return NULL; + +found: + ui->i_dir_start_lookup = n; + return de; +} + +/* + * Parent is locked. + */ +int ufs_add_link(struct dentry *dentry, struct inode *inode) +{ + struct inode *dir = d_inode(dentry->d_parent); + const unsigned char *name = dentry->d_name.name; + int namelen = dentry->d_name.len; + struct super_block *sb = dir->i_sb; + unsigned reclen = UFS_DIR_REC_LEN(namelen); + const unsigned int chunk_size = UFS_SB(sb)->s_uspi->s_dirblksize; + unsigned short rec_len, name_len; + struct folio *folio = NULL; + struct ufs_dir_entry *de; + unsigned long npages = dir_pages(dir); + unsigned long n; + loff_t pos; + int err; + + UFSD("ENTER, name %s, namelen %u\n", name, namelen); + + /* + * We take care of directory expansion in the same loop. + * This code plays outside i_size, so it locks the folio + * to protect that region. + */ + for (n = 0; n <= npages; n++) { + char *kaddr = ufs_get_folio(dir, n, &folio); + char *dir_end; + + if (IS_ERR(kaddr)) + return PTR_ERR(kaddr); + folio_lock(folio); + dir_end = kaddr + ufs_last_byte(dir, n); + de = (struct ufs_dir_entry *)kaddr; + kaddr += folio_size(folio) - reclen; + while ((char *)de <= kaddr) { + if ((char *)de == dir_end) { + /* We hit i_size */ + name_len = 0; + rec_len = chunk_size; + de->d_reclen = cpu_to_fs16(sb, chunk_size); + de->d_ino = 0; + goto got_it; + } + if (de->d_reclen == 0) { + ufs_error(dir->i_sb, __func__, + "zero-length directory entry"); + err = -EIO; + goto out_unlock; + } + err = -EEXIST; + if (ufs_match(sb, namelen, name, de)) + goto out_unlock; + name_len = UFS_DIR_REC_LEN(ufs_get_de_namlen(sb, de)); + rec_len = fs16_to_cpu(sb, de->d_reclen); + if (!de->d_ino && rec_len >= reclen) + goto got_it; + if (rec_len >= name_len + reclen) + goto got_it; + de = (struct ufs_dir_entry *) ((char *) de + rec_len); + } + folio_unlock(folio); + folio_release_kmap(folio, kaddr); + } + BUG(); + return -EINVAL; + +got_it: + pos = folio_pos(folio) + offset_in_folio(folio, de); + err = ufs_prepare_chunk(folio, pos, rec_len); + if (err) + goto out_unlock; + if (de->d_ino) { + struct ufs_dir_entry *de1 = + (struct ufs_dir_entry *) ((char *) de + name_len); + de1->d_reclen = cpu_to_fs16(sb, rec_len - name_len); + de->d_reclen = cpu_to_fs16(sb, name_len); + + de = de1; + } + + ufs_set_de_namlen(sb, de, namelen); + memcpy(de->d_name, name, namelen + 1); + de->d_ino = cpu_to_fs32(sb, inode->i_ino); + ufs_set_de_type(sb, de, inode->i_mode); + + ufs_commit_chunk(folio, pos, rec_len); + inode_set_mtime_to_ts(dir, inode_set_ctime_current(dir)); + + mark_inode_dirty(dir); + err = ufs_handle_dirsync(dir); + /* OFFSET_CACHE */ +out_put: + folio_release_kmap(folio, de); + return err; +out_unlock: + folio_unlock(folio); + goto out_put; +} + +static inline unsigned +ufs_validate_entry(struct super_block *sb, char *base, + unsigned offset, unsigned mask) +{ + struct ufs_dir_entry *de = (struct ufs_dir_entry*)(base + offset); + struct ufs_dir_entry *p = (struct ufs_dir_entry*)(base + (offset&mask)); + while ((char*)p < (char*)de) + p = ufs_next_entry(sb, p); + return (char *)p - base; +} + + +/* + * This is blatantly stolen from ext2fs + */ +static int +ufs_readdir(struct file *file, struct dir_context *ctx) +{ + loff_t pos = ctx->pos; + struct inode *inode = file_inode(file); + struct super_block *sb = inode->i_sb; + unsigned int offset = pos & ~PAGE_MASK; + unsigned long n = pos >> PAGE_SHIFT; + unsigned long npages = dir_pages(inode); + unsigned chunk_mask = ~(UFS_SB(sb)->s_uspi->s_dirblksize - 1); + bool need_revalidate = !inode_eq_iversion(inode, *(u64 *)file->private_data); + unsigned flags = UFS_SB(sb)->s_flags; + + UFSD("BEGIN\n"); + + if (pos > inode->i_size - UFS_DIR_REC_LEN(1)) + return 0; + + for ( ; n < npages; n++, offset = 0) { + struct ufs_dir_entry *de; + struct folio *folio; + char *kaddr = ufs_get_folio(inode, n, &folio); + char *limit; + + if (IS_ERR(kaddr)) { + ufs_error(sb, __func__, + "bad page in #%llu", + inode->i_ino); + ctx->pos += PAGE_SIZE - offset; + return PTR_ERR(kaddr); + } + if (unlikely(need_revalidate)) { + if (offset) { + offset = ufs_validate_entry(sb, kaddr, offset, chunk_mask); + ctx->pos = (n<<PAGE_SHIFT) + offset; + } + *(u64 *)file->private_data = inode_query_iversion(inode); + need_revalidate = false; + } + de = (struct ufs_dir_entry *)(kaddr+offset); + limit = kaddr + ufs_last_byte(inode, n) - UFS_DIR_REC_LEN(1); + for ( ;(char*)de <= limit; de = ufs_next_entry(sb, de)) { + if (de->d_ino) { + unsigned char d_type = DT_UNKNOWN; + + UFSD("filldir(%s,%u)\n", de->d_name, + fs32_to_cpu(sb, de->d_ino)); + UFSD("namlen %u\n", ufs_get_de_namlen(sb, de)); + + if ((flags & UFS_DE_MASK) == UFS_DE_44BSD) + d_type = de->d_u.d_44.d_type; + + if (!dir_emit(ctx, de->d_name, + ufs_get_de_namlen(sb, de), + fs32_to_cpu(sb, de->d_ino), + d_type)) { + folio_release_kmap(folio, de); + return 0; + } + } + ctx->pos += fs16_to_cpu(sb, de->d_reclen); + } + folio_release_kmap(folio, kaddr); + } + return 0; +} + + +/* + * ufs_delete_entry deletes a directory entry by merging it with the + * previous entry. + */ +int ufs_delete_entry(struct inode *inode, struct ufs_dir_entry *dir, + struct folio *folio) +{ + struct super_block *sb = inode->i_sb; + size_t from, to; + char *kaddr; + loff_t pos; + struct ufs_dir_entry *de, *pde = NULL; + int err; + + UFSD("ENTER\n"); + + from = offset_in_folio(folio, dir); + to = from + fs16_to_cpu(sb, dir->d_reclen); + kaddr = (char *)dir - from; + from &= ~(UFS_SB(sb)->s_uspi->s_dirblksize - 1); + de = (struct ufs_dir_entry *) (kaddr + from); + + UFSD("ino %u, reclen %u, namlen %u, name %s\n", + fs32_to_cpu(sb, de->d_ino), + fs16_to_cpu(sb, de->d_reclen), + ufs_get_de_namlen(sb, de), de->d_name); + + while ((char*)de < (char*)dir) { + if (de->d_reclen == 0) { + ufs_error(inode->i_sb, __func__, + "zero-length directory entry"); + return -EIO; + } + pde = de; + de = ufs_next_entry(sb, de); + } + if (pde) + from = offset_in_folio(folio, pde); + pos = folio_pos(folio) + from; + folio_lock(folio); + err = ufs_prepare_chunk(folio, pos, to - from); + if (unlikely(err)) { + folio_unlock(folio); + return err; + } + if (pde) + pde->d_reclen = cpu_to_fs16(sb, to - from); + dir->d_ino = 0; + ufs_commit_chunk(folio, pos, to - from); + inode_set_mtime_to_ts(inode, inode_set_ctime_current(inode)); + mark_inode_dirty(inode); + return ufs_handle_dirsync(inode); +} + +int ufs_make_empty(struct inode * inode, struct inode *dir) +{ + struct super_block * sb = dir->i_sb; + struct address_space *mapping = inode->i_mapping; + struct folio *folio = filemap_grab_folio(mapping, 0); + const unsigned int chunk_size = UFS_SB(sb)->s_uspi->s_dirblksize; + struct ufs_dir_entry * de; + int err; + char *kaddr; + + if (IS_ERR(folio)) + return PTR_ERR(folio); + + err = ufs_prepare_chunk(folio, 0, chunk_size); + if (err) { + folio_unlock(folio); + goto fail; + } + + kaddr = kmap_local_folio(folio, 0); + memset(kaddr, 0, folio_size(folio)); + + de = (struct ufs_dir_entry *)kaddr; + + de->d_ino = cpu_to_fs32(sb, inode->i_ino); + ufs_set_de_type(sb, de, inode->i_mode); + ufs_set_de_namlen(sb, de, 1); + de->d_reclen = cpu_to_fs16(sb, UFS_DIR_REC_LEN(1)); + strcpy (de->d_name, "."); + de = (struct ufs_dir_entry *) + ((char *)de + fs16_to_cpu(sb, de->d_reclen)); + de->d_ino = cpu_to_fs32(sb, dir->i_ino); + ufs_set_de_type(sb, de, dir->i_mode); + de->d_reclen = cpu_to_fs16(sb, chunk_size - UFS_DIR_REC_LEN(1)); + ufs_set_de_namlen(sb, de, 2); + strcpy (de->d_name, ".."); + kunmap_local(kaddr); + + ufs_commit_chunk(folio, 0, chunk_size); + err = ufs_handle_dirsync(inode); +fail: + folio_put(folio); + return err; +} + +/* + * routine to check that the specified directory is empty (for rmdir) + */ +int ufs_empty_dir(struct inode * inode) +{ + struct super_block *sb = inode->i_sb; + struct folio *folio; + char *kaddr; + unsigned long i, npages = dir_pages(inode); + + for (i = 0; i < npages; i++) { + struct ufs_dir_entry *de; + + kaddr = ufs_get_folio(inode, i, &folio); + if (IS_ERR(kaddr)) + continue; + + de = (struct ufs_dir_entry *)kaddr; + kaddr += ufs_last_byte(inode, i) - UFS_DIR_REC_LEN(1); + + while ((char *)de <= kaddr) { + if (de->d_reclen == 0) { + ufs_error(inode->i_sb, __func__, + "zero-length directory entry: " + "kaddr=%p, de=%p\n", kaddr, de); + goto not_empty; + } + if (de->d_ino) { + u16 namelen=ufs_get_de_namlen(sb, de); + /* check for . and .. */ + if (de->d_name[0] != '.') + goto not_empty; + if (namelen > 2) + goto not_empty; + if (namelen < 2) { + if (inode->i_ino != + fs32_to_cpu(sb, de->d_ino)) + goto not_empty; + } else if (de->d_name[1] != '.') + goto not_empty; + } + de = ufs_next_entry(sb, de); + } + folio_release_kmap(folio, kaddr); + } + return 1; + +not_empty: + folio_release_kmap(folio, kaddr); + return 0; +} + +static int ufs_dir_open(struct inode *inode, struct file *file) +{ + file->private_data = kzalloc(sizeof(u64), GFP_KERNEL); + if (!file->private_data) + return -ENOMEM; + return 0; +} + +static int ufs_dir_release(struct inode *inode, struct file *file) +{ + kfree(file->private_data); + return 0; +} + +static loff_t ufs_dir_llseek(struct file *file, loff_t offset, int whence) +{ + return generic_llseek_cookie(file, offset, whence, + (u64 *)file->private_data); +} + +const struct file_operations ufs_dir_operations = { + .open = ufs_dir_open, + .release = ufs_dir_release, + .read = generic_read_dir, + .iterate_shared = ufs_readdir, + .fsync = simple_fsync, + .llseek = ufs_dir_llseek, + .setlease = generic_setlease, +}; 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