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ubuntu-linux-kernel/fs/ext4/namei.c

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// 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 "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 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;
bh = ext4_bread(handle, inode, *block, EXT4_GET_BLOCKS_CREATE);
if (IS_ERR(bh))
return bh;
inode->i_size += inode->i_sb->s_blocksize;
EXT4_I(inode)->i_disksize = inode->i_size;
BUFFER_TRACE(bh, "get_write_access");
err = ext4_journal_get_write_access(handle, bh);
if (err) {
brelse(bh);
ext4_std_error(inode->i_sb, err);
return ERR_PTR(err);
}
return bh;
}
static int ext4_dx_csum_verify(struct inode *inode,
struct ext4_dir_entry *dirent);
typedef enum {
EITHER, INDEX, DIRENT
} 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;
bh = ext4_bread(NULL, inode, block, 0);
if (IS_ERR(bh)) {
__ext4_warning(inode->i_sb, func, line,
"inode #%lu: lblock %lu: comm %s: "
"error %ld reading directory block",
inode->i_ino, (unsigned long)block,
current->comm, PTR_ERR(bh));
return bh;
}
if (!bh) {
ext4_error_inode(inode, func, line, block,
"Directory hole found");
return ERR_PTR(-EFSCORRUPTED);
}
dirent = (struct ext4_dir_entry *) bh->b_data;
/* Determine whether or not we have an index block */
if (is_dx(inode)) {
if (block == 0)
is_dx_block = 1;
else if (ext4_rec_len_from_disk(dirent->rec_len,
inode->i_sb->s_blocksize) ==
inode->i_sb->s_blocksize)
is_dx_block = 1;
}
if (!is_dx_block && type == INDEX) {
ext4_error_inode(inode, func, line, block,
"directory leaf block found instead of index block");
return ERR_PTR(-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))
set_buffer_verified(bh);
else {
ext4_error_inode(inode, func, line, block,
"Directory index failed checksum");
brelse(bh);
return ERR_PTR(-EFSBADCRC);
}
}
if (!is_dx_block) {
if (ext4_dirent_csum_verify(inode, dirent))
set_buffer_verified(bh);
else {
ext4_error_inode(inode, func, line, block,
"Directory block failed checksum");
brelse(bh);
return ERR_PTR(-EFSBADCRC);
}
}
return bh;
}
#ifndef assert
#define assert(test) J_ASSERT(test)
#endif
#ifdef DX_DEBUG
#define dxtrace(command) command
#else
#define dxtrace(command)
#endif
struct fake_dirent
{
__le32 inode;
__le16 rec_len;
u8 name_len;
u8 file_type;
};
struct dx_countlimit
{
__le16 limit;
__le16 count;
};
struct dx_entry
{
__le32 hash;
__le32 block;
};
/*
* dx_root_info is laid out so that if it should somehow get overlaid by a
* dirent the two low bits of the hash version will be zero. Therefore, the
* hash version mod 4 should never be 0. Sincerely, the paranoia department.
*/
struct dx_root
{
struct fake_dirent dot;
char dot_name[4];
struct fake_dirent dotdot;
char dotdot_name[4];
struct dx_root_info
{
__le32 reserved_zero;
u8 hash_version;
u8 info_length; /* 8 */
u8 indirect_levels;
u8 unused_flags;
}
info;
struct dx_entry entries[0];
};
struct dx_node
{
struct fake_dirent fake;
struct dx_entry entries[0];
};
struct dx_frame
{
struct buffer_head *bh;
struct dx_entry *entries;
struct dx_entry *at;
};
struct dx_map_entry
{
u32 hash;
u16 offs;
u16 size;
};
/*
* This goes at the end of each htree block.
*/
struct dx_tail {
u32 dt_reserved;
__le32 dt_checksum; /* crc32c(uuid+inum+dirblock) */
};
static inline ext4_lblk_t dx_get_block(struct dx_entry *entry);
static void dx_set_block(struct dx_entry *entry, ext4_lblk_t value);
static inline unsigned dx_get_hash(struct dx_entry *entry);
static void dx_set_hash(struct dx_entry *entry, unsigned value);
static unsigned dx_get_count(struct dx_entry *entries);
static unsigned dx_get_limit(struct dx_entry *entries);
static void dx_set_count(struct dx_entry *entries, unsigned value);
static void dx_set_limit(struct dx_entry *entries, unsigned value);
static unsigned dx_root_limit(struct inode *dir, unsigned infosize);
static unsigned dx_node_limit(struct inode *dir);
static struct dx_frame *dx_probe(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 ext4_dir_entry_2 *de,
unsigned blocksize, struct dx_hash_info *hinfo,
struct dx_map_entry map[]);
static void dx_sort_map(struct dx_map_entry *map, unsigned count);
static struct ext4_dir_entry_2 *dx_move_dirents(char *from, char *to,
struct dx_map_entry *offsets, int count, unsigned blocksize);
static struct ext4_dir_entry_2* dx_pack_dirents(char *base, unsigned blocksize);
static void dx_insert_block(struct dx_frame *frame,
u32 hash, ext4_lblk_t block);
static int ext4_htree_next_block(struct inode *dir, __u32 hash,
struct dx_frame *frame,
struct dx_frame *frames,
__u32 *start_hash);
static struct buffer_head * ext4_dx_find_entry(struct inode *dir,
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 initialize_dirent_tail(struct ext4_dir_entry_tail *t,
unsigned int blocksize)
{
memset(t, 0, sizeof(struct ext4_dir_entry_tail));
t->det_rec_len = ext4_rec_len_to_disk(
sizeof(struct ext4_dir_entry_tail), blocksize);
t->det_reserved_ft = EXT4_FT_DIR_CSUM;
}
/* Walk through a dirent block to find a checksum "dirent" at the tail */
static struct ext4_dir_entry_tail *get_dirent_tail(struct inode *inode,
struct ext4_dir_entry *de)
{
struct ext4_dir_entry_tail *t;
#ifdef PARANOID
struct ext4_dir_entry *d, *top;
d = de;
top = (struct ext4_dir_entry *)(((void *)de) +
(EXT4_BLOCK_SIZE(inode->i_sb) -
sizeof(struct ext4_dir_entry_tail)));
while (d < top && d->rec_len)
d = (struct ext4_dir_entry *)(((void *)d) +
le16_to_cpu(d->rec_len));
if (d != top)
return NULL;
t = (struct ext4_dir_entry_tail *)d;
#else
t = EXT4_DIRENT_TAIL(de, EXT4_BLOCK_SIZE(inode->i_sb));
#endif
if (t->det_reserved_zero1 ||
le16_to_cpu(t->det_rec_len) != sizeof(struct ext4_dir_entry_tail) ||
t->det_reserved_zero2 ||
t->det_reserved_ft != EXT4_FT_DIR_CSUM)
return NULL;
return t;
}
static __le32 ext4_dirent_csum(struct inode *inode,
struct ext4_dir_entry *dirent, int size)
{
struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
struct ext4_inode_info *ei = EXT4_I(inode);
__u32 csum;
csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)dirent, size);
return cpu_to_le32(csum);
}
#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_dirent_csum_verify(struct inode *inode, struct ext4_dir_entry *dirent)
{
struct ext4_dir_entry_tail *t;
if (!ext4_has_metadata_csum(inode->i_sb))
return 1;
t = get_dirent_tail(inode, dirent);
if (!t) {
warn_no_space_for_csum(inode);
return 0;
}
if (t->det_checksum != ext4_dirent_csum(inode, dirent,
(void *)t - (void *)dirent))
return 0;
return 1;
}
static void ext4_dirent_csum_set(struct inode *inode,
struct ext4_dir_entry *dirent)
{
struct ext4_dir_entry_tail *t;
if (!ext4_has_metadata_csum(inode->i_sb))
return;
t = get_dirent_tail(inode, dirent);
if (!t) {
warn_no_space_for_csum(inode);
return;
}
t->det_checksum = ext4_dirent_csum(inode, dirent,
(void *)t - (void *)dirent);
}
int ext4_handle_dirty_dirent_node(handle_t *handle,
struct inode *inode,
struct buffer_head *bh)
{
ext4_dirent_csum_set(inode, (struct ext4_dir_entry *)bh->b_data);
return ext4_handle_dirty_metadata(handle, inode, bh);
}
static struct dx_countlimit *get_dx_countlimit(struct inode *inode,
struct ext4_dir_entry *dirent,
int *offset)
{
struct ext4_dir_entry *dp;
struct dx_root_info *root;
int count_offset;
if (le16_to_cpu(dirent->rec_len) == EXT4_BLOCK_SIZE(inode->i_sb))
count_offset = 8;
else if (le16_to_cpu(dirent->rec_len) == 12) {
dp = (struct ext4_dir_entry *)(((void *)dirent) + 12);
if (le16_to_cpu(dp->rec_len) !=
EXT4_BLOCK_SIZE(inode->i_sb) - 12)
return NULL;
root = (struct dx_root_info *)(((void *)dp + 12));
if (root->reserved_zero ||
root->info_length != sizeof(struct dx_root_info))
return NULL;
count_offset = 32;
} else
return NULL;
if (offset)
*offset = count_offset;
return (struct dx_countlimit *)(((void *)dirent) + count_offset);
}
static __le32 ext4_dx_csum(struct inode *inode, struct ext4_dir_entry *dirent,
int count_offset, int count, struct dx_tail *t)
{
struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
struct ext4_inode_info *ei = EXT4_I(inode);
__u32 csum;
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 entry_space = dir->i_sb->s_blocksize - EXT4_DIR_REC_LEN(1) -
EXT4_DIR_REC_LEN(2) - 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 entry_space = dir->i_sb->s_blocksize - EXT4_DIR_REC_LEN(0);
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_EXT4_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 (ext4_encrypted_inode(dir))
res = fscrypt_get_encryption_info(dir);
if (res) {
printk(KERN_WARNING "Error setting up"
" fname crypto: %d\n", res);
}
if (!fscrypt_has_encryption_key(dir)) {
/* Directory is not encrypted */
ext4fs_dirhash(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(
dir, 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;
}
ext4fs_dirhash(de->name, de->name_len,
&h);
printk("%*.s:(E)%x.%u ", len, name,
h.hash, (unsigned) ((char *) de
- base));
fscrypt_fname_free_buffer(
&fname_crypto_str);
}
#else
int len = de->name_len;
char *name = de->name;
ext4fs_dirhash(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);
names++;
}
de = ext4_next_entry(de, size);
}
printk(KERN_CONT "(%i)\n", names);
return (struct stats) { names, space, 1 };
}
struct stats dx_show_entries(struct dx_hash_info *hinfo, struct inode *dir,
struct dx_entry *entries, int levels)
{
unsigned blocksize = dir->i_sb->s_blocksize;
unsigned count = dx_get_count(entries), names = 0, space = 0, i;
unsigned bcount = 0;
struct buffer_head *bh;
printk("%i indexed blocks...\n", count);
for (i = 0; i < count; i++, entries++)
{
ext4_lblk_t block = dx_get_block(entries);
ext4_lblk_t hash = i ? dx_get_hash(entries): 0;
u32 range = i < count - 1? (dx_get_hash(entries + 1) - hash): ~hash;
struct stats stats;
printk("%s%3u:%03u hash %8x/%8x ",levels?"":" ", i, block, hash, range);
bh = ext4_bread(NULL,dir, block, 0);
if (!bh || IS_ERR(bh))
continue;
stats = levels?
dx_show_entries(hinfo, dir, ((struct dx_node *) bh->b_data)->entries, levels - 1):
dx_show_leaf(dir, hinfo, (struct ext4_dir_entry_2 *)
bh->b_data, blocksize, 0);
names += stats.names;
space += stats.space;
bcount += stats.bcount;
brelse(bh);
}
if (bcount)
printk(KERN_DEBUG "%snames %u, fullness %u (%u%%)\n",
levels ? "" : " ", names, space/bcount,
(space/bcount)*100/blocksize);
return (struct stats) { names, space, bcount};
}
#endif /* DX_DEBUG */
/*
* Probe for a directory leaf block to search.
*
* dx_probe can return ERR_BAD_DX_DIR, which means there was a format
* error in the directory index, and the caller should fall back to
* searching the directory normally. The callers of dx_probe **MUST**
* check for this error code, and make sure it never gets reflected
* back to userspace.
*/
static struct dx_frame *
dx_probe(struct ext4_filename *fname, struct inode *dir,
struct dx_hash_info *hinfo, struct dx_frame *frame_in)
{
unsigned count, indirect;
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;
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) {
ext4_warning_inode(dir, "Unrecognised inode hash code %u",
root->info.hash_version);
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;
if (fname && fname_name(fname))
ext4fs_dirhash(fname_name(fname), fname_len(fname), hinfo);
hash = hinfo->hash;
if (root->info.unused_flags & 1) {
ext4_warning_inode(dir, "Unimplemented hash flags: %#06x",
root->info.unused_flags);
goto fail;
}
indirect = root->info.indirect_levels;
if (indirect >= ext4_dir_htree_level(dir->i_sb)) {
ext4_warning(dir->i_sb,
"Directory (ino: %lu) htree depth %#06x exceed"
"supported value", dir->i_ino,
ext4_dir_htree_level(dir->i_sb));
if (ext4_dir_htree_level(dir->i_sb) < EXT4_HTREE_LEVEL) {
ext4_warning(dir->i_sb, "Enable large directory "
"feature to access it");
}
goto fail;
}
entries = (struct dx_entry *)(((char *)&root->info) +
root->info.info_length);
if (dx_get_limit(entries) != dx_root_limit(dir,
root->info.info_length)) {
ext4_warning_inode(dir, "dx entry: limit %u != root limit %u",
dx_get_limit(entries),
dx_root_limit(dir, root->info.info_length));
goto fail;
}
dxtrace(printk("Look up %x", hash));
while (1) {
count = dx_get_count(entries);
if (!count || count > dx_get_limit(entries)) {
ext4_warning_inode(dir,
"dx entry: count %u beyond limit %u",
count, dx_get_limit(entries));
goto fail;
}
p = entries + 1;
q = entries + count - 1;
while (p <= q) {
m = p + (q - p) / 2;
dxtrace(printk(KERN_CONT "."));
if (dx_get_hash(m) > hash)
q = m - 1;
else
p = m + 1;
}
if (0) { // linear search cross check
unsigned n = count - 1;
at = entries;
while (n--)
{
dxtrace(printk(KERN_CONT ","));
if (dx_get_hash(++at) > hash)
{
at--;
break;
}
}
assert (at == p - 1);
}
at = p - 1;
dxtrace(printk(KERN_CONT " %x->%u\n",
at == entries ? 0 : dx_get_hash(at),
dx_get_block(at)));
frame->entries = entries;
frame->at = at;
if (!indirect--)
return frame;
frame++;
frame->bh = ext4_read_dirblock(dir, dx_get_block(at), 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;
if (frames[0].bh == NULL)
return;
info = &((struct dx_root *)frames[0].bh->b_data)->info;
for (i = 0; i <= info->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 contiuation hash. If it doesn't, return since
* there's no point to read in the successive index pages.
*/
bhash = dx_get_hash(p->at);
if (start_hash)
*start_hash = bhash;
if ((hash & 1) == 0) {
if ((bhash & ~1) != hash)
return 0;
}
/*
* If the hash is HASH_NB_ALWAYS, we always go to the next
* block so no check is necessary
*/
while (num_frames--) {
bh = ext4_read_dirblock(dir, dx_get_block(p->at), INDEX);
if (IS_ERR(bh))
return PTR_ERR(bh);
p++;
brelse(p->bh);
p->bh = bh;
p->at = p->entries = ((struct dx_node *) bh->b_data)->entries;
}
return 1;
}
/*
* This function fills a red-black tree with information from a
* directory block. It returns the number directory entries loaded
* into the tree. If there is an error it is returned in err.
*/
static int htree_dirblock_to_tree(struct file *dir_file,
struct inode *dir, ext4_lblk_t block,
struct dx_hash_info *hinfo,
__u32 start_hash, __u32 start_minor_hash)
{
struct buffer_head *bh;
struct ext4_dir_entry_2 *de, *top;
int err = 0, count = 0;
struct fscrypt_str fname_crypto_str = FSTR_INIT(NULL, 0), tmp_str;
dxtrace(printk(KERN_INFO "In htree dirblock_to_tree: block %lu\n",
(unsigned long)block));
bh = ext4_read_dirblock(dir, block, DIRENT);
if (IS_ERR(bh))
return PTR_ERR(bh);
de = (struct ext4_dir_entry_2 *) bh->b_data;
top = (struct ext4_dir_entry_2 *) ((char *) de +
dir->i_sb->s_blocksize -
EXT4_DIR_REC_LEN(0));
#ifdef CONFIG_EXT4_FS_ENCRYPTION
/* Check if the directory is encrypted */
if (ext4_encrypted_inode(dir)) {
err = fscrypt_get_encryption_info(dir);
if (err < 0) {
brelse(bh);
return err;
}
err = fscrypt_fname_alloc_buffer(dir, EXT4_NAME_LEN,
&fname_crypto_str);
if (err < 0) {
brelse(bh);
return err;
}
}
#endif
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;
}
ext4fs_dirhash(de->name, de->name_len, hinfo);
if ((hinfo->hash < start_hash) ||
((hinfo->hash == start_hash) &&
(hinfo->minor_hash < start_minor_hash)))
continue;
if (de->inode == 0)
continue;
if (!ext4_encrypted_inode(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);
#ifdef CONFIG_EXT4_FS_ENCRYPTION
fscrypt_fname_free_buffer(&fname_crypto_str);
#endif
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))) {
hinfo.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version;
if (hinfo.hash_version <= DX_HASH_TEA)
hinfo.hash_version +=
EXT4_SB(dir->i_sb)->s_hash_unsigned;
hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed;
if (ext4_has_inline_data(dir)) {
int has_inline_data = 1;
count = htree_inlinedir_to_tree(dir_file, dir, 0,
&hinfo, start_hash,
start_minor_hash,
&has_inline_data);
if (has_inline_data) {
*next_hash = ~0;
return count;
}
}
count = htree_dirblock_to_tree(dir_file, dir, 0, &hinfo,
start_hash, start_minor_hash);
*next_hash = ~0;
return count;
}
hinfo.hash = start_hash;
hinfo.minor_hash = 0;
frame = dx_probe(NULL, dir, &hinfo, frames);
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 ext4_dir_entry_2 *de,
unsigned blocksize, struct dx_hash_info *hinfo,
struct dx_map_entry *map_tail)
{
int count = 0;
char *base = (char *) de;
struct dx_hash_info h = *hinfo;
while ((char *) de < base + blocksize) {
if (de->name_len && de->inode) {
ext4fs_dirhash(de->name, de->name_len, &h);
map_tail--;
map_tail->hash = h.hash;
map_tail->offs = ((char *) de - base)>>2;
map_tail->size = le16_to_cpu(de->rec_len);
count++;
cond_resched();
}
/* XXX: do we need to check rec_len == 0 case? -Chris */
de = ext4_next_entry(de, blocksize);
}
return count;
}
/* Sort map by hash value */
static void dx_sort_map (struct dx_map_entry *map, unsigned count)
{
struct dx_map_entry *p, *q, *top = map + count - 1;
int more;
/* Combsort until bubble sort doesn't suck */
while (count > 2) {
count = count*10/13;
if (count - 9 < 2) /* 9, 10 -> 11 */
count = 11;
for (p = top, q = p - count; q >= map; p--, q--)
if (p->hash < q->hash)
swap(*p, *q);
}
/* Garden variety bubble sort */
do {
more = 0;
q = top;
while (q-- > map) {
if (q[1].hash >= q[0].hash)
continue;
swap(*(q+1), *q);
more = 1;
}
} while(more);
}
static void dx_insert_block(struct dx_frame *frame, u32 hash, ext4_lblk_t block)
{
struct dx_entry *entries = frame->entries;
struct dx_entry *old = frame->at, *new = old + 1;
int count = dx_get_count(entries);
assert(count < dx_get_limit(entries));
assert(old < entries + count);
memmove(new + 1, new, (char *)(entries + count) - (char *)(new));
dx_set_hash(new, hash);
dx_set_block(new, block);
dx_set_count(entries, count + 1);
}
/*
* Test whether a directory entry matches the filename being searched for.
*
* Return: %true if the directory entry matches, otherwise %false.
*/
static inline bool ext4_match(const struct ext4_filename *fname,
const 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_EXT4_FS_ENCRYPTION
f.crypto_buf = fname->crypto_buf;
#endif
return fscrypt_match_name(&f, de->name, de->name_len);
}
/*
* Returns 0 if not found, -1 on failure, and 1 on success
*/
int ext4_search_dir(struct buffer_head *bh, char *search_buf, int buf_size,
struct inode *dir, struct ext4_filename *fname,
unsigned int offset, struct ext4_dir_entry_2 **res_dir)
{
struct ext4_dir_entry_2 * de;
char * dlimit;
int de_len;
de = (struct ext4_dir_entry_2 *)search_buf;
dlimit = search_buf + buf_size;
while ((char *) de < dlimit) {
/* this code is executed quadratically often */
/* do minimal checking `by hand' */
if ((char *) de + de->name_len <= dlimit &&
ext4_match(fname, de)) {
/* found a match - just to be sure, do
* a full check */
if (ext4_check_dir_entry(dir, NULL, de, bh, bh->b_data,
bh->b_size, offset))
return -1;
*res_dir = de;
return 1;
}
/* prevent looping on a bad block */
de_len = ext4_rec_len_from_disk(de->rec_len,
dir->i_sb->s_blocksize);
if (de_len <= 0)
return -1;
offset += de_len;
de = (struct ext4_dir_entry_2 *) ((char *) de + de_len);
}
return 0;
}
static int is_dx_internal_node(struct inode *dir, ext4_lblk_t block,
struct ext4_dir_entry *de)
{
struct super_block *sb = dir->i_sb;
if (!is_dx(dir))
return 0;
if (block == 0)
return 1;
if (de->inode == 0 &&
ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize) ==
sb->s_blocksize)
return 1;
return 0;
}
/*
* ext4_find_entry()
*
* finds an entry in the specified directory with the wanted name. It
* returns the cache buffer in which the entry was found, and the entry
* itself (as a parameter - res_dir). It does NOT read the inode of the
* entry - you'll have to do that yourself if you want to.
*
* The returned buffer_head has ->b_count elevated. The caller is expected
* to brelse() it when appropriate.
*/
static struct buffer_head * ext4_find_entry (struct inode *dir,
const struct qstr *d_name,
struct ext4_dir_entry_2 **res_dir,
int *inlined)
{
struct super_block *sb;
struct buffer_head *bh_use[NAMEI_RA_SIZE];
struct buffer_head *bh, *ret = NULL;
ext4_lblk_t start, block;
const u8 *name = d_name->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;
struct ext4_filename fname;
*res_dir = NULL;
sb = dir->i_sb;
namelen = d_name->len;
if (namelen > EXT4_NAME_LEN)
return NULL;
retval = ext4_fname_setup_filename(dir, d_name, 1, &fname);
if (retval == -ENOENT)
return NULL;
if (retval)
return ERR_PTR(retval);
if (ext4_has_inline_data(dir)) {
int has_inline_data = 1;
ret = ext4_find_inline_entry(dir, &fname, res_dir,
&has_inline_data);
if (has_inline_data) {
if (inlined)
*inlined = 1;
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"));
}
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.
*/
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(dir, "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_dirent_csum_verify(dir,
(struct ext4_dir_entry *)bh->b_data)) {
EXT4_ERROR_INODE(dir, "checksumming directory "
"block %lu", (unsigned long)block);
brelse(bh);
ret = ERR_PTR(-EFSBADCRC);
goto cleanup_and_exit;
}
set_buffer_verified(bh);
i = search_dirblock(bh, dir, &fname,
block << EXT4_BLOCK_SIZE_BITS(sb), res_dir);
if (i == 1) {
EXT4_I(dir)->i_dir_start_lookup = block;
ret = bh;
goto cleanup_and_exit;
} else {
brelse(bh);
if (i < 0)
goto cleanup_and_exit;
}
next:
if (++block >= nblocks)
block = 0;
} while (block != start);
/*
* If the directory has grown while we were searching, then
* search the last part of the directory before giving up.
*/
block = nblocks;
nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb);
if (block < nblocks) {
start = 0;
goto restart;
}
cleanup_and_exit:
/* Clean up the read-ahead blocks */
for (; ra_ptr < ra_max; ra_ptr++)
brelse(bh_use[ra_ptr]);
ext4_fname_free_filename(&fname);
return ret;
}
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_EXT4_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);
if (IS_ERR(bh))
goto errout;
retval = search_dirblock(bh, dir, fname,
block << EXT4_BLOCK_SIZE_BITS(sb),
res_dir);
if (retval == 1)
goto success;
brelse(bh);
if (retval == -1) {
bh = ERR_PTR(ERR_BAD_DX_DIR);
goto errout;
}
/* Check to see if we should continue to search */
retval = ext4_htree_next_block(dir, fname->hinfo.hash, frame,
frames, NULL);
if (retval < 0) {
ext4_warning_inode(dir,
"error %d reading directory index block",
retval);
bh = ERR_PTR(retval);
goto errout;
}
} while (retval == 1);
bh = NULL;
errout:
dxtrace(printk(KERN_DEBUG "%s not found\n", fname->usr_fname->name));
success:
dx_release(frames);
return bh;
}
static struct dentry *ext4_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
{
struct inode *inode;
struct ext4_dir_entry_2 *de;
struct buffer_head *bh;
int err;
err = fscrypt_prepare_lookup(dir, dentry, flags);
if (err)
return ERR_PTR(err);
if (dentry->d_name.len > EXT4_NAME_LEN)
return ERR_PTR(-ENAMETOOLONG);
bh = ext4_find_entry(dir, &dentry->d_name, &de, NULL);
if (IS_ERR(bh))
return (struct dentry *) 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_normal(dir->i_sb, ino);
if (inode == ERR_PTR(-ESTALE)) {
EXT4_ERROR_INODE(dir,
"deleted inode referenced: %u",
ino);
return ERR_PTR(-EFSCORRUPTED);
}
if (!IS_ERR(inode) && ext4_encrypted_inode(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);
}
}
return d_splice_alias(inode, dentry);
}
struct dentry *ext4_get_parent(struct dentry *child)
{
__u32 ino;
static const struct qstr dotdot = QSTR_INIT("..", 2);
struct ext4_dir_entry_2 * de;
struct buffer_head *bh;
bh = ext4_find_entry(d_inode(child), &dotdot, &de, NULL);
if (IS_ERR(bh))
return (struct dentry *) 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_normal(child->d_sb, ino));
}
/*
* Move count entries from end of map between two memory locations.
* Returns pointer to last entry moved.
*/
static struct ext4_dir_entry_2 *
dx_move_dirents(char *from, char *to, struct dx_map_entry *map, int count,
unsigned blocksize)
{
unsigned rec_len = 0;
while (count--) {
struct ext4_dir_entry_2 *de = (struct ext4_dir_entry_2 *)
(from + (map->offs<<2));
rec_len = EXT4_DIR_REC_LEN(de->name_len);
memcpy (to, de, rec_len);
((struct ext4_dir_entry_2 *) to)->rec_len =
ext4_rec_len_to_disk(rec_len, blocksize);
de->inode = 0;
map++;
to += rec_len;
}
return (struct ext4_dir_entry_2 *) (to - rec_len);
}
/*
* Compact each dir entry in the range to the minimal rec_len.
* Returns pointer to last entry in range.
*/
static struct ext4_dir_entry_2* dx_pack_dirents(char *base, unsigned blocksize)
{
struct ext4_dir_entry_2 *next, *to, *prev, *de = (struct ext4_dir_entry_2 *) base;
unsigned rec_len = 0;
prev = to = de;
while ((char*)de < base + blocksize) {
next = ext4_next_entry(de, blocksize);
if (de->inode && de->name_len) {
rec_len = EXT4_DIR_REC_LEN(de->name_len);
if (de > to)
memmove(to, de, rec_len);
to->rec_len = ext4_rec_len_to_disk(rec_len, blocksize);
prev = to;
to = (struct ext4_dir_entry_2 *) (((char *) to) + rec_len);
}
de = next;
}
return prev;
}
/*
* Split a full leaf block to make room for a new dir entry.
* Allocate a new block, and move entries so that they are approx. equally full.
* Returns pointer to de in block into which the new entry will be inserted.
*/
static struct ext4_dir_entry_2 *do_split(handle_t *handle, struct inode *dir,
struct buffer_head **bh,struct dx_frame *frame,
struct dx_hash_info *hinfo)
{
unsigned blocksize = dir->i_sb->s_blocksize;
unsigned count, continued;
struct buffer_head *bh2;
ext4_lblk_t newblock;
u32 hash2;
struct dx_map_entry *map;
char *data1 = (*bh)->b_data, *data2;
unsigned split, move, size;
struct ext4_dir_entry_2 *de = NULL, *de2;
struct ext4_dir_entry_tail *t;
int csum_size = 0;
int err = 0, i;
if (ext4_has_metadata_csum(dir->i_sb))
csum_size = sizeof(struct ext4_dir_entry_tail);
bh2 = ext4_append(handle, dir, &newblock);
if (IS_ERR(bh2)) {
brelse(*bh);
*bh = NULL;
return (struct ext4_dir_entry_2 *) bh2;
}
BUFFER_TRACE(*bh, "get_write_access");
err = ext4_journal_get_write_access(handle, *bh);
if (err)
goto journal_error;
BUFFER_TRACE(frame->bh, "get_write_access");
err = ext4_journal_get_write_access(handle, frame->bh);
if (err)
goto journal_error;
data2 = bh2->b_data;
/* create map in the end of data2 block */
map = (struct dx_map_entry *) (data2 + blocksize);
count = dx_make_map(dir, (struct ext4_dir_entry_2 *) data1,
blocksize, hinfo, map);
map -= count;
dx_sort_map(map, count);
/* Split the existing block in the middle, size-wise */
size = 0;
move = 0;
for (i = count-1; i >= 0; i--) {
/* is more than half of this entry in 2nd half of the block? */
if (size + map[i].size/2 > blocksize/2)
break;
size += map[i].size;
move++;
}
/* map index at which we will split */
split = count - move;
hash2 = map[split].hash;
continued = hash2 == map[split - 1].hash;
dxtrace(printk(KERN_INFO "Split block %lu at %x, %i/%i\n",
(unsigned long)dx_get_block(frame->at),
hash2, split, count-split));
/* Fancy dance to stay within two buffers */
de2 = dx_move_dirents(data1, data2, map + split, count - split,
blocksize);
de = dx_pack_dirents(data1, blocksize);
de->rec_len = ext4_rec_len_to_disk(data1 + (blocksize - csum_size) -
(char *) de,
blocksize);
de2->rec_len = ext4_rec_len_to_disk(data2 + (blocksize - csum_size) -
(char *) de2,
blocksize);
if (csum_size) {
t = EXT4_DIRENT_TAIL(data2, blocksize);
initialize_dirent_tail(t, blocksize);
t = EXT4_DIRENT_TAIL(data1, blocksize);
initialize_dirent_tail(t, blocksize);
}
dxtrace(dx_show_leaf(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_dirent_node(handle, dir, bh2);
if (err)
goto journal_error;
err = ext4_handle_dirty_dx_node(handle, dir, frame->bh);
if (err)
goto journal_error;
brelse(bh2);
dxtrace(dx_show_index("frame", frame->entries));
return de;
journal_error:
brelse(*bh);
brelse(bh2);
*bh = NULL;
ext4_std_error(dir->i_sb, err);
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));
int nlen, rlen;
unsigned int offset = 0;
char *top;
de = (struct ext4_dir_entry_2 *)buf;
top = buf + buf_size - reclen;
while ((char *) de <= top) {
if (ext4_check_dir_entry(dir, NULL, de, bh,
buf, buf_size, offset))
return -EFSCORRUPTED;
if (ext4_match(fname, de))
return -EEXIST;
nlen = EXT4_DIR_REC_LEN(de->name_len);
rlen = ext4_rec_len_from_disk(de->rec_len, buf_size);
if ((de->inode ? rlen - nlen : rlen) >= reclen)
break;
de = (struct ext4_dir_entry_2 *)((char *)de + rlen);
offset += rlen;
}
if ((char *) de > top)
return -ENOSPC;
*dest_de = de;
return 0;
}
void ext4_insert_dentry(struct inode *inode,
struct ext4_dir_entry_2 *de,
int buf_size,
struct ext4_filename *fname)
{
int nlen, rlen;
nlen = EXT4_DIR_REC_LEN(de->name_len);
rlen = ext4_rec_len_from_disk(de->rec_len, buf_size);
if (de->inode) {
struct ext4_dir_entry_2 *de1 =
(struct ext4_dir_entry_2 *)((char *)de + nlen);
de1->rec_len = ext4_rec_len_to_disk(rlen - nlen, buf_size);
de->rec_len = ext4_rec_len_to_disk(nlen, buf_size);
de = de1;
}
de->file_type = EXT4_FT_UNKNOWN;
de->inode = cpu_to_le32(inode->i_ino);
ext4_set_de_type(inode->i_sb, de, inode->i_mode);
de->name_len = fname_len(fname);
memcpy(de->name, fname_name(fname), fname_len(fname));
}
/*
* 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;
if (ext4_has_metadata_csum(inode->i_sb))
csum_size = sizeof(struct ext4_dir_entry_tail);
if (!de) {
err = ext4_find_dest_de(dir, inode, bh, bh->b_data,
blocksize - csum_size, fname, &de);
if (err)
return err;
}
BUFFER_TRACE(bh, "get_write_access");
err = ext4_journal_get_write_access(handle, bh);
if (err) {
ext4_std_error(dir->i_sb, err);
return err;
}
/* By now the buffer is marked for journaling */
ext4_insert_dentry(inode, de, blocksize, fname);
/*
* XXX shouldn't update any times until successful
* completion of syscall, but too many callers depend
* on this.
*
* XXX similarly, too many callers depend on
* ext4_new_inode() setting the times, but error
* recovery deletes the inode, so the worst that can
* happen is that the times are slightly out of date
* and/or different from the directory change time.
*/
dir->i_mtime = dir->i_ctime = current_time(dir);
ext4_update_dx_flag(dir);
inode_inc_iversion(dir);
ext4_mark_inode_dirty(handle, dir);
BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
err = ext4_handle_dirty_dirent_node(handle, dir, bh);
if (err)
ext4_std_error(dir->i_sb, err);
return 0;
}
/*
* This converts a one block unindexed directory to a 3 block indexed
* directory, and adds the dentry to the indexed directory.
*/
static int make_indexed_dir(handle_t *handle, struct 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;
struct ext4_dir_entry_tail *t;
char *data1, *top;
unsigned len;
int retval;
unsigned blocksize;
ext4_lblk_t block;
struct fake_dirent *fde;
int csum_size = 0;
if (ext4_has_metadata_csum(inode->i_sb))
csum_size = sizeof(struct ext4_dir_entry_tail);
blocksize = dir->i_sb->s_blocksize;
dxtrace(printk(KERN_DEBUG "Creating index: inode %lu\n", dir->i_ino));
BUFFER_TRACE(bh, "get_write_access");
retval = ext4_journal_get_write_access(handle, bh);
if (retval) {
ext4_std_error(dir->i_sb, retval);
brelse(bh);
return retval;
}
root = (struct dx_root *) bh->b_data;
/* The 0th block becomes the root, move the dirents out */
fde = &root->dotdot;
de = (struct ext4_dir_entry_2 *)((char *)fde +
ext4_rec_len_from_disk(fde->rec_len, blocksize));
if ((char *) de >= (((char *) root) + blocksize)) {
EXT4_ERROR_INODE(dir, "invalid rec_len for '..'");
brelse(bh);
return -EFSCORRUPTED;
}
len = ((char *) root) + (blocksize - csum_size) - (char *) de;
/* Allocate new block for the 0th block's dirents */
bh2 = ext4_append(handle, dir, &block);
if (IS_ERR(bh2)) {
brelse(bh);
return PTR_ERR(bh2);
}
ext4_set_inode_flag(dir, EXT4_INODE_INDEX);
data1 = bh2->b_data;
memcpy (data1, de, len);
de = (struct ext4_dir_entry_2 *) data1;
top = data1 + len;
while ((char *)(de2 = ext4_next_entry(de, blocksize)) < top)
de = de2;
de->rec_len = ext4_rec_len_to_disk(data1 + (blocksize - csum_size) -
(char *) de,
blocksize);
if (csum_size) {
t = EXT4_DIRENT_TAIL(data1, blocksize);
initialize_dirent_tail(t, blocksize);
}
/* Initialize the root; the dot dirents already exist */
de = (struct ext4_dir_entry_2 *) (&root->dotdot);
de->rec_len = ext4_rec_len_to_disk(blocksize - EXT4_DIR_REC_LEN(2),
blocksize);
memset (&root->info, 0, sizeof(root->info));
root->info.info_length = sizeof(root->info);
root->info.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version;
entries = root->entries;
dx_set_block(entries, 1);
dx_set_count(entries, 1);
dx_set_limit(entries, dx_root_limit(dir, sizeof(root->info)));
/* Initialize as for dx_probe */
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;
ext4fs_dirhash(fname_name(fname), fname_len(fname), &fname->hinfo);
memset(frames, 0, sizeof(frames));
frame = frames;
frame->entries = entries;
frame->at = entries;
frame->bh = bh;
retval = ext4_handle_dirty_dx_node(handle, dir, frame->bh);
if (retval)
goto out_frames;
retval = ext4_handle_dirty_dirent_node(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 ext4_dir_entry_tail *t;
struct super_block *sb;
struct ext4_filename fname;
int retval;
int dx_fallback=0;
unsigned blocksize;
ext4_lblk_t block, blocks;
int csum_size = 0;
if (ext4_has_metadata_csum(inode->i_sb))
csum_size = sizeof(struct ext4_dir_entry_tail);
sb = dir->i_sb;
blocksize = sb->s_blocksize;
if (!dentry->d_name.len)
return -EINVAL;
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;
ext4_clear_inode_flag(dir, EXT4_INODE_INDEX);
dx_fallback++;
ext4_mark_inode_dirty(handle, dir);
}
blocks = dir->i_size >> sb->s_blocksize_bits;
for (block = 0; block < blocks; block++) {
bh = ext4_read_dirblock(dir, block, DIRENT);
if (IS_ERR(bh)) {
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);
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) {
t = EXT4_DIRENT_TAIL(bh->b_data, blocksize);
initialize_dirent_tail(t, 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);
if (IS_ERR(bh)) {
err = PTR_ERR(bh);
bh = NULL;
goto cleanup;
}
BUFFER_TRACE(bh, "get_write_access");
err = ext4_journal_get_write_access(handle, bh);
if (err)
goto journal_error;
err = add_dirent_to_buf(handle, fname, dir, inode, NULL, bh);
if (err != -ENOSPC)
goto cleanup;
err = 0;
/* Block full, should compress but for now just split */
dxtrace(printk(KERN_DEBUG "using %u of %u node entries\n",
dx_get_count(entries), dx_get_limit(entries)));
/* Need to split index? */
if (dx_get_count(entries) == dx_get_limit(entries)) {
ext4_lblk_t newblock;
int levels = frame - frames + 1;
unsigned int icount;
int add_level = 1;
struct dx_entry *entries2;
struct dx_node *node2;
struct buffer_head *bh2;
while (frame > frames) {
if (dx_get_count((frame - 1)->entries) <
dx_get_limit((frame - 1)->entries)) {
add_level = 0;
break;
}
frame--; /* split higher index block */
at = frame->at;
entries = frame->entries;
restart = 1;
}
if (add_level && levels == ext4_dir_htree_level(sb)) {
ext4_warning(sb, "Directory (ino: %lu) index full, "
"reach max htree level :%d",
dir->i_ino, levels);
if (ext4_dir_htree_level(sb) < EXT4_HTREE_LEVEL) {
ext4_warning(sb, "Large directory feature is "
"not enabled on this "
"filesystem");
}
err = -ENOSPC;
goto cleanup;
}
icount = dx_get_count(entries);
bh2 = ext4_append(handle, dir, &newblock);
if (IS_ERR(bh2)) {
err = PTR_ERR(bh2);
goto cleanup;
}
node2 = (struct dx_node *)(bh2->b_data);
entries2 = node2->entries;
memset(&node2->fake, 0, sizeof(struct fake_dirent));
node2->fake.rec_len = ext4_rec_len_to_disk(sb->s_blocksize,
sb->s_blocksize);
BUFFER_TRACE(frame->bh, "get_write_access");
err = ext4_journal_get_write_access(handle, frame->bh);
if (err)
goto journal_error;
if (!add_level) {
unsigned icount1 = icount/2, icount2 = icount - icount1;
unsigned hash2 = dx_get_hash(entries + icount1);
dxtrace(printk(KERN_DEBUG "Split index %i/%i\n",
icount1, icount2));
BUFFER_TRACE(frame->bh, "get_write_access"); /* index root */
err = ext4_journal_get_write_access(handle,
(frame - 1)->bh);
if (err)
goto journal_error;
memcpy((char *) entries2, (char *) (entries + icount1),
icount2 * sizeof(struct dx_entry));
dx_set_count(entries, icount1);
dx_set_count(entries2, icount2);
dx_set_limit(entries2, dx_node_limit(dir));
/* Which index block gets the new entry? */
if (at - entries >= icount1) {
frame->at = at = at - entries - icount1 + entries2;
frame->entries = entries = entries2;
swap(frame->bh, bh2);
}
dx_insert_block((frame - 1), hash2, newblock);
dxtrace(dx_show_index("node", frame->entries));
dxtrace(dx_show_index("node",
((struct dx_node *) bh2->b_data)->entries));
err = ext4_handle_dirty_dx_node(handle, dir, bh2);
if (err)
goto journal_error;
brelse (bh2);
err = ext4_handle_dirty_dx_node(handle, dir,
(frame - 1)->bh);
if (err)
goto journal_error;
if (restart) {
err = ext4_handle_dirty_dx_node(handle, dir,
frame->bh);
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",
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(handle_t *handle,
struct inode *dir,
struct ext4_dir_entry_2 *de_del,
struct buffer_head *bh,
void *entry_buf,
int buf_size,
int csum_size)
{
struct ext4_dir_entry_2 *de, *pde;
unsigned int blocksize = dir->i_sb->s_blocksize;
int i;
i = 0;
pde = NULL;
de = (struct ext4_dir_entry_2 *)entry_buf;
while (i < buf_size - csum_size) {
if (ext4_check_dir_entry(dir, NULL, de, bh,
bh->b_data, bh->b_size, i))
return -EFSCORRUPTED;
if (de == de_del) {
if (pde)
pde->rec_len = ext4_rec_len_to_disk(
ext4_rec_len_from_disk(pde->rec_len,
blocksize) +
ext4_rec_len_from_disk(de->rec_len,
blocksize),
blocksize);
else
de->inode = 0;
inode_inc_iversion(dir);
return 0;
}
i += ext4_rec_len_from_disk(de->rec_len, blocksize);
pde = de;
de = ext4_next_entry(de, blocksize);
}
return -ENOENT;
}
static int ext4_delete_entry(handle_t *handle,
struct inode *dir,
struct ext4_dir_entry_2 *de_del,
struct buffer_head *bh)
{
int err, csum_size = 0;
if (ext4_has_inline_data(dir)) {
int has_inline_data = 1;
err = ext4_delete_inline_entry(handle, dir, de_del, bh,
&has_inline_data);
if (has_inline_data)
return err;
}
if (ext4_has_metadata_csum(dir->i_sb))
csum_size = sizeof(struct ext4_dir_entry_tail);
BUFFER_TRACE(bh, "get_write_access");
err = ext4_journal_get_write_access(handle, bh);
if (unlikely(err))
goto out;
err = ext4_generic_delete_entry(handle, dir, de_del,
bh, bh->b_data,
dir->i_sb->s_blocksize, csum_size);
if (err)
goto out;
BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
err = ext4_handle_dirty_dirent_node(handle, dir, bh);
if (unlikely(err))
goto out;
return 0;
out:
if (err != -ENOENT)
ext4_std_error(dir->i_sb, err);
return err;
}
/*
* 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(handle_t *handle, 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(handle_t *handle, struct inode *inode)
{
if (!S_ISDIR(inode->i_mode) || inode->i_nlink > 2)
drop_nlink(inode);
}
static int ext4_add_nondir(handle_t *handle,
struct dentry *dentry, struct inode *inode)
{
int err = ext4_add_entry(handle, dentry, inode);
if (!err) {
ext4_mark_inode_dirty(handle, inode);
unlock_new_inode(inode);
d_instantiate(dentry, inode);
return 0;
}
drop_nlink(inode);
unlock_new_inode(inode);
iput(inode);
return err;
}
/*
* By the time this is called, we already have created
* the directory cache entry for the new file, but it
* is so far negative - it has no inode.
*
* If the create succeeds, we fill in the inode information
* with d_instantiate().
*/
static int ext4_create(struct inode *dir, struct dentry *dentry, umode_t mode,
bool excl)
{
handle_t *handle;
struct inode *inode;
int err, credits, retries = 0;
err = dquot_initialize(dir);
if (err)
return err;
credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3);
retry:
inode = ext4_new_inode_start_handle(dir, mode, &dentry->d_name, 0,
NULL, EXT4_HT_DIR, credits);
handle = ext4_journal_current_handle();
err = PTR_ERR(inode);
if (!IS_ERR(inode)) {
inode->i_op = &ext4_file_inode_operations;
inode->i_fop = &ext4_file_operations;
ext4_set_aops(inode);
err = ext4_add_nondir(handle, dentry, inode);
if (!err && IS_DIRSYNC(dir))
ext4_handle_sync(handle);
}
if (handle)
ext4_journal_stop(handle);
if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
goto retry;
return err;
}
static int ext4_mknod(struct inode *dir, struct dentry *dentry,
umode_t mode, dev_t rdev)
{
handle_t *handle;
struct inode *inode;
int err, credits, retries = 0;
err = dquot_initialize(dir);
if (err)
return err;
credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3);
retry:
inode = ext4_new_inode_start_handle(dir, mode, &dentry->d_name, 0,
NULL, EXT4_HT_DIR, credits);
handle = ext4_journal_current_handle();
err = PTR_ERR(inode);
if (!IS_ERR(inode)) {
init_special_inode(inode, inode->i_mode, rdev);
inode->i_op = &ext4_special_inode_operations;
err = ext4_add_nondir(handle, dentry, inode);
if (!err && IS_DIRSYNC(dir))
ext4_handle_sync(handle);
}
if (handle)
ext4_journal_stop(handle);
if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
goto retry;
return err;
}
static int ext4_tmpfile(struct inode *dir, struct dentry *dentry, umode_t mode)
{
handle_t *handle;
struct inode *inode;
int err, retries = 0;
err = dquot_initialize(dir);
if (err)
return err;
retry:
inode = ext4_new_inode_start_handle(dir, mode,
NULL, 0, NULL,
EXT4_HT_DIR,
EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb) +
4 + EXT4_XATTR_TRANS_BLOCKS);
handle = ext4_journal_current_handle();
err = PTR_ERR(inode);
if (!IS_ERR(inode)) {
inode->i_op = &ext4_file_inode_operations;
inode->i_fop = &ext4_file_operations;
ext4_set_aops(inode);
d_tmpfile(dentry, inode);
err = ext4_orphan_add(handle, inode);
if (err)
goto err_unlock_inode;
mark_inode_dirty(inode);
unlock_new_inode(inode);
}
if (handle)
ext4_journal_stop(handle);
if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
goto retry;
return err;
err_unlock_inode:
ext4_journal_stop(handle);
unlock_new_inode(inode);
return err;
}
struct ext4_dir_entry_2 *ext4_init_dot_dotdot(struct inode *inode,
struct ext4_dir_entry_2 *de,
int blocksize, int csum_size,
unsigned int parent_ino, int dotdot_real_len)
{
de->inode = cpu_to_le32(inode->i_ino);
de->name_len = 1;
de->rec_len = ext4_rec_len_to_disk(EXT4_DIR_REC_LEN(de->name_len),
blocksize);
strcpy(de->name, ".");
ext4_set_de_type(inode->i_sb, de, S_IFDIR);
de = ext4_next_entry(de, blocksize);
de->inode = cpu_to_le32(parent_ino);
de->name_len = 2;
if (!dotdot_real_len)
de->rec_len = ext4_rec_len_to_disk(blocksize -
(csum_size + EXT4_DIR_REC_LEN(1)),
blocksize);
else
de->rec_len = ext4_rec_len_to_disk(
EXT4_DIR_REC_LEN(de->name_len), blocksize);
strcpy(de->name, "..");
ext4_set_de_type(inode->i_sb, de, S_IFDIR);
return ext4_next_entry(de, blocksize);
}
static int ext4_init_new_dir(handle_t *handle, struct inode *dir,
struct inode *inode)
{
struct buffer_head *dir_block = NULL;
struct ext4_dir_entry_2 *de;
struct ext4_dir_entry_tail *t;
ext4_lblk_t block = 0;
unsigned int blocksize = dir->i_sb->s_blocksize;
int csum_size = 0;
int err;
if (ext4_has_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) {
t = EXT4_DIRENT_TAIL(dir_block->b_data, blocksize);
initialize_dirent_tail(t, blocksize);
}
BUFFER_TRACE(dir_block, "call ext4_handle_dirty_metadata");
err = ext4_handle_dirty_dirent_node(handle, inode, dir_block);
if (err)
goto out;
set_buffer_verified(dir_block);
out:
brelse(dir_block);
return err;
}
static int ext4_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
{
handle_t *handle;
struct inode *inode;
int err, credits, retries = 0;
if (EXT4_DIR_LINK_MAX(dir))
return -EMLINK;
err = dquot_initialize(dir);
if (err)
return err;
credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3);
retry:
inode = ext4_new_inode_start_handle(dir, S_IFDIR | mode,
&dentry->d_name,
0, NULL, EXT4_HT_DIR, credits);
handle = ext4_journal_current_handle();
err = PTR_ERR(inode);
if (IS_ERR(inode))
goto out_stop;
inode->i_op = &ext4_dir_inode_operations;
inode->i_fop = &ext4_dir_operations;
err = ext4_init_new_dir(handle, dir, inode);
if (err)
goto out_clear_inode;
err = ext4_mark_inode_dirty(handle, inode);
if (!err)
err = ext4_add_entry(handle, dentry, inode);
if (err) {
out_clear_inode:
clear_nlink(inode);
unlock_new_inode(inode);
ext4_mark_inode_dirty(handle, inode);
iput(inode);
goto out_stop;
}
ext4_inc_count(handle, dir);
ext4_update_dx_flag(dir);
err = ext4_mark_inode_dirty(handle, dir);
if (err)
goto out_clear_inode;
unlock_new_inode(inode);
d_instantiate(dentry, inode);
if (IS_DIRSYNC(dir))
ext4_handle_sync(handle);
out_stop:
if (handle)
ext4_journal_stop(handle);
if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
goto retry;
return err;
}
/*
* routine to check that the specified directory is empty (for rmdir)
*/
bool ext4_empty_dir(struct inode *inode)
{
unsigned int offset;
struct buffer_head *bh;
struct ext4_dir_entry_2 *de, *de1;
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) + EXT4_DIR_REC_LEN(2)) {
EXT4_ERROR_INODE(inode, "invalid size");
return true;
}
bh = ext4_read_dirblock(inode, 0, EITHER);
if (IS_ERR(bh))
return true;
de = (struct ext4_dir_entry_2 *) bh->b_data;
de1 = ext4_next_entry(de, sb->s_blocksize);
if (le32_to_cpu(de->inode) != inode->i_ino ||
le32_to_cpu(de1->inode) == 0 ||
strcmp(".", de->name) || strcmp("..", de1->name)) {
ext4_warning_inode(inode, "directory missing '.' and/or '..'");
brelse(bh);
return true;
}
offset = ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize) +
ext4_rec_len_from_disk(de1->rec_len, sb->s_blocksize);
de = ext4_next_entry(de1, sb->s_blocksize);
while (offset < inode->i_size) {
if ((void *) de >= (void *) (bh->b_data+sb->s_blocksize)) {
unsigned int lblock;
brelse(bh);
lblock = offset >> EXT4_BLOCK_SIZE_BITS(sb);
bh = ext4_read_dirblock(inode, lblock, EITHER);
if (IS_ERR(bh))
return true;
de = (struct ext4_dir_entry_2 *) bh->b_data;
}
if (ext4_check_dir_entry(inode, NULL, de, bh,
bh->b_data, bh->b_size, offset)) {
de = (struct ext4_dir_entry_2 *)(bh->b_data +
sb->s_blocksize);
offset = (offset | (sb->s_blocksize - 1)) + 1;
continue;
}
if (le32_to_cpu(de->inode)) {
brelse(bh);
return false;
}
offset += ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize);
de = ext4_next_entry(de, sb->s_blocksize);
}
brelse(bh);
return true;
}
/*
* ext4_orphan_add() links an unlinked or truncated inode into a list of
* such inodes, starting at the superblock, in case we crash before the
* file is closed/deleted, or in case the inode truncate spans multiple
* transactions and the last transaction is not recovered after a crash.
*
* At filesystem recovery time, we walk this list deleting unlinked
* inodes and truncating linked inodes in ext4_orphan_cleanup().
*
* Orphan list manipulation functions must be called under i_mutex unless
* we are just creating the inode or deleting it.
*/
int ext4_orphan_add(handle_t *handle, struct inode *inode)
{
struct super_block *sb = inode->i_sb;
struct ext4_sb_info *sbi = EXT4_SB(sb);
struct ext4_iloc iloc;
int err = 0, rc;
bool dirty = false;
if (!sbi->s_journal || is_bad_inode(inode))
return 0;
WARN_ON_ONCE(!(inode->i_state & (I_NEW | I_FREEING)) &&
!inode_is_locked(inode));
/*
* Exit early if inode already is on orphan list. This is a big speedup
* since we don't have to contend on the global s_orphan_lock.
*/
if (!list_empty(&EXT4_I(inode)->i_orphan))
return 0;
/*
* Orphan handling is only valid for files with data blocks
* being truncated, or files being unlinked. Note that we either
* hold i_mutex, or the inode can not be referenced from outside,
* so i_nlink should not be bumped due to race
*/
J_ASSERT((S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
S_ISLNK(inode->i_mode)) || inode->i_nlink == 0);
BUFFER_TRACE(sbi->s_sbh, "get_write_access");
err = ext4_journal_get_write_access(handle, sbi->s_sbh);
if (err)
goto out;
err = ext4_reserve_inode_write(handle, inode, &iloc);
if (err)
goto out;
mutex_lock(&sbi->s_orphan_lock);
/*
* Due to previous errors inode may be already a part of on-disk
* orphan list. If so skip on-disk list modification.
*/
if (!NEXT_ORPHAN(inode) || NEXT_ORPHAN(inode) >
(le32_to_cpu(sbi->s_es->s_inodes_count))) {
/* Insert this inode at the head of the on-disk orphan list */
NEXT_ORPHAN(inode) = le32_to_cpu(sbi->s_es->s_last_orphan);
sbi->s_es->s_last_orphan = cpu_to_le32(inode->i_ino);
dirty = true;
}
list_add(&EXT4_I(inode)->i_orphan, &sbi->s_orphan);
mutex_unlock(&sbi->s_orphan_lock);
if (dirty) {
err = ext4_handle_dirty_super(handle, sb);
rc = ext4_mark_iloc_dirty(handle, inode, &iloc);
if (!err)
err = rc;
if (err) {
/*
* We have to remove inode from in-memory list if
* addition to on disk orphan list failed. Stray orphan
* list entries can cause panics at unmount time.
*/
mutex_lock(&sbi->s_orphan_lock);
list_del_init(&EXT4_I(inode)->i_orphan);
mutex_unlock(&sbi->s_orphan_lock);
}
}
jbd_debug(4, "superblock will point to %lu\n", inode->i_ino);
jbd_debug(4, "orphan inode %lu will point to %d\n",
inode->i_ino, NEXT_ORPHAN(inode));
out:
ext4_std_error(sb, err);
return err;
}
/*
* ext4_orphan_del() removes an unlinked or truncated inode from the list
* of such inodes stored on disk, because it is finally being cleaned up.
*/
int ext4_orphan_del(handle_t *handle, struct inode *inode)
{
struct list_head *prev;
struct ext4_inode_info *ei = EXT4_I(inode);
struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
__u32 ino_next;
struct ext4_iloc iloc;
int err = 0;
if (!sbi->s_journal && !(sbi->s_mount_state & EXT4_ORPHAN_FS))
return 0;
WARN_ON_ONCE(!(inode->i_state & (I_NEW | I_FREEING)) &&
!inode_is_locked(inode));
/* Do this quick check before taking global s_orphan_lock. */
if (list_empty(&ei->i_orphan))
return 0;
if (handle) {
/* Grab inode buffer early before taking global s_orphan_lock */
err = ext4_reserve_inode_write(handle, inode, &iloc);
}
mutex_lock(&sbi->s_orphan_lock);
jbd_debug(4, "remove inode %lu from orphan list\n", inode->i_ino);
prev = ei->i_orphan.prev;
list_del_init(&ei->i_orphan);
/* If we're on an error path, we may not have a valid
* transaction handle with which to update the orphan list on
* disk, but we still need to remove the inode from the linked
* list in memory. */
if (!handle || err) {
mutex_unlock(&sbi->s_orphan_lock);
goto out_err;
}
ino_next = NEXT_ORPHAN(inode);
if (prev == &sbi->s_orphan) {
jbd_debug(4, "superblock will point to %u\n", ino_next);
BUFFER_TRACE(sbi->s_sbh, "get_write_access");
err = ext4_journal_get_write_access(handle, sbi->s_sbh);
if (err) {
mutex_unlock(&sbi->s_orphan_lock);
goto out_brelse;
}
sbi->s_es->s_last_orphan = cpu_to_le32(ino_next);
mutex_unlock(&sbi->s_orphan_lock);
err = ext4_handle_dirty_super(handle, inode->i_sb);
} else {
struct ext4_iloc iloc2;
struct inode *i_prev =
&list_entry(prev, struct ext4_inode_info, i_orphan)->vfs_inode;
jbd_debug(4, "orphan inode %lu will point to %u\n",
i_prev->i_ino, ino_next);
err = ext4_reserve_inode_write(handle, i_prev, &iloc2);
if (err) {
mutex_unlock(&sbi->s_orphan_lock);
goto out_brelse;
}
NEXT_ORPHAN(i_prev) = ino_next;
err = ext4_mark_iloc_dirty(handle, i_prev, &iloc2);
mutex_unlock(&sbi->s_orphan_lock);
}
if (err)
goto out_brelse;
NEXT_ORPHAN(inode) = 0;
err = ext4_mark_iloc_dirty(handle, inode, &iloc);
out_err:
ext4_std_error(inode->i_sb, err);
return err;
out_brelse:
brelse(iloc.bh);
goto out_err;
}
static int ext4_rmdir(struct inode *dir, struct dentry *dentry)
{
int retval;
struct inode *inode;
struct buffer_head *bh;
struct ext4_dir_entry_2 *de;
handle_t *handle = NULL;
if (unlikely(ext4_forced_shutdown(EXT4_SB(dir->i_sb))))
return -EIO;
/* Initialize quotas before so that eventual writes go in
* separate transaction */
retval = dquot_initialize(dir);
if (retval)
return retval;
retval = dquot_initialize(d_inode(dentry));
if (retval)
return retval;
retval = -ENOENT;
bh = ext4_find_entry(dir, &dentry->d_name, &de, NULL);
if (IS_ERR(bh))
return PTR_ERR(bh);
if (!bh)
goto end_rmdir;
inode = d_inode(dentry);
retval = -EFSCORRUPTED;
if (le32_to_cpu(de->inode) != inode->i_ino)
goto end_rmdir;
retval = -ENOTEMPTY;
if (!ext4_empty_dir(inode))
goto end_rmdir;
handle = ext4_journal_start(dir, EXT4_HT_DIR,
EXT4_DATA_TRANS_BLOCKS(dir->i_sb));
if (IS_ERR(handle)) {
retval = PTR_ERR(handle);
handle = NULL;
goto end_rmdir;
}
if (IS_DIRSYNC(dir))
ext4_handle_sync(handle);
retval = ext4_delete_entry(handle, dir, de, bh);
if (retval)
goto end_rmdir;
if (!EXT4_DIR_LINK_EMPTY(inode))
ext4_warning_inode(inode,
"empty directory '%.*s' has too many links (%u)",
dentry->d_name.len, dentry->d_name.name,
inode->i_nlink);
inode->i_version++;
clear_nlink(inode);
/* There's no need to set i_disksize: the fact that i_nlink is
* zero will ensure that the right thing happens during any
* recovery. */
inode->i_size = 0;
ext4_orphan_add(handle, inode);
inode->i_ctime = dir->i_ctime = dir->i_mtime = current_time(inode);
ext4_mark_inode_dirty(handle, inode);
ext4_dec_count(handle, dir);
ext4_update_dx_flag(dir);
ext4_mark_inode_dirty(handle, dir);
end_rmdir:
brelse(bh);
if (handle)
ext4_journal_stop(handle);
return retval;
}
static int ext4_unlink(struct inode *dir, struct dentry *dentry)
{
int retval;
struct inode *inode;
struct buffer_head *bh;
struct ext4_dir_entry_2 *de;
handle_t *handle = NULL;
if (unlikely(ext4_forced_shutdown(EXT4_SB(dir->i_sb))))
return -EIO;
trace_ext4_unlink_enter(dir, dentry);
/* Initialize quotas before so that eventual writes go
* in separate transaction */
retval = dquot_initialize(dir);
if (retval)
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_unlink;
inode = d_inode(dentry);
retval = -EFSCORRUPTED;
if (le32_to_cpu(de->inode) != inode->i_ino)
goto end_unlink;
handle = ext4_journal_start(dir, EXT4_HT_DIR,
EXT4_DATA_TRANS_BLOCKS(dir->i_sb));
if (IS_ERR(handle)) {
retval = PTR_ERR(handle);
handle = NULL;
goto end_unlink;
}
if (IS_DIRSYNC(dir))
ext4_handle_sync(handle);
if (inode->i_nlink == 0) {
ext4_warning_inode(inode, "Deleting file '%.*s' with no links",
dentry->d_name.len, dentry->d_name.name);
set_nlink(inode, 1);
}
retval = ext4_delete_entry(handle, dir, de, bh);
if (retval)
goto end_unlink;
dir->i_ctime = dir->i_mtime = current_time(dir);
ext4_update_dx_flag(dir);
ext4_mark_inode_dirty(handle, dir);
drop_nlink(inode);
if (!inode->i_nlink)
ext4_orphan_add(handle, inode);
inode->i_ctime = current_time(inode);
ext4_mark_inode_dirty(handle, inode);
end_unlink:
brelse(bh);
if (handle)
ext4_journal_stop(handle);
trace_ext4_unlink_exit(dentry, retval);
return retval;
}
static int ext4_symlink(struct inode *dir,
struct dentry *dentry, const char *symname)
{
handle_t *handle;
struct inode *inode;
int err, len = strlen(symname);
int credits;
bool encryption_required;
struct fscrypt_str disk_link;
struct fscrypt_symlink_data *sd = NULL;
if (unlikely(ext4_forced_shutdown(EXT4_SB(dir->i_sb))))
return -EIO;
disk_link.len = len + 1;
disk_link.name = (char *) symname;
encryption_required = (ext4_encrypted_inode(dir) ||
DUMMY_ENCRYPTION_ENABLED(EXT4_SB(dir->i_sb)));
if (encryption_required) {
err = fscrypt_get_encryption_info(dir);
if (err)
return err;
if (!fscrypt_has_encryption_key(dir))
return -ENOKEY;
disk_link.len = (fscrypt_fname_encrypted_size(dir, len) +
sizeof(struct fscrypt_symlink_data));
sd = kzalloc(disk_link.len, GFP_KERNEL);
if (!sd)
return -ENOMEM;
}
if (disk_link.len > dir->i_sb->s_blocksize) {
err = -ENAMETOOLONG;
goto err_free_sd;
}
err = dquot_initialize(dir);
if (err)
goto err_free_sd;
if ((disk_link.len > EXT4_N_BLOCKS * 4)) {
/*
* For non-fast symlinks, we just allocate inode and put it on
* orphan list in the first transaction => we need bitmap,
* group descriptor, sb, inode block, quota blocks, and
* possibly selinux xattr blocks.
*/
credits = 4 + EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb) +
EXT4_XATTR_TRANS_BLOCKS;
} else {
/*
* Fast symlink. We have to add entry to directory
* (EXT4_DATA_TRANS_BLOCKS + EXT4_INDEX_EXTRA_TRANS_BLOCKS),
* allocate new inode (bitmap, group descriptor, inode block,
* quota blocks, sb is already counted in previous macros).
*/
credits = EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3;
}
inode = ext4_new_inode_start_handle(dir, S_IFLNK|S_IRWXUGO,
&dentry->d_name, 0, NULL,
EXT4_HT_DIR, credits);
handle = ext4_journal_current_handle();
if (IS_ERR(inode)) {
if (handle)
ext4_journal_stop(handle);
err = PTR_ERR(inode);
goto err_free_sd;
}
if (encryption_required) {
struct qstr istr;
struct fscrypt_str ostr =
FSTR_INIT(sd->encrypted_path, disk_link.len);
istr.name = (const unsigned char *) symname;
istr.len = len;
err = fscrypt_fname_usr_to_disk(inode, &istr, &ostr);
if (err)
goto err_drop_inode;
sd->len = cpu_to_le16(ostr.len);
disk_link.name = (char *) sd;
inode->i_op = &ext4_encrypted_symlink_inode_operations;
}
if ((disk_link.len > EXT4_N_BLOCKS * 4)) {
if (!encryption_required)
inode->i_op = &ext4_symlink_inode_operations;
inode_nohighmem(inode);
ext4_set_aops(inode);
/*
* We cannot call page_symlink() with transaction started
* because it calls into ext4_write_begin() which can wait
* for transaction commit if we are running out of space
* and thus we deadlock. So we have to stop transaction now
* and restart it when symlink contents is written.
*
* To keep fs consistent in case of crash, we have to put inode
* to orphan list in the mean time.
*/
drop_nlink(inode);
err = ext4_orphan_add(handle, inode);
ext4_journal_stop(handle);
handle = NULL;
if (err)
goto err_drop_inode;
err = __page_symlink(inode, disk_link.name, disk_link.len, 1);
if (err)
goto err_drop_inode;
/*
* Now inode is being linked into dir (EXT4_DATA_TRANS_BLOCKS
* + EXT4_INDEX_EXTRA_TRANS_BLOCKS), inode is also modified
*/
handle = ext4_journal_start(dir, EXT4_HT_DIR,
EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
EXT4_INDEX_EXTRA_TRANS_BLOCKS + 1);
if (IS_ERR(handle)) {
err = PTR_ERR(handle);
handle = NULL;
goto err_drop_inode;
}
set_nlink(inode, 1);
err = ext4_orphan_del(handle, inode);
if (err)
goto err_drop_inode;
} else {
/* clear the extent format for fast symlink */
ext4_clear_inode_flag(inode, EXT4_INODE_EXTENTS);
if (!encryption_required) {
inode->i_op = &ext4_fast_symlink_inode_operations;
inode->i_link = (char *)&EXT4_I(inode)->i_data;
}
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 (!err && IS_DIRSYNC(dir))
ext4_handle_sync(handle);
if (handle)
ext4_journal_stop(handle);
kfree(sd);
return err;
err_drop_inode:
if (handle)
ext4_journal_stop(handle);
clear_nlink(inode);
unlock_new_inode(inode);
iput(inode);
err_free_sd:
kfree(sd);
return err;
}
static int ext4_link(struct dentry *old_dentry,
struct inode *dir, struct dentry *dentry)
{
handle_t *handle;
struct inode *inode = d_inode(old_dentry);
int err, retries = 0;
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;
retry:
handle = ext4_journal_start(dir, EXT4_HT_DIR,
(EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
EXT4_INDEX_EXTRA_TRANS_BLOCKS) + 1);
if (IS_ERR(handle))
return PTR_ERR(handle);
if (IS_DIRSYNC(dir))
ext4_handle_sync(handle);
inode->i_ctime = current_time(inode);
ext4_inc_count(handle, inode);
ihold(inode);
err = ext4_add_entry(handle, dentry, inode);
if (!err) {
ext4_mark_inode_dirty(handle, inode);
/* this can happen only for tmpfile being
* linked the first time
*/
if (inode->i_nlink == 1)
ext4_orphan_del(handle, inode);
d_instantiate(dentry, inode);
} else {
drop_nlink(inode);
iput(inode);
}
ext4_journal_stop(handle);
if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
goto retry;
return err;
}
/*
* Try to find buffer head where contains the parent block.
* It should be the inode block if it is inlined or the 1st block
* if it is a normal dir.
*/
static struct buffer_head *ext4_get_first_dir_block(handle_t *handle,
struct inode *inode,
int *retval,
struct ext4_dir_entry_2 **parent_de,
int *inlined)
{
struct buffer_head *bh;
if (!ext4_has_inline_data(inode)) {
bh = ext4_read_dirblock(inode, 0, EITHER);
if (IS_ERR(bh)) {
*retval = PTR_ERR(bh);
return NULL;
}
*parent_de = ext4_next_entry(
(struct ext4_dir_entry_2 *)bh->b_data,
inode->i_sb->s_blocksize);
return bh;
}
*inlined = 1;
return ext4_get_first_inline_block(inode, parent_de, retval);
}
struct ext4_renament {
struct inode *dir;
struct dentry *dentry;
struct inode *inode;
bool is_dir;
int dir_nlink_delta;
/* entry for "dentry" */
struct buffer_head *bh;
struct ext4_dir_entry_2 *de;
int inlined;
/* entry for ".." in inode if it's a directory */
struct buffer_head *dir_bh;
struct ext4_dir_entry_2 *parent_de;
int dir_inlined;
};
static int ext4_rename_dir_prepare(handle_t *handle, struct ext4_renament *ent)
{
int retval;
ent->dir_bh = ext4_get_first_dir_block(handle, ent->inode,
&retval, &ent->parent_de,
&ent->dir_inlined);
if (!ent->dir_bh)
return retval;
if (le32_to_cpu(ent->parent_de->inode) != ent->dir->i_ino)
return -EFSCORRUPTED;
BUFFER_TRACE(ent->dir_bh, "get_write_access");
return ext4_journal_get_write_access(handle, ent->dir_bh);
}
static int ext4_rename_dir_finish(handle_t *handle, struct ext4_renament *ent,
unsigned dir_ino)
{
int retval;
ent->parent_de->inode = cpu_to_le32(dir_ino);
BUFFER_TRACE(ent->dir_bh, "call ext4_handle_dirty_metadata");
if (!ent->dir_inlined) {
if (is_dx(ent->inode)) {
retval = ext4_handle_dirty_dx_node(handle,
ent->inode,
ent->dir_bh);
} else {
retval = ext4_handle_dirty_dirent_node(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;
BUFFER_TRACE(ent->bh, "get write access");
retval = ext4_journal_get_write_access(handle, ent->bh);
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;
ent->dir->i_version++;
ent->dir->i_ctime = ent->dir->i_mtime =
current_time(ent->dir);
ext4_mark_inode_dirty(handle, ent->dir);
BUFFER_TRACE(ent->bh, "call ext4_handle_dirty_metadata");
if (!ent->inlined) {
retval = ext4_handle_dirty_dirent_node(handle,
ent->dir, ent->bh);
if (unlikely(retval)) {
ext4_std_error(ent->dir->i_sb, retval);
return retval;
}
}
brelse(ent->bh);
ent->bh = NULL;
return 0;
}
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(handle, ent->dir);
else
ext4_inc_count(handle, ent->dir);
ext4_mark_inode_dirty(handle, ent->dir);
}
}
static struct inode *ext4_whiteout_for_rename(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(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 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 ((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(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, NULL);
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;
}
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);
handle = NULL;
goto end_rename;
}
} else {
whiteout = ext4_whiteout_for_rename(&old, credits, &handle);
if (IS_ERR(whiteout)) {
retval = PTR_ERR(whiteout);
whiteout = NULL;
goto end_rename;
}
}
if (IS_DIRSYNC(old.dir) || IS_DIRSYNC(new.dir))
ext4_handle_sync(handle);
if (S_ISDIR(old.inode->i_mode)) {
if (new.inode) {
retval = -ENOTEMPTY;
if (!ext4_empty_dir(new.inode))
goto end_rename;
} else {
retval = -EMLINK;
if (new.dir != old.dir && EXT4_DIR_LINK_MAX(new.dir))
goto end_rename;
}
retval = ext4_rename_dir_prepare(handle, &old);
if (retval)
goto end_rename;
}
/*
* If we're renaming a file within an inline_data dir and adding or
* setting the new dirent causes a conversion from inline_data to
* extents/blockmap, we need to force the dirent delete code to
* re-read the directory, or else we end up trying to delete a dirent
* from what is now the extent tree root (or a block map).
*/
force_reread = (new.dir->i_ino == old.dir->i_ino &&
ext4_test_inode_flag(new.dir, EXT4_INODE_INLINE_DATA));
old_file_type = old.de->file_type;
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;
ext4_mark_inode_dirty(handle, whiteout);
}
if (!new.bh) {
retval = ext4_add_entry(handle, new.dentry, old.inode);
if (retval)
goto end_rename;
} else {
retval = ext4_setent(handle, &new,
old.inode->i_ino, old_file_type);
if (retval)
goto end_rename;
}
if (force_reread)
force_reread = !ext4_test_inode_flag(new.dir,
EXT4_INODE_INLINE_DATA);
/*
* Like most other Unix systems, set the ctime for inodes on a
* rename.
*/
old.inode->i_ctime = current_time(old.inode);
ext4_mark_inode_dirty(handle, old.inode);
if (!whiteout) {
/*
* ok, that's it
*/
ext4_rename_delete(handle, &old, force_reread);
}
if (new.inode) {
ext4_dec_count(handle, new.inode);
new.inode->i_ctime = current_time(new.inode);
}
old.dir->i_ctime = old.dir->i_mtime = current_time(old.dir);
ext4_update_dx_flag(old.dir);
if (old.dir_bh) {
retval = ext4_rename_dir_finish(handle, &old, new.dir->i_ino);
if (retval)
goto end_rename;
ext4_dec_count(handle, 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(handle, new.dir);
ext4_update_dx_flag(new.dir);
ext4_mark_inode_dirty(handle, new.dir);
}
}
ext4_mark_inode_dirty(handle, old.dir);
if (new.inode) {
ext4_mark_inode_dirty(handle, new.inode);
if (!new.inode->i_nlink)
ext4_orphan_add(handle, new.inode);
}
retval = 0;
end_rename:
brelse(old.dir_bh);
brelse(old.bh);
brelse(new.bh);
if (whiteout) {
if (retval)
drop_nlink(whiteout);
unlock_new_inode(whiteout);
iput(whiteout);
}
if (handle)
ext4_journal_stop(handle);
return retval;
}
static int ext4_cross_rename(struct inode *old_dir, struct dentry *old_dentry,
struct inode *new_dir, struct dentry *new_dentry)
{
handle_t *handle = NULL;
struct ext4_renament old = {
.dir = old_dir,
.dentry = old_dentry,
.inode = d_inode(old_dentry),
};
struct ext4_renament new = {
.dir = new_dir,
.dentry = new_dentry,
.inode = d_inode(new_dentry),
};
u8 new_file_type;
int retval;
struct timespec ctime;
if ((ext4_test_inode_flag(new_dir, EXT4_INODE_PROJINHERIT) &&
!projid_eq(EXT4_I(new_dir)->i_projid,
EXT4_I(old_dentry->d_inode)->i_projid)) ||
(ext4_test_inode_flag(old_dir, EXT4_INODE_PROJINHERIT) &&
!projid_eq(EXT4_I(old_dir)->i_projid,
EXT4_I(new_dentry->d_inode)->i_projid)))
return -EXDEV;
retval = dquot_initialize(old.dir);
if (retval)
return retval;
retval = dquot_initialize(new.dir);
if (retval)
return retval;
old.bh = ext4_find_entry(old.dir, &old.dentry->d_name,
&old.de, &old.inlined);
if (IS_ERR(old.bh))
return PTR_ERR(old.bh);
/*
* Check for inode number is _not_ due to possible IO errors.
* We might rmdir the source, keep it as pwd of some process
* and merrily kill the link to whatever was created under the
* same name. Goodbye sticky bit ;-<
*/
retval = -ENOENT;
if (!old.bh || le32_to_cpu(old.de->inode) != old.inode->i_ino)
goto end_rename;
new.bh = ext4_find_entry(new.dir, &new.dentry->d_name,
&new.de, &new.inlined);
if (IS_ERR(new.bh)) {
retval = PTR_ERR(new.bh);
new.bh = NULL;
goto end_rename;
}
/* RENAME_EXCHANGE case: old *and* new must both exist */
if (!new.bh || le32_to_cpu(new.de->inode) != new.inode->i_ino)
goto end_rename;
handle = ext4_journal_start(old.dir, EXT4_HT_DIR,
(2 * EXT4_DATA_TRANS_BLOCKS(old.dir->i_sb) +
2 * EXT4_INDEX_EXTRA_TRANS_BLOCKS + 2));
if (IS_ERR(handle)) {
retval = PTR_ERR(handle);
handle = NULL;
goto end_rename;
}
if (IS_DIRSYNC(old.dir) || IS_DIRSYNC(new.dir))
ext4_handle_sync(handle);
if (S_ISDIR(old.inode->i_mode)) {
old.is_dir = true;
retval = ext4_rename_dir_prepare(handle, &old);
if (retval)
goto end_rename;
}
if (S_ISDIR(new.inode->i_mode)) {
new.is_dir = true;
retval = ext4_rename_dir_prepare(handle, &new);
if (retval)
goto end_rename;
}
/*
* Other than the special case of overwriting a directory, parents'
* nlink only needs to be modified if this is a cross directory rename.
*/
if (old.dir != new.dir && old.is_dir != new.is_dir) {
old.dir_nlink_delta = old.is_dir ? -1 : 1;
new.dir_nlink_delta = -old.dir_nlink_delta;
retval = -EMLINK;
if ((old.dir_nlink_delta > 0 && EXT4_DIR_LINK_MAX(old.dir)) ||
(new.dir_nlink_delta > 0 && EXT4_DIR_LINK_MAX(new.dir)))
goto end_rename;
}
new_file_type = new.de->file_type;
retval = ext4_setent(handle, &new, old.inode->i_ino, old.de->file_type);
if (retval)
goto end_rename;
retval = ext4_setent(handle, &old, new.inode->i_ino, new_file_type);
if (retval)
goto end_rename;
/*
* Like most other Unix systems, set the ctime for inodes on a
* rename.
*/
ctime = current_time(old.inode);
old.inode->i_ctime = ctime;
new.inode->i_ctime = ctime;
ext4_mark_inode_dirty(handle, old.inode);
ext4_mark_inode_dirty(handle, new.inode);
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 inode *old_dir, struct dentry *old_dentry,
struct inode *new_dir, struct dentry *new_dentry,
unsigned int flags)
{
int err;
if (unlikely(ext4_forced_shutdown(EXT4_SB(old_dir->i_sb))))
return -EIO;
if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE | RENAME_WHITEOUT))
return -EINVAL;
err = fscrypt_prepare_rename(old_dir, old_dentry, new_dir, new_dentry,
flags);
if (err)
return err;
if (flags & RENAME_EXCHANGE) {
return ext4_cross_rename(old_dir, old_dentry,
new_dir, new_dentry);
}
return ext4_rename(old_dir, old_dentry, new_dir, new_dentry, flags);
}
/*
* directories can handle most operations...
*/
const struct inode_operations ext4_dir_inode_operations = {
.create = ext4_create,
.lookup = ext4_lookup,
.link = ext4_link,
.unlink = ext4_unlink,
.symlink = ext4_symlink,
.mkdir = ext4_mkdir,
.rmdir = ext4_rmdir,
.mknod = ext4_mknod,
.tmpfile = ext4_tmpfile,
.rename = ext4_rename2,
.setattr = ext4_setattr,
.getattr = ext4_getattr,
.listxattr = ext4_listxattr,
.get_acl = ext4_get_acl,
.set_acl = ext4_set_acl,
.fiemap = ext4_fiemap,
};
const struct inode_operations ext4_special_inode_operations = {
.setattr = ext4_setattr,
.getattr = ext4_getattr,
.listxattr = ext4_listxattr,
.get_acl = ext4_get_acl,
.set_acl = ext4_set_acl,
};
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