| // 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; |
| BUFFER_TRACE(bh, "get_write_access"); |
| err = ext4_journal_get_write_access(handle, bh); |
| if (err) { |
| brelse(bh); |
| ext4_std_error(inode->i_sb, err); |
| return ERR_PTR(err); |
| } |
| return bh; |
| } |
| |
| static int ext4_dx_csum_verify(struct inode *inode, |
| struct ext4_dir_entry *dirent); |
| |
| /* |
| * 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; |
| } |
| |
| #ifndef assert |
| #define assert(test) J_ASSERT(test) |
| #endif |
| |
| #ifdef DX_DEBUG |
| #define dxtrace(command) command |
| #else |
| #define dxtrace(command) |
| #endif |
| |
| struct fake_dirent |
| { |
| __le32 inode; |
| __le16 rec_len; |
| u8 name_len; |
| u8 file_type; |
| }; |
| |
| struct dx_countlimit |
| { |
| __le16 limit; |
| __le16 count; |
| }; |
| |
| struct dx_entry |
| { |
| __le32 hash; |
| __le32 block; |
| }; |
| |
| /* |
| * dx_root_info is laid out so that if it should somehow get overlaid by a |
| * dirent the two low bits of the hash version will be zero. Therefore, the |
| * hash version mod 4 should never be 0. Sincerely, the paranoia department. |
| */ |
| |
| struct dx_root |
| { |
| struct fake_dirent dot; |
| char dot_name[4]; |
| struct fake_dirent dotdot; |
| char dotdot_name[4]; |
| struct dx_root_info |
| { |
| __le32 reserved_zero; |
| u8 hash_version; |
| u8 info_length; /* 8 */ |
| u8 indirect_levels; |
| u8 unused_flags; |
| } |
| info; |
| struct dx_entry entries[]; |
| }; |
| |
| 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 */ |
| 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 |
| 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; |
| 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}; |
| } |
| #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))) |
| ext4fs_dirhash(dir, fname_name(fname), fname_len(fname), hinfo); |
| 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; |
| } |
| |
| if (0) { // linear search cross check |
| unsigned n = count - 1; |
| at = entries; |
| while (n--) |
| { |
| dxtrace(printk(KERN_CONT ",")); |
| if (dx_get_hash(++at) > hash) |
| { |
| at--; |
| break; |
| } |
| } |
| assert (at == p - 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 { |
| ext4fs_dirhash(dir, de->name, de->name_len, hinfo); |
| } |
| if ((hinfo->hash < start_hash) || |
| ((hinfo->hash == start_hash) && |
| (hinfo->minor_hash < start_minor_hash))) |
| continue; |
| if (de->inode == 0) |
| continue; |
| if (!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 |
| ext4fs_dirhash(dir, de->name, de->name_len, &h); |
| 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); |
| } |
| |
| #ifdef 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) |
| ext4fs_dirhash(dir, cf_name->name, cf_name->len, hinfo); |
| else |
| ext4fs_dirhash(dir, iname->name, iname->len, hinfo); |
| return 0; |
| } |
| #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 |
| |
| #ifdef 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 0; |
| } |
| } |
| 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); |
| } |
| } |
| |
| #ifdef 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; |
| static const struct qstr dotdot = QSTR_INIT("..", 2); |
| struct ext4_dir_entry_2 * de; |
| struct buffer_head *bh; |
| |
| bh = ext4_find_entry(d_inode(child), &dotdot, &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); |
| de->inode = 0; |
| map++; |
| to += rec_len; |
| } |
| return (struct ext4_dir_entry_2 *) (to - rec_len); |
| } |
| |
| /* |
| * Compact each dir entry in the range to the minimal rec_len. |
| * Returns pointer to last entry in range. |
| */ |
| static struct ext4_dir_entry_2 *dx_pack_dirents(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, *bh); |
| if (err) |
| goto journal_error; |
| |
| BUFFER_TRACE(frame->bh, "get_write_access"); |
| err = ext4_journal_get_write_access(handle, frame->bh); |
| if (err) |
| goto journal_error; |
| |
| data2 = bh2->b_data; |
| |
| /* create map in the end of data2 block */ |
| map = (struct dx_map_entry *) (data2 + blocksize); |
| count = dx_make_map(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 = (struct ext4_dir_entry_2 *)buf; |
| top = buf + buf_size - reclen; |
| while ((char *) de <= top) { |
| if (ext4_check_dir_entry(dir, NULL, de, bh, |
| buf, buf_size, offset)) |
| return -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, bh); |
| 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, bh); |
| if (retval) { |
| ext4_std_error(dir->i_sb, retval); |
| brelse(bh); |
| return retval; |
| } |
| root = (struct dx_root *) bh->b_data; |
| |
| /* The 0th block becomes the root, move the dirents out */ |
| fde = &root->dotdot; |
| de = (struct ext4_dir_entry_2 *)((char *)fde + |
| ext4_rec_len_from_disk(fde->rec_len, blocksize)); |
| if ((char *) de >= (((char *) root) + blocksize)) { |
| EXT4_ERROR_INODE(dir, "invalid rec_len for '..'"); |
| brelse(bh); |
| return -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); |
| 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)) |
| ext4fs_dirhash(dir, fname_name(fname), |
| fname_len(fname), &fname->hinfo); |
| |
| 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; |
| |
| #ifdef 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, bh); |
| 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, frame->bh); |
| 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, |
| (frame - 1)->bh); |
| if (err) |
| goto journal_error; |
| |
| memcpy((char *) entries2, (char *) (entries + icount1), |
| icount2 * sizeof(struct dx_entry)); |
| dx_set_count(entries, icount1); |
| dx_set_count(entries2, icount2); |
| dx_set_limit(entries2, dx_node_limit(dir)); |
| |
| /* Which index block gets the new entry? */ |
| if (at - entries >= icount1) { |
| frame->at = at = at - entries - icount1 + entries2; |
| frame->entries = entries = entries2; |
| swap(frame->bh, bh2); |
| } |
| dx_insert_block((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 = (struct ext4_dir_entry_2 *)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); |
| else |
| de->inode = 0; |
| 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, bh); |
| 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_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 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(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 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(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 inode *dir, struct dentry *dentry, 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(dir, mode, |
| NULL, 0, NULL, |
| EXT4_HT_DIR, |
| EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb) + |
| 4 + EXT4_XATTR_TRANS_BLOCKS); |
| handle = ext4_journal_current_handle(); |
| err = PTR_ERR(inode); |
| if (!IS_ERR(inode)) { |
| inode->i_op = &ext4_file_inode_operations; |
| inode->i_fop = &ext4_file_operations; |
| ext4_set_aops(inode); |
| d_tmpfile(dentry, inode); |
| err = ext4_orphan_add(handle, inode); |
| if (err) |
| goto err_unlock_inode; |
| mark_inode_dirty(inode); |
| unlock_new_inode(inode); |
| } |
| if (handle) |
| ext4_journal_stop(handle); |
| if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries)) |
| goto retry; |
| return err; |
| err_unlock_inode: |
| ext4_journal_stop(handle); |
| unlock_new_inode(inode); |
| return err; |
| } |
| |
| struct ext4_dir_entry_2 *ext4_init_dot_dotdot(struct inode *inode, |
| struct ext4_dir_entry_2 *de, |
| int blocksize, int csum_size, |
| unsigned int parent_ino, int dotdot_real_len) |
| { |
| de->inode = cpu_to_le32(inode->i_ino); |
| de->name_len = 1; |
| de->rec_len = ext4_rec_len_to_disk(ext4_dir_rec_len(de->name_len, 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); |
|