diff options
Diffstat (limited to 'fs/ext4/namei.c')
| -rw-r--r-- | fs/ext4/namei.c | 4248 |
1 files changed, 4248 insertions, 0 deletions
diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c new file mode 100644 index 000000000..bbfb37390 --- /dev/null +++ b/fs/ext4/namei.c @@ -0,0 +1,4248 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * 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 <linux/fs.h> +#include <linux/pagemap.h> +#include <linux/time.h> +#include <linux/fcntl.h> +#include <linux/stat.h> +#include <linux/string.h> +#include <linux/quotaops.h> +#include <linux/buffer_head.h> +#include <linux/bio.h> +#include <linux/iversion.h> +#include <linux/unicode.h> +#include "ext4.h" +#include "ext4_jbd2.h" + +#include "xattr.h" +#include "acl.h" + +#include <trace/events/ext4.h> +/* + * 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 ext4_map_blocks map; + struct buffer_head *bh; + int err; + + 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; + map.m_lblk = *block; + map.m_len = 1; + + /* + * We're appending new directory block. Make sure the block is not + * allocated yet, otherwise we will end up corrupting the + * directory. + */ + err = ext4_map_blocks(NULL, inode, &map, 0); + if (err < 0) + return ERR_PTR(err); + if (err) { + EXT4_ERROR_INODE(inode, "Logical block already allocated"); + return ERR_PTR(-EFSCORRUPTED); + } + + bh = ext4_bread(handle, inode, *block, EXT4_GET_BLOCKS_CREATE); + if (IS_ERR(bh)) + return bh; + inode->i_size += inode->i_sb->s_blocksize; + EXT4_I(inode)->i_disksize = inode->i_size; + err = ext4_mark_inode_dirty(handle, inode); + if (err) + goto out; + BUFFER_TRACE(bh, "get_write_access"); + err = ext4_journal_get_write_access(handle, inode->i_sb, bh, + EXT4_JTR_NONE); + if (err) + goto out; + return bh; + +out: + brelse(bh); + ext4_std_error(inode->i_sb, err); + return ERR_PTR(err); +} + +static int ext4_dx_csum_verify(struct inode *inode, + struct ext4_dir_entry *dirent); + +/* + * Hints to ext4_read_dirblock regarding whether we expect a directory + * block being read to be an index block, or a block containing + * directory entries (and if the latter, whether it was found via a + * logical block in an htree index block). This is used to control + * what sort of sanity checkinig ext4_read_dirblock() will do on the + * directory block read from the storage device. EITHER will means + * the caller doesn't know what kind of directory block will be read, + * so no specific verification will be done. + */ +typedef enum { + EITHER, INDEX, DIRENT, DIRENT_HTREE +} dirblock_type_t; + +#define ext4_read_dirblock(inode, block, type) \ + __ext4_read_dirblock((inode), (block), (type), __func__, __LINE__) + +static struct buffer_head *__ext4_read_dirblock(struct inode *inode, + ext4_lblk_t block, + dirblock_type_t type, + const char *func, + unsigned int line) +{ + struct buffer_head *bh; + struct ext4_dir_entry *dirent; + int is_dx_block = 0; + + if (block >= inode->i_size >> inode->i_blkbits) { + ext4_error_inode(inode, func, line, block, + "Attempting to read directory block (%u) that is past i_size (%llu)", + block, inode->i_size); + return ERR_PTR(-EFSCORRUPTED); + } + + if (ext4_simulate_fail(inode->i_sb, EXT4_SIM_DIRBLOCK_EIO)) + bh = ERR_PTR(-EIO); + else + bh = ext4_bread(NULL, inode, block, 0); + if (IS_ERR(bh)) { + __ext4_warning(inode->i_sb, func, line, + "inode #%lu: lblock %lu: comm %s: " + "error %ld reading directory block", + inode->i_ino, (unsigned long)block, + current->comm, PTR_ERR(bh)); + + return bh; + } + if (!bh && (type == INDEX || type == DIRENT_HTREE)) { + ext4_error_inode(inode, func, line, block, + "Directory hole found for htree %s block", + (type == INDEX) ? "index" : "leaf"); + return ERR_PTR(-EFSCORRUPTED); + } + if (!bh) + return NULL; + 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"); + brelse(bh); + return ERR_PTR(-EFSCORRUPTED); + } + if (!ext4_has_metadata_csum(inode->i_sb) || + 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) && + !ext4_simulate_fail(inode->i_sb, EXT4_SIM_DIRBLOCK_CRC)) + set_buffer_verified(bh); + else { + ext4_error_inode_err(inode, func, line, block, + EFSBADCRC, + "Directory index failed checksum"); + brelse(bh); + return ERR_PTR(-EFSBADCRC); + } + } + if (!is_dx_block) { + if (ext4_dirblock_csum_verify(inode, bh) && + !ext4_simulate_fail(inode->i_sb, EXT4_SIM_DIRBLOCK_CRC)) + set_buffer_verified(bh); + else { + ext4_error_inode_err(inode, func, line, block, + EFSBADCRC, + "Directory block failed checksum"); + brelse(bh); + return ERR_PTR(-EFSBADCRC); + } + } + return bh; +} + +#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[]; +}; + +struct dx_node +{ + struct fake_dirent fake; + struct dx_entry entries[]; +}; + + +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(struct ext4_filename *fname, + struct inode *dir, + struct dx_hash_info *hinfo, + struct dx_frame *frame); +static void dx_release(struct dx_frame *frames); +static int dx_make_map(struct inode *dir, struct buffer_head *bh, + struct dx_hash_info *hinfo, + struct dx_map_entry *map_tail); +static void dx_sort_map(struct dx_map_entry *map, unsigned count); +static struct ext4_dir_entry_2 *dx_move_dirents(struct inode *dir, char *from, + char *to, struct dx_map_entry *offsets, + int count, unsigned int blocksize); +static struct ext4_dir_entry_2 *dx_pack_dirents(struct inode *dir, char *base, + unsigned int 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, + struct ext4_filename *fname, + struct ext4_dir_entry_2 **res_dir); +static int ext4_dx_add_entry(handle_t *handle, struct ext4_filename *fname, + struct inode *dir, struct inode *inode); + +/* checksumming functions */ +void ext4_initialize_dirent_tail(struct buffer_head *bh, + unsigned int blocksize) +{ + struct ext4_dir_entry_tail *t = EXT4_DIRENT_TAIL(bh->b_data, 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 buffer_head *bh) +{ + struct ext4_dir_entry_tail *t; + int blocksize = EXT4_BLOCK_SIZE(inode->i_sb); + +#ifdef PARANOID + struct ext4_dir_entry *d, *top; + + d = (struct ext4_dir_entry *)bh->b_data; + top = (struct ext4_dir_entry *)(bh->b_data + + (blocksize - sizeof(struct ext4_dir_entry_tail))); + while (d < top && ext4_rec_len_from_disk(d->rec_len, blocksize)) + d = (struct ext4_dir_entry *)(((void *)d) + + ext4_rec_len_from_disk(d->rec_len, blocksize)); + + if (d != top) + return NULL; + + t = (struct ext4_dir_entry_tail *)d; +#else + t = EXT4_DIRENT_TAIL(bh->b_data, EXT4_BLOCK_SIZE(inode->i_sb)); +#endif + + if (t->det_reserved_zero1 || + (ext4_rec_len_from_disk(t->det_rec_len, blocksize) != + 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_dirblock_csum(struct inode *inode, void *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); +} + +#define warn_no_space_for_csum(inode) \ + __warn_no_space_for_csum((inode), __func__, __LINE__) + +static void __warn_no_space_for_csum(struct inode *inode, const char *func, + unsigned int line) +{ + __ext4_warning_inode(inode, func, line, + "No space for directory leaf checksum. Please run e2fsck -D."); +} + +int ext4_dirblock_csum_verify(struct inode *inode, struct buffer_head *bh) +{ + struct ext4_dir_entry_tail *t; + + if (!ext4_has_metadata_csum(inode->i_sb)) + return 1; + + t = get_dirent_tail(inode, bh); + if (!t) { + warn_no_space_for_csum(inode); + return 0; + } + + if (t->det_checksum != ext4_dirblock_csum(inode, bh->b_data, + (char *)t - bh->b_data)) + return 0; + + return 1; +} + +static void ext4_dirblock_csum_set(struct inode *inode, + struct buffer_head *bh) +{ + struct ext4_dir_entry_tail *t; + + if (!ext4_has_metadata_csum(inode->i_sb)) + return; + + t = get_dirent_tail(inode, bh); + if (!t) { + warn_no_space_for_csum(inode); + return; + } + + t->det_checksum = ext4_dirblock_csum(inode, bh->b_data, + (char *)t - bh->b_data); +} + +int ext4_handle_dirty_dirblock(handle_t *handle, + struct inode *inode, + struct buffer_head *bh) +{ + ext4_dirblock_csum_set(inode, bh); + 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; + int blocksize = EXT4_BLOCK_SIZE(inode->i_sb); + unsigned int rlen = ext4_rec_len_from_disk(dirent->rec_len, blocksize); + + if (rlen == blocksize) + count_offset = 8; + else if (rlen == 12) { + dp = (struct ext4_dir_entry *)(((void *)dirent) + 12); + if (ext4_rec_len_from_disk(dp->rec_len, blocksize) != blocksize - 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; + int size; + __u32 dummy_csum = 0; + int offset = offsetof(struct dx_tail, dt_checksum); + + size = count_offset + (count * sizeof(struct dx_entry)); + csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)dirent, size); + csum = ext4_chksum(sbi, csum, (__u8 *)t, offset); + csum = ext4_chksum(sbi, csum, (__u8 *)&dummy_csum, sizeof(dummy_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_metadata_csum(inode->i_sb)) + return 1; + + c = get_dx_countlimit(inode, dirent, &count_offset); + if (!c) { + EXT4_ERROR_INODE(inode, "dir seems corrupt? Run e2fsck -D."); + return 0; + } + 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 0; + } + 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_metadata_csum(inode->i_sb)) + 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) & 0x0fffffff; +} + +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 int entry_space = dir->i_sb->s_blocksize - + ext4_dir_rec_len(1, NULL) - + ext4_dir_rec_len(2, NULL) - infosize; + + if (ext4_has_metadata_csum(dir->i_sb)) + entry_space -= sizeof(struct dx_tail); + return entry_space / sizeof(struct dx_entry); +} + +static inline unsigned dx_node_limit(struct inode *dir) +{ + unsigned int entry_space = dir->i_sb->s_blocksize - + ext4_dir_rec_len(0, dir); + + if (ext4_has_metadata_csum(dir->i_sb)) + 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(KERN_CONT " %x->%lu", + i ? dx_get_hash(entries + i) : 0, + (unsigned long)dx_get_block(entries + i)); + } + printk(KERN_CONT "\n"); +} + +struct stats +{ + unsigned names; + unsigned space; + unsigned bcount; +}; + +static struct stats dx_show_leaf(struct inode *dir, + 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) + { +#ifdef CONFIG_FS_ENCRYPTION + int len; + char *name; + struct fscrypt_str fname_crypto_str = + FSTR_INIT(NULL, 0); + int res = 0; + + name = de->name; + len = de->name_len; + if (!IS_ENCRYPTED(dir)) { + /* Directory is not encrypted */ + (void) ext4fs_dirhash(dir, de->name, + de->name_len, &h); + printk("%*.s:(U)%x.%u ", len, + name, h.hash, + (unsigned) ((char *) de + - base)); + } else { + struct fscrypt_str de_name = + FSTR_INIT(name, len); + + /* Directory is encrypted */ + res = fscrypt_fname_alloc_buffer( + len, &fname_crypto_str); + if (res) + printk(KERN_WARNING "Error " + "allocating crypto " + "buffer--skipping " + "crypto\n"); + res = fscrypt_fname_disk_to_usr(dir, + 0, 0, &de_name, + &fname_crypto_str); + if (res) { + printk(KERN_WARNING "Error " + "converting filename " + "from disk to usr" + "\n"); + name = "??"; + len = 2; + } else { + name = fname_crypto_str.name; + len = fname_crypto_str.len; + } + if (IS_CASEFOLDED(dir)) + h.hash = EXT4_DIRENT_HASH(de); + else + (void) ext4fs_dirhash(dir, + de->name, + de->name_len, &h); + printk("%*.s:(E)%x.%u ", len, name, + h.hash, (unsigned) ((char *) de + - base)); + fscrypt_fname_free_buffer( + &fname_crypto_str); + } +#else + int len = de->name_len; + char *name = de->name; + (void) ext4fs_dirhash(dir, de->name, + de->name_len, &h); + printk("%*.s:%x.%u ", len, name, h.hash, + (unsigned) ((char *) de - base)); +#endif + } + space += ext4_dir_rec_len(de->name_len, dir); + names++; + } + de = ext4_next_entry(de, size); + } + printk(KERN_CONT "(%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; + 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); + bh = ext4_bread(NULL,dir, block, 0); + if (!bh || IS_ERR(bh)) + continue; + stats = levels? + dx_show_entries(hinfo, dir, ((struct dx_node *) bh->b_data)->entries, levels - 1): + dx_show_leaf(dir, 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}; +} + +/* + * Linear search cross check + */ +static inline void htree_rep_invariant_check(struct dx_entry *at, + struct dx_entry *target, + u32 hash, unsigned int n) +{ + while (n--) { + dxtrace(printk(KERN_CONT ",")); + if (dx_get_hash(++at) > hash) { + at--; + break; + } + } + ASSERT(at == target - 1); +} +#else /* DX_DEBUG */ +static inline void htree_rep_invariant_check(struct dx_entry *at, + struct dx_entry *target, + u32 hash, unsigned int n) +{ +} +#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(struct ext4_filename *fname, struct inode *dir, + struct dx_hash_info *hinfo, struct dx_frame *frame_in) +{ + unsigned count, indirect, level, i; + struct dx_entry *at, *entries, *p, *q, *m; + struct dx_root *root; + struct dx_frame *frame = frame_in; + struct dx_frame *ret_err = ERR_PTR(ERR_BAD_DX_DIR); + u32 hash; + ext4_lblk_t block; + ext4_lblk_t blocks[EXT4_HTREE_LEVEL]; + + memset(frame_in, 0, EXT4_HTREE_LEVEL * sizeof(frame_in[0])); + frame->bh = ext4_read_dirblock(dir, 0, INDEX); + if (IS_ERR(frame->bh)) + return (struct dx_frame *) frame->bh; + + root = (struct dx_root *) frame->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 && + root->info.hash_version != DX_HASH_SIPHASH) { + ext4_warning_inode(dir, "Unrecognised inode hash code %u", + root->info.hash_version); + goto fail; + } + if (ext4_hash_in_dirent(dir)) { + if (root->info.hash_version != DX_HASH_SIPHASH) { + ext4_warning_inode(dir, + "Hash in dirent, but hash is not SIPHASH"); + goto fail; + } + } else { + if (root->info.hash_version == DX_HASH_SIPHASH) { + ext4_warning_inode(dir, + "Hash code is SIPHASH, but hash not in dirent"); + goto fail; + } + } + if (fname) + hinfo = &fname->hinfo; + 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; + /* hash is already computed for encrypted casefolded directory */ + if (fname && fname_name(fname) && + !(IS_ENCRYPTED(dir) && IS_CASEFOLDED(dir))) { + int ret = ext4fs_dirhash(dir, fname_name(fname), + fname_len(fname), hinfo); + if (ret < 0) { + ret_err = ERR_PTR(ret); + goto fail; + } + } + hash = hinfo->hash; + + if (root->info.unused_flags & 1) { + ext4_warning_inode(dir, "Unimplemented hash flags: %#06x", + root->info.unused_flags); + goto fail; + } + + indirect = root->info.indirect_levels; + if (indirect >= ext4_dir_htree_level(dir->i_sb)) { + ext4_warning(dir->i_sb, + "Directory (ino: %lu) htree depth %#06x exceed" + "supported value", dir->i_ino, + ext4_dir_htree_level(dir->i_sb)); + if (ext4_dir_htree_level(dir->i_sb) < EXT4_HTREE_LEVEL) { + ext4_warning(dir->i_sb, "Enable large directory " + "feature to access it"); + } + 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_inode(dir, "dx entry: limit %u != root limit %u", + dx_get_limit(entries), + dx_root_limit(dir, root->info.info_length)); + goto fail; + } + + dxtrace(printk("Look up %x", hash)); + level = 0; + blocks[0] = 0; + while (1) { + count = dx_get_count(entries); + if (!count || count > dx_get_limit(entries)) { + ext4_warning_inode(dir, + "dx entry: count %u beyond limit %u", + count, dx_get_limit(entries)); + goto fail; + } + + p = entries + 1; + q = entries + count - 1; + while (p <= q) { + m = p + (q - p) / 2; + dxtrace(printk(KERN_CONT ".")); + if (dx_get_hash(m) > hash) + q = m - 1; + else + p = m + 1; + } + + htree_rep_invariant_check(entries, p, hash, count - 1); + + at = p - 1; + dxtrace(printk(KERN_CONT " %x->%u\n", + at == entries ? 0 : dx_get_hash(at), + dx_get_block(at))); + frame->entries = entries; + frame->at = at; + + block = dx_get_block(at); + for (i = 0; i <= level; i++) { + if (blocks[i] == block) { + ext4_warning_inode(dir, + "dx entry: tree cycle block %u points back to block %u", + blocks[level], block); + goto fail; + } + } + if (++level > indirect) + return frame; + blocks[level] = block; + frame++; + frame->bh = ext4_read_dirblock(dir, block, INDEX); + if (IS_ERR(frame->bh)) { + ret_err = (struct dx_frame *) frame->bh; + frame->bh = NULL; + goto fail; + } + + entries = ((struct dx_node *) frame->bh->b_data)->entries; + + if (dx_get_limit(entries) != dx_node_limit(dir)) { + ext4_warning_inode(dir, + "dx entry: limit %u != node limit %u", + dx_get_limit(entries), dx_node_limit(dir)); + goto fail; + } + } +fail: + while (frame >= frame_in) { + brelse(frame->bh); + frame--; + } + + if (ret_err == ERR_PTR(ERR_BAD_DX_DIR)) + ext4_warning_inode(dir, + "Corrupt directory, running e2fsck is recommended"); + return ret_err; +} + +static void dx_release(struct dx_frame *frames) +{ + struct dx_root_info *info; + int i; + unsigned int indirect_levels; + + if (frames[0].bh == NULL) + return; + + info = &((struct dx_root *)frames[0].bh->b_data)->info; + /* save local copy, "info" may be freed after brelse() */ + indirect_levels = info->indirect_levels; + for (i = 0; i <= indirect_levels; i++) { + if (frames[i].bh == NULL) + break; + brelse(frames[i].bh); + frames[i].bh = NULL; + } +} + +/* + * 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 continuation 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; + struct fscrypt_str fname_crypto_str = FSTR_INIT(NULL, 0), tmp_str; + int csum = ext4_has_metadata_csum(dir->i_sb); + + dxtrace(printk(KERN_INFO "In htree dirblock_to_tree: block %lu\n", + (unsigned long)block)); + bh = ext4_read_dirblock(dir, block, DIRENT_HTREE); + if (IS_ERR(bh)) + return PTR_ERR(bh); + + de = (struct ext4_dir_entry_2 *) bh->b_data; + /* csum entries are not larger in the casefolded encrypted case */ + top = (struct ext4_dir_entry_2 *) ((char *) de + + dir->i_sb->s_blocksize - + ext4_dir_rec_len(0, + csum ? NULL : dir)); + /* Check if the directory is encrypted */ + if (IS_ENCRYPTED(dir)) { + err = fscrypt_prepare_readdir(dir); + if (err < 0) { + brelse(bh); + return err; + } + err = fscrypt_fname_alloc_buffer(EXT4_NAME_LEN, + &fname_crypto_str); + if (err < 0) { + brelse(bh); + return err; + } + } + + 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<<EXT4_BLOCK_SIZE_BITS(dir->i_sb)) + + ((char *)de - bh->b_data))) { + /* silently ignore the rest of the block */ + break; + } + if (ext4_hash_in_dirent(dir)) { + if (de->name_len && de->inode) { + hinfo->hash = EXT4_DIRENT_HASH(de); + hinfo->minor_hash = EXT4_DIRENT_MINOR_HASH(de); + } else { + hinfo->hash = 0; + hinfo->minor_hash = 0; + } + } else { + err = ext4fs_dirhash(dir, de->name, + de->name_len, hinfo); + if (err < 0) { + count = err; + goto errout; + } + } + if ((hinfo->hash < start_hash) || + ((hinfo->hash == start_hash) && + (hinfo->minor_hash < start_minor_hash))) + continue; + if (de->inode == 0) + continue; + if (!IS_ENCRYPTED(dir)) { + tmp_str.name = de->name; + tmp_str.len = de->name_len; + err = ext4_htree_store_dirent(dir_file, + hinfo->hash, hinfo->minor_hash, de, + &tmp_str); + } else { + int save_len = fname_crypto_str.len; + struct fscrypt_str de_name = FSTR_INIT(de->name, + de->name_len); + + /* Directory is encrypted */ + err = fscrypt_fname_disk_to_usr(dir, hinfo->hash, + hinfo->minor_hash, &de_name, + &fname_crypto_str); + if (err) { + count = err; + goto errout; + } + err = ext4_htree_store_dirent(dir_file, + hinfo->hash, hinfo->minor_hash, de, + &fname_crypto_str); + fname_crypto_str.len = save_len; + } + if (err != 0) { + count = err; + goto errout; + } + count++; + } +errout: + brelse(bh); + fscrypt_fname_free_buffer(&fname_crypto_str); + 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[EXT4_HTREE_LEVEL], *frame; + struct inode *dir; + ext4_lblk_t block; + int count = 0; + int ret, err; + __u32 hashval; + struct fscrypt_str tmp_str; + + 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))) { + if (ext4_hash_in_dirent(dir)) + hinfo.hash_version = DX_HASH_SIPHASH; + else + 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 = ext4_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); + if (IS_ERR(frame)) + return PTR_ERR(frame); + + /* Add '.' and '..' from the htree header */ + if (!start_hash && !start_minor_hash) { + de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data; + tmp_str.name = de->name; + tmp_str.len = de->name_len; + err = ext4_htree_store_dirent(dir_file, 0, 0, + de, &tmp_str); + if (err != 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); + tmp_str.name = de->name; + tmp_str.len = de->name_len; + err = ext4_htree_store_dirent(dir_file, 2, 0, + de, &tmp_str); + if (err != 0) + goto errout; + count++; + } + + while (1) { + if (fatal_signal_pending(current)) { + err = -ERESTARTSYS; + goto errout; + } + cond_resched(); + 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, + struct ext4_filename *fname, + unsigned int offset, + struct ext4_dir_entry_2 **res_dir) +{ + return ext4_search_dir(bh, bh->b_data, dir->i_sb->s_blocksize, dir, + fname, 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 inode *dir, struct buffer_head *bh, + struct dx_hash_info *hinfo, + struct dx_map_entry *map_tail) +{ + int count = 0; + struct ext4_dir_entry_2 *de = (struct ext4_dir_entry_2 *)bh->b_data; + unsigned int buflen = bh->b_size; + char *base = bh->b_data; + struct dx_hash_info h = *hinfo; + int blocksize = EXT4_BLOCK_SIZE(dir->i_sb); + + if (ext4_has_metadata_csum(dir->i_sb)) + buflen -= sizeof(struct ext4_dir_entry_tail); + + while ((char *) de < base + buflen) { + if (ext4_check_dir_entry(dir, NULL, de, bh, base, buflen, + ((char *)de) - base)) + return -EFSCORRUPTED; + if (de->name_len && de->inode) { + if (ext4_hash_in_dirent(dir)) + h.hash = EXT4_DIRENT_HASH(de); + else { + int err = ext4fs_dirhash(dir, de->name, + de->name_len, &h); + if (err < 0) + return err; + } + map_tail--; + map_tail->hash = h.hash; + map_tail->offs = ((char *) de - base)>>2; + map_tail->size = ext4_rec_len_from_disk(de->rec_len, + blocksize); + count++; + cond_resched(); + } + 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); +} + +#if IS_ENABLED(CONFIG_UNICODE) +/* + * Test whether a case-insensitive directory entry matches the filename + * being searched for. If quick is set, assume the name being looked up + * is already in the casefolded form. + * + * Returns: 0 if the directory entry matches, more than 0 if it + * doesn't match or less than zero on error. + */ +static int ext4_ci_compare(const struct inode *parent, const struct qstr *name, + u8 *de_name, size_t de_name_len, bool quick) +{ + const struct super_block *sb = parent->i_sb; + const struct unicode_map *um = sb->s_encoding; + struct fscrypt_str decrypted_name = FSTR_INIT(NULL, de_name_len); + struct qstr entry = QSTR_INIT(de_name, de_name_len); + int ret; + + if (IS_ENCRYPTED(parent)) { + const struct fscrypt_str encrypted_name = + FSTR_INIT(de_name, de_name_len); + + decrypted_name.name = kmalloc(de_name_len, GFP_KERNEL); + if (!decrypted_name.name) + return -ENOMEM; + ret = fscrypt_fname_disk_to_usr(parent, 0, 0, &encrypted_name, + &decrypted_name); + if (ret < 0) + goto out; + entry.name = decrypted_name.name; + entry.len = decrypted_name.len; + } + + if (quick) + ret = utf8_strncasecmp_folded(um, name, &entry); + else + ret = utf8_strncasecmp(um, name, &entry); + if (ret < 0) { + /* Handle invalid character sequence as either an error + * or as an opaque byte sequence. + */ + if (sb_has_strict_encoding(sb)) + ret = -EINVAL; + else if (name->len != entry.len) + ret = 1; + else + ret = !!memcmp(name->name, entry.name, entry.len); + } +out: + kfree(decrypted_name.name); + return ret; +} + +int ext4_fname_setup_ci_filename(struct inode *dir, const struct qstr *iname, + struct ext4_filename *name) +{ + struct fscrypt_str *cf_name = &name->cf_name; + struct dx_hash_info *hinfo = &name->hinfo; + int len; + + if (!IS_CASEFOLDED(dir) || !dir->i_sb->s_encoding || + (IS_ENCRYPTED(dir) && !fscrypt_has_encryption_key(dir))) { + cf_name->name = NULL; + return 0; + } + + cf_name->name = kmalloc(EXT4_NAME_LEN, GFP_NOFS); + if (!cf_name->name) + return -ENOMEM; + + len = utf8_casefold(dir->i_sb->s_encoding, + iname, cf_name->name, + EXT4_NAME_LEN); + if (len <= 0) { + kfree(cf_name->name); + cf_name->name = NULL; + } + cf_name->len = (unsigned) len; + if (!IS_ENCRYPTED(dir)) + return 0; + + hinfo->hash_version = DX_HASH_SIPHASH; + hinfo->seed = NULL; + if (cf_name->name) + return ext4fs_dirhash(dir, cf_name->name, cf_name->len, hinfo); + else + return ext4fs_dirhash(dir, iname->name, iname->len, hinfo); +} +#endif + +/* + * Test whether a directory entry matches the filename being searched for. + * + * Return: %true if the directory entry matches, otherwise %false. + */ +static bool ext4_match(struct inode *parent, + const struct ext4_filename *fname, + struct ext4_dir_entry_2 *de) +{ + struct fscrypt_name f; + + if (!de->inode) + return false; + + f.usr_fname = fname->usr_fname; + f.disk_name = fname->disk_name; +#ifdef CONFIG_FS_ENCRYPTION + f.crypto_buf = fname->crypto_buf; +#endif + +#if IS_ENABLED(CONFIG_UNICODE) + if (parent->i_sb->s_encoding && IS_CASEFOLDED(parent) && + (!IS_ENCRYPTED(parent) || fscrypt_has_encryption_key(parent))) { + if (fname->cf_name.name) { + struct qstr cf = {.name = fname->cf_name.name, + .len = fname->cf_name.len}; + if (IS_ENCRYPTED(parent)) { + if (fname->hinfo.hash != EXT4_DIRENT_HASH(de) || + fname->hinfo.minor_hash != + EXT4_DIRENT_MINOR_HASH(de)) { + + return false; + } + } + return !ext4_ci_compare(parent, &cf, de->name, + de->name_len, true); + } + return !ext4_ci_compare(parent, fname->usr_fname, de->name, + de->name_len, false); + } +#endif + + return fscrypt_match_name(&f, de->name, de->name_len); +} + +/* + * Returns 0 if not found, -1 on failure, and 1 on success + */ +int ext4_search_dir(struct buffer_head *bh, char *search_buf, int buf_size, + struct inode *dir, struct ext4_filename *fname, + unsigned int offset, struct ext4_dir_entry_2 **res_dir) +{ + struct ext4_dir_entry_2 * de; + char * dlimit; + int de_len; + + de = (struct ext4_dir_entry_2 *)search_buf; + dlimit = search_buf + buf_size; + while ((char *) de < dlimit - EXT4_BASE_DIR_LEN) { + /* this code is executed quadratically often */ + /* do minimal checking `by hand' */ + if (de->name + de->name_len <= dlimit && + ext4_match(dir, fname, de)) { + /* found a match - just to be sure, do + * a full check */ + if (ext4_check_dir_entry(dir, NULL, de, bh, search_buf, + buf_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, + struct ext4_filename *fname, + 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; + const u8 *name = fname->usr_fname->name; + size_t ra_max = 0; /* Number of bh's in the readahead + buffer, bh_use[] */ + size_t ra_ptr = 0; /* Current index into readahead + buffer */ + ext4_lblk_t nblocks; + int i, namelen, retval; + + *res_dir = NULL; + sb = dir->i_sb; + namelen = fname->usr_fname->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, fname, res_dir, + &has_inline_data); + if (inlined) + *inlined = has_inline_data; + if (has_inline_data) + goto cleanup_and_exit; + } + + 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)) { + ret = ext4_dx_find_entry(dir, fname, res_dir); + /* + * On success, or if the error was file not found, + * return. Otherwise, fall back to doing a search the + * old fashioned way. + */ + if (!IS_ERR(ret) || PTR_ERR(ret) != ERR_BAD_DX_DIR) + goto cleanup_and_exit; + dxtrace(printk(KERN_DEBUG "ext4_find_entry: dx failed, " + "falling back\n")); + ret = NULL; + } + nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb); + if (!nblocks) { + ret = NULL; + goto cleanup_and_exit; + } + 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. + */ + cond_resched(); + if (ra_ptr >= ra_max) { + /* Refill the readahead buffer */ + ra_ptr = 0; + if (block < start) + ra_max = start - block; + else + ra_max = nblocks - block; + ra_max = min(ra_max, ARRAY_SIZE(bh_use)); + retval = ext4_bread_batch(dir, block, ra_max, + false /* wait */, bh_use); + if (retval) { + ret = ERR_PTR(retval); + ra_max = 0; + goto cleanup_and_exit; + } + } + if ((bh = bh_use[ra_ptr++]) == NULL) + goto next; + wait_on_buffer(bh); + if (!buffer_uptodate(bh)) { + EXT4_ERROR_INODE_ERR(dir, EIO, + "reading directory lblock %lu", + (unsigned long) block); + brelse(bh); + ret = ERR_PTR(-EIO); + goto cleanup_and_exit; + } + if (!buffer_verified(bh) && + !is_dx_internal_node(dir, block, + (struct ext4_dir_entry *)bh->b_data) && + !ext4_dirblock_csum_verify(dir, bh)) { + EXT4_ERROR_INODE_ERR(dir, EFSBADCRC, + "checksumming directory " + "block %lu", (unsigned long)block); + brelse(bh); + ret = ERR_PTR(-EFSBADCRC); + goto cleanup_and_exit; + } + set_buffer_verified(bh); + i = search_dirblock(bh, dir, fname, + 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_find_entry(struct inode *dir, + const struct qstr *d_name, + struct ext4_dir_entry_2 **res_dir, + int *inlined) +{ + int err; + struct ext4_filename fname; + struct buffer_head *bh; + + err = ext4_fname_setup_filename(dir, d_name, 1, &fname); + if (err == -ENOENT) + return NULL; + if (err) + return ERR_PTR(err); + + bh = __ext4_find_entry(dir, &fname, res_dir, inlined); + + ext4_fname_free_filename(&fname); + return bh; +} + +static struct buffer_head *ext4_lookup_entry(struct inode *dir, + struct dentry *dentry, + struct ext4_dir_entry_2 **res_dir) +{ + int err; + struct ext4_filename fname; + struct buffer_head *bh; + + err = ext4_fname_prepare_lookup(dir, dentry, &fname); + generic_set_encrypted_ci_d_ops(dentry); + if (err == -ENOENT) + return NULL; + if (err) + return ERR_PTR(err); + + bh = __ext4_find_entry(dir, &fname, res_dir, NULL); + + ext4_fname_free_filename(&fname); + return bh; +} + +static struct buffer_head * ext4_dx_find_entry(struct inode *dir, + struct ext4_filename *fname, + struct ext4_dir_entry_2 **res_dir) +{ + struct super_block * sb = dir->i_sb; + struct dx_frame frames[EXT4_HTREE_LEVEL], *frame; + struct buffer_head *bh; + ext4_lblk_t block; + int retval; + +#ifdef CONFIG_FS_ENCRYPTION + *res_dir = NULL; +#endif + frame = dx_probe(fname, dir, NULL, frames); + if (IS_ERR(frame)) + return (struct buffer_head *) frame; + do { + block = dx_get_block(frame->at); + bh = ext4_read_dirblock(dir, block, DIRENT_HTREE); + if (IS_ERR(bh)) + goto errout; + + retval = search_dirblock(bh, dir, fname, + block << EXT4_BLOCK_SIZE_BITS(sb), + res_dir); + if (retval == 1) + goto success; + brelse(bh); + if (retval == -1) { + bh = ERR_PTR(ERR_BAD_DX_DIR); + goto errout; + } + + /* Check to see if we should continue to search */ + retval = ext4_htree_next_block(dir, fname->hinfo.hash, frame, + frames, NULL); + if (retval < 0) { + ext4_warning_inode(dir, + "error %d reading directory index block", + retval); + bh = ERR_PTR(retval); + goto errout; + } + } while (retval == 1); + + bh = NULL; +errout: + dxtrace(printk(KERN_DEBUG "%s not found\n", fname->usr_fname->name)); +success: + dx_release(frames); + return bh; +} + +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_lookup_entry(dir, dentry, &de); + if (IS_ERR(bh)) + return ERR_CAST(bh); + 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(-EFSCORRUPTED); + } + if (unlikely(ino == dir->i_ino)) { + EXT4_ERROR_INODE(dir, "'%pd' linked to parent dir", + dentry); + return ERR_PTR(-EFSCORRUPTED); + } + inode = ext4_iget(dir->i_sb, ino, EXT4_IGET_NORMAL); + if (inode == ERR_PTR(-ESTALE)) { + EXT4_ERROR_INODE(dir, + "deleted inode referenced: %u", + ino); + return ERR_PTR(-EFSCORRUPTED); + } + if (!IS_ERR(inode) && IS_ENCRYPTED(dir) && + (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode)) && + !fscrypt_has_permitted_context(dir, inode)) { + ext4_warning(inode->i_sb, + "Inconsistent encryption contexts: %lu/%lu", + dir->i_ino, inode->i_ino); + iput(inode); + return ERR_PTR(-EPERM); + } + } + +#if IS_ENABLED(CONFIG_UNICODE) + if (!inode && IS_CASEFOLDED(dir)) { + /* Eventually we want to call d_add_ci(dentry, NULL) + * for negative dentries in the encoding case as + * well. For now, prevent the negative dentry + * from being cached. + */ + return NULL; + } +#endif + return d_splice_alias(inode, dentry); +} + + +struct dentry *ext4_get_parent(struct dentry *child) +{ + __u32 ino; + struct ext4_dir_entry_2 * de; + struct buffer_head *bh; + + bh = ext4_find_entry(d_inode(child), &dotdot_name, &de, NULL); + if (IS_ERR(bh)) + return ERR_CAST(bh); + if (!bh) + return ERR_PTR(-ENOENT); + ino = le32_to_cpu(de->inode); + brelse(bh); + + if (!ext4_valid_inum(child->d_sb, ino)) { + EXT4_ERROR_INODE(d_inode(child), + "bad parent inode number: %u", ino); + return ERR_PTR(-EFSCORRUPTED); + } + + return d_obtain_alias(ext4_iget(child->d_sb, ino, EXT4_IGET_NORMAL)); +} + +/* + * 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(struct inode *dir, 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, dir); + + memcpy (to, de, rec_len); + ((struct ext4_dir_entry_2 *) to)->rec_len = + ext4_rec_len_to_disk(rec_len, blocksize); + + /* wipe dir_entry excluding the rec_len field */ + de->inode = 0; + memset(&de->name_len, 0, ext4_rec_len_from_disk(de->rec_len, + blocksize) - + offsetof(struct ext4_dir_entry_2, + name_len)); + + 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(struct inode *dir, char *base, + unsigned int 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, dir); + 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) +{ + unsigned blocksize = dir->i_sb->s_blocksize; + unsigned continued; + int count; + 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; + int csum_size = 0; + int err = 0, i; + + if (ext4_has_metadata_csum(dir->i_sb)) + csum_size = sizeof(struct ext4_dir_entry_tail); + + bh2 = ext4_append(handle, dir, &newblock); + if (IS_ERR(bh2)) { + brelse(*bh); + *bh = NULL; + return (struct ext4_dir_entry_2 *) bh2; + } + + BUFFER_TRACE(*bh, "get_write_access"); + err = ext4_journal_get_write_access(handle, dir->i_sb, *bh, + EXT4_JTR_NONE); + if (err) + goto journal_error; + + BUFFER_TRACE(frame->bh, "get_write_access"); + err = ext4_journal_get_write_access(handle, dir->i_sb, frame->bh, + EXT4_JTR_NONE); + 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(dir, *bh, hinfo, map); + if (count < 0) { + err = count; + goto journal_error; + } + map -= count; + dx_sort_map(map, count); + /* Ensure that neither split block is over half full */ + 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 + * + * If the sum of active entries didn't exceed half the block size, just + * split it in half by count; each resulting block will have at least + * half the space free. + */ + if (i > 0) + split = count - move; + else + split = count/2; + + 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(dir, data1, data2, map + split, count - split, + blocksize); + de = dx_pack_dirents(dir, 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) { + ext4_initialize_dirent_tail(*bh, blocksize); + ext4_initialize_dirent_tail(bh2, blocksize); + } + + dxtrace(dx_show_leaf(dir, hinfo, (struct ext4_dir_entry_2 *) data1, + blocksize, 1)); + dxtrace(dx_show_leaf(dir, 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_dirblock(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); + return ERR_PTR(err); +} + +int ext4_find_dest_de(struct inode *dir, struct inode *inode, + struct buffer_head *bh, + void *buf, int buf_size, + struct ext4_filename *fname, + struct ext4_dir_entry_2 **dest_de) +{ + struct ext4_dir_entry_2 *de; + unsigned short reclen = ext4_dir_rec_len(fname_len(fname), dir); + int nlen, rlen; + unsigned int offset = 0; + char *top; + + de = buf; + top = buf + buf_size - reclen; + while ((char *) de <= top) { + if (ext4_check_dir_entry(dir, NULL, de, bh, + buf, buf_size, offset)) + return -EFSCORRUPTED; + if (ext4_match(dir, fname, de)) + return -EEXIST; + nlen = ext4_dir_rec_len(de->name_len, dir); + 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 *dir, + struct inode *inode, + struct ext4_dir_entry_2 *de, + int buf_size, + struct ext4_filename *fname) +{ + + int nlen, rlen; + + nlen = ext4_dir_rec_len(de->name_len, dir); + 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 = fname_len(fname); + memcpy(de->name, fname_name(fname), fname_len(fname)); + if (ext4_hash_in_dirent(dir)) { + struct dx_hash_info *hinfo = &fname->hinfo; + + EXT4_DIRENT_HASHES(de)->hash = cpu_to_le32(hinfo->hash); + EXT4_DIRENT_HASHES(de)->minor_hash = + cpu_to_le32(hinfo->minor_hash); + } +} + +/* + * 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 ext4_filename *fname, + struct inode *dir, + struct inode *inode, struct ext4_dir_entry_2 *de, + struct buffer_head *bh) +{ + unsigned int blocksize = dir->i_sb->s_blocksize; + int csum_size = 0; + int err, err2; + + if (ext4_has_metadata_csum(inode->i_sb)) + csum_size = sizeof(struct ext4_dir_entry_tail); + + if (!de) { + err = ext4_find_dest_de(dir, inode, bh, bh->b_data, + blocksize - csum_size, fname, &de); + if (err) + return err; + } + BUFFER_TRACE(bh, "get_write_access"); + err = ext4_journal_get_write_access(handle, dir->i_sb, bh, + EXT4_JTR_NONE); + if (err) { + ext4_std_error(dir->i_sb, err); + return err; + } + + /* By now the buffer is marked for journaling */ + ext4_insert_dentry(dir, inode, de, blocksize, fname); + + /* + * 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 = current_time(dir); + ext4_update_dx_flag(dir); + inode_inc_iversion(dir); + err2 = ext4_mark_inode_dirty(handle, dir); + BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata"); + err = ext4_handle_dirty_dirblock(handle, dir, bh); + if (err) + ext4_std_error(dir->i_sb, err); + return err ? err : err2; +} + +/* + * 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 ext4_filename *fname, + struct inode *dir, + struct inode *inode, struct buffer_head *bh) +{ + struct buffer_head *bh2; + struct dx_root *root; + struct dx_frame frames[EXT4_HTREE_LEVEL], *frame; + struct dx_entry *entries; + struct ext4_dir_entry_2 *de, *de2; + char *data2, *top; + unsigned len; + int retval; + unsigned blocksize; + ext4_lblk_t block; + struct fake_dirent *fde; + int csum_size = 0; + + if (ext4_has_metadata_csum(inode->i_sb)) + 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)); + BUFFER_TRACE(bh, "get_write_access"); + retval = ext4_journal_get_write_access(handle, dir->i_sb, bh, + EXT4_JTR_NONE); + 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 -EFSCORRUPTED; + } + 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); + data2 = bh2->b_data; + + memcpy(data2, de, len); + memset(de, 0, len); /* wipe old data */ + de = (struct ext4_dir_entry_2 *) data2; + top = data2 + len; + while ((char *)(de2 = ext4_next_entry(de, blocksize)) < top) { + if (ext4_check_dir_entry(dir, NULL, de, bh2, data2, len, + (data2 + (blocksize - csum_size) - + (char *) de))) { + brelse(bh2); + brelse(bh); + return -EFSCORRUPTED; + } + de = de2; + } + de->rec_len = ext4_rec_len_to_disk(data2 + (blocksize - csum_size) - + (char *) de, blocksize); + + if (csum_size) + ext4_initialize_dirent_tail(bh2, 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, NULL), blocksize); + memset (&root->info, 0, sizeof(root->info)); + root->info.info_length = sizeof(root->info); + if (ext4_hash_in_dirent(dir)) + root->info.hash_version = DX_HASH_SIPHASH; + else + 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 */ + fname->hinfo.hash_version = root->info.hash_version; + if (fname->hinfo.hash_version <= DX_HASH_TEA) + fname->hinfo.hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned; + fname->hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed; + + /* casefolded encrypted hashes are computed on fname setup */ + if (!ext4_hash_in_dirent(dir)) { + int err = ext4fs_dirhash(dir, fname_name(fname), + fname_len(fname), &fname->hinfo); + if (err < 0) { + brelse(bh2); + brelse(bh); + return err; + } + } + memset(frames, 0, sizeof(frames)); + frame = frames; + frame->entries = entries; + frame->at = entries; + frame->bh = bh; + + retval = ext4_handle_dirty_dx_node(handle, dir, frame->bh); + if (retval) + goto out_frames; + retval = ext4_handle_dirty_dirblock(handle, dir, bh2); + if (retval) + goto out_frames; + + de = do_split(handle,dir, &bh2, frame, &fname->hinfo); + if (IS_ERR(de)) { + retval = PTR_ERR(de); + goto out_frames; + } + + retval = add_dirent_to_buf(handle, fname, dir, inode, de, bh2); +out_frames: + /* + * 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. + */ + if (retval) + ext4_mark_inode_dirty(handle, dir); + dx_release(frames); + brelse(bh2); + 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 = d_inode(dentry->d_parent); + struct buffer_head *bh = NULL; + struct ext4_dir_entry_2 *de; + struct super_block *sb; + struct ext4_filename fname; + int retval; + int dx_fallback=0; + unsigned blocksize; + ext4_lblk_t block, blocks; + int csum_size = 0; + + if (ext4_has_metadata_csum(inode->i_sb)) + csum_size = sizeof(struct ext4_dir_entry_tail); + + sb = dir->i_sb; + blocksize = sb->s_blocksize; + if (!dentry->d_name.len) + return -EINVAL; + + if (fscrypt_is_nokey_name(dentry)) + return -ENOKEY; + +#if IS_ENABLED(CONFIG_UNICODE) + if (sb_has_strict_encoding(sb) && IS_CASEFOLDED(dir) && + sb->s_encoding && utf8_validate(sb->s_encoding, &dentry->d_name)) + return -EINVAL; +#endif + + retval = ext4_fname_setup_filename(dir, &dentry->d_name, 0, &fname); + if (retval) + return retval; + + if (ext4_has_inline_data(dir)) { + retval = ext4_try_add_inline_entry(handle, &fname, dir, inode); + if (retval < 0) + goto out; + if (retval == 1) { + retval = 0; + goto out; + } + } + + if (is_dx(dir)) { + retval = ext4_dx_add_entry(handle, &fname, dir, inode); + if (!retval || (retval != ERR_BAD_DX_DIR)) + goto out; + /* Can we just ignore htree data? */ + if (ext4_has_metadata_csum(sb)) { + EXT4_ERROR_INODE(dir, + "Directory has corrupted htree index."); + retval = -EFSCORRUPTED; + goto out; + } + ext4_clear_inode_flag(dir, EXT4_INODE_INDEX); + dx_fallback++; + retval = ext4_mark_inode_dirty(handle, dir); + if (unlikely(retval)) + goto out; + } + blocks = dir->i_size >> sb->s_blocksize_bits; + for (block = 0; block < blocks; block++) { + bh = ext4_read_dirblock(dir, block, DIRENT); + if (bh == NULL) { + bh = ext4_bread(handle, dir, block, + EXT4_GET_BLOCKS_CREATE); + goto add_to_new_block; + } + if (IS_ERR(bh)) { + retval = PTR_ERR(bh); + bh = NULL; + goto out; + } + retval = add_dirent_to_buf(handle, &fname, dir, inode, + NULL, bh); + if (retval != -ENOSPC) + goto out; + + if (blocks == 1 && !dx_fallback && + ext4_has_feature_dir_index(sb)) { + retval = make_indexed_dir(handle, &fname, dir, + inode, bh); + bh = NULL; /* make_indexed_dir releases bh */ + goto out; + } + brelse(bh); + } + bh = ext4_append(handle, dir, &block); +add_to_new_block: + if (IS_ERR(bh)) { + retval = PTR_ERR(bh); + bh = NULL; + goto out; + } + 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) + ext4_initialize_dirent_tail(bh, blocksize); + + retval = add_dirent_to_buf(handle, &fname, dir, inode, de, bh); +out: + ext4_fname_free_filename(&fname); + 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 ext4_filename *fname, + struct inode *dir, struct inode *inode) +{ + struct dx_frame frames[EXT4_HTREE_LEVEL], *frame; + struct dx_entry *entries, *at; + struct buffer_head *bh; + struct super_block *sb = dir->i_sb; + struct ext4_dir_entry_2 *de; + int restart; + int err; + +again: + restart = 0; + frame = dx_probe(fname, dir, NULL, frames); + if (IS_ERR(frame)) + return PTR_ERR(frame); + entries = frame->entries; + at = frame->at; + bh = ext4_read_dirblock(dir, dx_get_block(frame->at), DIRENT_HTREE); + 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, sb, bh, EXT4_JTR_NONE); + if (err) + goto journal_error; + + err = add_dirent_to_buf(handle, fname, dir, inode, NULL, bh); + if (err != -ENOSPC) + goto cleanup; + + err = 0; + /* 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; + int levels = frame - frames + 1; + unsigned int icount; + int add_level = 1; + struct dx_entry *entries2; + struct dx_node *node2; + struct buffer_head *bh2; + + while (frame > frames) { + if (dx_get_count((frame - 1)->entries) < + dx_get_limit((frame - 1)->entries)) { + add_level = 0; + break; + } + frame--; /* split higher index block */ + at = frame->at; + entries = frame->entries; + restart = 1; + } + if (add_level && levels == ext4_dir_htree_level(sb)) { + ext4_warning(sb, "Directory (ino: %lu) index full, " + "reach max htree level :%d", + dir->i_ino, levels); + if (ext4_dir_htree_level(sb) < EXT4_HTREE_LEVEL) { + ext4_warning(sb, "Large directory feature is " + "not enabled on this " + "filesystem"); + } + err = -ENOSPC; + goto cleanup; + } + icount = dx_get_count(entries); + 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, sb, frame->bh, + EXT4_JTR_NONE); + if (err) + goto journal_error; + if (!add_level) { + 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, sb, + (frame - 1)->bh, + EXT4_JTR_NONE); + 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 - entries - icount1 + entries2; + frame->entries = entries = entries2; + swap(frame->bh, bh2); + } + dx_insert_block((frame - 1), hash2, newblock); + dxtrace(dx_show_index("node", frame->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); + err = ext4_handle_dirty_dx_node(handle, dir, + (frame - 1)->bh); + if (err) + goto journal_error; + err = ext4_handle_dirty_dx_node(handle, dir, + frame->bh); + if (restart || err) + goto journal_error; + } else { + struct dx_root *dxroot; + 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); + dxroot = (struct dx_root *)frames[0].bh->b_data; + dxroot->info.indirect_levels += 1; + dxtrace(printk(KERN_DEBUG + "Creating %d level index...\n", + dxroot->info.indirect_levels)); + err = ext4_handle_dirty_dx_node(handle, dir, frame->bh); + if (err) + goto journal_error; + err = ext4_handle_dirty_dx_node(handle, dir, bh2); + brelse(bh2); + restart = 1; + goto journal_error; + } + } + de = do_split(handle, dir, &bh, frame, &fname->hinfo); + if (IS_ERR(de)) { + err = PTR_ERR(de); + goto cleanup; + } + err = add_dirent_to_buf(handle, fname, dir, inode, de, bh); + goto cleanup; + +journal_error: + ext4_std_error(dir->i_sb, err); /* this is a no-op if err == 0 */ +cleanup: + brelse(bh); + dx_release(frames); + /* @restart is true means htree-path has been changed, we need to + * repeat dx_probe() to find out valid htree-path + */ + if (restart && err == 0) + goto again; + return err; +} + +/* + * ext4_generic_delete_entry deletes a directory entry by merging it + * with the previous entry + */ +int ext4_generic_delete_entry(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 = entry_buf; + while (i < buf_size - csum_size) { + if (ext4_check_dir_entry(dir, NULL, de, bh, + entry_buf, buf_size, i)) + return -EFSCORRUPTED; + 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); + + /* wipe entire dir_entry */ + memset(de, 0, ext4_rec_len_from_disk(de->rec_len, + blocksize)); + } else { + /* wipe dir_entry excluding the rec_len field */ + de->inode = 0; + memset(&de->name_len, 0, + ext4_rec_len_from_disk(de->rec_len, + blocksize) - + offsetof(struct ext4_dir_entry_2, + name_len)); + } + + inode_inc_iversion(dir); + 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_metadata_csum(dir->i_sb)) + csum_size = sizeof(struct ext4_dir_entry_tail); + + BUFFER_TRACE(bh, "get_write_access"); + err = ext4_journal_get_write_access(handle, dir->i_sb, bh, + EXT4_JTR_NONE); + if (unlikely(err)) + goto out; + + err = ext4_generic_delete_entry(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_dirblock(handle, dir, bh); + if (unlikely(err)) + goto out; + + return 0; +out: + if (err != -ENOENT) + ext4_std_error(dir->i_sb, err); + return err; +} + +/* + * Set directory link count to 1 if nlinks > EXT4_LINK_MAX, or if nlinks == 2 + * since this indicates that nlinks count was previously 1 to avoid overflowing + * the 16-bit i_links_count field on disk. Directories with i_nlink == 1 mean + * that subdirectory link counts are not being maintained accurately. + * + * The caller has already checked for i_nlink overflow in case the DIR_LINK + * feature is not enabled and returned -EMLINK. The is_dx() check is a proxy + * for checking S_ISDIR(inode) (since the INODE_INDEX feature will not be set + * on regular files) and to avoid creating huge/slow non-HTREE directories. + */ +static void ext4_inc_count(struct inode *inode) +{ + inc_nlink(inode); + if (is_dx(inode) && + (inode->i_nlink > EXT4_LINK_MAX || inode->i_nlink == 2)) + set_nlink(inode, 1); +} + +/* + * 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(struct inode *inode) +{ + if (!S_ISDIR(inode->i_mode) || inode->i_nlink > 2) + drop_nlink(inode); +} + + +/* + * Add non-directory inode to a directory. On success, the inode reference is + * consumed by dentry is instantiation. This is also indicated by clearing of + * *inodep pointer. On failure, the caller is responsible for dropping the + * inode reference in the safe context. + */ +static int ext4_add_nondir(handle_t *handle, + struct dentry *dentry, struct inode **inodep) +{ + struct inode *dir = d_inode(dentry->d_parent); + struct inode *inode = *inodep; + int err = ext4_add_entry(handle, dentry, inode); + if (!err) { + err = ext4_mark_inode_dirty(handle, inode); + if (IS_DIRSYNC(dir)) + ext4_handle_sync(handle); + d_instantiate_new(dentry, inode); + *inodep = NULL; + return err; + } + drop_nlink(inode); + ext4_mark_inode_dirty(handle, inode); + ext4_orphan_add(handle, inode); + unlock_new_inode(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 user_namespace *mnt_userns, struct inode *dir, + struct dentry *dentry, umode_t mode, bool excl) +{ + handle_t *handle; + struct inode *inode; + int err, credits, retries = 0; + + err = dquot_initialize(dir); + if (err) + return err; + + credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) + + EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3); +retry: + inode = ext4_new_inode_start_handle(mnt_userns, 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) + ext4_fc_track_create(handle, dentry); + } + if (handle) + ext4_journal_stop(handle); + if (!IS_ERR_OR_NULL(inode)) + iput(inode); + if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries)) + goto retry; + return err; +} + +static int ext4_mknod(struct user_namespace *mnt_userns, struct inode *dir, + struct dentry *dentry, umode_t mode, dev_t rdev) +{ + handle_t *handle; + struct inode *inode; + int err, credits, retries = 0; + + err = dquot_initialize(dir); + if (err) + return err; + + credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) + + EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3); +retry: + inode = ext4_new_inode_start_handle(mnt_userns, 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) + ext4_fc_track_create(handle, dentry); + } + if (handle) + ext4_journal_stop(handle); + if (!IS_ERR_OR_NULL(inode)) + iput(inode); + if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries)) + goto retry; + return err; +} + +static int ext4_tmpfile(struct user_namespace *mnt_userns, struct inode *dir, + struct file *file, umode_t mode) +{ + handle_t *handle; + struct inode *inode; + int err, retries = 0; + + err = dquot_initialize(dir); + if (err) + return err; + +retry: + inode = ext4_new_inode_start_handle(mnt_userns, 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(file, 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 finish_open_simple(file, 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, NULL), + 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, NULL)), + blocksize); + else + de->rec_len = ext4_rec_len_to_disk( + ext4_dir_rec_len(de->name_len, NULL), + blocksize); + strcpy(de->name, ".."); + ext4_set_de_type(inode->i_sb, de, S_IFDIR); + + return ext4_next_entry(de, blocksize); +} + +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; + ext4_lblk_t block = 0; + unsigned int blocksize = dir->i_sb->s_blocksize; + int csum_size = 0; + int err; + + if (ext4_has_metadata_csum(dir->i_sb)) + 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); + 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) + ext4_initialize_dirent_tail(dir_block, blocksize); + + BUFFER_TRACE(dir_block, "call ext4_handle_dirty_metadata"); + err = ext4_handle_dirty_dirblock(handle, inode, dir_block); + if (err) + goto out; + set_buffer_verified(dir_block); +out: + brelse(dir_block); + return err; +} + +static int ext4_mkdir(struct user_namespace *mnt_userns, struct inode *dir, + struct dentry *dentry, umode_t mode) +{ + handle_t *handle; + struct inode *inode; + int err, err2 = 0, credits, retries = 0; + + if (EXT4_DIR_LINK_MAX(dir)) + return -EMLINK; + + err = dquot_initialize(dir); + if (err) + return err; + + credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) + + EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3); +retry: + inode = ext4_new_inode_start_handle(mnt_userns, 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); + ext4_orphan_add(handle, inode); + unlock_new_inode(inode); + err2 = ext4_mark_inode_dirty(handle, inode); + if (unlikely(err2)) + err = err2; + ext4_journal_stop(handle); + iput(inode); + goto out_retry; + } + ext4_inc_count(dir); + + ext4_update_dx_flag(dir); + err = ext4_mark_inode_dirty(handle, dir); + if (err) + goto out_clear_inode; + d_instantiate_new(dentry, inode); + ext4_fc_track_create(handle, dentry); + if (IS_DIRSYNC(dir)) + ext4_handle_sync(handle); + +out_stop: + if (handle) + ext4_journal_stop(handle); +out_retry: + 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) + */ +bool ext4_empty_dir(struct inode *inode) +{ + unsigned int offset; + struct buffer_head *bh; + struct ext4_dir_entry_2 *de; + struct super_block *sb; + + if (ext4_has_inline_data(inode)) { + int has_inline_data = 1; + int ret; + + ret = empty_inline_dir(inode, &has_inline_data); + if (has_inline_data) + return ret; + } + + sb = inode->i_sb; + if (inode->i_size < ext4_dir_rec_len(1, NULL) + + ext4_dir_rec_len(2, NULL)) { + EXT4_ERROR_INODE(inode, "invalid size"); + return false; + } + /* The first directory block must not be a hole, + * so treat it as DIRENT_HTREE + */ + bh = ext4_read_dirblock(inode, 0, DIRENT_HTREE); + if (IS_ERR(bh)) + return false; + + de = (struct ext4_dir_entry_2 *) bh->b_data; + if (ext4_check_dir_entry(inode, NULL, de, bh, bh->b_data, bh->b_size, + 0) || + le32_to_cpu(de->inode) != inode->i_ino || strcmp(".", de->name)) { + ext4_warning_inode(inode, "directory missing '.'"); + brelse(bh); + return false; + } + offset = ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize); + de = ext4_next_entry(de, sb->s_blocksize); + if (ext4_check_dir_entry(inode, NULL, de, bh, bh->b_data, bh->b_size, + offset) || + le32_to_cpu(de->inode) == 0 || strcmp("..", de->name)) { + ext4_warning_inode(inode, "directory missing '..'"); + brelse(bh); + return false; + } + offset += ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize); + while (offset < inode->i_size) { + if (!(offset & (sb->s_blocksize - 1))) { + unsigned int lblock; + brelse(bh); + lblock = offset >> EXT4_BLOCK_SIZE_BITS(sb); + bh = ext4_read_dirblock(inode, lblock, EITHER); + if (bh == NULL) { + offset += sb->s_blocksize; + continue; + } + if (IS_ERR(bh)) + return false; + } + de = (struct ext4_dir_entry_2 *) (bh->b_data + + (offset & (sb->s_blocksize - 1))); + if (ext4_check_dir_entry(inode, NULL, de, bh, + bh->b_data, bh->b_size, offset) || + le32_to_cpu(de->inode)) { + brelse(bh); + return false; + } + offset += ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize); + } + brelse(bh); + return true; +} + +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; + + if (unlikely(ext4_forced_shutdown(EXT4_SB(dir->i_sb)))) + return -EIO; + + /* Initialize quotas before so that eventual writes go in + * separate transaction */ + retval = dquot_initialize(dir); + if (retval) + return retval; + retval = dquot_initialize(d_inode(dentry)); + if (retval) + return retval; + + retval = -ENOENT; + bh = ext4_find_entry(dir, &dentry->d_name, &de, NULL); + if (IS_ERR(bh)) + return PTR_ERR(bh); + if (!bh) + goto end_rmdir; + + inode = d_inode(dentry); + + retval = -EFSCORRUPTED; + if (le32_to_cpu(de->inode) != inode->i_ino) + goto end_rmdir; + + retval = -ENOTEMPTY; + if (!ext4_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(inode, + "empty directory '%.*s' has too many links (%u)", + dentry->d_name.len, dentry->d_name.name, + inode->i_nlink); + inode_inc_iversion(inode); + 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 = current_time(inode); + retval = ext4_mark_inode_dirty(handle, inode); + if (retval) + goto end_rmdir; + ext4_dec_count(dir); + ext4_update_dx_flag(dir); + ext4_fc_track_unlink(handle, dentry); + retval = ext4_mark_inode_dirty(handle, dir); + +#if IS_ENABLED(CONFIG_UNICODE) + /* VFS negative dentries are incompatible with Encoding and + * Case-insensitiveness. Eventually we'll want avoid + * invalidating the dentries here, alongside with returning the + * negative dentries at ext4_lookup(), when it is better + * supported by the VFS for the CI case. + */ + if (IS_CASEFOLDED(dir)) + d_invalidate(dentry); +#endif + +end_rmdir: + brelse(bh); + if (handle) + ext4_journal_stop(handle); + return retval; +} + +int __ext4_unlink(struct inode *dir, const struct qstr *d_name, + struct inode *inode, + struct dentry *dentry /* NULL during fast_commit recovery */) +{ + int retval = -ENOENT; + struct buffer_head *bh; + struct ext4_dir_entry_2 *de; + handle_t *handle; + int skip_remove_dentry = 0; + + /* + * Keep this outside the transaction; it may have to set up the + * directory's encryption key, which isn't GFP_NOFS-safe. + */ + bh = ext4_find_entry(dir, d_name, &de, NULL); + if (IS_ERR(bh)) + return PTR_ERR(bh); + + if (!bh) + return -ENOENT; + + if (le32_to_cpu(de->inode) != inode->i_ino) { + /* + * It's okay if we find dont find dentry which matches + * the inode. That's because it might have gotten + * renamed to a different inode number + */ + if (EXT4_SB(inode->i_sb)->s_mount_state & EXT4_FC_REPLAY) + skip_remove_dentry = 1; + else + goto out_bh; + } + + handle = ext4_journal_start(dir, EXT4_HT_DIR, + EXT4_DATA_TRANS_BLOCKS(dir->i_sb)); + if (IS_ERR(handle)) { + retval = PTR_ERR(handle); + goto out_bh; + } + + if (IS_DIRSYNC(dir)) + ext4_handle_sync(handle); + + if (!skip_remove_dentry) { + retval = ext4_delete_entry(handle, dir, de, bh); + if (retval) + goto out_handle; + dir->i_ctime = dir->i_mtime = current_time(dir); + ext4_update_dx_flag(dir); + retval = ext4_mark_inode_dirty(handle, dir); + if (retval) + goto out_handle; + } else { + retval = 0; + } + if (inode->i_nlink == 0) + ext4_warning_inode(inode, "Deleting file '%.*s' with no links", + d_name->len, d_name->name); + else + drop_nlink(inode); + if (!inode->i_nlink) + ext4_orphan_add(handle, inode); + inode->i_ctime = current_time(inode); + retval = ext4_mark_inode_dirty(handle, inode); + if (dentry && !retval) + ext4_fc_track_unlink(handle, dentry); +out_handle: + ext4_journal_stop(handle); +out_bh: + brelse(bh); + return retval; +} + +static int ext4_unlink(struct inode *dir, struct dentry *dentry) +{ + int retval; + + if (unlikely(ext4_forced_shutdown(EXT4_SB(dir->i_sb)))) + return -EIO; + + trace_ext4_unlink_enter(dir, dentry); + /* + * Initialize quotas before so that eventual writes go + * in separate transaction + */ + retval = dquot_initialize(dir); + if (retval) + goto out_trace; + retval = dquot_initialize(d_inode(dentry)); + if (retval) + goto out_trace; + + retval = __ext4_unlink(dir, &dentry->d_name, d_inode(dentry), dentry); +#if IS_ENABLED(CONFIG_UNICODE) + /* VFS negative dentries are incompatible with Encoding and + * Case-insensitiveness. Eventually we'll want avoid + * invalidating the dentries here, alongside with returning the + * negative dentries at ext4_lookup(), when it is better + * supported by the VFS for the CI case. + */ + if (IS_CASEFOLDED(dir)) + d_invalidate(dentry); +#endif + +out_trace: + trace_ext4_unlink_exit(dentry, retval); + return retval; +} + +static int ext4_init_symlink_block(handle_t *handle, struct inode *inode, + struct fscrypt_str *disk_link) +{ + struct buffer_head *bh; + char *kaddr; + int err = 0; + + bh = ext4_bread(handle, inode, 0, EXT4_GET_BLOCKS_CREATE); + if (IS_ERR(bh)) + return PTR_ERR(bh); + + BUFFER_TRACE(bh, "get_write_access"); + err = ext4_journal_get_write_access(handle, inode->i_sb, bh, EXT4_JTR_NONE); + if (err) + goto out; + + kaddr = (char *)bh->b_data; + memcpy(kaddr, disk_link->name, disk_link->len); + inode->i_size = disk_link->len - 1; + EXT4_I(inode)->i_disksize = inode->i_size; + err = ext4_handle_dirty_metadata(handle, inode, bh); +out: + brelse(bh); + return err; +} + +static int ext4_symlink(struct user_namespace *mnt_userns, struct inode *dir, + struct dentry *dentry, const char *symname) +{ + handle_t *handle; + struct inode *inode; + int err, len = strlen(symname); + int credits; + struct fscrypt_str disk_link; + int retries = 0; + + if (unlikely(ext4_forced_shutdown(EXT4_SB(dir->i_sb)))) + return -EIO; + + err = fscrypt_prepare_symlink(dir, symname, len, dir->i_sb->s_blocksize, + &disk_link); + if (err) + return err; + + err = dquot_initialize(dir); + if (err) + return err; + + /* + * EXT4_INDEX_EXTRA_TRANS_BLOCKS for addition of entry into the + * directory. +3 for inode, inode bitmap, group descriptor allocation. + * EXT4_DATA_TRANS_BLOCKS for the data block allocation and + * modification. + */ + credits = EXT4_DATA_TRANS_BLOCKS(dir->i_sb) + + EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3; +retry: + inode = ext4_new_inode_start_handle(mnt_userns, dir, S_IFLNK|S_IRWXUGO, + &dentry->d_name, 0, NULL, + EXT4_HT_DIR, credits); + handle = ext4_journal_current_handle(); + if (IS_ERR(inode)) { + if (handle) + ext4_journal_stop(handle); + err = PTR_ERR(inode); + goto out_retry; + } + + if (IS_ENCRYPTED(inode)) { + err = fscrypt_encrypt_symlink(inode, symname, len, &disk_link); + if (err) + goto err_drop_inode; + inode->i_op = &ext4_encrypted_symlink_inode_operations; + } else { + if ((disk_link.len > EXT4_N_BLOCKS * 4)) { + inode->i_op = &ext4_symlink_inode_operations; + } else { + inode->i_op = &ext4_fast_symlink_inode_operations; + inode->i_link = (char *)&EXT4_I(inode)->i_data; + } + } + + if ((disk_link.len > EXT4_N_BLOCKS * 4)) { + /* alloc symlink block and fill it */ + err = ext4_init_symlink_block(handle, inode, &disk_link); + if (err) + goto err_drop_inode; + } else { + /* clear the extent format for fast symlink */ + ext4_clear_inode_flag(inode, EXT4_INODE_EXTENTS); + memcpy((char *)&EXT4_I(inode)->i_data, disk_link.name, + disk_link.len); + inode->i_size = disk_link.len - 1; + EXT4_I(inode)->i_disksize = inode->i_size; + } + err = ext4_add_nondir(handle, dentry, &inode); + if (handle) + ext4_journal_stop(handle); + iput(inode); + goto out_retry; + +err_drop_inode: + clear_nlink(inode); + ext4_mark_inode_dirty(handle, inode); + ext4_orphan_add(handle, inode); + unlock_new_inode(inode); + if (handle) + ext4_journal_stop(handle); + iput(inode); +out_retry: + if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries)) + goto retry; + if (disk_link.name != (unsigned char *)symname) + kfree(disk_link.name); + return err; +} + +int __ext4_link(struct inode *dir, struct inode *inode, struct dentry *dentry) +{ + handle_t *handle; + int err, retries = 0; +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 = current_time(inode); + ext4_inc_count(inode); + ihold(inode); + + err = ext4_add_entry(handle, dentry, inode); + if (!err) { + 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); + ext4_fc_track_link(handle, dentry); + } 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; +} + +static int ext4_link(struct dentry *old_dentry, + struct inode *dir, struct dentry *dentry) +{ + struct inode *inode = d_inode(old_dentry); + int err; + + if (inode->i_nlink >= EXT4_LINK_MAX) + return -EMLINK; + + err = fscrypt_prepare_link(old_dentry, dir, dentry); + if (err) + return err; + + if ((ext4_test_inode_flag(dir, EXT4_INODE_PROJINHERIT)) && + (!projid_eq(EXT4_I(dir)->i_projid, + EXT4_I(old_dentry->d_inode)->i_projid))) + return -EXDEV; + + err = dquot_initialize(dir); + if (err) + return err; + return __ext4_link(dir, inode, dentry); +} + +/* + * 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)) { + struct ext4_dir_entry_2 *de; + unsigned int offset; + + /* The first directory block must not be a hole, so + * treat it as DIRENT_HTREE + */ + bh = ext4_read_dirblock(inode, 0, DIRENT_HTREE); + if (IS_ERR(bh)) { + *retval = PTR_ERR(bh); + return NULL; + } + + de = (struct ext4_dir_entry_2 *) bh->b_data; + if (ext4_check_dir_entry(inode, NULL, de, bh, bh->b_data, + bh->b_size, 0) || + le32_to_cpu(de->inode) != inode->i_ino || + strcmp(".", de->name)) { + EXT4_ERROR_INODE(inode, "directory missing '.'"); + brelse(bh); + *retval = -EFSCORRUPTED; + return NULL; + } + offset = ext4_rec_len_from_disk(de->rec_len, + inode->i_sb->s_blocksize); + de = ext4_next_entry(de, inode->i_sb->s_blocksize); + if (ext4_check_dir_entry(inode, NULL, de, bh, bh->b_data, + bh->b_size, offset) || + le32_to_cpu(de->inode) == 0 || strcmp("..", de->name)) { + EXT4_ERROR_INODE(inode, "directory missing '..'"); + brelse(bh); + *retval = -EFSCORRUPTED; + return NULL; + } + *parent_de = de; + + return bh; + } + + *inlined = 1; + return ext4_get_first_inline_block(inode, parent_de, retval); +} + +struct ext4_renament { + struct inode *dir; + struct dentry *dentry; + struct inode *inode; + bool is_dir; + int dir_nlink_delta; + + /* entry for "dentry" */ + struct buffer_head *bh; + struct ext4_dir_entry_2 *de; + int inlined; + + /* entry for ".." in inode if it's a directory */ + struct buffer_head *dir_bh; + struct ext4_dir_entry_2 *parent_de; + int dir_inlined; +}; + +static int ext4_rename_dir_prepare(handle_t *handle, struct ext4_renament *ent) +{ + int retval; + + ent->dir_bh = ext4_get_first_dir_block(handle, ent->inode, + &retval, &ent->parent_de, + &ent->dir_inlined); + if (!ent->dir_bh) + return retval; + if (le32_to_cpu(ent->parent_de->inode) != ent->dir->i_ino) + return -EFSCORRUPTED; + BUFFER_TRACE(ent->dir_bh, "get_write_access"); + return ext4_journal_get_write_access(handle, ent->dir->i_sb, + ent->dir_bh, EXT4_JTR_NONE); +} + +static int ext4_rename_dir_finish(handle_t *handle, struct ext4_renament *ent, + unsigned dir_ino) +{ + int retval; + + ent->parent_de->inode = cpu_to_le32(dir_ino); + BUFFER_TRACE(ent->dir_bh, "call ext4_handle_dirty_metadata"); + if (!ent->dir_inlined) { + if (is_dx(ent->inode)) { + retval = ext4_handle_dirty_dx_node(handle, + ent->inode, + ent->dir_bh); + } else { + retval = ext4_handle_dirty_dirblock(handle, ent->inode, + ent->dir_bh); + } + } else { + retval = ext4_mark_inode_dirty(handle, ent->inode); + } + if (retval) { + ext4_std_error(ent->dir->i_sb, retval); + return retval; + } + return 0; +} + +static int ext4_setent(handle_t *handle, struct ext4_renament *ent, + unsigned ino, unsigned file_type) +{ + int retval, retval2; + + BUFFER_TRACE(ent->bh, "get write access"); + retval = ext4_journal_get_write_access(handle, ent->dir->i_sb, ent->bh, + EXT4_JTR_NONE); + if (retval) + return retval; + ent->de->inode = cpu_to_le32(ino); + if (ext4_has_feature_filetype(ent->dir->i_sb)) + ent->de->file_type = file_type; + inode_inc_iversion(ent->dir); + ent->dir->i_ctime = ent->dir->i_mtime = + current_time(ent->dir); + retval = ext4_mark_inode_dirty(handle, ent->dir); + BUFFER_TRACE(ent->bh, "call ext4_handle_dirty_metadata"); + if (!ent->inlined) { + retval2 = ext4_handle_dirty_dirblock(handle, ent->dir, ent->bh); + if (unlikely(retval2)) { + ext4_std_error(ent->dir->i_sb, retval2); + return retval2; + } + } + return retval; +} + +static void ext4_resetent(handle_t *handle, struct ext4_renament *ent, + unsigned ino, unsigned file_type) +{ + struct ext4_renament old = *ent; + int retval = 0; + + /* + * old->de could have moved from under us during make indexed dir, + * so the old->de may no longer valid and need to find it again + * before reset old inode info. + */ + old.bh = ext4_find_entry(old.dir, &old.dentry->d_name, &old.de, + &old.inlined); + if (IS_ERR(old.bh)) + retval = PTR_ERR(old.bh); + if (!old.bh) + retval = -ENOENT; + if (retval) { + ext4_std_error(old.dir->i_sb, retval); + return; + } + + ext4_setent(handle, &old, ino, file_type); + brelse(old.bh); +} + +static int ext4_find_delete_entry(handle_t *handle, struct inode *dir, + const struct qstr *d_name) +{ + int retval = -ENOENT; + struct buffer_head *bh; + struct ext4_dir_entry_2 *de; + + bh = ext4_find_entry(dir, d_name, &de, NULL); + if (IS_ERR(bh)) + return PTR_ERR(bh); + if (bh) { + retval = ext4_delete_entry(handle, dir, de, bh); + brelse(bh); + } + return retval; +} + +static void ext4_rename_delete(handle_t *handle, struct ext4_renament *ent, + int force_reread) +{ + int retval; + /* + * ent->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 ent->bh so just checking inum + * and the name isn't enough. + */ + if (le32_to_cpu(ent->de->inode) != ent->inode->i_ino || + ent->de->name_len != ent->dentry->d_name.len || + strncmp(ent->de->name, ent->dentry->d_name.name, + ent->de->name_len) || + force_reread) { + retval = ext4_find_delete_entry(handle, ent->dir, + &ent->dentry->d_name); + } else { + retval = ext4_delete_entry(handle, ent->dir, ent->de, ent->bh); + if (retval == -ENOENT) { + retval = ext4_find_delete_entry(handle, ent->dir, + &ent->dentry->d_name); + } + } + + if (retval) { + ext4_warning_inode(ent->dir, + "Deleting old file: nlink %d, error=%d", + ent->dir->i_nlink, retval); + } +} + +static void ext4_update_dir_count(handle_t *handle, struct ext4_renament *ent) +{ + if (ent->dir_nlink_delta) { + if (ent->dir_nlink_delta == -1) + ext4_dec_count(ent->dir); + else + ext4_inc_count(ent->dir); + ext4_mark_inode_dirty(handle, ent->dir); + } +} + +static struct inode *ext4_whiteout_for_rename(struct user_namespace *mnt_userns, + struct ext4_renament *ent, + int credits, handle_t **h) +{ + struct inode *wh; + handle_t *handle; + int retries = 0; + + /* + * for inode block, sb block, group summaries, + * and inode bitmap + */ + credits += (EXT4_MAXQUOTAS_TRANS_BLOCKS(ent->dir->i_sb) + + EXT4_XATTR_TRANS_BLOCKS + 4); +retry: + wh = ext4_new_inode_start_handle(mnt_userns, ent->dir, + S_IFCHR | WHITEOUT_MODE, + &ent->dentry->d_name, 0, NULL, + EXT4_HT_DIR, credits); + + handle = ext4_journal_current_handle(); + if (IS_ERR(wh)) { + if (handle) + ext4_journal_stop(handle); + if (PTR_ERR(wh) == -ENOSPC && + ext4_should_retry_alloc(ent->dir->i_sb, &retries)) + goto retry; + } else { + *h = handle; + init_special_inode(wh, wh->i_mode, WHITEOUT_DEV); + wh->i_op = &ext4_special_inode_operations; + } + return wh; +} + +/* + * 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 user_namespace *mnt_userns, struct inode *old_dir, + struct dentry *old_dentry, struct inode *new_dir, + struct dentry *new_dentry, unsigned int flags) +{ + handle_t *handle = NULL; + struct ext4_renament old = { + .dir = old_dir, + .dentry = old_dentry, + .inode = d_inode(old_dentry), + }; + struct ext4_renament new = { + .dir = new_dir, + .dentry = new_dentry, + .inode = d_inode(new_dentry), + }; + int force_reread; + int retval; + struct inode *whiteout = NULL; + int credits; + u8 old_file_type; + + if (new.inode && new.inode->i_nlink == 0) { + EXT4_ERROR_INODE(new.inode, + "target of rename is already freed"); + return -EFSCORRUPTED; + } + + if ((ext4_test_inode_flag(new_dir, EXT4_INODE_PROJINHERIT)) && + (!projid_eq(EXT4_I(new_dir)->i_projid, + EXT4_I(old_dentry->d_inode)->i_projid))) + return -EXDEV; + + retval = dquot_initialize(old.dir); + if (retval) + return retval; + retval = dquot_initialize(old.inode); + if (retval) + return retval; + retval = dquot_initialize(new.dir); + if (retval) + return retval; + + /* Initialize quotas before so that eventual writes go + * in separate transaction */ + if (new.inode) { + retval = dquot_initialize(new.inode); + if (retval) + return retval; + } + + old.bh = ext4_find_entry(old.dir, &old.dentry->d_name, &old.de, + &old.inlined); + if (IS_ERR(old.bh)) + return PTR_ERR(old.bh); + + /* + * 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 ;-< + */ + retval = -ENOENT; + if (!old.bh || le32_to_cpu(old.de->inode) != old.inode->i_ino) + goto release_bh; + + new.bh = ext4_find_entry(new.dir, &new.dentry->d_name, + &new.de, &new.inlined); + if (IS_ERR(new.bh)) { + retval = PTR_ERR(new.bh); + new.bh = NULL; + goto release_bh; + } + 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); + + credits = (2 * EXT4_DATA_TRANS_BLOCKS(old.dir->i_sb) + + EXT4_INDEX_EXTRA_TRANS_BLOCKS + 2); + if (!(flags & RENAME_WHITEOUT)) { + handle = ext4_journal_start(old.dir, EXT4_HT_DIR, credits); + if (IS_ERR(handle)) { + retval = PTR_ERR(handle); + goto release_bh; + } + } else { + whiteout = ext4_whiteout_for_rename(mnt_userns, &old, credits, &handle); + if (IS_ERR(whiteout)) { + retval = PTR_ERR(whiteout); + goto release_bh; + } + } + + old_file_type = old.de->file_type; + 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 (!ext4_empty_dir(new.inode)) + goto end_rename; + } else { + retval = -EMLINK; + if (new.dir != old.dir && EXT4_DIR_LINK_MAX(new.dir)) + goto end_rename; + } + retval = ext4_rename_dir_prepare(handle, &old); + if (retval) + goto end_rename; + } + /* + * If we're renaming a file within an inline_data dir and adding or + * setting the new dirent causes a conversion from inline_data to + * extents/blockmap, we need to force the dirent delete code to + * re-read the directory, or else we end up trying to delete a dirent + * from what is now the extent tree root (or a block map). + */ + force_reread = (new.dir->i_ino == old.dir->i_ino && + ext4_test_inode_flag(new.dir, EXT4_INODE_INLINE_DATA)); + + if (whiteout) { + /* + * Do this before adding a new entry, so the old entry is sure + * to be still pointing to the valid old entry. + */ + retval = ext4_setent(handle, &old, whiteout->i_ino, + EXT4_FT_CHRDEV); + if (retval) + goto end_rename; + retval = ext4_mark_inode_dirty(handle, whiteout); + if (unlikely(retval)) + goto end_rename; + + } + if (!new.bh) { + retval = ext4_add_entry(handle, new.dentry, old.inode); + if (retval) + goto end_rename; + } else { + retval = ext4_setent(handle, &new, + old.inode->i_ino, old_file_type); + if (retval) + goto end_rename; + } + if (force_reread) + force_reread = !ext4_test_inode_flag(new.dir, + EXT4_INODE_INLINE_DATA); + + /* + * Like most other Unix systems, set the ctime for inodes on a + * rename. + */ + old.inode->i_ctime = current_time(old.inode); + retval = ext4_mark_inode_dirty(handle, old.inode); + if (unlikely(retval)) + goto end_rename; + + if (!whiteout) { + /* + * ok, that's it + */ + ext4_rename_delete(handle, &old, force_reread); + } + + if (new.inode) { + ext4_dec_count(new.inode); + new.inode->i_ctime = current_time(new.inode); + } + old.dir->i_ctime = old.dir->i_mtime = current_time(old.dir); + ext4_update_dx_flag(old.dir); + if (old.dir_bh) { + retval = ext4_rename_dir_finish(handle, &old, new.dir->i_ino); + if (retval) + goto end_rename; + + ext4_dec_count(old.dir); + if (new.inode) { + /* checked ext4_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(new.dir); + ext4_update_dx_flag(new.dir); + retval = ext4_mark_inode_dirty(handle, new.dir); + if (unlikely(retval)) + goto end_rename; + } + } + retval = ext4_mark_inode_dirty(handle, old.dir); + if (unlikely(retval)) + goto end_rename; + + if (S_ISDIR(old.inode->i_mode)) { + /* + * We disable fast commits here that's because the + * replay code is not yet capable of changing dot dot + * dirents in directories. + */ + ext4_fc_mark_ineligible(old.inode->i_sb, + EXT4_FC_REASON_RENAME_DIR, handle); + } else { + struct super_block *sb = old.inode->i_sb; + + if (new.inode) + ext4_fc_track_unlink(handle, new.dentry); + if (test_opt2(sb, JOURNAL_FAST_COMMIT) && + !(EXT4_SB(sb)->s_mount_state & EXT4_FC_REPLAY) && + !(ext4_test_mount_flag(sb, EXT4_MF_FC_INELIGIBLE))) { + __ext4_fc_track_link(handle, old.inode, new.dentry); + __ext4_fc_track_unlink(handle, old.inode, old.dentry); + if (whiteout) + __ext4_fc_track_create(handle, whiteout, + old.dentry); + } + } + + if (new.inode) { + retval = ext4_mark_inode_dirty(handle, new.inode); + if (unlikely(retval)) + goto end_rename; + if (!new.inode->i_nlink) + ext4_orphan_add(handle, new.inode); + } + retval = 0; + +end_rename: + if (whiteout) { + if (retval) { + ext4_resetent(handle, &old, + old.inode->i_ino, old_file_type); + drop_nlink(whiteout); + ext4_mark_inode_dirty(handle, whiteout); + ext4_orphan_add(handle, whiteout); + } + unlock_new_inode(whiteout); + ext4_journal_stop(handle); + iput(whiteout); + } else { + ext4_journal_stop(handle); + } +release_bh: + brelse(old.dir_bh); + brelse(old.bh); + brelse(new.bh); + + return retval; +} + +static int ext4_cross_rename(struct inode *old_dir, struct dentry *old_dentry, + struct inode *new_dir, struct dentry *new_dentry) +{ + handle_t *handle = NULL; + struct ext4_renament old = { + .dir = old_dir, + .dentry = old_dentry, + .inode = d_inode(old_dentry), + }; + struct ext4_renament new = { + .dir = new_dir, + .dentry = new_dentry, + .inode = d_inode(new_dentry), + }; + u8 new_file_type; + int retval; + struct timespec64 ctime; + + if ((ext4_test_inode_flag(new_dir, EXT4_INODE_PROJINHERIT) && + !projid_eq(EXT4_I(new_dir)->i_projid, + EXT4_I(old_dentry->d_inode)->i_projid)) || + (ext4_test_inode_flag(old_dir, EXT4_INODE_PROJINHERIT) && + !projid_eq(EXT4_I(old_dir)->i_projid, + EXT4_I(new_dentry->d_inode)->i_projid))) + return -EXDEV; + + retval = dquot_initialize(old.dir); + if (retval) + return retval; + retval = dquot_initialize(new.dir); + if (retval) + return retval; + + old.bh = ext4_find_entry(old.dir, &old.dentry->d_name, + &old.de, &old.inlined); + if (IS_ERR(old.bh)) + return PTR_ERR(old.bh); + /* + * 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 ;-< + */ + retval = -ENOENT; + if (!old.bh || le32_to_cpu(old.de->inode) != old.inode->i_ino) + goto end_rename; + + new.bh = ext4_find_entry(new.dir, &new.dentry->d_name, + &new.de, &new.inlined); + if (IS_ERR(new.bh)) { + retval = PTR_ERR(new.bh); + new.bh = NULL; + goto end_rename; + } + + /* RENAME_EXCHANGE case: old *and* new must both exist */ + if (!new.bh || le32_to_cpu(new.de->inode) != new.inode->i_ino) + goto end_rename; + + handle = ext4_journal_start(old.dir, EXT4_HT_DIR, + (2 * EXT4_DATA_TRANS_BLOCKS(old.dir->i_sb) + + 2 * EXT4_INDEX_EXTRA_TRANS_BLOCKS + 2)); + if (IS_ERR(handle)) { + retval = PTR_ERR(handle); + handle = NULL; + goto end_rename; + } + + if (IS_DIRSYNC(old.dir) || IS_DIRSYNC(new.dir)) + ext4_handle_sync(handle); + + if (S_ISDIR(old.inode->i_mode)) { + old.is_dir = true; + retval = ext4_rename_dir_prepare(handle, &old); + if (retval) + goto end_rename; + } + if (S_ISDIR(new.inode->i_mode)) { + new.is_dir = true; + retval = ext4_rename_dir_prepare(handle, &new); + if (retval) + goto end_rename; + } + + /* + * Other than the special case of overwriting a directory, parents' + * nlink only needs to be modified if this is a cross directory rename. + */ + if (old.dir != new.dir && old.is_dir != new.is_dir) { + old.dir_nlink_delta = old.is_dir ? -1 : 1; + new.dir_nlink_delta = -old.dir_nlink_delta; + retval = -EMLINK; + if ((old.dir_nlink_delta > 0 && EXT4_DIR_LINK_MAX(old.dir)) || + (new.dir_nlink_delta > 0 && EXT4_DIR_LINK_MAX(new.dir))) + goto end_rename; + } + + new_file_type = new.de->file_type; + retval = ext4_setent(handle, &new, old.inode->i_ino, old.de->file_type); + if (retval) + goto end_rename; + + retval = ext4_setent(handle, &old, new.inode->i_ino, new_file_type); + if (retval) + goto end_rename; + + /* + * Like most other Unix systems, set the ctime for inodes on a + * rename. + */ + ctime = current_time(old.inode); + old.inode->i_ctime = ctime; + new.inode->i_ctime = ctime; + retval = ext4_mark_inode_dirty(handle, old.inode); + if (unlikely(retval)) + goto end_rename; + retval = ext4_mark_inode_dirty(handle, new.inode); + if (unlikely(retval)) + goto end_rename; + ext4_fc_mark_ineligible(new.inode->i_sb, + EXT4_FC_REASON_CROSS_RENAME, handle); + if (old.dir_bh) { + retval = ext4_rename_dir_finish(handle, &old, new.dir->i_ino); + if (retval) + goto end_rename; + } + if (new.dir_bh) { + retval = ext4_rename_dir_finish(handle, &new, old.dir->i_ino); + if (retval) + goto end_rename; + } + ext4_update_dir_count(handle, &old); + ext4_update_dir_count(handle, &new); + retval = 0; + +end_rename: + brelse(old.dir_bh); + brelse(new.dir_bh); + brelse(old.bh); + brelse(new.bh); + if (handle) + ext4_journal_stop(handle); + return retval; +} + +static int ext4_rename2(struct user_namespace *mnt_userns, + struct inode *old_dir, struct dentry *old_dentry, + struct inode *new_dir, struct dentry *new_dentry, + unsigned int flags) +{ + int err; + + if (unlikely(ext4_forced_shutdown(EXT4_SB(old_dir->i_sb)))) + return -EIO; + + if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE | RENAME_WHITEOUT)) + return -EINVAL; + + err = fscrypt_prepare_rename(old_dir, old_dentry, new_dir, new_dentry, + flags); + if (err) + return err; + + if (flags & RENAME_EXCHANGE) { + return ext4_cross_rename(old_dir, old_dentry, + new_dir, new_dentry); + } + + return ext4_rename(mnt_userns, old_dir, old_dentry, new_dir, new_dentry, flags); +} + +/* + * 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_rename2, + .setattr = ext4_setattr, + .getattr = ext4_getattr, + .listxattr = ext4_listxattr, + .get_acl = ext4_get_acl, + .set_acl = ext4_set_acl, + .fiemap = ext4_fiemap, + .fileattr_get = ext4_fileattr_get, + .fileattr_set = ext4_fileattr_set, +}; + +const struct inode_operations ext4_special_inode_operations = { + .setattr = ext4_setattr, + .getattr = ext4_getattr, + .listxattr = ext4_listxattr, + .get_acl = ext4_get_acl, + .set_acl = ext4_set_acl, +}; |