/* * linux/fs/ext4/namei.c * * Copyright (C) 1992, 1993, 1994, 1995 * Remy Card (card@masi.ibp.fr) * Laboratoire MASI - Institut Blaise Pascal * Universite Pierre et Marie Curie (Paris VI) * * from * * linux/fs/minix/namei.c * * Copyright (C) 1991, 1992 Linus Torvalds * * Big-endian to little-endian byte-swapping/bitmaps by * David S. Miller (davem@caip.rutgers.edu), 1995 * Directory entry file type support and forward compatibility hooks * for B-tree directories by Theodore Ts'o (tytso@mit.edu), 1998 * Hash Tree Directory indexing (c) * Daniel Phillips, 2001 * Hash Tree Directory indexing porting * Christopher Li, 2002 * Hash Tree Directory indexing cleanup * Theodore Ts'o, 2002 */ #include #include #include #include #include #include #include #include #include #include #include "ext4.h" #include "ext4_jbd2.h" #include "xattr.h" #include "acl.h" #include /* * define how far ahead to read directories while searching them. */ #define NAMEI_RA_CHUNKS 2 #define NAMEI_RA_BLOCKS 4 #define NAMEI_RA_SIZE (NAMEI_RA_CHUNKS * NAMEI_RA_BLOCKS) static struct buffer_head *ext4_append(handle_t *handle, struct inode *inode, ext4_lblk_t *block) { struct buffer_head *bh; int err = 0; if (unlikely(EXT4_SB(inode->i_sb)->s_max_dir_size_kb && ((inode->i_size >> 10) >= EXT4_SB(inode->i_sb)->s_max_dir_size_kb))) return ERR_PTR(-ENOSPC); *block = inode->i_size >> inode->i_sb->s_blocksize_bits; bh = ext4_bread(handle, inode, *block, 1, &err); if (!bh) return ERR_PTR(err); inode->i_size += inode->i_sb->s_blocksize; EXT4_I(inode)->i_disksize = inode->i_size; err = ext4_journal_get_write_access(handle, bh); if (err) { brelse(bh); ext4_std_error(inode->i_sb, err); return ERR_PTR(err); } return bh; } static int ext4_dx_csum_verify(struct inode *inode, struct ext4_dir_entry *dirent); typedef enum { EITHER, INDEX, DIRENT } dirblock_type_t; #define ext4_read_dirblock(inode, block, type) \ __ext4_read_dirblock((inode), (block), (type), __LINE__) static struct buffer_head *__ext4_read_dirblock(struct inode *inode, ext4_lblk_t block, dirblock_type_t type, unsigned int line) { struct buffer_head *bh; struct ext4_dir_entry *dirent; int err = 0, is_dx_block = 0; bh = ext4_bread(NULL, inode, block, 0, &err); if (!bh) { if (err == 0) { ext4_error_inode(inode, __func__, line, block, "Directory hole found"); return ERR_PTR(-EIO); } __ext4_warning(inode->i_sb, __func__, line, "error reading directory block " "(ino %lu, block %lu)", inode->i_ino, (unsigned long) block); return ERR_PTR(err); } dirent = (struct ext4_dir_entry *) bh->b_data; /* Determine whether or not we have an index block */ if (is_dx(inode)) { if (block == 0) is_dx_block = 1; else if (ext4_rec_len_from_disk(dirent->rec_len, inode->i_sb->s_blocksize) == inode->i_sb->s_blocksize) is_dx_block = 1; } if (!is_dx_block && type == INDEX) { ext4_error_inode(inode, __func__, line, block, "directory leaf block found instead of index block"); return ERR_PTR(-EIO); } if (!EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb, EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) || buffer_verified(bh)) return bh; /* * An empty leaf block can get mistaken for a index block; for * this reason, we can only check the index checksum when the * caller is sure it should be an index block. */ if (is_dx_block && type == INDEX) { if (ext4_dx_csum_verify(inode, dirent)) set_buffer_verified(bh); else { ext4_error_inode(inode, __func__, line, block, "Directory index failed checksum"); brelse(bh); return ERR_PTR(-EIO); } } if (!is_dx_block) { if (ext4_dirent_csum_verify(inode, dirent)) set_buffer_verified(bh); else { ext4_error_inode(inode, __func__, line, block, "Directory block failed checksum"); brelse(bh); return ERR_PTR(-EIO); } } return bh; } #ifndef assert #define assert(test) J_ASSERT(test) #endif #ifdef DX_DEBUG #define dxtrace(command) command #else #define dxtrace(command) #endif struct fake_dirent { __le32 inode; __le16 rec_len; u8 name_len; u8 file_type; }; struct dx_countlimit { __le16 limit; __le16 count; }; struct dx_entry { __le32 hash; __le32 block; }; /* * dx_root_info is laid out so that if it should somehow get overlaid by a * dirent the two low bits of the hash version will be zero. Therefore, the * hash version mod 4 should never be 0. Sincerely, the paranoia department. */ struct dx_root { struct fake_dirent dot; char dot_name[4]; struct fake_dirent dotdot; char dotdot_name[4]; struct dx_root_info { __le32 reserved_zero; u8 hash_version; u8 info_length; /* 8 */ u8 indirect_levels; u8 unused_flags; } info; struct dx_entry entries[0]; }; struct dx_node { struct fake_dirent fake; struct dx_entry entries[0]; }; struct dx_frame { struct buffer_head *bh; struct dx_entry *entries; struct dx_entry *at; }; struct dx_map_entry { u32 hash; u16 offs; u16 size; }; /* * This goes at the end of each htree block. */ struct dx_tail { u32 dt_reserved; __le32 dt_checksum; /* crc32c(uuid+inum+dirblock) */ }; static inline ext4_lblk_t dx_get_block(struct dx_entry *entry); static void dx_set_block(struct dx_entry *entry, ext4_lblk_t value); static inline unsigned dx_get_hash(struct dx_entry *entry); static void dx_set_hash(struct dx_entry *entry, unsigned value); static unsigned dx_get_count(struct dx_entry *entries); static unsigned dx_get_limit(struct dx_entry *entries); static void dx_set_count(struct dx_entry *entries, unsigned value); static void dx_set_limit(struct dx_entry *entries, unsigned value); static unsigned dx_root_limit(struct inode *dir, unsigned infosize); static unsigned dx_node_limit(struct inode *dir); static struct dx_frame *dx_probe(const struct qstr *d_name, struct inode *dir, struct dx_hash_info *hinfo, struct dx_frame *frame, int *err); static void dx_release(struct dx_frame *frames); static int dx_make_map(struct ext4_dir_entry_2 *de, unsigned blocksize, struct dx_hash_info *hinfo, struct dx_map_entry map[]); static void dx_sort_map(struct dx_map_entry *map, unsigned count); static struct ext4_dir_entry_2 *dx_move_dirents(char *from, char *to, struct dx_map_entry *offsets, int count, unsigned blocksize); static struct ext4_dir_entry_2* dx_pack_dirents(char *base, unsigned blocksize); static void dx_insert_block(struct dx_frame *frame, u32 hash, ext4_lblk_t block); static int ext4_htree_next_block(struct inode *dir, __u32 hash, struct dx_frame *frame, struct dx_frame *frames, __u32 *start_hash); static struct buffer_head * ext4_dx_find_entry(struct inode *dir, const struct qstr *d_name, struct ext4_dir_entry_2 **res_dir, int *err); static int ext4_dx_add_entry(handle_t *handle, struct dentry *dentry, struct inode *inode); /* checksumming functions */ void initialize_dirent_tail(struct ext4_dir_entry_tail *t, unsigned int blocksize) { memset(t, 0, sizeof(struct ext4_dir_entry_tail)); t->det_rec_len = ext4_rec_len_to_disk( sizeof(struct ext4_dir_entry_tail), blocksize); t->det_reserved_ft = EXT4_FT_DIR_CSUM; } /* Walk through a dirent block to find a checksum "dirent" at the tail */ static struct ext4_dir_entry_tail *get_dirent_tail(struct inode *inode, struct ext4_dir_entry *de) { struct ext4_dir_entry_tail *t; #ifdef PARANOID struct ext4_dir_entry *d, *top; d = de; top = (struct ext4_dir_entry *)(((void *)de) + (EXT4_BLOCK_SIZE(inode->i_sb) - sizeof(struct ext4_dir_entry_tail))); while (d < top && d->rec_len) d = (struct ext4_dir_entry *)(((void *)d) + le16_to_cpu(d->rec_len)); if (d != top) return NULL; t = (struct ext4_dir_entry_tail *)d; #else t = EXT4_DIRENT_TAIL(de, EXT4_BLOCK_SIZE(inode->i_sb)); #endif if (t->det_reserved_zero1 || le16_to_cpu(t->det_rec_len) != sizeof(struct ext4_dir_entry_tail) || t->det_reserved_zero2 || t->det_reserved_ft != EXT4_FT_DIR_CSUM) return NULL; return t; } static __le32 ext4_dirent_csum(struct inode *inode, struct ext4_dir_entry *dirent, int size) { struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); struct ext4_inode_info *ei = EXT4_I(inode); __u32 csum; csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)dirent, size); return cpu_to_le32(csum); } static void warn_no_space_for_csum(struct inode *inode) { ext4_warning(inode->i_sb, "no space in directory inode %lu leaf for " "checksum. Please run e2fsck -D.", inode->i_ino); } int ext4_dirent_csum_verify(struct inode *inode, struct ext4_dir_entry *dirent) { struct ext4_dir_entry_tail *t; if (!EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb, EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) return 1; t = get_dirent_tail(inode, dirent); if (!t) { warn_no_space_for_csum(inode); return 0; } if (t->det_checksum != ext4_dirent_csum(inode, dirent, (void *)t - (void *)dirent)) return 0; return 1; } static void ext4_dirent_csum_set(struct inode *inode, struct ext4_dir_entry *dirent) { struct ext4_dir_entry_tail *t; if (!EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb, EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) return; t = get_dirent_tail(inode, dirent); if (!t) { warn_no_space_for_csum(inode); return; } t->det_checksum = ext4_dirent_csum(inode, dirent, (void *)t - (void *)dirent); } int ext4_handle_dirty_dirent_node(handle_t *handle, struct inode *inode, struct buffer_head *bh) { ext4_dirent_csum_set(inode, (struct ext4_dir_entry *)bh->b_data); return ext4_handle_dirty_metadata(handle, inode, bh); } static struct dx_countlimit *get_dx_countlimit(struct inode *inode, struct ext4_dir_entry *dirent, int *offset) { struct ext4_dir_entry *dp; struct dx_root_info *root; int count_offset; if (le16_to_cpu(dirent->rec_len) == EXT4_BLOCK_SIZE(inode->i_sb)) count_offset = 8; else if (le16_to_cpu(dirent->rec_len) == 12) { dp = (struct ext4_dir_entry *)(((void *)dirent) + 12); if (le16_to_cpu(dp->rec_len) != EXT4_BLOCK_SIZE(inode->i_sb) - 12) return NULL; root = (struct dx_root_info *)(((void *)dp + 12)); if (root->reserved_zero || root->info_length != sizeof(struct dx_root_info)) return NULL; count_offset = 32; } else return NULL; if (offset) *offset = count_offset; return (struct dx_countlimit *)(((void *)dirent) + count_offset); } static __le32 ext4_dx_csum(struct inode *inode, struct ext4_dir_entry *dirent, int count_offset, int count, struct dx_tail *t) { struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); struct ext4_inode_info *ei = EXT4_I(inode); __u32 csum; __le32 save_csum; int size; size = count_offset + (count * sizeof(struct dx_entry)); save_csum = t->dt_checksum; t->dt_checksum = 0; csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)dirent, size); csum = ext4_chksum(sbi, csum, (__u8 *)t, sizeof(struct dx_tail)); t->dt_checksum = save_csum; return cpu_to_le32(csum); } static int ext4_dx_csum_verify(struct inode *inode, struct ext4_dir_entry *dirent) { struct dx_countlimit *c; struct dx_tail *t; int count_offset, limit, count; if (!EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb, EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) return 1; c = get_dx_countlimit(inode, dirent, &count_offset); if (!c) { EXT4_ERROR_INODE(inode, "dir seems corrupt? Run e2fsck -D."); return 1; } limit = le16_to_cpu(c->limit); count = le16_to_cpu(c->count); if (count_offset + (limit * sizeof(struct dx_entry)) > EXT4_BLOCK_SIZE(inode->i_sb) - sizeof(struct dx_tail)) { warn_no_space_for_csum(inode); return 1; } t = (struct dx_tail *)(((struct dx_entry *)c) + limit); if (t->dt_checksum != ext4_dx_csum(inode, dirent, count_offset, count, t)) return 0; return 1; } static void ext4_dx_csum_set(struct inode *inode, struct ext4_dir_entry *dirent) { struct dx_countlimit *c; struct dx_tail *t; int count_offset, limit, count; if (!EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb, EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) return; c = get_dx_countlimit(inode, dirent, &count_offset); if (!c) { EXT4_ERROR_INODE(inode, "dir seems corrupt? Run e2fsck -D."); return; } limit = le16_to_cpu(c->limit); count = le16_to_cpu(c->count); if (count_offset + (limit * sizeof(struct dx_entry)) > EXT4_BLOCK_SIZE(inode->i_sb) - sizeof(struct dx_tail)) { warn_no_space_for_csum(inode); return; } t = (struct dx_tail *)(((struct dx_entry *)c) + limit); t->dt_checksum = ext4_dx_csum(inode, dirent, count_offset, count, t); } static inline int ext4_handle_dirty_dx_node(handle_t *handle, struct inode *inode, struct buffer_head *bh) { ext4_dx_csum_set(inode, (struct ext4_dir_entry *)bh->b_data); return ext4_handle_dirty_metadata(handle, inode, bh); } /* * p is at least 6 bytes before the end of page */ static inline struct ext4_dir_entry_2 * ext4_next_entry(struct ext4_dir_entry_2 *p, unsigned long blocksize) { return (struct ext4_dir_entry_2 *)((char *)p + ext4_rec_len_from_disk(p->rec_len, blocksize)); } /* * Future: use high four bits of block for coalesce-on-delete flags * Mask them off for now. */ static inline ext4_lblk_t dx_get_block(struct dx_entry *entry) { return le32_to_cpu(entry->block) & 0x00ffffff; } static inline void dx_set_block(struct dx_entry *entry, ext4_lblk_t value) { entry->block = cpu_to_le32(value); } static inline unsigned dx_get_hash(struct dx_entry *entry) { return le32_to_cpu(entry->hash); } static inline void dx_set_hash(struct dx_entry *entry, unsigned value) { entry->hash = cpu_to_le32(value); } static inline unsigned dx_get_count(struct dx_entry *entries) { return le16_to_cpu(((struct dx_countlimit *) entries)->count); } static inline unsigned dx_get_limit(struct dx_entry *entries) { return le16_to_cpu(((struct dx_countlimit *) entries)->limit); } static inline void dx_set_count(struct dx_entry *entries, unsigned value) { ((struct dx_countlimit *) entries)->count = cpu_to_le16(value); } static inline void dx_set_limit(struct dx_entry *entries, unsigned value) { ((struct dx_countlimit *) entries)->limit = cpu_to_le16(value); } static inline unsigned dx_root_limit(struct inode *dir, unsigned infosize) { unsigned entry_space = dir->i_sb->s_blocksize - EXT4_DIR_REC_LEN(1) - EXT4_DIR_REC_LEN(2) - infosize; if (EXT4_HAS_RO_COMPAT_FEATURE(dir->i_sb, EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) entry_space -= sizeof(struct dx_tail); return entry_space / sizeof(struct dx_entry); } static inline unsigned dx_node_limit(struct inode *dir) { unsigned entry_space = dir->i_sb->s_blocksize - EXT4_DIR_REC_LEN(0); if (EXT4_HAS_RO_COMPAT_FEATURE(dir->i_sb, EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) entry_space -= sizeof(struct dx_tail); return entry_space / sizeof(struct dx_entry); } /* * Debug */ #ifdef DX_DEBUG static void dx_show_index(char * label, struct dx_entry *entries) { int i, n = dx_get_count (entries); printk(KERN_DEBUG "%s index ", label); for (i = 0; i < n; i++) { printk("%x->%lu ", i ? dx_get_hash(entries + i) : 0, (unsigned long)dx_get_block(entries + i)); } printk("\n"); } struct stats { unsigned names; unsigned space; unsigned bcount; }; static struct stats dx_show_leaf(struct dx_hash_info *hinfo, struct ext4_dir_entry_2 *de, int size, int show_names) { unsigned names = 0, space = 0; char *base = (char *) de; struct dx_hash_info h = *hinfo; printk("names: "); while ((char *) de < base + size) { if (de->inode) { if (show_names) { int len = de->name_len; char *name = de->name; while (len--) printk("%c", *name++); ext4fs_dirhash(de->name, de->name_len, &h); printk(":%x.%u ", h.hash, (unsigned) ((char *) de - base)); } space += EXT4_DIR_REC_LEN(de->name_len); names++; } de = ext4_next_entry(de, size); } printk("(%i)\n", names); return (struct stats) { names, space, 1 }; } struct stats dx_show_entries(struct dx_hash_info *hinfo, struct inode *dir, struct dx_entry *entries, int levels) { unsigned blocksize = dir->i_sb->s_blocksize; unsigned count = dx_get_count(entries), names = 0, space = 0, i; unsigned bcount = 0; struct buffer_head *bh; int err; printk("%i indexed blocks...\n", count); for (i = 0; i < count; i++, entries++) { ext4_lblk_t block = dx_get_block(entries); ext4_lblk_t hash = i ? dx_get_hash(entries): 0; u32 range = i < count - 1? (dx_get_hash(entries + 1) - hash): ~hash; struct stats stats; printk("%s%3u:%03u hash %8x/%8x ",levels?"":" ", i, block, hash, range); if (!(bh = ext4_bread (NULL,dir, block, 0,&err))) continue; stats = levels? dx_show_entries(hinfo, dir, ((struct dx_node *) bh->b_data)->entries, levels - 1): dx_show_leaf(hinfo, (struct ext4_dir_entry_2 *) bh->b_data, blocksize, 0); names += stats.names; space += stats.space; bcount += stats.bcount; brelse(bh); } if (bcount) printk(KERN_DEBUG "%snames %u, fullness %u (%u%%)\n", levels ? "" : " ", names, space/bcount, (space/bcount)*100/blocksize); return (struct stats) { names, space, bcount}; } #endif /* DX_DEBUG */ /* * Probe for a directory leaf block to search. * * dx_probe can return ERR_BAD_DX_DIR, which means there was a format * error in the directory index, and the caller should fall back to * searching the directory normally. The callers of dx_probe **MUST** * check for this error code, and make sure it never gets reflected * back to userspace. */ static struct dx_frame * dx_probe(const struct qstr *d_name, struct inode *dir, struct dx_hash_info *hinfo, struct dx_frame *frame_in, int *err) { unsigned count, indirect; struct dx_entry *at, *entries, *p, *q, *m; struct dx_root *root; struct buffer_head *bh; struct dx_frame *frame = frame_in; u32 hash; frame->bh = NULL; bh = ext4_read_dirblock(dir, 0, INDEX); if (IS_ERR(bh)) { *err = PTR_ERR(bh); goto fail; } root = (struct dx_root *) bh->b_data; if (root->info.hash_version != DX_HASH_TEA && root->info.hash_version != DX_HASH_HALF_MD4 && root->info.hash_version != DX_HASH_LEGACY) { ext4_warning(dir->i_sb, "Unrecognised inode hash code %d", root->info.hash_version); brelse(bh); *err = ERR_BAD_DX_DIR; goto fail; } hinfo->hash_version = root->info.hash_version; if (hinfo->hash_version <= DX_HASH_TEA) hinfo->hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned; hinfo->seed = EXT4_SB(dir->i_sb)->s_hash_seed; if (d_name) ext4fs_dirhash(d_name->name, d_name->len, hinfo); hash = hinfo->hash; if (root->info.unused_flags & 1) { ext4_warning(dir->i_sb, "Unimplemented inode hash flags: %#06x", root->info.unused_flags); brelse(bh); *err = ERR_BAD_DX_DIR; goto fail; } if ((indirect = root->info.indirect_levels) > 1) { ext4_warning(dir->i_sb, "Unimplemented inode hash depth: %#06x", root->info.indirect_levels); brelse(bh); *err = ERR_BAD_DX_DIR; goto fail; } entries = (struct dx_entry *) (((char *)&root->info) + root->info.info_length); if (dx_get_limit(entries) != dx_root_limit(dir, root->info.info_length)) { ext4_warning(dir->i_sb, "dx entry: limit != root limit"); brelse(bh); *err = ERR_BAD_DX_DIR; goto fail; } dxtrace(printk("Look up %x", hash)); while (1) { count = dx_get_count(entries); if (!count || count > dx_get_limit(entries)) { ext4_warning(dir->i_sb, "dx entry: no count or count > limit"); brelse(bh); *err = ERR_BAD_DX_DIR; goto fail2; } p = entries + 1; q = entries + count - 1; while (p <= q) { m = p + (q - p)/2; dxtrace(printk(".")); if (dx_get_hash(m) > hash) q = m - 1; else p = m + 1; } if (0) // linear search cross check { unsigned n = count - 1; at = entries; while (n--) { dxtrace(printk(",")); if (dx_get_hash(++at) > hash) { at--; break; } } assert (at == p - 1); } at = p - 1; dxtrace(printk(" %x->%u\n", at == entries? 0: dx_get_hash(at), dx_get_block(at))); frame->bh = bh; frame->entries = entries; frame->at = at; if (!indirect--) return frame; bh = ext4_read_dirblock(dir, dx_get_block(at), INDEX); if (IS_ERR(bh)) { *err = PTR_ERR(bh); goto fail2; } entries = ((struct dx_node *) bh->b_data)->entries; if (dx_get_limit(entries) != dx_node_limit (dir)) { ext4_warning(dir->i_sb, "dx entry: limit != node limit"); brelse(bh); *err = ERR_BAD_DX_DIR; goto fail2; } frame++; frame->bh = NULL; } fail2: while (frame >= frame_in) { brelse(frame->bh); frame--; } fail: if (*err == ERR_BAD_DX_DIR) ext4_warning(dir->i_sb, "Corrupt dir inode %lu, running e2fsck is " "recommended.", dir->i_ino); return NULL; } static void dx_release (struct dx_frame *frames) { if (frames[0].bh == NULL) return; if (((struct dx_root *) frames[0].bh->b_data)->info.indirect_levels) brelse(frames[1].bh); brelse(frames[0].bh); } /* * This function increments the frame pointer to search the next leaf * block, and reads in the necessary intervening nodes if the search * should be necessary. Whether or not the search is necessary is * controlled by the hash parameter. If the hash value is even, then * the search is only continued if the next block starts with that * hash value. This is used if we are searching for a specific file. * * If the hash value is HASH_NB_ALWAYS, then always go to the next block. * * This function returns 1 if the caller should continue to search, * or 0 if it should not. If there is an error reading one of the * index blocks, it will a negative error code. * * If start_hash is non-null, it will be filled in with the starting * hash of the next page. */ static int ext4_htree_next_block(struct inode *dir, __u32 hash, struct dx_frame *frame, struct dx_frame *frames, __u32 *start_hash) { struct dx_frame *p; struct buffer_head *bh; int num_frames = 0; __u32 bhash; p = frame; /* * Find the next leaf page by incrementing the frame pointer. * If we run out of entries in the interior node, loop around and * increment pointer in the parent node. When we break out of * this loop, num_frames indicates the number of interior * nodes need to be read. */ while (1) { if (++(p->at) < p->entries + dx_get_count(p->entries)) break; if (p == frames) return 0; num_frames++; p--; } /* * If the hash is 1, then continue only if the next page has a * continuation hash of any value. This is used for readdir * handling. Otherwise, check to see if the hash matches the * desired contiuation hash. If it doesn't, return since * there's no point to read in the successive index pages. */ bhash = dx_get_hash(p->at); if (start_hash) *start_hash = bhash; if ((hash & 1) == 0) { if ((bhash & ~1) != hash) return 0; } /* * If the hash is HASH_NB_ALWAYS, we always go to the next * block so no check is necessary */ while (num_frames--) { bh = ext4_read_dirblock(dir, dx_get_block(p->at), INDEX); if (IS_ERR(bh)) return PTR_ERR(bh); p++; brelse(p->bh); p->bh = bh; p->at = p->entries = ((struct dx_node *) bh->b_data)->entries; } return 1; } /* * This function fills a red-black tree with information from a * directory block. It returns the number directory entries loaded * into the tree. If there is an error it is returned in err. */ static int htree_dirblock_to_tree(struct file *dir_file, struct inode *dir, ext4_lblk_t block, struct dx_hash_info *hinfo, __u32 start_hash, __u32 start_minor_hash) { struct buffer_head *bh; struct ext4_dir_entry_2 *de, *top; int err = 0, count = 0; dxtrace(printk(KERN_INFO "In htree dirblock_to_tree: block %lu\n", (unsigned long)block)); bh = ext4_read_dirblock(dir, block, DIRENT); if (IS_ERR(bh)) return PTR_ERR(bh); de = (struct ext4_dir_entry_2 *) bh->b_data; top = (struct ext4_dir_entry_2 *) ((char *) de + dir->i_sb->s_blocksize - EXT4_DIR_REC_LEN(0)); for (; de < top; de = ext4_next_entry(de, dir->i_sb->s_blocksize)) { if (ext4_check_dir_entry(dir, NULL, de, bh, bh->b_data, bh->b_size, (block<i_sb)) + ((char *)de - bh->b_data))) { /* silently ignore the rest of the block */ break; } ext4fs_dirhash(de->name, de->name_len, hinfo); if ((hinfo->hash < start_hash) || ((hinfo->hash == start_hash) && (hinfo->minor_hash < start_minor_hash))) continue; if (de->inode == 0) continue; if ((err = ext4_htree_store_dirent(dir_file, hinfo->hash, hinfo->minor_hash, de)) != 0) { brelse(bh); return err; } count++; } brelse(bh); return count; } /* * This function fills a red-black tree with information from a * directory. We start scanning the directory in hash order, starting * at start_hash and start_minor_hash. * * This function returns the number of entries inserted into the tree, * or a negative error code. */ int ext4_htree_fill_tree(struct file *dir_file, __u32 start_hash, __u32 start_minor_hash, __u32 *next_hash) { struct dx_hash_info hinfo; struct ext4_dir_entry_2 *de; struct dx_frame frames[2], *frame; struct inode *dir; ext4_lblk_t block; int count = 0; int ret, err; __u32 hashval; dxtrace(printk(KERN_DEBUG "In htree_fill_tree, start hash: %x:%x\n", start_hash, start_minor_hash)); dir = file_inode(dir_file); if (!(ext4_test_inode_flag(dir, EXT4_INODE_INDEX))) { hinfo.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version; if (hinfo.hash_version <= DX_HASH_TEA) hinfo.hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned; hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed; if (ext4_has_inline_data(dir)) { int has_inline_data = 1; count = htree_inlinedir_to_tree(dir_file, dir, 0, &hinfo, start_hash, start_minor_hash, &has_inline_data); if (has_inline_data) { *next_hash = ~0; return count; } } count = htree_dirblock_to_tree(dir_file, dir, 0, &hinfo, start_hash, start_minor_hash); *next_hash = ~0; return count; } hinfo.hash = start_hash; hinfo.minor_hash = 0; frame = dx_probe(NULL, dir, &hinfo, frames, &err); if (!frame) return err; /* Add '.' and '..' from the htree header */ if (!start_hash && !start_minor_hash) { de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data; if ((err = ext4_htree_store_dirent(dir_file, 0, 0, de)) != 0) goto errout; count++; } if (start_hash < 2 || (start_hash ==2 && start_minor_hash==0)) { de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data; de = ext4_next_entry(de, dir->i_sb->s_blocksize); if ((err = ext4_htree_store_dirent(dir_file, 2, 0, de)) != 0) goto errout; count++; } while (1) { block = dx_get_block(frame->at); ret = htree_dirblock_to_tree(dir_file, dir, block, &hinfo, start_hash, start_minor_hash); if (ret < 0) { err = ret; goto errout; } count += ret; hashval = ~0; ret = ext4_htree_next_block(dir, HASH_NB_ALWAYS, frame, frames, &hashval); *next_hash = hashval; if (ret < 0) { err = ret; goto errout; } /* * Stop if: (a) there are no more entries, or * (b) we have inserted at least one entry and the * next hash value is not a continuation */ if ((ret == 0) || (count && ((hashval & 1) == 0))) break; } dx_release(frames); dxtrace(printk(KERN_DEBUG "Fill tree: returned %d entries, " "next hash: %x\n", count, *next_hash)); return count; errout: dx_release(frames); return (err); } static inline int search_dirblock(struct buffer_head *bh, struct inode *dir, const struct qstr *d_name, unsigned int offset, struct ext4_dir_entry_2 **res_dir) { return search_dir(bh, bh->b_data, dir->i_sb->s_blocksize, dir, d_name, offset, res_dir); } /* * Directory block splitting, compacting */ /* * Create map of hash values, offsets, and sizes, stored at end of block. * Returns number of entries mapped. */ static int dx_make_map(struct ext4_dir_entry_2 *de, unsigned blocksize, struct dx_hash_info *hinfo, struct dx_map_entry *map_tail) { int count = 0; char *base = (char *) de; struct dx_hash_info h = *hinfo; while ((char *) de < base + blocksize) { if (de->name_len && de->inode) { ext4fs_dirhash(de->name, de->name_len, &h); map_tail--; map_tail->hash = h.hash; map_tail->offs = ((char *) de - base)>>2; map_tail->size = le16_to_cpu(de->rec_len); count++; cond_resched(); } /* XXX: do we need to check rec_len == 0 case? -Chris */ de = ext4_next_entry(de, blocksize); } return count; } /* Sort map by hash value */ static void dx_sort_map (struct dx_map_entry *map, unsigned count) { struct dx_map_entry *p, *q, *top = map + count - 1; int more; /* Combsort until bubble sort doesn't suck */ while (count > 2) { count = count*10/13; if (count - 9 < 2) /* 9, 10 -> 11 */ count = 11; for (p = top, q = p - count; q >= map; p--, q--) if (p->hash < q->hash) swap(*p, *q); } /* Garden variety bubble sort */ do { more = 0; q = top; while (q-- > map) { if (q[1].hash >= q[0].hash) continue; swap(*(q+1), *q); more = 1; } } while(more); } static void dx_insert_block(struct dx_frame *frame, u32 hash, ext4_lblk_t block) { struct dx_entry *entries = frame->entries; struct dx_entry *old = frame->at, *new = old + 1; int count = dx_get_count(entries); assert(count < dx_get_limit(entries)); assert(old < entries + count); memmove(new + 1, new, (char *)(entries + count) - (char *)(new)); dx_set_hash(new, hash); dx_set_block(new, block); dx_set_count(entries, count + 1); } /* * NOTE! unlike strncmp, ext4_match returns 1 for success, 0 for failure. * * `len <= EXT4_NAME_LEN' is guaranteed by caller. * `de != NULL' is guaranteed by caller. */ static inline int ext4_match (int len, const char * const name, struct ext4_dir_entry_2 * de) { if (len != de->name_len) return 0; if (!de->inode) return 0; return !memcmp(name, de->name, len); } /* * Returns 0 if not found, -1 on failure, and 1 on success */ int search_dir(struct buffer_head *bh, char *search_buf, int buf_size, struct inode *dir, const struct qstr *d_name, unsigned int offset, struct ext4_dir_entry_2 **res_dir) { struct ext4_dir_entry_2 * de; char * dlimit; int de_len; const char *name = d_name->name; int namelen = d_name->len; de = (struct ext4_dir_entry_2 *)search_buf; dlimit = search_buf + buf_size; while ((char *) de < dlimit) { /* this code is executed quadratically often */ /* do minimal checking `by hand' */ if ((char *) de + namelen <= dlimit && ext4_match (namelen, name, de)) { /* found a match - just to be sure, do a full check */ if (ext4_check_dir_entry(dir, NULL, de, bh, bh->b_data, bh->b_size, offset)) return -1; *res_dir = de; return 1; } /* prevent looping on a bad block */ de_len = ext4_rec_len_from_disk(de->rec_len, dir->i_sb->s_blocksize); if (de_len <= 0) return -1; offset += de_len; de = (struct ext4_dir_entry_2 *) ((char *) de + de_len); } return 0; } static int is_dx_internal_node(struct inode *dir, ext4_lblk_t block, struct ext4_dir_entry *de) { struct super_block *sb = dir->i_sb; if (!is_dx(dir)) return 0; if (block == 0) return 1; if (de->inode == 0 && ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize) == sb->s_blocksize) return 1; return 0; } /* * ext4_find_entry() * * finds an entry in the specified directory with the wanted name. It * returns the cache buffer in which the entry was found, and the entry * itself (as a parameter - res_dir). It does NOT read the inode of the * entry - you'll have to do that yourself if you want to. * * The returned buffer_head has ->b_count elevated. The caller is expected * to brelse() it when appropriate. */ static struct buffer_head * ext4_find_entry (struct inode *dir, const struct qstr *d_name, struct ext4_dir_entry_2 **res_dir, int *inlined) { struct super_block *sb; struct buffer_head *bh_use[NAMEI_RA_SIZE]; struct buffer_head *bh, *ret = NULL; ext4_lblk_t start, block, b; const u8 *name = d_name->name; int ra_max = 0; /* Number of bh's in the readahead buffer, bh_use[] */ int ra_ptr = 0; /* Current index into readahead buffer */ int num = 0; ext4_lblk_t nblocks; int i, err; int namelen; *res_dir = NULL; sb = dir->i_sb; namelen = d_name->len; if (namelen > EXT4_NAME_LEN) return NULL; if (ext4_has_inline_data(dir)) { int has_inline_data = 1; ret = ext4_find_inline_entry(dir, d_name, res_dir, &has_inline_data); if (has_inline_data) { if (inlined) *inlined = 1; return ret; } } if ((namelen <= 2) && (name[0] == '.') && (name[1] == '.' || name[1] == '\0')) { /* * "." or ".." will only be in the first block * NFS may look up ".."; "." should be handled by the VFS */ block = start = 0; nblocks = 1; goto restart; } if (is_dx(dir)) { bh = ext4_dx_find_entry(dir, d_name, res_dir, &err); /* * On success, or if the error was file not found, * return. Otherwise, fall back to doing a search the * old fashioned way. */ if (bh || (err != ERR_BAD_DX_DIR)) return bh; dxtrace(printk(KERN_DEBUG "ext4_find_entry: dx failed, " "falling back\n")); } nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb); start = EXT4_I(dir)->i_dir_start_lookup; if (start >= nblocks) start = 0; block = start; restart: do { /* * We deal with the read-ahead logic here. */ if (ra_ptr >= ra_max) { /* Refill the readahead buffer */ ra_ptr = 0; b = block; for (ra_max = 0; ra_max < NAMEI_RA_SIZE; ra_max++) { /* * Terminate if we reach the end of the * directory and must wrap, or if our * search has finished at this block. */ if (b >= nblocks || (num && block == start)) { bh_use[ra_max] = NULL; break; } num++; bh = ext4_getblk(NULL, dir, b++, 0, &err); bh_use[ra_max] = bh; if (bh) ll_rw_block(READ | REQ_META | REQ_PRIO, 1, &bh); } } if ((bh = bh_use[ra_ptr++]) == NULL) goto next; wait_on_buffer(bh); if (!buffer_uptodate(bh)) { /* read error, skip block & hope for the best */ EXT4_ERROR_INODE(dir, "reading directory lblock %lu", (unsigned long) block); brelse(bh); goto next; } if (!buffer_verified(bh) && !is_dx_internal_node(dir, block, (struct ext4_dir_entry *)bh->b_data) && !ext4_dirent_csum_verify(dir, (struct ext4_dir_entry *)bh->b_data)) { EXT4_ERROR_INODE(dir, "checksumming directory " "block %lu", (unsigned long)block); brelse(bh); goto next; } set_buffer_verified(bh); i = search_dirblock(bh, dir, d_name, block << EXT4_BLOCK_SIZE_BITS(sb), res_dir); if (i == 1) { EXT4_I(dir)->i_dir_start_lookup = block; ret = bh; goto cleanup_and_exit; } else { brelse(bh); if (i < 0) goto cleanup_and_exit; } next: if (++block >= nblocks) block = 0; } while (block != start); /* * If the directory has grown while we were searching, then * search the last part of the directory before giving up. */ block = nblocks; nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb); if (block < nblocks) { start = 0; goto restart; } cleanup_and_exit: /* Clean up the read-ahead blocks */ for (; ra_ptr < ra_max; ra_ptr++) brelse(bh_use[ra_ptr]); return ret; } static struct buffer_head * ext4_dx_find_entry(struct inode *dir, const struct qstr *d_name, struct ext4_dir_entry_2 **res_dir, int *err) { struct super_block * sb = dir->i_sb; struct dx_hash_info hinfo; struct dx_frame frames[2], *frame; struct buffer_head *bh; ext4_lblk_t block; int retval; if (!(frame = dx_probe(d_name, dir, &hinfo, frames, err))) return NULL; do { block = dx_get_block(frame->at); bh = ext4_read_dirblock(dir, block, DIRENT); if (IS_ERR(bh)) { *err = PTR_ERR(bh); goto errout; } retval = search_dirblock(bh, dir, d_name, block << EXT4_BLOCK_SIZE_BITS(sb), res_dir); if (retval == 1) { /* Success! */ dx_release(frames); return bh; } brelse(bh); if (retval == -1) { *err = ERR_BAD_DX_DIR; goto errout; } /* Check to see if we should continue to search */ retval = ext4_htree_next_block(dir, hinfo.hash, frame, frames, NULL); if (retval < 0) { ext4_warning(sb, "error reading index page in directory #%lu", dir->i_ino); *err = retval; goto errout; } } while (retval == 1); *err = -ENOENT; errout: dxtrace(printk(KERN_DEBUG "%s not found\n", d_name->name)); dx_release (frames); return NULL; } static struct dentry *ext4_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags) { struct inode *inode; struct ext4_dir_entry_2 *de; struct buffer_head *bh; if (dentry->d_name.len > EXT4_NAME_LEN) return ERR_PTR(-ENAMETOOLONG); bh = ext4_find_entry(dir, &dentry->d_name, &de, NULL); inode = NULL; if (bh) { __u32 ino = le32_to_cpu(de->inode); brelse(bh); if (!ext4_valid_inum(dir->i_sb, ino)) { EXT4_ERROR_INODE(dir, "bad inode number: %u", ino); return ERR_PTR(-EIO); } if (unlikely(ino == dir->i_ino)) { EXT4_ERROR_INODE(dir, "'%pd' linked to parent dir", dentry); return ERR_PTR(-EIO); } inode = ext4_iget(dir->i_sb, ino); if (inode == ERR_PTR(-ESTALE)) { EXT4_ERROR_INODE(dir, "deleted inode referenced: %u", ino); return ERR_PTR(-EIO); } } return d_splice_alias(inode, dentry); } struct dentry *ext4_get_parent(struct dentry *child) { __u32 ino; static const struct qstr dotdot = QSTR_INIT("..", 2); struct ext4_dir_entry_2 * de; struct buffer_head *bh; bh = ext4_find_entry(child->d_inode, &dotdot, &de, NULL); if (!bh) return ERR_PTR(-ENOENT); ino = le32_to_cpu(de->inode); brelse(bh); if (!ext4_valid_inum(child->d_inode->i_sb, ino)) { EXT4_ERROR_INODE(child->d_inode, "bad parent inode number: %u", ino); return ERR_PTR(-EIO); } return d_obtain_alias(ext4_iget(child->d_inode->i_sb, ino)); } /* * Move count entries from end of map between two memory locations. * Returns pointer to last entry moved. */ static struct ext4_dir_entry_2 * dx_move_dirents(char *from, char *to, struct dx_map_entry *map, int count, unsigned blocksize) { unsigned rec_len = 0; while (count--) { struct ext4_dir_entry_2 *de = (struct ext4_dir_entry_2 *) (from + (map->offs<<2)); rec_len = EXT4_DIR_REC_LEN(de->name_len); memcpy (to, de, rec_len); ((struct ext4_dir_entry_2 *) to)->rec_len = ext4_rec_len_to_disk(rec_len, blocksize); de->inode = 0; map++; to += rec_len; } return (struct ext4_dir_entry_2 *) (to - rec_len); } /* * Compact each dir entry in the range to the minimal rec_len. * Returns pointer to last entry in range. */ static struct ext4_dir_entry_2* dx_pack_dirents(char *base, unsigned blocksize) { struct ext4_dir_entry_2 *next, *to, *prev, *de = (struct ext4_dir_entry_2 *) base; unsigned rec_len = 0; prev = to = de; while ((char*)de < base + blocksize) { next = ext4_next_entry(de, blocksize); if (de->inode && de->name_len) { rec_len = EXT4_DIR_REC_LEN(de->name_len); if (de > to) memmove(to, de, rec_len); to->rec_len = ext4_rec_len_to_disk(rec_len, blocksize); prev = to; to = (struct ext4_dir_entry_2 *) (((char *) to) + rec_len); } de = next; } return prev; } /* * Split a full leaf block to make room for a new dir entry. * Allocate a new block, and move entries so that they are approx. equally full. * Returns pointer to de in block into which the new entry will be inserted. */ static struct ext4_dir_entry_2 *do_split(handle_t *handle, struct inode *dir, struct buffer_head **bh,struct dx_frame *frame, struct dx_hash_info *hinfo, int *error) { unsigned blocksize = dir->i_sb->s_blocksize; unsigned count, continued; struct buffer_head *bh2; ext4_lblk_t newblock; u32 hash2; struct dx_map_entry *map; char *data1 = (*bh)->b_data, *data2; unsigned split, move, size; struct ext4_dir_entry_2 *de = NULL, *de2; struct ext4_dir_entry_tail *t; int csum_size = 0; int err = 0, i; if (EXT4_HAS_RO_COMPAT_FEATURE(dir->i_sb, EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) csum_size = sizeof(struct ext4_dir_entry_tail); bh2 = ext4_append(handle, dir, &newblock); if (IS_ERR(bh2)) { brelse(*bh); *bh = NULL; *error = PTR_ERR(bh2); return NULL; } BUFFER_TRACE(*bh, "get_write_access"); err = ext4_journal_get_write_access(handle, *bh); if (err) goto journal_error; BUFFER_TRACE(frame->bh, "get_write_access"); err = ext4_journal_get_write_access(handle, frame->bh); if (err) goto journal_error; data2 = bh2->b_data; /* create map in the end of data2 block */ map = (struct dx_map_entry *) (data2 + blocksize); count = dx_make_map((struct ext4_dir_entry_2 *) data1, blocksize, hinfo, map); map -= count; dx_sort_map(map, count); /* Split the existing block in the middle, size-wise */ size = 0; move = 0; for (i = count-1; i >= 0; i--) { /* is more than half of this entry in 2nd half of the block? */ if (size + map[i].size/2 > blocksize/2) break; size += map[i].size; move++; } /* map index at which we will split */ split = count - move; hash2 = map[split].hash; continued = hash2 == map[split - 1].hash; dxtrace(printk(KERN_INFO "Split block %lu at %x, %i/%i\n", (unsigned long)dx_get_block(frame->at), hash2, split, count-split)); /* Fancy dance to stay within two buffers */ de2 = dx_move_dirents(data1, data2, map + split, count - split, blocksize); de = dx_pack_dirents(data1, blocksize); de->rec_len = ext4_rec_len_to_disk(data1 + (blocksize - csum_size) - (char *) de, blocksize); de2->rec_len = ext4_rec_len_to_disk(data2 + (blocksize - csum_size) - (char *) de2, blocksize); if (csum_size) { t = EXT4_DIRENT_TAIL(data2, blocksize); initialize_dirent_tail(t, blocksize); t = EXT4_DIRENT_TAIL(data1, blocksize); initialize_dirent_tail(t, blocksize); } dxtrace(dx_show_leaf (hinfo, (struct ext4_dir_entry_2 *) data1, blocksize, 1)); dxtrace(dx_show_leaf (hinfo, (struct ext4_dir_entry_2 *) data2, blocksize, 1)); /* Which block gets the new entry? */ if (hinfo->hash >= hash2) { swap(*bh, bh2); de = de2; } dx_insert_block(frame, hash2 + continued, newblock); err = ext4_handle_dirty_dirent_node(handle, dir, bh2); if (err) goto journal_error; err = ext4_handle_dirty_dx_node(handle, dir, frame->bh); if (err) goto journal_error; brelse(bh2); dxtrace(dx_show_index("frame", frame->entries)); return de; journal_error: brelse(*bh); brelse(bh2); *bh = NULL; ext4_std_error(dir->i_sb, err); *error = err; return NULL; } int ext4_find_dest_de(struct inode *dir, struct inode *inode, struct buffer_head *bh, void *buf, int buf_size, const char *name, int namelen, struct ext4_dir_entry_2 **dest_de) { struct ext4_dir_entry_2 *de; unsigned short reclen = EXT4_DIR_REC_LEN(namelen); int nlen, rlen; unsigned int offset = 0; char *top; de = (struct ext4_dir_entry_2 *)buf; top = buf + buf_size - reclen; while ((char *) de <= top) { if (ext4_check_dir_entry(dir, NULL, de, bh, buf, buf_size, offset)) return -EIO; if (ext4_match(namelen, name, de)) return -EEXIST; nlen = EXT4_DIR_REC_LEN(de->name_len); rlen = ext4_rec_len_from_disk(de->rec_len, buf_size); if ((de->inode ? rlen - nlen : rlen) >= reclen) break; de = (struct ext4_dir_entry_2 *)((char *)de + rlen); offset += rlen; } if ((char *) de > top) return -ENOSPC; *dest_de = de; return 0; } void ext4_insert_dentry(struct inode *inode, struct ext4_dir_entry_2 *de, int buf_size, const char *name, int namelen) { int nlen, rlen; nlen = EXT4_DIR_REC_LEN(de->name_len); rlen = ext4_rec_len_from_disk(de->rec_len, buf_size); if (de->inode) { struct ext4_dir_entry_2 *de1 = (struct ext4_dir_entry_2 *)((char *)de + nlen); de1->rec_len = ext4_rec_len_to_disk(rlen - nlen, buf_size); de->rec_len = ext4_rec_len_to_disk(nlen, buf_size); de = de1; } de->file_type = EXT4_FT_UNKNOWN; de->inode = cpu_to_le32(inode->i_ino); ext4_set_de_type(inode->i_sb, de, inode->i_mode); de->name_len = namelen; memcpy(de->name, name, namelen); } /* * Add a new entry into a directory (leaf) block. If de is non-NULL, * it points to a directory entry which is guaranteed to be large * enough for new directory entry. If de is NULL, then * add_dirent_to_buf will attempt search the directory block for * space. It will return -ENOSPC if no space is available, and -EIO * and -EEXIST if directory entry already exists. */ static int add_dirent_to_buf(handle_t *handle, struct dentry *dentry, struct inode *inode, struct ext4_dir_entry_2 *de, struct buffer_head *bh) { struct inode *dir = dentry->d_parent->d_inode; const char *name = dentry->d_name.name; int namelen = dentry->d_name.len; unsigned int blocksize = dir->i_sb->s_blocksize; int csum_size = 0; int err; if (EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb, EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) csum_size = sizeof(struct ext4_dir_entry_tail); if (!de) { err = ext4_find_dest_de(dir, inode, bh, bh->b_data, blocksize - csum_size, name, namelen, &de); if (err) return err; } BUFFER_TRACE(bh, "get_write_access"); err = ext4_journal_get_write_access(handle, bh); if (err) { ext4_std_error(dir->i_sb, err); return err; } /* By now the buffer is marked for journaling */ ext4_insert_dentry(inode, de, blocksize, name, namelen); /* * XXX shouldn't update any times until successful * completion of syscall, but too many callers depend * on this. * * XXX similarly, too many callers depend on * ext4_new_inode() setting the times, but error * recovery deletes the inode, so the worst that can * happen is that the times are slightly out of date * and/or different from the directory change time. */ dir->i_mtime = dir->i_ctime = ext4_current_time(dir); ext4_update_dx_flag(dir); dir->i_version++; ext4_mark_inode_dirty(handle, dir); BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata"); err = ext4_handle_dirty_dirent_node(handle, dir, bh); if (err) ext4_std_error(dir->i_sb, err); return 0; } /* * This converts a one block unindexed directory to a 3 block indexed * directory, and adds the dentry to the indexed directory. */ static int make_indexed_dir(handle_t *handle, struct dentry *dentry, struct inode *inode, struct buffer_head *bh) { struct inode *dir = dentry->d_parent->d_inode; const char *name = dentry->d_name.name; int namelen = dentry->d_name.len; struct buffer_head *bh2; struct dx_root *root; struct dx_frame frames[2], *frame; struct dx_entry *entries; struct ext4_dir_entry_2 *de, *de2; struct ext4_dir_entry_tail *t; char *data1, *top; unsigned len; int retval; unsigned blocksize; struct dx_hash_info hinfo; ext4_lblk_t block; struct fake_dirent *fde; int csum_size = 0; if (EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb, EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) csum_size = sizeof(struct ext4_dir_entry_tail); blocksize = dir->i_sb->s_blocksize; dxtrace(printk(KERN_DEBUG "Creating index: inode %lu\n", dir->i_ino)); retval = ext4_journal_get_write_access(handle, bh); if (retval) { ext4_std_error(dir->i_sb, retval); brelse(bh); return retval; } root = (struct dx_root *) bh->b_data; /* The 0th block becomes the root, move the dirents out */ fde = &root->dotdot; de = (struct ext4_dir_entry_2 *)((char *)fde + ext4_rec_len_from_disk(fde->rec_len, blocksize)); if ((char *) de >= (((char *) root) + blocksize)) { EXT4_ERROR_INODE(dir, "invalid rec_len for '..'"); brelse(bh); return -EIO; } len = ((char *) root) + (blocksize - csum_size) - (char *) de; /* Allocate new block for the 0th block's dirents */ bh2 = ext4_append(handle, dir, &block); if (IS_ERR(bh2)) { brelse(bh); return PTR_ERR(bh2); } ext4_set_inode_flag(dir, EXT4_INODE_INDEX); data1 = bh2->b_data; memcpy (data1, de, len); de = (struct ext4_dir_entry_2 *) data1; top = data1 + len; while ((char *)(de2 = ext4_next_entry(de, blocksize)) < top) de = de2; de->rec_len = ext4_rec_len_to_disk(data1 + (blocksize - csum_size) - (char *) de, blocksize); if (csum_size) { t = EXT4_DIRENT_TAIL(data1, blocksize); initialize_dirent_tail(t, blocksize); } /* Initialize the root; the dot dirents already exist */ de = (struct ext4_dir_entry_2 *) (&root->dotdot); de->rec_len = ext4_rec_len_to_disk(blocksize - EXT4_DIR_REC_LEN(2), blocksize); memset (&root->info, 0, sizeof(root->info)); root->info.info_length = sizeof(root->info); root->info.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version; entries = root->entries; dx_set_block(entries, 1); dx_set_count(entries, 1); dx_set_limit(entries, dx_root_limit(dir, sizeof(root->info))); /* Initialize as for dx_probe */ hinfo.hash_version = root->info.hash_version; if (hinfo.hash_version <= DX_HASH_TEA) hinfo.hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned; hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed; ext4fs_dirhash(name, namelen, &hinfo); frame = frames; frame->entries = entries; frame->at = entries; frame->bh = bh; bh = bh2; ext4_handle_dirty_dx_node(handle, dir, frame->bh); ext4_handle_dirty_dirent_node(handle, dir, bh); de = do_split(handle,dir, &bh, frame, &hinfo, &retval); if (!de) { /* * Even if the block split failed, we have to properly write * out all the changes we did so far. Otherwise we can end up * with corrupted filesystem. */ ext4_mark_inode_dirty(handle, dir); dx_release(frames); return retval; } dx_release(frames); retval = add_dirent_to_buf(handle, dentry, inode, de, bh); brelse(bh); return retval; } /* * ext4_add_entry() * * adds a file entry to the specified directory, using the same * semantics as ext4_find_entry(). It returns NULL if it failed. * * NOTE!! The inode part of 'de' is left at 0 - which means you * may not sleep between calling this and putting something into * the entry, as someone else might have used it while you slept. */ static int ext4_add_entry(handle_t *handle, struct dentry *dentry, struct inode *inode) { struct inode *dir = dentry->d_parent->d_inode; struct buffer_head *bh; struct ext4_dir_entry_2 *de; struct ext4_dir_entry_tail *t; struct super_block *sb; int retval; int dx_fallback=0; unsigned blocksize; ext4_lblk_t block, blocks; int csum_size = 0; if (EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb, EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) csum_size = sizeof(struct ext4_dir_entry_tail); sb = dir->i_sb; blocksize = sb->s_blocksize; if (!dentry->d_name.len) return -EINVAL; if (ext4_has_inline_data(dir)) { retval = ext4_try_add_inline_entry(handle, dentry, inode); if (retval < 0) return retval; if (retval == 1) { retval = 0; return retval; } } if (is_dx(dir)) { retval = ext4_dx_add_entry(handle, dentry, inode); if (!retval || (retval != ERR_BAD_DX_DIR)) return retval; ext4_clear_inode_flag(dir, EXT4_INODE_INDEX); dx_fallback++; ext4_mark_inode_dirty(handle, dir); } blocks = dir->i_size >> sb->s_blocksize_bits; for (block = 0; block < blocks; block++) { bh = ext4_read_dirblock(dir, block, DIRENT); if (IS_ERR(bh)) return PTR_ERR(bh); retval = add_dirent_to_buf(handle, dentry, inode, NULL, bh); if (retval != -ENOSPC) { brelse(bh); return retval; } if (blocks == 1 && !dx_fallback && EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_DIR_INDEX)) return make_indexed_dir(handle, dentry, inode, bh); brelse(bh); } bh = ext4_append(handle, dir, &block); if (IS_ERR(bh)) return PTR_ERR(bh); de = (struct ext4_dir_entry_2 *) bh->b_data; de->inode = 0; de->rec_len = ext4_rec_len_to_disk(blocksize - csum_size, blocksize); if (csum_size) { t = EXT4_DIRENT_TAIL(bh->b_data, blocksize); initialize_dirent_tail(t, blocksize); } retval = add_dirent_to_buf(handle, dentry, inode, de, bh); brelse(bh); if (retval == 0) ext4_set_inode_state(inode, EXT4_STATE_NEWENTRY); return retval; } /* * Returns 0 for success, or a negative error value */ static int ext4_dx_add_entry(handle_t *handle, struct dentry *dentry, struct inode *inode) { struct dx_frame frames[2], *frame; struct dx_entry *entries, *at; struct dx_hash_info hinfo; struct buffer_head *bh; struct inode *dir = dentry->d_parent->d_inode; struct super_block *sb = dir->i_sb; struct ext4_dir_entry_2 *de; int err; frame = dx_probe(&dentry->d_name, dir, &hinfo, frames, &err); if (!frame) return err; entries = frame->entries; at = frame->at; bh = ext4_read_dirblock(dir, dx_get_block(frame->at), DIRENT); if (IS_ERR(bh)) { err = PTR_ERR(bh); bh = NULL; goto cleanup; } BUFFER_TRACE(bh, "get_write_access"); err = ext4_journal_get_write_access(handle, bh); if (err) goto journal_error; err = add_dirent_to_buf(handle, dentry, inode, NULL, bh); if (err != -ENOSPC) goto cleanup; /* Block full, should compress but for now just split */ dxtrace(printk(KERN_DEBUG "using %u of %u node entries\n", dx_get_count(entries), dx_get_limit(entries))); /* Need to split index? */ if (dx_get_count(entries) == dx_get_limit(entries)) { ext4_lblk_t newblock; unsigned icount = dx_get_count(entries); int levels = frame - frames; struct dx_entry *entries2; struct dx_node *node2; struct buffer_head *bh2; if (levels && (dx_get_count(frames->entries) == dx_get_limit(frames->entries))) { ext4_warning(sb, "Directory index full!"); err = -ENOSPC; goto cleanup; } bh2 = ext4_append(handle, dir, &newblock); if (IS_ERR(bh2)) { err = PTR_ERR(bh2); goto cleanup; } node2 = (struct dx_node *)(bh2->b_data); entries2 = node2->entries; memset(&node2->fake, 0, sizeof(struct fake_dirent)); node2->fake.rec_len = ext4_rec_len_to_disk(sb->s_blocksize, sb->s_blocksize); BUFFER_TRACE(frame->bh, "get_write_access"); err = ext4_journal_get_write_access(handle, frame->bh); if (err) goto journal_error; if (levels) { unsigned icount1 = icount/2, icount2 = icount - icount1; unsigned hash2 = dx_get_hash(entries + icount1); dxtrace(printk(KERN_DEBUG "Split index %i/%i\n", icount1, icount2)); BUFFER_TRACE(frame->bh, "get_write_access"); /* index root */ err = ext4_journal_get_write_access(handle, frames[0].bh); if (err) goto journal_error; memcpy((char *) entries2, (char *) (entries + icount1), icount2 * sizeof(struct dx_entry)); dx_set_count(entries, icount1); dx_set_count(entries2, icount2); dx_set_limit(entries2, dx_node_limit(dir)); /* Which index block gets the new entry? */ if (at - entries >= icount1) { frame->at = at = at - entries - icount1 + entries2; frame->entries = entries = entries2; swap(frame->bh, bh2); } dx_insert_block(frames + 0, hash2, newblock); dxtrace(dx_show_index("node", frames[1].entries)); dxtrace(dx_show_index("node", ((struct dx_node *) bh2->b_data)->entries)); err = ext4_handle_dirty_dx_node(handle, dir, bh2); if (err) goto journal_error; brelse (bh2); } else { dxtrace(printk(KERN_DEBUG "Creating second level index...\n")); memcpy((char *) entries2, (char *) entries, icount * sizeof(struct dx_entry)); dx_set_limit(entries2, dx_node_limit(dir)); /* Set up root */ dx_set_count(entries, 1); dx_set_block(entries + 0, newblock); ((struct dx_root *) frames[0].bh->b_data)->info.indirect_levels = 1; /* Add new access path frame */ frame = frames + 1; frame->at = at = at - entries + entries2; frame->entries = entries = entries2; frame->bh = bh2; err = ext4_journal_get_write_access(handle, frame->bh); if (err) goto journal_error; } err = ext4_handle_dirty_dx_node(handle, dir, frames[0].bh); if (err) { ext4_std_error(inode->i_sb, err); goto cleanup; } } de = do_split(handle, dir, &bh, frame, &hinfo, &err); if (!de) goto cleanup; err = add_dirent_to_buf(handle, dentry, inode, de, bh); goto cleanup; journal_error: ext4_std_error(dir->i_sb, err); cleanup: brelse(bh); dx_release(frames); return err; } /* * ext4_generic_delete_entry deletes a directory entry by merging it * with the previous entry */ int ext4_generic_delete_entry(handle_t *handle, struct inode *dir, struct ext4_dir_entry_2 *de_del, struct buffer_head *bh, void *entry_buf, int buf_size, int csum_size) { struct ext4_dir_entry_2 *de, *pde; unsigned int blocksize = dir->i_sb->s_blocksize; int i; i = 0; pde = NULL; de = (struct ext4_dir_entry_2 *)entry_buf; while (i < buf_size - csum_size) { if (ext4_check_dir_entry(dir, NULL, de, bh, bh->b_data, bh->b_size, i)) return -EIO; if (de == de_del) { if (pde) pde->rec_len = ext4_rec_len_to_disk( ext4_rec_len_from_disk(pde->rec_len, blocksize) + ext4_rec_len_from_disk(de->rec_len, blocksize), blocksize); else de->inode = 0; dir->i_version++; return 0; } i += ext4_rec_len_from_disk(de->rec_len, blocksize); pde = de; de = ext4_next_entry(de, blocksize); } return -ENOENT; } static int ext4_delete_entry(handle_t *handle, struct inode *dir, struct ext4_dir_entry_2 *de_del, struct buffer_head *bh) { int err, csum_size = 0; if (ext4_has_inline_data(dir)) { int has_inline_data = 1; err = ext4_delete_inline_entry(handle, dir, de_del, bh, &has_inline_data); if (has_inline_data) return err; } if (EXT4_HAS_RO_COMPAT_FEATURE(dir->i_sb, EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) csum_size = sizeof(struct ext4_dir_entry_tail); BUFFER_TRACE(bh, "get_write_access"); err = ext4_journal_get_write_access(handle, bh); if (unlikely(err)) goto out; err = ext4_generic_delete_entry(handle, dir, de_del, bh, bh->b_data, dir->i_sb->s_blocksize, csum_size); if (err) goto out; BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata"); err = ext4_handle_dirty_dirent_node(handle, dir, bh); if (unlikely(err)) goto out; return 0; out: if (err != -ENOENT) ext4_std_error(dir->i_sb, err); return err; } /* * DIR_NLINK feature is set if 1) nlinks > EXT4_LINK_MAX or 2) nlinks == 2, * since this indicates that nlinks count was previously 1. */ static void ext4_inc_count(handle_t *handle, struct inode *inode) { inc_nlink(inode); if (is_dx(inode) && inode->i_nlink > 1) { /* limit is 16-bit i_links_count */ if (inode->i_nlink >= EXT4_LINK_MAX || inode->i_nlink == 2) { set_nlink(inode, 1); EXT4_SET_RO_COMPAT_FEATURE(inode->i_sb, EXT4_FEATURE_RO_COMPAT_DIR_NLINK); } } } /* * If a directory had nlink == 1, then we should let it be 1. This indicates * directory has >EXT4_LINK_MAX subdirs. */ static void ext4_dec_count(handle_t *handle, struct inode *inode) { if (!S_ISDIR(inode->i_mode) || inode->i_nlink > 2) drop_nlink(inode); } static int ext4_add_nondir(handle_t *handle, struct dentry *dentry, struct inode *inode) { int err = ext4_add_entry(handle, dentry, inode); if (!err) { ext4_mark_inode_dirty(handle, inode); unlock_new_inode(inode); d_instantiate(dentry, inode); return 0; } drop_nlink(inode); unlock_new_inode(inode); iput(inode); return err; } /* * By the time this is called, we already have created * the directory cache entry for the new file, but it * is so far negative - it has no inode. * * If the create succeeds, we fill in the inode information * with d_instantiate(). */ static int ext4_create(struct inode *dir, struct dentry *dentry, umode_t mode, bool excl) { handle_t *handle; struct inode *inode; int err, credits, retries = 0; dquot_initialize(dir); credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) + EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3); retry: inode = ext4_new_inode_start_handle(dir, mode, &dentry->d_name, 0, NULL, EXT4_HT_DIR, credits); handle = ext4_journal_current_handle(); err = PTR_ERR(inode); if (!IS_ERR(inode)) { inode->i_op = &ext4_file_inode_operations; inode->i_fop = &ext4_file_operations; ext4_set_aops(inode); err = ext4_add_nondir(handle, dentry, inode); if (!err && IS_DIRSYNC(dir)) ext4_handle_sync(handle); } if (handle) ext4_journal_stop(handle); if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries)) goto retry; return err; } static int ext4_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t rdev) { handle_t *handle; struct inode *inode; int err, credits, retries = 0; if (!new_valid_dev(rdev)) return -EINVAL; dquot_initialize(dir); credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) + EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3); retry: inode = ext4_new_inode_start_handle(dir, mode, &dentry->d_name, 0, NULL, EXT4_HT_DIR, credits); handle = ext4_journal_current_handle(); err = PTR_ERR(inode); if (!IS_ERR(inode)) { init_special_inode(inode, inode->i_mode, rdev); inode->i_op = &ext4_special_inode_operations; err = ext4_add_nondir(handle, dentry, inode); if (!err && IS_DIRSYNC(dir)) ext4_handle_sync(handle); } if (handle) ext4_journal_stop(handle); if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries)) goto retry; return err; } static int ext4_tmpfile(struct inode *dir, struct dentry *dentry, umode_t mode) { handle_t *handle; struct inode *inode; int err, retries = 0; dquot_initialize(dir); retry: inode = ext4_new_inode_start_handle(dir, mode, NULL, 0, NULL, EXT4_HT_DIR, EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb) + 4 + EXT4_XATTR_TRANS_BLOCKS); handle = ext4_journal_current_handle(); err = PTR_ERR(inode); if (!IS_ERR(inode)) { inode->i_op = &ext4_file_inode_operations; inode->i_fop = &ext4_file_operations; ext4_set_aops(inode); d_tmpfile(dentry, inode); err = ext4_orphan_add(handle, inode); if (err) goto err_unlock_inode; mark_inode_dirty(inode); unlock_new_inode(inode); } if (handle) ext4_journal_stop(handle); if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries)) goto retry; return err; err_unlock_inode: ext4_journal_stop(handle); unlock_new_inode(inode); return err; } struct ext4_dir_entry_2 *ext4_init_dot_dotdot(struct inode *inode, struct ext4_dir_entry_2 *de, int blocksize, int csum_size, unsigned int parent_ino, int dotdot_real_len) { de->inode = cpu_to_le32(inode->i_ino); de->name_len = 1; de->rec_len = ext4_rec_len_to_disk(EXT4_DIR_REC_LEN(de->name_len), blocksize); strcpy(de->name, "."); ext4_set_de_type(inode->i_sb, de, S_IFDIR); de = ext4_next_entry(de, blocksize); de->inode = cpu_to_le32(parent_ino); de->name_len = 2; if (!dotdot_real_len) de->rec_len = ext4_rec_len_to_disk(blocksize - (csum_size + EXT4_DIR_REC_LEN(1)), blocksize); else de->rec_len = ext4_rec_len_to_disk( EXT4_DIR_REC_LEN(de->name_len), blocksize); strcpy(de->name, ".."); ext4_set_de_type(inode->i_sb, de, S_IFDIR); return ext4_next_entry(de, blocksize); } static int ext4_init_new_dir(handle_t *handle, struct inode *dir, struct inode *inode) { struct buffer_head *dir_block = NULL; struct ext4_dir_entry_2 *de; struct ext4_dir_entry_tail *t; ext4_lblk_t block = 0; unsigned int blocksize = dir->i_sb->s_blocksize; int csum_size = 0; int err; if (EXT4_HAS_RO_COMPAT_FEATURE(dir->i_sb, EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) csum_size = sizeof(struct ext4_dir_entry_tail); if (ext4_test_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA)) { err = ext4_try_create_inline_dir(handle, dir, inode); if (err < 0 && err != -ENOSPC) goto out; if (!err) goto out; } inode->i_size = 0; dir_block = ext4_append(handle, inode, &block); if (IS_ERR(dir_block)) return PTR_ERR(dir_block); BUFFER_TRACE(dir_block, "get_write_access"); err = ext4_journal_get_write_access(handle, dir_block); if (err) goto out; de = (struct ext4_dir_entry_2 *)dir_block->b_data; ext4_init_dot_dotdot(inode, de, blocksize, csum_size, dir->i_ino, 0); set_nlink(inode, 2); if (csum_size) { t = EXT4_DIRENT_TAIL(dir_block->b_data, blocksize); initialize_dirent_tail(t, blocksize); } BUFFER_TRACE(dir_block, "call ext4_handle_dirty_metadata"); err = ext4_handle_dirty_dirent_node(handle, inode, dir_block); if (err) goto out; set_buffer_verified(dir_block); out: brelse(dir_block); return err; } static int ext4_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode) { handle_t *handle; struct inode *inode; int err, credits, retries = 0; if (EXT4_DIR_LINK_MAX(dir)) return -EMLINK; dquot_initialize(dir); credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) + EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3); retry: inode = ext4_new_inode_start_handle(dir, S_IFDIR | mode, &dentry->d_name, 0, NULL, EXT4_HT_DIR, credits); handle = ext4_journal_current_handle(); err = PTR_ERR(inode); if (IS_ERR(inode)) goto out_stop; inode->i_op = &ext4_dir_inode_operations; inode->i_fop = &ext4_dir_operations; err = ext4_init_new_dir(handle, dir, inode); if (err) goto out_clear_inode; err = ext4_mark_inode_dirty(handle, inode); if (!err) err = ext4_add_entry(handle, dentry, inode); if (err) { out_clear_inode: clear_nlink(inode); unlock_new_inode(inode); ext4_mark_inode_dirty(handle, inode); iput(inode); goto out_stop; } ext4_inc_count(handle, dir); ext4_update_dx_flag(dir); err = ext4_mark_inode_dirty(handle, dir); if (err) goto out_clear_inode; unlock_new_inode(inode); d_instantiate(dentry, inode); if (IS_DIRSYNC(dir)) ext4_handle_sync(handle); out_stop: if (handle) ext4_journal_stop(handle); if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries)) goto retry; return err; } /* * routine to check that the specified directory is empty (for rmdir) */ static int empty_dir(struct inode *inode) { unsigned int offset; struct buffer_head *bh; struct ext4_dir_entry_2 *de, *de1; struct super_block *sb; int err = 0; if (ext4_has_inline_data(inode)) { int has_inline_data = 1; err = empty_inline_dir(inode, &has_inline_data); if (has_inline_data) return err; } sb = inode->i_sb; if (inode->i_size < EXT4_DIR_REC_LEN(1) + EXT4_DIR_REC_LEN(2)) { EXT4_ERROR_INODE(inode, "invalid size"); return 1; } bh = ext4_read_dirblock(inode, 0, EITHER); if (IS_ERR(bh)) return 1; de = (struct ext4_dir_entry_2 *) bh->b_data; de1 = ext4_next_entry(de, sb->s_blocksize); if (le32_to_cpu(de->inode) != inode->i_ino || !le32_to_cpu(de1->inode) || strcmp(".", de->name) || strcmp("..", de1->name)) { ext4_warning(inode->i_sb, "bad directory (dir #%lu) - no `.' or `..'", inode->i_ino); brelse(bh); return 1; } offset = ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize) + ext4_rec_len_from_disk(de1->rec_len, sb->s_blocksize); de = ext4_next_entry(de1, sb->s_blocksize); while (offset < inode->i_size) { if (!bh || (void *) de >= (void *) (bh->b_data+sb->s_blocksize)) { unsigned int lblock; err = 0; brelse(bh); lblock = offset >> EXT4_BLOCK_SIZE_BITS(sb); bh = ext4_read_dirblock(inode, lblock, EITHER); if (IS_ERR(bh)) return 1; de = (struct ext4_dir_entry_2 *) bh->b_data; } if (ext4_check_dir_entry(inode, NULL, de, bh, bh->b_data, bh->b_size, offset)) { de = (struct ext4_dir_entry_2 *)(bh->b_data + sb->s_blocksize); offset = (offset | (sb->s_blocksize - 1)) + 1; continue; } if (le32_to_cpu(de->inode)) { brelse(bh); return 0; } offset += ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize); de = ext4_next_entry(de, sb->s_blocksize); } brelse(bh); return 1; } /* ext4_orphan_add() links an unlinked or truncated inode into a list of * such inodes, starting at the superblock, in case we crash before the * file is closed/deleted, or in case the inode truncate spans multiple * transactions and the last transaction is not recovered after a crash. * * At filesystem recovery time, we walk this list deleting unlinked * inodes and truncating linked inodes in ext4_orphan_cleanup(). */ int ext4_orphan_add(handle_t *handle, struct inode *inode) { struct super_block *sb = inode->i_sb; struct ext4_iloc iloc; int err = 0, rc; if (!EXT4_SB(sb)->s_journal) return 0; mutex_lock(&EXT4_SB(sb)->s_orphan_lock); if (!list_empty(&EXT4_I(inode)->i_orphan)) goto out_unlock; /* * Orphan handling is only valid for files with data blocks * being truncated, or files being unlinked. Note that we either * hold i_mutex, or the inode can not be referenced from outside, * so i_nlink should not be bumped due to race */ J_ASSERT((S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode)) || inode->i_nlink == 0); BUFFER_TRACE(EXT4_SB(sb)->s_sbh, "get_write_access"); err = ext4_journal_get_write_access(handle, EXT4_SB(sb)->s_sbh); if (err) goto out_unlock; err = ext4_reserve_inode_write(handle, inode, &iloc); if (err) goto out_unlock; /* * Due to previous errors inode may be already a part of on-disk * orphan list. If so skip on-disk list modification. */ if (NEXT_ORPHAN(inode) && NEXT_ORPHAN(inode) <= (le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count))) goto mem_insert; /* Insert this inode at the head of the on-disk orphan list... */ NEXT_ORPHAN(inode) = le32_to_cpu(EXT4_SB(sb)->s_es->s_last_orphan); EXT4_SB(sb)->s_es->s_last_orphan = cpu_to_le32(inode->i_ino); err = ext4_handle_dirty_super(handle, sb); rc = ext4_mark_iloc_dirty(handle, inode, &iloc); if (!err) err = rc; /* Only add to the head of the in-memory list if all the * previous operations succeeded. If the orphan_add is going to * fail (possibly taking the journal offline), we can't risk * leaving the inode on the orphan list: stray orphan-list * entries can cause panics at unmount time. * * This is safe: on error we're going to ignore the orphan list * anyway on the next recovery. */ mem_insert: if (!err) list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan); jbd_debug(4, "superblock will point to %lu\n", inode->i_ino); jbd_debug(4, "orphan inode %lu will point to %d\n", inode->i_ino, NEXT_ORPHAN(inode)); out_unlock: mutex_unlock(&EXT4_SB(sb)->s_orphan_lock); ext4_std_error(inode->i_sb, err); return err; } /* * ext4_orphan_del() removes an unlinked or truncated inode from the list * of such inodes stored on disk, because it is finally being cleaned up. */ int ext4_orphan_del(handle_t *handle, struct inode *inode) { struct list_head *prev; struct ext4_inode_info *ei = EXT4_I(inode); struct ext4_sb_info *sbi; __u32 ino_next; struct ext4_iloc iloc; int err = 0; if ((!EXT4_SB(inode->i_sb)->s_journal) && !(EXT4_SB(inode->i_sb)->s_mount_state & EXT4_ORPHAN_FS)) return 0; mutex_lock(&EXT4_SB(inode->i_sb)->s_orphan_lock); if (list_empty(&ei->i_orphan)) goto out; ino_next = NEXT_ORPHAN(inode); prev = ei->i_orphan.prev; sbi = EXT4_SB(inode->i_sb); jbd_debug(4, "remove inode %lu from orphan list\n", inode->i_ino); list_del_init(&ei->i_orphan); /* If we're on an error path, we may not have a valid * transaction handle with which to update the orphan list on * disk, but we still need to remove the inode from the linked * list in memory. */ if (!handle) goto out; err = ext4_reserve_inode_write(handle, inode, &iloc); if (err) goto out_err; if (prev == &sbi->s_orphan) { jbd_debug(4, "superblock will point to %u\n", ino_next); BUFFER_TRACE(sbi->s_sbh, "get_write_access"); err = ext4_journal_get_write_access(handle, sbi->s_sbh); if (err) goto out_brelse; sbi->s_es->s_last_orphan = cpu_to_le32(ino_next); err = ext4_handle_dirty_super(handle, inode->i_sb); } else { struct ext4_iloc iloc2; struct inode *i_prev = &list_entry(prev, struct ext4_inode_info, i_orphan)->vfs_inode; jbd_debug(4, "orphan inode %lu will point to %u\n", i_prev->i_ino, ino_next); err = ext4_reserve_inode_write(handle, i_prev, &iloc2); if (err) goto out_brelse; NEXT_ORPHAN(i_prev) = ino_next; err = ext4_mark_iloc_dirty(handle, i_prev, &iloc2); } if (err) goto out_brelse; NEXT_ORPHAN(inode) = 0; err = ext4_mark_iloc_dirty(handle, inode, &iloc); out_err: ext4_std_error(inode->i_sb, err); out: mutex_unlock(&EXT4_SB(inode->i_sb)->s_orphan_lock); return err; out_brelse: brelse(iloc.bh); goto out_err; } static int ext4_rmdir(struct inode *dir, struct dentry *dentry) { int retval; struct inode *inode; struct buffer_head *bh; struct ext4_dir_entry_2 *de; handle_t *handle = NULL; /* Initialize quotas before so that eventual writes go in * separate transaction */ dquot_initialize(dir); dquot_initialize(dentry->d_inode); retval = -ENOENT; bh = ext4_find_entry(dir, &dentry->d_name, &de, NULL); if (!bh) goto end_rmdir; inode = dentry->d_inode; retval = -EIO; if (le32_to_cpu(de->inode) != inode->i_ino) goto end_rmdir; retval = -ENOTEMPTY; if (!empty_dir(inode)) goto end_rmdir; handle = ext4_journal_start(dir, EXT4_HT_DIR, EXT4_DATA_TRANS_BLOCKS(dir->i_sb)); if (IS_ERR(handle)) { retval = PTR_ERR(handle); handle = NULL; goto end_rmdir; } if (IS_DIRSYNC(dir)) ext4_handle_sync(handle); retval = ext4_delete_entry(handle, dir, de, bh); if (retval) goto end_rmdir; if (!EXT4_DIR_LINK_EMPTY(inode)) ext4_warning(inode->i_sb, "empty directory has too many links (%d)", inode->i_nlink); inode->i_version++; clear_nlink(inode); /* There's no need to set i_disksize: the fact that i_nlink is * zero will ensure that the right thing happens during any * recovery. */ inode->i_size = 0; ext4_orphan_add(handle, inode); inode->i_ctime = dir->i_ctime = dir->i_mtime = ext4_current_time(inode); ext4_mark_inode_dirty(handle, inode); ext4_dec_count(handle, dir); ext4_update_dx_flag(dir); ext4_mark_inode_dirty(handle, dir); end_rmdir: brelse(bh); if (handle) ext4_journal_stop(handle); return retval; } static int ext4_unlink(struct inode *dir, struct dentry *dentry) { int retval; struct inode *inode; struct buffer_head *bh; struct ext4_dir_entry_2 *de; handle_t *handle = NULL; trace_ext4_unlink_enter(dir, dentry); /* Initialize quotas before so that eventual writes go * in separate transaction */ dquot_initialize(dir); dquot_initialize(dentry->d_inode); retval = -ENOENT; bh = ext4_find_entry(dir, &dentry->d_name, &de, NULL); if (!bh) goto end_unlink; inode = dentry->d_inode; retval = -EIO; if (le32_to_cpu(de->inode) != inode->i_ino) goto end_unlink; handle = ext4_journal_start(dir, EXT4_HT_DIR, EXT4_DATA_TRANS_BLOCKS(dir->i_sb)); if (IS_ERR(handle)) { retval = PTR_ERR(handle); handle = NULL; goto end_unlink; } if (IS_DIRSYNC(dir)) ext4_handle_sync(handle); if (!inode->i_nlink) { ext4_warning(inode->i_sb, "Deleting nonexistent file (%lu), %d", inode->i_ino, inode->i_nlink); set_nlink(inode, 1); } retval = ext4_delete_entry(handle, dir, de, bh); if (retval) goto end_unlink; dir->i_ctime = dir->i_mtime = ext4_current_time(dir); ext4_update_dx_flag(dir); ext4_mark_inode_dirty(handle, dir); drop_nlink(inode); if (!inode->i_nlink) ext4_orphan_add(handle, inode); inode->i_ctime = ext4_current_time(inode); ext4_mark_inode_dirty(handle, inode); retval = 0; end_unlink: brelse(bh); if (handle) ext4_journal_stop(handle); trace_ext4_unlink_exit(dentry, retval); return retval; } static int ext4_symlink(struct inode *dir, struct dentry *dentry, const char *symname) { handle_t *handle; struct inode *inode; int l, err, retries = 0; int credits; l = strlen(symname)+1; if (l > dir->i_sb->s_blocksize) return -ENAMETOOLONG; dquot_initialize(dir); if (l > EXT4_N_BLOCKS * 4) { /* * For non-fast symlinks, we just allocate inode and put it on * orphan list in the first transaction => we need bitmap, * group descriptor, sb, inode block, quota blocks, and * possibly selinux xattr blocks. */ credits = 4 + EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb) + EXT4_XATTR_TRANS_BLOCKS; } else { /* * Fast symlink. We have to add entry to directory * (EXT4_DATA_TRANS_BLOCKS + EXT4_INDEX_EXTRA_TRANS_BLOCKS), * allocate new inode (bitmap, group descriptor, inode block, * quota blocks, sb is already counted in previous macros). */ credits = EXT4_DATA_TRANS_BLOCKS(dir->i_sb) + EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3; } retry: inode = ext4_new_inode_start_handle(dir, S_IFLNK|S_IRWXUGO, &dentry->d_name, 0, NULL, EXT4_HT_DIR, credits); handle = ext4_journal_current_handle(); err = PTR_ERR(inode); if (IS_ERR(inode)) goto out_stop; if (l > EXT4_N_BLOCKS * 4) { inode->i_op = &ext4_symlink_inode_operations; ext4_set_aops(inode); /* * We cannot call page_symlink() with transaction started * because it calls into ext4_write_begin() which can wait * for transaction commit if we are running out of space * and thus we deadlock. So we have to stop transaction now * and restart it when symlink contents is written. * * To keep fs consistent in case of crash, we have to put inode * to orphan list in the mean time. */ drop_nlink(inode); err = ext4_orphan_add(handle, inode); ext4_journal_stop(handle); if (err) goto err_drop_inode; err = __page_symlink(inode, symname, l, 1); if (err) goto err_drop_inode; /* * Now inode is being linked into dir (EXT4_DATA_TRANS_BLOCKS * + EXT4_INDEX_EXTRA_TRANS_BLOCKS), inode is also modified */ handle = ext4_journal_start(dir, EXT4_HT_DIR, EXT4_DATA_TRANS_BLOCKS(dir->i_sb) + EXT4_INDEX_EXTRA_TRANS_BLOCKS + 1); if (IS_ERR(handle)) { err = PTR_ERR(handle); goto err_drop_inode; } set_nlink(inode, 1); err = ext4_orphan_del(handle, inode); if (err) { ext4_journal_stop(handle); clear_nlink(inode); goto err_drop_inode; } } else { /* clear the extent format for fast symlink */ ext4_clear_inode_flag(inode, EXT4_INODE_EXTENTS); inode->i_op = &ext4_fast_symlink_inode_operations; memcpy((char *)&EXT4_I(inode)->i_data, symname, l); inode->i_size = l-1; } EXT4_I(inode)->i_disksize = inode->i_size; err = ext4_add_nondir(handle, dentry, inode); if (!err && IS_DIRSYNC(dir)) ext4_handle_sync(handle); out_stop: if (handle) ext4_journal_stop(handle); if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries)) goto retry; return err; err_drop_inode: unlock_new_inode(inode); iput(inode); return err; } static int ext4_link(struct dentry *old_dentry, struct inode *dir, struct dentry *dentry) { handle_t *handle; struct inode *inode = old_dentry->d_inode; int err, retries = 0; if (inode->i_nlink >= EXT4_LINK_MAX) return -EMLINK; dquot_initialize(dir); retry: handle = ext4_journal_start(dir, EXT4_HT_DIR, (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) + EXT4_INDEX_EXTRA_TRANS_BLOCKS) + 1); if (IS_ERR(handle)) return PTR_ERR(handle); if (IS_DIRSYNC(dir)) ext4_handle_sync(handle); inode->i_ctime = ext4_current_time(inode); ext4_inc_count(handle, inode); ihold(inode); err = ext4_add_entry(handle, dentry, inode); if (!err) { ext4_mark_inode_dirty(handle, inode); /* this can happen only for tmpfile being * linked the first time */ if (inode->i_nlink == 1) ext4_orphan_del(handle, inode); d_instantiate(dentry, inode); } else { drop_nlink(inode); iput(inode); } ext4_journal_stop(handle); if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries)) goto retry; return err; } /* * Try to find buffer head where contains the parent block. * It should be the inode block if it is inlined or the 1st block * if it is a normal dir. */ static struct buffer_head *ext4_get_first_dir_block(handle_t *handle, struct inode *inode, int *retval, struct ext4_dir_entry_2 **parent_de, int *inlined) { struct buffer_head *bh; if (!ext4_has_inline_data(inode)) { bh = ext4_read_dirblock(inode, 0, EITHER); if (IS_ERR(bh)) { *retval = PTR_ERR(bh); return NULL; } *parent_de = ext4_next_entry( (struct ext4_dir_entry_2 *)bh->b_data, inode->i_sb->s_blocksize); return bh; } *inlined = 1; return ext4_get_first_inline_block(inode, parent_de, retval); } /* * Anybody can rename anything with this: the permission checks are left to the * higher-level routines. * * n.b. old_{dentry,inode) refers to the source dentry/inode * while new_{dentry,inode) refers to the destination dentry/inode * This comes from rename(const char *oldpath, const char *newpath) */ static int ext4_rename(struct inode *old_dir, struct dentry *old_dentry, struct inode *new_dir, struct dentry *new_dentry) { handle_t *handle = NULL; struct inode *old_inode, *new_inode; struct buffer_head *old_bh, *new_bh, *dir_bh; struct ext4_dir_entry_2 *old_de, *new_de; int retval; int inlined = 0, new_inlined = 0; struct ext4_dir_entry_2 *parent_de; dquot_initialize(old_dir); dquot_initialize(new_dir); old_bh = new_bh = dir_bh = NULL; /* Initialize quotas before so that eventual writes go * in separate transaction */ if (new_dentry->d_inode) dquot_initialize(new_dentry->d_inode); old_bh = ext4_find_entry(old_dir, &old_dentry->d_name, &old_de, NULL); /* * Check for inode number is _not_ due to possible IO errors. * We might rmdir the source, keep it as pwd of some process * and merrily kill the link to whatever was created under the * same name. Goodbye sticky bit ;-< */ old_inode = old_dentry->d_inode; retval = -ENOENT; if (!old_bh || le32_to_cpu(old_de->inode) != old_inode->i_ino) goto end_rename; new_inode = new_dentry->d_inode; new_bh = ext4_find_entry(new_dir, &new_dentry->d_name, &new_de, &new_inlined); if (new_bh) { if (!new_inode) { brelse(new_bh); new_bh = NULL; } } if (new_inode && !test_opt(new_dir->i_sb, NO_AUTO_DA_ALLOC)) ext4_alloc_da_blocks(old_inode); handle = ext4_journal_start(old_dir, EXT4_HT_DIR, (2 * EXT4_DATA_TRANS_BLOCKS(old_dir->i_sb) + EXT4_INDEX_EXTRA_TRANS_BLOCKS + 2)); if (IS_ERR(handle)) return PTR_ERR(handle); if (IS_DIRSYNC(old_dir) || IS_DIRSYNC(new_dir)) ext4_handle_sync(handle); if (S_ISDIR(old_inode->i_mode)) { if (new_inode) { retval = -ENOTEMPTY; if (!empty_dir(new_inode)) goto end_rename; } retval = -EIO; dir_bh = ext4_get_first_dir_block(handle, old_inode, &retval, &parent_de, &inlined); if (!dir_bh) goto end_rename; if (le32_to_cpu(parent_de->inode) != old_dir->i_ino) goto end_rename; retval = -EMLINK; if (!new_inode && new_dir != old_dir && EXT4_DIR_LINK_MAX(new_dir)) goto end_rename; BUFFER_TRACE(dir_bh, "get_write_access"); retval = ext4_journal_get_write_access(handle, dir_bh); if (retval) goto end_rename; } if (!new_bh) { retval = ext4_add_entry(handle, new_dentry, old_inode); if (retval) goto end_rename; } else { BUFFER_TRACE(new_bh, "get write access"); retval = ext4_journal_get_write_access(handle, new_bh); if (retval) goto end_rename; new_de->inode = cpu_to_le32(old_inode->i_ino); if (EXT4_HAS_INCOMPAT_FEATURE(new_dir->i_sb, EXT4_FEATURE_INCOMPAT_FILETYPE)) new_de->file_type = old_de->file_type; new_dir->i_version++; new_dir->i_ctime = new_dir->i_mtime = ext4_current_time(new_dir); ext4_mark_inode_dirty(handle, new_dir); BUFFER_TRACE(new_bh, "call ext4_handle_dirty_metadata"); if (!new_inlined) { retval = ext4_handle_dirty_dirent_node(handle, new_dir, new_bh); if (unlikely(retval)) { ext4_std_error(new_dir->i_sb, retval); goto end_rename; } } brelse(new_bh); new_bh = NULL; } /* * Like most other Unix systems, set the ctime for inodes on a * rename. */ old_inode->i_ctime = ext4_current_time(old_inode); ext4_mark_inode_dirty(handle, old_inode); /* * ok, that's it */ if (le32_to_cpu(old_de->inode) != old_inode->i_ino || old_de->name_len != old_dentry->d_name.len || strncmp(old_de->name, old_dentry->d_name.name, old_de->name_len) || (retval = ext4_delete_entry(handle, old_dir, old_de, old_bh)) == -ENOENT) { /* old_de could have moved from under us during htree split, so * make sure that we are deleting the right entry. We might * also be pointing to a stale entry in the unused part of * old_bh so just checking inum and the name isn't enough. */ struct buffer_head *old_bh2; struct ext4_dir_entry_2 *old_de2; old_bh2 = ext4_find_entry(old_dir, &old_dentry->d_name, &old_de2, NULL); if (old_bh2) { retval = ext4_delete_entry(handle, old_dir, old_de2, old_bh2); brelse(old_bh2); } } if (retval) { ext4_warning(old_dir->i_sb, "Deleting old file (%lu), %d, error=%d", old_dir->i_ino, old_dir->i_nlink, retval); } if (new_inode) { ext4_dec_count(handle, new_inode); new_inode->i_ctime = ext4_current_time(new_inode); } old_dir->i_ctime = old_dir->i_mtime = ext4_current_time(old_dir); ext4_update_dx_flag(old_dir); if (dir_bh) { parent_de->inode = cpu_to_le32(new_dir->i_ino); BUFFER_TRACE(dir_bh, "call ext4_handle_dirty_metadata"); if (!inlined) { if (is_dx(old_inode)) { retval = ext4_handle_dirty_dx_node(handle, old_inode, dir_bh); } else { retval = ext4_handle_dirty_dirent_node(handle, old_inode, dir_bh); } } else { retval = ext4_mark_inode_dirty(handle, old_inode); } if (retval) { ext4_std_error(old_dir->i_sb, retval); goto end_rename; } ext4_dec_count(handle, old_dir); if (new_inode) { /* checked empty_dir above, can't have another parent, * ext4_dec_count() won't work for many-linked dirs */ clear_nlink(new_inode); } else { ext4_inc_count(handle, new_dir); ext4_update_dx_flag(new_dir); ext4_mark_inode_dirty(handle, new_dir); } } ext4_mark_inode_dirty(handle, old_dir); if (new_inode) { ext4_mark_inode_dirty(handle, new_inode); if (!new_inode->i_nlink) ext4_orphan_add(handle, new_inode); } retval = 0; end_rename: brelse(dir_bh); brelse(old_bh); brelse(new_bh); if (handle) ext4_journal_stop(handle); return retval; } /* * directories can handle most operations... */ const struct inode_operations ext4_dir_inode_operations = { .create = ext4_create, .lookup = ext4_lookup, .link = ext4_link, .unlink = ext4_unlink, .symlink = ext4_symlink, .mkdir = ext4_mkdir, .rmdir = ext4_rmdir, .mknod = ext4_mknod, .tmpfile = ext4_tmpfile, .rename = ext4_rename, .setattr = ext4_setattr, .setxattr = generic_setxattr, .getxattr = generic_getxattr, .listxattr = ext4_listxattr, .removexattr = generic_removexattr, .get_acl = ext4_get_acl, .fiemap = ext4_fiemap, }; const struct inode_operations ext4_special_inode_operations = { .setattr = ext4_setattr, .setxattr = generic_setxattr, .getxattr = generic_getxattr, .listxattr = ext4_listxattr, .removexattr = generic_removexattr, .get_acl = ext4_get_acl, };