Minki/linux
1
0
Fork 1
mirror of https://github.com/torvalds/linux.git synced 2024-11-22 12:11:40 +00:00
Code Issues Packages Projects Releases Wiki Activity
c3be7ebbbc
linux/fs/ext4/namei.c
Thadeu Lima de Souza Cascardo 51e14e78b5 ext4: explicitly exit when ext4_find_inline_entry returns an error 
__ext4_find_entry currently ignores the return of ext4_find_inline_entry,
except for returning the bh or NULL when has_inline_data is 1.

Even though has_inline_data is set to 1 before calling
ext4_find_inline_entry and would only be set to 0 when that function
returns NULL, check for an encoded error return explicitly in order to
exit.

That makes the code more readable, not requiring that one assumes the cases
when has_inline_data is 1.

Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@igalia.com>
Link: https://patch.msgid.link/20240821152324.3621860-4-cascardo@igalia.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2024-09-03 22:12:16 -04:00

4243 lines
111 KiB
C
Raw Blame History

// 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;
}
/* The first directory block must not be a hole. */
if (!bh && (type == INDEX || type == DIRENT_HTREE || block == 0)) {
ext4_error_inode(inode, func, line, block,
"Directory hole found for htree %s block %u",
(type == INDEX) ? "index" : "leaf", block);
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)
int ext4_fname_setup_ci_filename(struct inode *dir, const struct qstr *iname,
struct ext4_filename *name)
{
struct qstr *cf_name = &name->cf_name;
unsigned char *buf;
struct dx_hash_info *hinfo = &name->hinfo;
int len;
if (!IS_CASEFOLDED(dir) ||
(IS_ENCRYPTED(dir) && !fscrypt_has_encryption_key(dir))) {
cf_name->name = NULL;
return 0;
}
buf = kmalloc(EXT4_NAME_LEN, GFP_NOFS);
if (!buf)
return -ENOMEM;
len = utf8_casefold(dir->i_sb->s_encoding, iname, buf, EXT4_NAME_LEN);
if (len <= 0) {
kfree(buf);
buf = NULL;
}
cf_name->name = buf;
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 (IS_CASEFOLDED(parent) &&
(!IS_ENCRYPTED(parent) || fscrypt_has_encryption_key(parent))) {
/*
* Just checking IS_ENCRYPTED(parent) below is not
* sufficient to decide whether one can use the hash for
* skipping the string comparison, because the key might
* have been added right after
* ext4_fname_setup_ci_filename(). In this case, a hash
* mismatch will be a false negative. Therefore, make
* sure cf_name was properly initialized before
* considering the calculated hash.
*/
if (IS_ENCRYPTED(parent) && fname->cf_name.name &&
(fname->hinfo.hash != EXT4_DIRENT_HASH(de) ||
fname->hinfo.minor_hash != EXT4_DIRENT_MINOR_HASH(de)))
return false;
/*
* Treat comparison errors as not a match. The
* only case where it happens is on a disk
* corruption or ENOMEM.
*/
return generic_ci_match(parent, fname->usr_fname,
&fname->cf_name, de->name,
de->name_len) > 0;
}
#endif
return fscrypt_match_name(&f, de->name, de->name_len);
}
/*
* Returns 0 if not found, -EFSCORRUPTED 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 -EFSCORRUPTED;
*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 -EFSCORRUPTED;
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 || IS_ERR(ret))
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) {
ret = ERR_PTR(i);
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);
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 < 0) {
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) && !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;
}
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 = split > 0 ? hash2 == map[split - 1].hash : 0;
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.
*/
inode_set_mtime_to_ts(dir, inode_set_ctime_current(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;
}
static bool ext4_check_dx_root(struct inode *dir, struct dx_root *root)
{
struct fake_dirent *fde;
const char *error_msg;
unsigned int rlen;
unsigned int blocksize = dir->i_sb->s_blocksize;
char *blockend = (char *)root + dir->i_sb->s_blocksize;
fde = &root->dot;
if (unlikely(fde->name_len != 1)) {
error_msg = "invalid name_len for '.'";
goto corrupted;
}
if (unlikely(strncmp(root->dot_name, ".", fde->name_len))) {
error_msg = "invalid name for '.'";
goto corrupted;
}
rlen = ext4_rec_len_from_disk(fde->rec_len, blocksize);
if (unlikely((char *)fde + rlen >= blockend)) {
error_msg = "invalid rec_len for '.'";
goto corrupted;
}
fde = &root->dotdot;
if (unlikely(fde->name_len != 2)) {
error_msg = "invalid name_len for '..'";
goto corrupted;
}
if (unlikely(strncmp(root->dotdot_name, "..", fde->name_len))) {
error_msg = "invalid name for '..'";
goto corrupted;
}
rlen = ext4_rec_len_from_disk(fde->rec_len, blocksize);
if (unlikely((char *)fde + rlen >= blockend)) {
error_msg = "invalid rec_len for '..'";
goto corrupted;
}
return true;
corrupted:
EXT4_ERROR_INODE(dir, "Corrupt dir, %s, running e2fsck is recommended",
error_msg);
return false;
}
/*
* 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;
if (!ext4_check_dx_root(dir, root)) {
brelse(bh);
return -EFSCORRUPTED;
}
/* 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));
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,
(char *)de - data2)) {
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 (fscrypt_is_nokey_name(dentry))
return -ENOKEY;
#if IS_ENABLED(CONFIG_UNICODE)
if (sb_has_strict_encoding(sb) && IS_CASEFOLDED(dir) &&
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 mnt_idmap *idmap, 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(idmap, 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 mnt_idmap *idmap, 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(idmap, 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 mnt_idmap *idmap, 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(idmap, dir, mode,
NULL, 0, NULL,
EXT4_HT_DIR,
EXT4_MAXQUOTAS_TRANS_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 mnt_idmap *idmap, 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(idmap, 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;
}
bh = ext4_read_dirblock(inode, 0, EITHER);
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(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_set_mtime_to_ts(dir, inode_set_ctime_current(dir));
inode_set_ctime_current(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);
/* 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_ENABLED(CONFIG_UNICODE) && IS_CASEFOLDED(dir))
d_invalidate(dentry);
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;
inode_set_mtime_to_ts(dir, inode_set_ctime_current(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_set_ctime_current(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(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);
/* 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_ENABLED(CONFIG_UNICODE) && IS_CASEFOLDED(dir))
d_invalidate(dentry);
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 mnt_idmap *idmap, 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(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(idmap, 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_set_ctime_current(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;
bh = ext4_read_dirblock(inode, 0, EITHER);
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, bool is_cross)
{
int retval;
ent->is_dir = true;
if (!is_cross)
return 0;
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;
if (!ent->dir_bh)
return 0;
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);
inode_set_mtime_to_ts(ent->dir, inode_set_ctime_current(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 mnt_idmap *idmap,
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(idmap, 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 mnt_idmap *idmap, 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(idmap, &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, new.dir != old.dir);
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.
*/
inode_set_ctime_current(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);
inode_set_ctime_current(new.inode);
}
inode_set_mtime_to_ts(old.dir, inode_set_ctime_current(old.dir));
ext4_update_dx_flag(old.dir);
if (old.is_dir) {
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 (old.is_dir) {
/*
* 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;
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)) {
retval = ext4_rename_dir_prepare(handle, &old, new.dir != old.dir);
if (retval)
goto end_rename;
}
if (S_ISDIR(new.inode->i_mode)) {
retval = ext4_rename_dir_prepare(handle, &new, new.dir != old.dir);
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.
*/
inode_set_ctime_current(old.inode);
inode_set_ctime_current(new.inode);
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 mnt_idmap *idmap,
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(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(idmap, 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_inode_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_inode_acl = ext4_get_acl,
.set_acl = ext4_set_acl,
};
Reference in New Issue View Git Blame Copy Permalink