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linux/fs/ext4/namei.c
Theodore Ts'o 0e20270454 ext4: allocate delayed allocation blocks before rename 
When ext4_rename() overwrites an already existing file, call
ext4_alloc_da_blocks() before starting the journal handle which
actually does the rename, instead of doing this afterwards.  This
improves the likelihood that the contents will survive a crash if an
application replaces a file using the sequence:

1)  write replacement contents to foo.new
2)  <omit fsync of foo.new>
3)  rename foo.new to foo

It is still not a guarantee, since ext4_alloc_da_blocks() is *not*
doing a file integrity sync; this means if foo.new is a very large
file, it may not be completely flushed out to disk.

However, for files smaller than a megabyte or so, any dirty pages
should be flushed out before we do the rename operation, and so at the
next journal commit, the CACHE FLUSH command will make sure al of
these pages are safely on the disk platter.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2013-08-16 22:06:53 -04:00

3240 lines
86 KiB
C
Raw Blame History

/*
* 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/jbd2.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 = 0;
if (unlikely(EXT4_SB(inode->i_sb)->s_max_dir_size_kb &&
((inode->i_size >> 10) >=
EXT4_SB(inode->i_sb)->s_max_dir_size_kb)))
return ERR_PTR(-ENOSPC);
*block = inode->i_size >> inode->i_sb->s_blocksize_bits;
bh = ext4_bread(handle, inode, *block, 1, &err);
if (!bh)
return ERR_PTR(err);
inode->i_size += inode->i_sb->s_blocksize;
EXT4_I(inode)->i_disksize = inode->i_size;
err = ext4_journal_get_write_access(handle, bh);
if (err) {
brelse(bh);
ext4_std_error(inode->i_sb, err);
return ERR_PTR(err);
}
return bh;
}
static int ext4_dx_csum_verify(struct inode *inode,
struct ext4_dir_entry *dirent);
typedef enum {
EITHER, INDEX, DIRENT
} dirblock_type_t;
#define ext4_read_dirblock(inode, block, type) \
__ext4_read_dirblock((inode), (block), (type), __LINE__)
static struct buffer_head *__ext4_read_dirblock(struct inode *inode,
ext4_lblk_t block,
dirblock_type_t type,
unsigned int line)
{
struct buffer_head *bh;
struct ext4_dir_entry *dirent;
int err = 0, is_dx_block = 0;
bh = ext4_bread(NULL, inode, block, 0, &err);
if (!bh) {
if (err == 0) {
ext4_error_inode(inode, __func__, line, block,
"Directory hole found");
return ERR_PTR(-EIO);
}
__ext4_warning(inode->i_sb, __func__, line,
"error reading directory block "
"(ino %lu, block %lu)", inode->i_ino,
(unsigned long) block);
return ERR_PTR(err);
}
dirent = (struct ext4_dir_entry *) bh->b_data;
/* Determine whether or not we have an index block */
if (is_dx(inode)) {
if (block == 0)
is_dx_block = 1;
else if (ext4_rec_len_from_disk(dirent->rec_len,
inode->i_sb->s_blocksize) ==
inode->i_sb->s_blocksize)
is_dx_block = 1;
}
if (!is_dx_block && type == INDEX) {
ext4_error_inode(inode, __func__, line, block,
"directory leaf block found instead of index block");
return ERR_PTR(-EIO);
}
if (!EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) ||
buffer_verified(bh))
return bh;
/*
* An empty leaf block can get mistaken for a index block; for
* this reason, we can only check the index checksum when the
* caller is sure it should be an index block.
*/
if (is_dx_block && type == INDEX) {
if (ext4_dx_csum_verify(inode, dirent))
set_buffer_verified(bh);
else {
ext4_error_inode(inode, __func__, line, block,
"Directory index failed checksum");
brelse(bh);
return ERR_PTR(-EIO);
}
}
if (!is_dx_block) {
if (ext4_dirent_csum_verify(inode, dirent))
set_buffer_verified(bh);
else {
ext4_error_inode(inode, __func__, line, block,
"Directory block failed checksum");
brelse(bh);
return ERR_PTR(-EIO);
}
}
return bh;
}
#ifndef assert
#define assert(test) J_ASSERT(test)
#endif
#ifdef DX_DEBUG
#define dxtrace(command) command
#else
#define dxtrace(command)
#endif
struct fake_dirent
{
__le32 inode;
__le16 rec_len;
u8 name_len;
u8 file_type;
};
struct dx_countlimit
{
__le16 limit;
__le16 count;
};
struct dx_entry
{
__le32 hash;
__le32 block;
};
/*
* dx_root_info is laid out so that if it should somehow get overlaid by a
* dirent the two low bits of the hash version will be zero. Therefore, the
* hash version mod 4 should never be 0. Sincerely, the paranoia department.
*/
struct dx_root
{
struct fake_dirent dot;
char dot_name[4];
struct fake_dirent dotdot;
char dotdot_name[4];
struct dx_root_info
{
__le32 reserved_zero;
u8 hash_version;
u8 info_length; /* 8 */
u8 indirect_levels;
u8 unused_flags;
}
info;
struct dx_entry entries[0];
};
struct dx_node
{
struct fake_dirent fake;
struct dx_entry entries[0];
};
struct dx_frame
{
struct buffer_head *bh;
struct dx_entry *entries;
struct dx_entry *at;
};
struct dx_map_entry
{
u32 hash;
u16 offs;
u16 size;
};
/*
* This goes at the end of each htree block.
*/
struct dx_tail {
u32 dt_reserved;
__le32 dt_checksum; /* crc32c(uuid+inum+dirblock) */
};
static inline ext4_lblk_t dx_get_block(struct dx_entry *entry);
static void dx_set_block(struct dx_entry *entry, ext4_lblk_t value);
static inline unsigned dx_get_hash(struct dx_entry *entry);
static void dx_set_hash(struct dx_entry *entry, unsigned value);
static unsigned dx_get_count(struct dx_entry *entries);
static unsigned dx_get_limit(struct dx_entry *entries);
static void dx_set_count(struct dx_entry *entries, unsigned value);
static void dx_set_limit(struct dx_entry *entries, unsigned value);
static unsigned dx_root_limit(struct inode *dir, unsigned infosize);
static unsigned dx_node_limit(struct inode *dir);
static struct dx_frame *dx_probe(const struct qstr *d_name,
struct inode *dir,
struct dx_hash_info *hinfo,
struct dx_frame *frame,
int *err);
static void dx_release(struct dx_frame *frames);
static int dx_make_map(struct ext4_dir_entry_2 *de, unsigned blocksize,
struct dx_hash_info *hinfo, struct dx_map_entry map[]);
static void dx_sort_map(struct dx_map_entry *map, unsigned count);
static struct ext4_dir_entry_2 *dx_move_dirents(char *from, char *to,
struct dx_map_entry *offsets, int count, unsigned blocksize);
static struct ext4_dir_entry_2* dx_pack_dirents(char *base, unsigned blocksize);
static void dx_insert_block(struct dx_frame *frame,
u32 hash, ext4_lblk_t block);
static int ext4_htree_next_block(struct inode *dir, __u32 hash,
struct dx_frame *frame,
struct dx_frame *frames,
__u32 *start_hash);
static struct buffer_head * ext4_dx_find_entry(struct inode *dir,
const struct qstr *d_name,
struct ext4_dir_entry_2 **res_dir,
int *err);
static int ext4_dx_add_entry(handle_t *handle, struct dentry *dentry,
struct inode *inode);
/* checksumming functions */
void initialize_dirent_tail(struct ext4_dir_entry_tail *t,
unsigned int blocksize)
{
memset(t, 0, sizeof(struct ext4_dir_entry_tail));
t->det_rec_len = ext4_rec_len_to_disk(
sizeof(struct ext4_dir_entry_tail), blocksize);
t->det_reserved_ft = EXT4_FT_DIR_CSUM;
}
/* Walk through a dirent block to find a checksum "dirent" at the tail */
static struct ext4_dir_entry_tail *get_dirent_tail(struct inode *inode,
struct ext4_dir_entry *de)
{
struct ext4_dir_entry_tail *t;
#ifdef PARANOID
struct ext4_dir_entry *d, *top;
d = de;
top = (struct ext4_dir_entry *)(((void *)de) +
(EXT4_BLOCK_SIZE(inode->i_sb) -
sizeof(struct ext4_dir_entry_tail)));
while (d < top && d->rec_len)
d = (struct ext4_dir_entry *)(((void *)d) +
le16_to_cpu(d->rec_len));
if (d != top)
return NULL;
t = (struct ext4_dir_entry_tail *)d;
#else
t = EXT4_DIRENT_TAIL(de, EXT4_BLOCK_SIZE(inode->i_sb));
#endif
if (t->det_reserved_zero1 ||
le16_to_cpu(t->det_rec_len) != sizeof(struct ext4_dir_entry_tail) ||
t->det_reserved_zero2 ||
t->det_reserved_ft != EXT4_FT_DIR_CSUM)
return NULL;
return t;
}
static __le32 ext4_dirent_csum(struct inode *inode,
struct ext4_dir_entry *dirent, int size)
{
struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
struct ext4_inode_info *ei = EXT4_I(inode);
__u32 csum;
csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)dirent, size);
return cpu_to_le32(csum);
}
static void warn_no_space_for_csum(struct inode *inode)
{
ext4_warning(inode->i_sb, "no space in directory inode %lu leaf for "
"checksum. Please run e2fsck -D.", inode->i_ino);
}
int ext4_dirent_csum_verify(struct inode *inode, struct ext4_dir_entry *dirent)
{
struct ext4_dir_entry_tail *t;
if (!EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
return 1;
t = get_dirent_tail(inode, dirent);
if (!t) {
warn_no_space_for_csum(inode);
return 0;
}
if (t->det_checksum != ext4_dirent_csum(inode, dirent,
(void *)t - (void *)dirent))
return 0;
return 1;
}
static void ext4_dirent_csum_set(struct inode *inode,
struct ext4_dir_entry *dirent)
{
struct ext4_dir_entry_tail *t;
if (!EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
return;
t = get_dirent_tail(inode, dirent);
if (!t) {
warn_no_space_for_csum(inode);
return;
}
t->det_checksum = ext4_dirent_csum(inode, dirent,
(void *)t - (void *)dirent);
}
int ext4_handle_dirty_dirent_node(handle_t *handle,
struct inode *inode,
struct buffer_head *bh)
{
ext4_dirent_csum_set(inode, (struct ext4_dir_entry *)bh->b_data);
return ext4_handle_dirty_metadata(handle, inode, bh);
}
static struct dx_countlimit *get_dx_countlimit(struct inode *inode,
struct ext4_dir_entry *dirent,
int *offset)
{
struct ext4_dir_entry *dp;
struct dx_root_info *root;
int count_offset;
if (le16_to_cpu(dirent->rec_len) == EXT4_BLOCK_SIZE(inode->i_sb))
count_offset = 8;
else if (le16_to_cpu(dirent->rec_len) == 12) {
dp = (struct ext4_dir_entry *)(((void *)dirent) + 12);
if (le16_to_cpu(dp->rec_len) !=
EXT4_BLOCK_SIZE(inode->i_sb) - 12)
return NULL;
root = (struct dx_root_info *)(((void *)dp + 12));
if (root->reserved_zero ||
root->info_length != sizeof(struct dx_root_info))
return NULL;
count_offset = 32;
} else
return NULL;
if (offset)
*offset = count_offset;
return (struct dx_countlimit *)(((void *)dirent) + count_offset);
}
static __le32 ext4_dx_csum(struct inode *inode, struct ext4_dir_entry *dirent,
int count_offset, int count, struct dx_tail *t)
{
struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
struct ext4_inode_info *ei = EXT4_I(inode);
__u32 csum;
__le32 save_csum;
int size;
size = count_offset + (count * sizeof(struct dx_entry));
save_csum = t->dt_checksum;
t->dt_checksum = 0;
csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)dirent, size);
csum = ext4_chksum(sbi, csum, (__u8 *)t, sizeof(struct dx_tail));
t->dt_checksum = save_csum;
return cpu_to_le32(csum);
}
static int ext4_dx_csum_verify(struct inode *inode,
struct ext4_dir_entry *dirent)
{
struct dx_countlimit *c;
struct dx_tail *t;
int count_offset, limit, count;
if (!EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
return 1;
c = get_dx_countlimit(inode, dirent, &count_offset);
if (!c) {
EXT4_ERROR_INODE(inode, "dir seems corrupt? Run e2fsck -D.");
return 1;
}
limit = le16_to_cpu(c->limit);
count = le16_to_cpu(c->count);
if (count_offset + (limit * sizeof(struct dx_entry)) >
EXT4_BLOCK_SIZE(inode->i_sb) - sizeof(struct dx_tail)) {
warn_no_space_for_csum(inode);
return 1;
}
t = (struct dx_tail *)(((struct dx_entry *)c) + limit);
if (t->dt_checksum != ext4_dx_csum(inode, dirent, count_offset,
count, t))
return 0;
return 1;
}
static void ext4_dx_csum_set(struct inode *inode, struct ext4_dir_entry *dirent)
{
struct dx_countlimit *c;
struct dx_tail *t;
int count_offset, limit, count;
if (!EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
return;
c = get_dx_countlimit(inode, dirent, &count_offset);
if (!c) {
EXT4_ERROR_INODE(inode, "dir seems corrupt? Run e2fsck -D.");
return;
}
limit = le16_to_cpu(c->limit);
count = le16_to_cpu(c->count);
if (count_offset + (limit * sizeof(struct dx_entry)) >
EXT4_BLOCK_SIZE(inode->i_sb) - sizeof(struct dx_tail)) {
warn_no_space_for_csum(inode);
return;
}
t = (struct dx_tail *)(((struct dx_entry *)c) + limit);
t->dt_checksum = ext4_dx_csum(inode, dirent, count_offset, count, t);
}
static inline int ext4_handle_dirty_dx_node(handle_t *handle,
struct inode *inode,
struct buffer_head *bh)
{
ext4_dx_csum_set(inode, (struct ext4_dir_entry *)bh->b_data);
return ext4_handle_dirty_metadata(handle, inode, bh);
}
/*
* p is at least 6 bytes before the end of page
*/
static inline struct ext4_dir_entry_2 *
ext4_next_entry(struct ext4_dir_entry_2 *p, unsigned long blocksize)
{
return (struct ext4_dir_entry_2 *)((char *)p +
ext4_rec_len_from_disk(p->rec_len, blocksize));
}
/*
* Future: use high four bits of block for coalesce-on-delete flags
* Mask them off for now.
*/
static inline ext4_lblk_t dx_get_block(struct dx_entry *entry)
{
return le32_to_cpu(entry->block) & 0x00ffffff;
}
static inline void dx_set_block(struct dx_entry *entry, ext4_lblk_t value)
{
entry->block = cpu_to_le32(value);
}
static inline unsigned dx_get_hash(struct dx_entry *entry)
{
return le32_to_cpu(entry->hash);
}
static inline void dx_set_hash(struct dx_entry *entry, unsigned value)
{
entry->hash = cpu_to_le32(value);
}
static inline unsigned dx_get_count(struct dx_entry *entries)
{
return le16_to_cpu(((struct dx_countlimit *) entries)->count);
}
static inline unsigned dx_get_limit(struct dx_entry *entries)
{
return le16_to_cpu(((struct dx_countlimit *) entries)->limit);
}
static inline void dx_set_count(struct dx_entry *entries, unsigned value)
{
((struct dx_countlimit *) entries)->count = cpu_to_le16(value);
}
static inline void dx_set_limit(struct dx_entry *entries, unsigned value)
{
((struct dx_countlimit *) entries)->limit = cpu_to_le16(value);
}
static inline unsigned dx_root_limit(struct inode *dir, unsigned infosize)
{
unsigned entry_space = dir->i_sb->s_blocksize - EXT4_DIR_REC_LEN(1) -
EXT4_DIR_REC_LEN(2) - infosize;
if (EXT4_HAS_RO_COMPAT_FEATURE(dir->i_sb,
EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
entry_space -= sizeof(struct dx_tail);
return entry_space / sizeof(struct dx_entry);
}
static inline unsigned dx_node_limit(struct inode *dir)
{
unsigned entry_space = dir->i_sb->s_blocksize - EXT4_DIR_REC_LEN(0);
if (EXT4_HAS_RO_COMPAT_FEATURE(dir->i_sb,
EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
entry_space -= sizeof(struct dx_tail);
return entry_space / sizeof(struct dx_entry);
}
/*
* Debug
*/
#ifdef DX_DEBUG
static void dx_show_index(char * label, struct dx_entry *entries)
{
int i, n = dx_get_count (entries);
printk(KERN_DEBUG "%s index ", label);
for (i = 0; i < n; i++) {
printk("%x->%lu ", i ? dx_get_hash(entries + i) :
0, (unsigned long)dx_get_block(entries + i));
}
printk("\n");
}
struct stats
{
unsigned names;
unsigned space;
unsigned bcount;
};
static struct stats dx_show_leaf(struct dx_hash_info *hinfo, struct ext4_dir_entry_2 *de,
int size, int show_names)
{
unsigned names = 0, space = 0;
char *base = (char *) de;
struct dx_hash_info h = *hinfo;
printk("names: ");
while ((char *) de < base + size)
{
if (de->inode)
{
if (show_names)
{
int len = de->name_len;
char *name = de->name;
while (len--) printk("%c", *name++);
ext4fs_dirhash(de->name, de->name_len, &h);
printk(":%x.%u ", h.hash,
(unsigned) ((char *) de - base));
}
space += EXT4_DIR_REC_LEN(de->name_len);
names++;
}
de = ext4_next_entry(de, size);
}
printk("(%i)\n", names);
return (struct stats) { names, space, 1 };
}
struct stats dx_show_entries(struct dx_hash_info *hinfo, struct inode *dir,
struct dx_entry *entries, int levels)
{
unsigned blocksize = dir->i_sb->s_blocksize;
unsigned count = dx_get_count(entries), names = 0, space = 0, i;
unsigned bcount = 0;
struct buffer_head *bh;
int err;
printk("%i indexed blocks...\n", count);
for (i = 0; i < count; i++, entries++)
{
ext4_lblk_t block = dx_get_block(entries);
ext4_lblk_t hash = i ? dx_get_hash(entries): 0;
u32 range = i < count - 1? (dx_get_hash(entries + 1) - hash): ~hash;
struct stats stats;
printk("%s%3u:%03u hash %8x/%8x ",levels?"":" ", i, block, hash, range);
if (!(bh = ext4_bread (NULL,dir, block, 0,&err))) continue;
stats = levels?
dx_show_entries(hinfo, dir, ((struct dx_node *) bh->b_data)->entries, levels - 1):
dx_show_leaf(hinfo, (struct ext4_dir_entry_2 *) bh->b_data, blocksize, 0);
names += stats.names;
space += stats.space;
bcount += stats.bcount;
brelse(bh);
}
if (bcount)
printk(KERN_DEBUG "%snames %u, fullness %u (%u%%)\n",
levels ? "" : " ", names, space/bcount,
(space/bcount)*100/blocksize);
return (struct stats) { names, space, bcount};
}
#endif /* DX_DEBUG */
/*
* Probe for a directory leaf block to search.
*
* dx_probe can return ERR_BAD_DX_DIR, which means there was a format
* error in the directory index, and the caller should fall back to
* searching the directory normally. The callers of dx_probe **MUST**
* check for this error code, and make sure it never gets reflected
* back to userspace.
*/
static struct dx_frame *
dx_probe(const struct qstr *d_name, struct inode *dir,
struct dx_hash_info *hinfo, struct dx_frame *frame_in, int *err)
{
unsigned count, indirect;
struct dx_entry *at, *entries, *p, *q, *m;
struct dx_root *root;
struct buffer_head *bh;
struct dx_frame *frame = frame_in;
u32 hash;
frame->bh = NULL;
bh = ext4_read_dirblock(dir, 0, INDEX);
if (IS_ERR(bh)) {
*err = PTR_ERR(bh);
goto fail;
}
root = (struct dx_root *) bh->b_data;
if (root->info.hash_version != DX_HASH_TEA &&
root->info.hash_version != DX_HASH_HALF_MD4 &&
root->info.hash_version != DX_HASH_LEGACY) {
ext4_warning(dir->i_sb, "Unrecognised inode hash code %d",
root->info.hash_version);
brelse(bh);
*err = ERR_BAD_DX_DIR;
goto fail;
}
hinfo->hash_version = root->info.hash_version;
if (hinfo->hash_version <= DX_HASH_TEA)
hinfo->hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned;
hinfo->seed = EXT4_SB(dir->i_sb)->s_hash_seed;
if (d_name)
ext4fs_dirhash(d_name->name, d_name->len, hinfo);
hash = hinfo->hash;
if (root->info.unused_flags & 1) {
ext4_warning(dir->i_sb, "Unimplemented inode hash flags: %#06x",
root->info.unused_flags);
brelse(bh);
*err = ERR_BAD_DX_DIR;
goto fail;
}
if ((indirect = root->info.indirect_levels) > 1) {
ext4_warning(dir->i_sb, "Unimplemented inode hash depth: %#06x",
root->info.indirect_levels);
brelse(bh);
*err = ERR_BAD_DX_DIR;
goto fail;
}
entries = (struct dx_entry *) (((char *)&root->info) +
root->info.info_length);
if (dx_get_limit(entries) != dx_root_limit(dir,
root->info.info_length)) {
ext4_warning(dir->i_sb, "dx entry: limit != root limit");
brelse(bh);
*err = ERR_BAD_DX_DIR;
goto fail;
}
dxtrace(printk("Look up %x", hash));
while (1)
{
count = dx_get_count(entries);
if (!count || count > dx_get_limit(entries)) {
ext4_warning(dir->i_sb,
"dx entry: no count or count > limit");
brelse(bh);
*err = ERR_BAD_DX_DIR;
goto fail2;
}
p = entries + 1;
q = entries + count - 1;
while (p <= q)
{
m = p + (q - p)/2;
dxtrace(printk("."));
if (dx_get_hash(m) > hash)
q = m - 1;
else
p = m + 1;
}
if (0) // linear search cross check
{
unsigned n = count - 1;
at = entries;
while (n--)
{
dxtrace(printk(","));
if (dx_get_hash(++at) > hash)
{
at--;
break;
}
}
assert (at == p - 1);
}
at = p - 1;
dxtrace(printk(" %x->%u\n", at == entries? 0: dx_get_hash(at), dx_get_block(at)));
frame->bh = bh;
frame->entries = entries;
frame->at = at;
if (!indirect--) return frame;
bh = ext4_read_dirblock(dir, dx_get_block(at), INDEX);
if (IS_ERR(bh)) {
*err = PTR_ERR(bh);
goto fail2;
}
entries = ((struct dx_node *) bh->b_data)->entries;
if (dx_get_limit(entries) != dx_node_limit (dir)) {
ext4_warning(dir->i_sb,
"dx entry: limit != node limit");
brelse(bh);
*err = ERR_BAD_DX_DIR;
goto fail2;
}
frame++;
frame->bh = NULL;
}
fail2:
while (frame >= frame_in) {
brelse(frame->bh);
frame--;
}
fail:
if (*err == ERR_BAD_DX_DIR)
ext4_warning(dir->i_sb,
"Corrupt dir inode %lu, running e2fsck is "
"recommended.", dir->i_ino);
return NULL;
}
static void dx_release (struct dx_frame *frames)
{
if (frames[0].bh == NULL)
return;
if (((struct dx_root *) frames[0].bh->b_data)->info.indirect_levels)
brelse(frames[1].bh);
brelse(frames[0].bh);
}
/*
* This function increments the frame pointer to search the next leaf
* block, and reads in the necessary intervening nodes if the search
* should be necessary. Whether or not the search is necessary is
* controlled by the hash parameter. If the hash value is even, then
* the search is only continued if the next block starts with that
* hash value. This is used if we are searching for a specific file.
*
* If the hash value is HASH_NB_ALWAYS, then always go to the next block.
*
* This function returns 1 if the caller should continue to search,
* or 0 if it should not. If there is an error reading one of the
* index blocks, it will a negative error code.
*
* If start_hash is non-null, it will be filled in with the starting
* hash of the next page.
*/
static int ext4_htree_next_block(struct inode *dir, __u32 hash,
struct dx_frame *frame,
struct dx_frame *frames,
__u32 *start_hash)
{
struct dx_frame *p;
struct buffer_head *bh;
int num_frames = 0;
__u32 bhash;
p = frame;
/*
* Find the next leaf page by incrementing the frame pointer.
* If we run out of entries in the interior node, loop around and
* increment pointer in the parent node. When we break out of
* this loop, num_frames indicates the number of interior
* nodes need to be read.
*/
while (1) {
if (++(p->at) < p->entries + dx_get_count(p->entries))
break;
if (p == frames)
return 0;
num_frames++;
p--;
}
/*
* If the hash is 1, then continue only if the next page has a
* continuation hash of any value. This is used for readdir
* handling. Otherwise, check to see if the hash matches the
* desired contiuation hash. If it doesn't, return since
* there's no point to read in the successive index pages.
*/
bhash = dx_get_hash(p->at);
if (start_hash)
*start_hash = bhash;
if ((hash & 1) == 0) {
if ((bhash & ~1) != hash)
return 0;
}
/*
* If the hash is HASH_NB_ALWAYS, we always go to the next
* block so no check is necessary
*/
while (num_frames--) {
bh = ext4_read_dirblock(dir, dx_get_block(p->at), INDEX);
if (IS_ERR(bh))
return PTR_ERR(bh);
p++;
brelse(p->bh);
p->bh = bh;
p->at = p->entries = ((struct dx_node *) bh->b_data)->entries;
}
return 1;
}
/*
* This function fills a red-black tree with information from a
* directory block. It returns the number directory entries loaded
* into the tree. If there is an error it is returned in err.
*/
static int htree_dirblock_to_tree(struct file *dir_file,
struct inode *dir, ext4_lblk_t block,
struct dx_hash_info *hinfo,
__u32 start_hash, __u32 start_minor_hash)
{
struct buffer_head *bh;
struct ext4_dir_entry_2 *de, *top;
int err = 0, count = 0;
dxtrace(printk(KERN_INFO "In htree dirblock_to_tree: block %lu\n",
(unsigned long)block));
bh = ext4_read_dirblock(dir, block, DIRENT);
if (IS_ERR(bh))
return PTR_ERR(bh);
de = (struct ext4_dir_entry_2 *) bh->b_data;
top = (struct ext4_dir_entry_2 *) ((char *) de +
dir->i_sb->s_blocksize -
EXT4_DIR_REC_LEN(0));
for (; de < top; de = ext4_next_entry(de, dir->i_sb->s_blocksize)) {
if (ext4_check_dir_entry(dir, NULL, de, bh,
bh->b_data, bh->b_size,
(block<<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 ((err = ext4_htree_store_dirent(dir_file,
hinfo->hash, hinfo->minor_hash, de)) != 0) {
brelse(bh);
return err;
}
count++;
}
brelse(bh);
return count;
}
/*
* This function fills a red-black tree with information from a
* directory. We start scanning the directory in hash order, starting
* at start_hash and start_minor_hash.
*
* This function returns the number of entries inserted into the tree,
* or a negative error code.
*/
int ext4_htree_fill_tree(struct file *dir_file, __u32 start_hash,
__u32 start_minor_hash, __u32 *next_hash)
{
struct dx_hash_info hinfo;
struct ext4_dir_entry_2 *de;
struct dx_frame frames[2], *frame;
struct inode *dir;
ext4_lblk_t block;
int count = 0;
int ret, err;
__u32 hashval;
dxtrace(printk(KERN_DEBUG "In htree_fill_tree, start hash: %x:%x\n",
start_hash, start_minor_hash));
dir = file_inode(dir_file);
if (!(ext4_test_inode_flag(dir, EXT4_INODE_INDEX))) {
hinfo.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version;
if (hinfo.hash_version <= DX_HASH_TEA)
hinfo.hash_version +=
EXT4_SB(dir->i_sb)->s_hash_unsigned;
hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed;
if (ext4_has_inline_data(dir)) {
int has_inline_data = 1;
count = htree_inlinedir_to_tree(dir_file, dir, 0,
&hinfo, start_hash,
start_minor_hash,
&has_inline_data);
if (has_inline_data) {
*next_hash = ~0;
return count;
}
}
count = htree_dirblock_to_tree(dir_file, dir, 0, &hinfo,
start_hash, start_minor_hash);
*next_hash = ~0;
return count;
}
hinfo.hash = start_hash;
hinfo.minor_hash = 0;
frame = dx_probe(NULL, dir, &hinfo, frames, &err);
if (!frame)
return err;
/* Add '.' and '..' from the htree header */
if (!start_hash && !start_minor_hash) {
de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data;
if ((err = ext4_htree_store_dirent(dir_file, 0, 0, de)) != 0)
goto errout;
count++;
}
if (start_hash < 2 || (start_hash ==2 && start_minor_hash==0)) {
de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data;
de = ext4_next_entry(de, dir->i_sb->s_blocksize);
if ((err = ext4_htree_store_dirent(dir_file, 2, 0, de)) != 0)
goto errout;
count++;
}
while (1) {
block = dx_get_block(frame->at);
ret = htree_dirblock_to_tree(dir_file, dir, block, &hinfo,
start_hash, start_minor_hash);
if (ret < 0) {
err = ret;
goto errout;
}
count += ret;
hashval = ~0;
ret = ext4_htree_next_block(dir, HASH_NB_ALWAYS,
frame, frames, &hashval);
*next_hash = hashval;
if (ret < 0) {
err = ret;
goto errout;
}
/*
* Stop if: (a) there are no more entries, or
* (b) we have inserted at least one entry and the
* next hash value is not a continuation
*/
if ((ret == 0) ||
(count && ((hashval & 1) == 0)))
break;
}
dx_release(frames);
dxtrace(printk(KERN_DEBUG "Fill tree: returned %d entries, "
"next hash: %x\n", count, *next_hash));
return count;
errout:
dx_release(frames);
return (err);
}
static inline int search_dirblock(struct buffer_head *bh,
struct inode *dir,
const struct qstr *d_name,
unsigned int offset,
struct ext4_dir_entry_2 **res_dir)
{
return search_dir(bh, bh->b_data, dir->i_sb->s_blocksize, dir,
d_name, offset, res_dir);
}
/*
* Directory block splitting, compacting
*/
/*
* Create map of hash values, offsets, and sizes, stored at end of block.
* Returns number of entries mapped.
*/
static int dx_make_map(struct ext4_dir_entry_2 *de, unsigned blocksize,
struct dx_hash_info *hinfo,
struct dx_map_entry *map_tail)
{
int count = 0;
char *base = (char *) de;
struct dx_hash_info h = *hinfo;
while ((char *) de < base + blocksize) {
if (de->name_len && de->inode) {
ext4fs_dirhash(de->name, de->name_len, &h);
map_tail--;
map_tail->hash = h.hash;
map_tail->offs = ((char *) de - base)>>2;
map_tail->size = le16_to_cpu(de->rec_len);
count++;
cond_resched();
}
/* XXX: do we need to check rec_len == 0 case? -Chris */
de = ext4_next_entry(de, blocksize);
}
return count;
}
/* Sort map by hash value */
static void dx_sort_map (struct dx_map_entry *map, unsigned count)
{
struct dx_map_entry *p, *q, *top = map + count - 1;
int more;
/* Combsort until bubble sort doesn't suck */
while (count > 2) {
count = count*10/13;
if (count - 9 < 2) /* 9, 10 -> 11 */
count = 11;
for (p = top, q = p - count; q >= map; p--, q--)
if (p->hash < q->hash)
swap(*p, *q);
}
/* Garden variety bubble sort */
do {
more = 0;
q = top;
while (q-- > map) {
if (q[1].hash >= q[0].hash)
continue;
swap(*(q+1), *q);
more = 1;
}
} while(more);
}
static void dx_insert_block(struct dx_frame *frame, u32 hash, ext4_lblk_t block)
{
struct dx_entry *entries = frame->entries;
struct dx_entry *old = frame->at, *new = old + 1;
int count = dx_get_count(entries);
assert(count < dx_get_limit(entries));
assert(old < entries + count);
memmove(new + 1, new, (char *)(entries + count) - (char *)(new));
dx_set_hash(new, hash);
dx_set_block(new, block);
dx_set_count(entries, count + 1);
}
/*
* NOTE! unlike strncmp, ext4_match returns 1 for success, 0 for failure.
*
* `len <= EXT4_NAME_LEN' is guaranteed by caller.
* `de != NULL' is guaranteed by caller.
*/
static inline int ext4_match (int len, const char * const name,
struct ext4_dir_entry_2 * de)
{
if (len != de->name_len)
return 0;
if (!de->inode)
return 0;
return !memcmp(name, de->name, len);
}
/*
* Returns 0 if not found, -1 on failure, and 1 on success
*/
int search_dir(struct buffer_head *bh,
char *search_buf,
int buf_size,
struct inode *dir,
const struct qstr *d_name,
unsigned int offset,
struct ext4_dir_entry_2 **res_dir)
{
struct ext4_dir_entry_2 * de;
char * dlimit;
int de_len;
const char *name = d_name->name;
int namelen = d_name->len;
de = (struct ext4_dir_entry_2 *)search_buf;
dlimit = search_buf + buf_size;
while ((char *) de < dlimit) {
/* this code is executed quadratically often */
/* do minimal checking `by hand' */
if ((char *) de + namelen <= dlimit &&
ext4_match (namelen, name, de)) {
/* found a match - just to be sure, do a full check */
if (ext4_check_dir_entry(dir, NULL, de, bh, bh->b_data,
bh->b_size, offset))
return -1;
*res_dir = de;
return 1;
}
/* prevent looping on a bad block */
de_len = ext4_rec_len_from_disk(de->rec_len,
dir->i_sb->s_blocksize);
if (de_len <= 0)
return -1;
offset += de_len;
de = (struct ext4_dir_entry_2 *) ((char *) de + de_len);
}
return 0;
}
static int is_dx_internal_node(struct inode *dir, ext4_lblk_t block,
struct ext4_dir_entry *de)
{
struct super_block *sb = dir->i_sb;
if (!is_dx(dir))
return 0;
if (block == 0)
return 1;
if (de->inode == 0 &&
ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize) ==
sb->s_blocksize)
return 1;
return 0;
}
/*
* ext4_find_entry()
*
* finds an entry in the specified directory with the wanted name. It
* returns the cache buffer in which the entry was found, and the entry
* itself (as a parameter - res_dir). It does NOT read the inode of the
* entry - you'll have to do that yourself if you want to.
*
* The returned buffer_head has ->b_count elevated. The caller is expected
* to brelse() it when appropriate.
*/
static struct buffer_head * ext4_find_entry (struct inode *dir,
const struct qstr *d_name,
struct ext4_dir_entry_2 **res_dir,
int *inlined)
{
struct super_block *sb;
struct buffer_head *bh_use[NAMEI_RA_SIZE];
struct buffer_head *bh, *ret = NULL;
ext4_lblk_t start, block, b;
const u8 *name = d_name->name;
int ra_max = 0; /* Number of bh's in the readahead
buffer, bh_use[] */
int ra_ptr = 0; /* Current index into readahead
buffer */
int num = 0;
ext4_lblk_t nblocks;
int i, err;
int namelen;
*res_dir = NULL;
sb = dir->i_sb;
namelen = d_name->len;
if (namelen > EXT4_NAME_LEN)
return NULL;
if (ext4_has_inline_data(dir)) {
int has_inline_data = 1;
ret = ext4_find_inline_entry(dir, d_name, res_dir,
&has_inline_data);
if (has_inline_data) {
if (inlined)
*inlined = 1;
return ret;
}
}
if ((namelen <= 2) && (name[0] == '.') &&
(name[1] == '.' || name[1] == '\0')) {
/*
* "." or ".." will only be in the first block
* NFS may look up ".."; "." should be handled by the VFS
*/
block = start = 0;
nblocks = 1;
goto restart;
}
if (is_dx(dir)) {
bh = ext4_dx_find_entry(dir, d_name, res_dir, &err);
/*
* On success, or if the error was file not found,
* return. Otherwise, fall back to doing a search the
* old fashioned way.
*/
if (bh || (err != ERR_BAD_DX_DIR))
return bh;
dxtrace(printk(KERN_DEBUG "ext4_find_entry: dx failed, "
"falling back\n"));
}
nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb);
start = EXT4_I(dir)->i_dir_start_lookup;
if (start >= nblocks)
start = 0;
block = start;
restart:
do {
/*
* We deal with the read-ahead logic here.
*/
if (ra_ptr >= ra_max) {
/* Refill the readahead buffer */
ra_ptr = 0;
b = block;
for (ra_max = 0; ra_max < NAMEI_RA_SIZE; ra_max++) {
/*
* Terminate if we reach the end of the
* directory and must wrap, or if our
* search has finished at this block.
*/
if (b >= nblocks || (num && block == start)) {
bh_use[ra_max] = NULL;
break;
}
num++;
bh = ext4_getblk(NULL, dir, b++, 0, &err);
bh_use[ra_max] = bh;
if (bh)
ll_rw_block(READ | REQ_META | REQ_PRIO,
1, &bh);
}
}
if ((bh = bh_use[ra_ptr++]) == NULL)
goto next;
wait_on_buffer(bh);
if (!buffer_uptodate(bh)) {
/* read error, skip block & hope for the best */
EXT4_ERROR_INODE(dir, "reading directory lblock %lu",
(unsigned long) block);
brelse(bh);
goto next;
}
if (!buffer_verified(bh) &&
!is_dx_internal_node(dir, block,
(struct ext4_dir_entry *)bh->b_data) &&
!ext4_dirent_csum_verify(dir,
(struct ext4_dir_entry *)bh->b_data)) {
EXT4_ERROR_INODE(dir, "checksumming directory "
"block %lu", (unsigned long)block);
brelse(bh);
goto next;
}
set_buffer_verified(bh);
i = search_dirblock(bh, dir, d_name,
block << EXT4_BLOCK_SIZE_BITS(sb), res_dir);
if (i == 1) {
EXT4_I(dir)->i_dir_start_lookup = block;
ret = bh;
goto cleanup_and_exit;
} else {
brelse(bh);
if (i < 0)
goto cleanup_and_exit;
}
next:
if (++block >= nblocks)
block = 0;
} while (block != start);
/*
* If the directory has grown while we were searching, then
* search the last part of the directory before giving up.
*/
block = nblocks;
nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb);
if (block < nblocks) {
start = 0;
goto restart;
}
cleanup_and_exit:
/* Clean up the read-ahead blocks */
for (; ra_ptr < ra_max; ra_ptr++)
brelse(bh_use[ra_ptr]);
return ret;
}
static struct buffer_head * ext4_dx_find_entry(struct inode *dir, const struct qstr *d_name,
struct ext4_dir_entry_2 **res_dir, int *err)
{
struct super_block * sb = dir->i_sb;
struct dx_hash_info hinfo;
struct dx_frame frames[2], *frame;
struct buffer_head *bh;
ext4_lblk_t block;
int retval;
if (!(frame = dx_probe(d_name, dir, &hinfo, frames, err)))
return NULL;
do {
block = dx_get_block(frame->at);
bh = ext4_read_dirblock(dir, block, DIRENT);
if (IS_ERR(bh)) {
*err = PTR_ERR(bh);
goto errout;
}
retval = search_dirblock(bh, dir, d_name,
block << EXT4_BLOCK_SIZE_BITS(sb),
res_dir);
if (retval == 1) { /* Success! */
dx_release(frames);
return bh;
}
brelse(bh);
if (retval == -1) {
*err = ERR_BAD_DX_DIR;
goto errout;
}
/* Check to see if we should continue to search */
retval = ext4_htree_next_block(dir, hinfo.hash, frame,
frames, NULL);
if (retval < 0) {
ext4_warning(sb,
"error reading index page in directory #%lu",
dir->i_ino);
*err = retval;
goto errout;
}
} while (retval == 1);
*err = -ENOENT;
errout:
dxtrace(printk(KERN_DEBUG "%s not found\n", d_name->name));
dx_release (frames);
return NULL;
}
static struct dentry *ext4_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
{
struct inode *inode;
struct ext4_dir_entry_2 *de;
struct buffer_head *bh;
if (dentry->d_name.len > EXT4_NAME_LEN)
return ERR_PTR(-ENAMETOOLONG);
bh = ext4_find_entry(dir, &dentry->d_name, &de, NULL);
inode = NULL;
if (bh) {
__u32 ino = le32_to_cpu(de->inode);
brelse(bh);
if (!ext4_valid_inum(dir->i_sb, ino)) {
EXT4_ERROR_INODE(dir, "bad inode number: %u", ino);
return ERR_PTR(-EIO);
}
if (unlikely(ino == dir->i_ino)) {
EXT4_ERROR_INODE(dir, "'%.*s' linked to parent dir",
dentry->d_name.len,
dentry->d_name.name);
return ERR_PTR(-EIO);
}
inode = ext4_iget(dir->i_sb, ino);
if (inode == ERR_PTR(-ESTALE)) {
EXT4_ERROR_INODE(dir,
"deleted inode referenced: %u",
ino);
return ERR_PTR(-EIO);
}
}
return d_splice_alias(inode, dentry);
}
struct dentry *ext4_get_parent(struct dentry *child)
{
__u32 ino;
static const struct qstr dotdot = QSTR_INIT("..", 2);
struct ext4_dir_entry_2 * de;
struct buffer_head *bh;
bh = ext4_find_entry(child->d_inode, &dotdot, &de, NULL);
if (!bh)
return ERR_PTR(-ENOENT);
ino = le32_to_cpu(de->inode);
brelse(bh);
if (!ext4_valid_inum(child->d_inode->i_sb, ino)) {
EXT4_ERROR_INODE(child->d_inode,
"bad parent inode number: %u", ino);
return ERR_PTR(-EIO);
}
return d_obtain_alias(ext4_iget(child->d_inode->i_sb, ino));
}
/*
* Move count entries from end of map between two memory locations.
* Returns pointer to last entry moved.
*/
static struct ext4_dir_entry_2 *
dx_move_dirents(char *from, char *to, struct dx_map_entry *map, int count,
unsigned blocksize)
{
unsigned rec_len = 0;
while (count--) {
struct ext4_dir_entry_2 *de = (struct ext4_dir_entry_2 *)
(from + (map->offs<<2));
rec_len = EXT4_DIR_REC_LEN(de->name_len);
memcpy (to, de, rec_len);
((struct ext4_dir_entry_2 *) to)->rec_len =
ext4_rec_len_to_disk(rec_len, blocksize);
de->inode = 0;
map++;
to += rec_len;
}
return (struct ext4_dir_entry_2 *) (to - rec_len);
}
/*
* Compact each dir entry in the range to the minimal rec_len.
* Returns pointer to last entry in range.
*/
static struct ext4_dir_entry_2* dx_pack_dirents(char *base, unsigned blocksize)
{
struct ext4_dir_entry_2 *next, *to, *prev, *de = (struct ext4_dir_entry_2 *) base;
unsigned rec_len = 0;
prev = to = de;
while ((char*)de < base + blocksize) {
next = ext4_next_entry(de, blocksize);
if (de->inode && de->name_len) {
rec_len = EXT4_DIR_REC_LEN(de->name_len);
if (de > to)
memmove(to, de, rec_len);
to->rec_len = ext4_rec_len_to_disk(rec_len, blocksize);
prev = to;
to = (struct ext4_dir_entry_2 *) (((char *) to) + rec_len);
}
de = next;
}
return prev;
}
/*
* Split a full leaf block to make room for a new dir entry.
* Allocate a new block, and move entries so that they are approx. equally full.
* Returns pointer to de in block into which the new entry will be inserted.
*/
static struct ext4_dir_entry_2 *do_split(handle_t *handle, struct inode *dir,
struct buffer_head **bh,struct dx_frame *frame,
struct dx_hash_info *hinfo, int *error)
{
unsigned blocksize = dir->i_sb->s_blocksize;
unsigned count, continued;
struct buffer_head *bh2;
ext4_lblk_t newblock;
u32 hash2;
struct dx_map_entry *map;
char *data1 = (*bh)->b_data, *data2;
unsigned split, move, size;
struct ext4_dir_entry_2 *de = NULL, *de2;
struct ext4_dir_entry_tail *t;
int csum_size = 0;
int err = 0, i;
if (EXT4_HAS_RO_COMPAT_FEATURE(dir->i_sb,
EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
csum_size = sizeof(struct ext4_dir_entry_tail);
bh2 = ext4_append(handle, dir, &newblock);
if (IS_ERR(bh2)) {
brelse(*bh);
*bh = NULL;
*error = PTR_ERR(bh2);
return NULL;
}
BUFFER_TRACE(*bh, "get_write_access");
err = ext4_journal_get_write_access(handle, *bh);
if (err)
goto journal_error;
BUFFER_TRACE(frame->bh, "get_write_access");
err = ext4_journal_get_write_access(handle, frame->bh);
if (err)
goto journal_error;
data2 = bh2->b_data;
/* create map in the end of data2 block */
map = (struct dx_map_entry *) (data2 + blocksize);
count = dx_make_map((struct ext4_dir_entry_2 *) data1,
blocksize, hinfo, map);
map -= count;
dx_sort_map(map, count);
/* Split the existing block in the middle, size-wise */
size = 0;
move = 0;
for (i = count-1; i >= 0; i--) {
/* is more than half of this entry in 2nd half of the block? */
if (size + map[i].size/2 > blocksize/2)
break;
size += map[i].size;
move++;
}
/* map index at which we will split */
split = count - move;
hash2 = map[split].hash;
continued = hash2 == map[split - 1].hash;
dxtrace(printk(KERN_INFO "Split block %lu at %x, %i/%i\n",
(unsigned long)dx_get_block(frame->at),
hash2, split, count-split));
/* Fancy dance to stay within two buffers */
de2 = dx_move_dirents(data1, data2, map + split, count - split, blocksize);
de = dx_pack_dirents(data1, blocksize);
de->rec_len = ext4_rec_len_to_disk(data1 + (blocksize - csum_size) -
(char *) de,
blocksize);
de2->rec_len = ext4_rec_len_to_disk(data2 + (blocksize - csum_size) -
(char *) de2,
blocksize);
if (csum_size) {
t = EXT4_DIRENT_TAIL(data2, blocksize);
initialize_dirent_tail(t, blocksize);
t = EXT4_DIRENT_TAIL(data1, blocksize);
initialize_dirent_tail(t, blocksize);
}
dxtrace(dx_show_leaf (hinfo, (struct ext4_dir_entry_2 *) data1, blocksize, 1));
dxtrace(dx_show_leaf (hinfo, (struct ext4_dir_entry_2 *) data2, blocksize, 1));
/* Which block gets the new entry? */
if (hinfo->hash >= hash2)
{
swap(*bh, bh2);
de = de2;
}
dx_insert_block(frame, hash2 + continued, newblock);
err = ext4_handle_dirty_dirent_node(handle, dir, bh2);
if (err)
goto journal_error;
err = ext4_handle_dirty_dx_node(handle, dir, frame->bh);
if (err)
goto journal_error;
brelse(bh2);
dxtrace(dx_show_index("frame", frame->entries));
return de;
journal_error:
brelse(*bh);
brelse(bh2);
*bh = NULL;
ext4_std_error(dir->i_sb, err);
*error = err;
return NULL;
}
int ext4_find_dest_de(struct inode *dir, struct inode *inode,
struct buffer_head *bh,
void *buf, int buf_size,
const char *name, int namelen,
struct ext4_dir_entry_2 **dest_de)
{
struct ext4_dir_entry_2 *de;
unsigned short reclen = EXT4_DIR_REC_LEN(namelen);
int nlen, rlen;
unsigned int offset = 0;
char *top;
de = (struct ext4_dir_entry_2 *)buf;
top = buf + buf_size - reclen;
while ((char *) de <= top) {
if (ext4_check_dir_entry(dir, NULL, de, bh,
buf, buf_size, offset))
return -EIO;
if (ext4_match(namelen, name, de))
return -EEXIST;
nlen = EXT4_DIR_REC_LEN(de->name_len);
rlen = ext4_rec_len_from_disk(de->rec_len, buf_size);
if ((de->inode ? rlen - nlen : rlen) >= reclen)
break;
de = (struct ext4_dir_entry_2 *)((char *)de + rlen);
offset += rlen;
}
if ((char *) de > top)
return -ENOSPC;
*dest_de = de;
return 0;
}
void ext4_insert_dentry(struct inode *inode,
struct ext4_dir_entry_2 *de,
int buf_size,
const char *name, int namelen)
{
int nlen, rlen;
nlen = EXT4_DIR_REC_LEN(de->name_len);
rlen = ext4_rec_len_from_disk(de->rec_len, buf_size);
if (de->inode) {
struct ext4_dir_entry_2 *de1 =
(struct ext4_dir_entry_2 *)((char *)de + nlen);
de1->rec_len = ext4_rec_len_to_disk(rlen - nlen, buf_size);
de->rec_len = ext4_rec_len_to_disk(nlen, buf_size);
de = de1;
}
de->file_type = EXT4_FT_UNKNOWN;
de->inode = cpu_to_le32(inode->i_ino);
ext4_set_de_type(inode->i_sb, de, inode->i_mode);
de->name_len = namelen;
memcpy(de->name, name, namelen);
}
/*
* Add a new entry into a directory (leaf) block. If de is non-NULL,
* it points to a directory entry which is guaranteed to be large
* enough for new directory entry. If de is NULL, then
* add_dirent_to_buf will attempt search the directory block for
* space. It will return -ENOSPC if no space is available, and -EIO
* and -EEXIST if directory entry already exists.
*/
static int add_dirent_to_buf(handle_t *handle, struct dentry *dentry,
struct inode *inode, struct ext4_dir_entry_2 *de,
struct buffer_head *bh)
{
struct inode *dir = dentry->d_parent->d_inode;
const char *name = dentry->d_name.name;
int namelen = dentry->d_name.len;
unsigned int blocksize = dir->i_sb->s_blocksize;
int csum_size = 0;
int err;
if (EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
csum_size = sizeof(struct ext4_dir_entry_tail);
if (!de) {
err = ext4_find_dest_de(dir, inode,
bh, bh->b_data, blocksize - csum_size,
name, namelen, &de);
if (err)
return err;
}
BUFFER_TRACE(bh, "get_write_access");
err = ext4_journal_get_write_access(handle, bh);
if (err) {
ext4_std_error(dir->i_sb, err);
return err;
}
/* By now the buffer is marked for journaling */
ext4_insert_dentry(inode, de, blocksize, name, namelen);
/*
* XXX shouldn't update any times until successful
* completion of syscall, but too many callers depend
* on this.
*
* XXX similarly, too many callers depend on
* ext4_new_inode() setting the times, but error
* recovery deletes the inode, so the worst that can
* happen is that the times are slightly out of date
* and/or different from the directory change time.
*/
dir->i_mtime = dir->i_ctime = ext4_current_time(dir);
ext4_update_dx_flag(dir);
dir->i_version++;
ext4_mark_inode_dirty(handle, dir);
BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
err = ext4_handle_dirty_dirent_node(handle, dir, bh);
if (err)
ext4_std_error(dir->i_sb, err);
return 0;
}
/*
* This converts a one block unindexed directory to a 3 block indexed
* directory, and adds the dentry to the indexed directory.
*/
static int make_indexed_dir(handle_t *handle, struct dentry *dentry,
struct inode *inode, struct buffer_head *bh)
{
struct inode *dir = dentry->d_parent->d_inode;
const char *name = dentry->d_name.name;
int namelen = dentry->d_name.len;
struct buffer_head *bh2;
struct dx_root *root;
struct dx_frame frames[2], *frame;
struct dx_entry *entries;
struct ext4_dir_entry_2 *de, *de2;
struct ext4_dir_entry_tail *t;
char *data1, *top;
unsigned len;
int retval;
unsigned blocksize;
struct dx_hash_info hinfo;
ext4_lblk_t block;
struct fake_dirent *fde;
int csum_size = 0;
if (EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
csum_size = sizeof(struct ext4_dir_entry_tail);
blocksize = dir->i_sb->s_blocksize;
dxtrace(printk(KERN_DEBUG "Creating index: inode %lu\n", dir->i_ino));
retval = ext4_journal_get_write_access(handle, bh);
if (retval) {
ext4_std_error(dir->i_sb, retval);
brelse(bh);
return retval;
}
root = (struct dx_root *) bh->b_data;
/* The 0th block becomes the root, move the dirents out */
fde = &root->dotdot;
de = (struct ext4_dir_entry_2 *)((char *)fde +
ext4_rec_len_from_disk(fde->rec_len, blocksize));
if ((char *) de >= (((char *) root) + blocksize)) {
EXT4_ERROR_INODE(dir, "invalid rec_len for '..'");
brelse(bh);
return -EIO;
}
len = ((char *) root) + (blocksize - csum_size) - (char *) de;
/* Allocate new block for the 0th block's dirents */
bh2 = ext4_append(handle, dir, &block);
if (IS_ERR(bh2)) {
brelse(bh);
return PTR_ERR(bh2);
}
ext4_set_inode_flag(dir, EXT4_INODE_INDEX);
data1 = bh2->b_data;
memcpy (data1, de, len);
de = (struct ext4_dir_entry_2 *) data1;
top = data1 + len;
while ((char *)(de2 = ext4_next_entry(de, blocksize)) < top)
de = de2;
de->rec_len = ext4_rec_len_to_disk(data1 + (blocksize - csum_size) -
(char *) de,
blocksize);
if (csum_size) {
t = EXT4_DIRENT_TAIL(data1, blocksize);
initialize_dirent_tail(t, blocksize);
}
/* Initialize the root; the dot dirents already exist */
de = (struct ext4_dir_entry_2 *) (&root->dotdot);
de->rec_len = ext4_rec_len_to_disk(blocksize - EXT4_DIR_REC_LEN(2),
blocksize);
memset (&root->info, 0, sizeof(root->info));
root->info.info_length = sizeof(root->info);
root->info.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version;
entries = root->entries;
dx_set_block(entries, 1);
dx_set_count(entries, 1);
dx_set_limit(entries, dx_root_limit(dir, sizeof(root->info)));
/* Initialize as for dx_probe */
hinfo.hash_version = root->info.hash_version;
if (hinfo.hash_version <= DX_HASH_TEA)
hinfo.hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned;
hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed;
ext4fs_dirhash(name, namelen, &hinfo);
frame = frames;
frame->entries = entries;
frame->at = entries;
frame->bh = bh;
bh = bh2;
ext4_handle_dirty_dx_node(handle, dir, frame->bh);
ext4_handle_dirty_dirent_node(handle, dir, bh);
de = do_split(handle,dir, &bh, frame, &hinfo, &retval);
if (!de) {
/*
* Even if the block split failed, we have to properly write
* out all the changes we did so far. Otherwise we can end up
* with corrupted filesystem.
*/
ext4_mark_inode_dirty(handle, dir);
dx_release(frames);
return retval;
}
dx_release(frames);
retval = add_dirent_to_buf(handle, dentry, inode, de, bh);
brelse(bh);
return retval;
}
/*
* ext4_add_entry()
*
* adds a file entry to the specified directory, using the same
* semantics as ext4_find_entry(). It returns NULL if it failed.
*
* NOTE!! The inode part of 'de' is left at 0 - which means you
* may not sleep between calling this and putting something into
* the entry, as someone else might have used it while you slept.
*/
static int ext4_add_entry(handle_t *handle, struct dentry *dentry,
struct inode *inode)
{
struct inode *dir = dentry->d_parent->d_inode;
struct buffer_head *bh;
struct ext4_dir_entry_2 *de;
struct ext4_dir_entry_tail *t;
struct super_block *sb;
int retval;
int dx_fallback=0;
unsigned blocksize;
ext4_lblk_t block, blocks;
int csum_size = 0;
if (EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
csum_size = sizeof(struct ext4_dir_entry_tail);
sb = dir->i_sb;
blocksize = sb->s_blocksize;
if (!dentry->d_name.len)
return -EINVAL;
if (ext4_has_inline_data(dir)) {
retval = ext4_try_add_inline_entry(handle, dentry, inode);
if (retval < 0)
return retval;
if (retval == 1) {
retval = 0;
return retval;
}
}
if (is_dx(dir)) {
retval = ext4_dx_add_entry(handle, dentry, inode);
if (!retval || (retval != ERR_BAD_DX_DIR))
return retval;
ext4_clear_inode_flag(dir, EXT4_INODE_INDEX);
dx_fallback++;
ext4_mark_inode_dirty(handle, dir);
}
blocks = dir->i_size >> sb->s_blocksize_bits;
for (block = 0; block < blocks; block++) {
bh = ext4_read_dirblock(dir, block, DIRENT);
if (IS_ERR(bh))
return PTR_ERR(bh);
retval = add_dirent_to_buf(handle, dentry, inode, NULL, bh);
if (retval != -ENOSPC) {
brelse(bh);
return retval;
}
if (blocks == 1 && !dx_fallback &&
EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_DIR_INDEX))
return make_indexed_dir(handle, dentry, inode, bh);
brelse(bh);
}
bh = ext4_append(handle, dir, &block);
if (IS_ERR(bh))
return PTR_ERR(bh);
de = (struct ext4_dir_entry_2 *) bh->b_data;
de->inode = 0;
de->rec_len = ext4_rec_len_to_disk(blocksize - csum_size, blocksize);
if (csum_size) {
t = EXT4_DIRENT_TAIL(bh->b_data, blocksize);
initialize_dirent_tail(t, blocksize);
}
retval = add_dirent_to_buf(handle, dentry, inode, de, bh);
brelse(bh);
if (retval == 0)
ext4_set_inode_state(inode, EXT4_STATE_NEWENTRY);
return retval;
}
/*
* Returns 0 for success, or a negative error value
*/
static int ext4_dx_add_entry(handle_t *handle, struct dentry *dentry,
struct inode *inode)
{
struct dx_frame frames[2], *frame;
struct dx_entry *entries, *at;
struct dx_hash_info hinfo;
struct buffer_head *bh;
struct inode *dir = dentry->d_parent->d_inode;
struct super_block *sb = dir->i_sb;
struct ext4_dir_entry_2 *de;
int err;
frame = dx_probe(&dentry->d_name, dir, &hinfo, frames, &err);
if (!frame)
return err;
entries = frame->entries;
at = frame->at;
bh = ext4_read_dirblock(dir, dx_get_block(frame->at), DIRENT);
if (IS_ERR(bh)) {
err = PTR_ERR(bh);
bh = NULL;
goto cleanup;
}
BUFFER_TRACE(bh, "get_write_access");
err = ext4_journal_get_write_access(handle, bh);
if (err)
goto journal_error;
err = add_dirent_to_buf(handle, dentry, inode, NULL, bh);
if (err != -ENOSPC)
goto cleanup;
/* Block full, should compress but for now just split */
dxtrace(printk(KERN_DEBUG "using %u of %u node entries\n",
dx_get_count(entries), dx_get_limit(entries)));
/* Need to split index? */
if (dx_get_count(entries) == dx_get_limit(entries)) {
ext4_lblk_t newblock;
unsigned icount = dx_get_count(entries);
int levels = frame - frames;
struct dx_entry *entries2;
struct dx_node *node2;
struct buffer_head *bh2;
if (levels && (dx_get_count(frames->entries) ==
dx_get_limit(frames->entries))) {
ext4_warning(sb, "Directory index full!");
err = -ENOSPC;
goto cleanup;
}
bh2 = ext4_append(handle, dir, &newblock);
if (IS_ERR(bh2)) {
err = PTR_ERR(bh2);
goto cleanup;
}
node2 = (struct dx_node *)(bh2->b_data);
entries2 = node2->entries;
memset(&node2->fake, 0, sizeof(struct fake_dirent));
node2->fake.rec_len = ext4_rec_len_to_disk(sb->s_blocksize,
sb->s_blocksize);
BUFFER_TRACE(frame->bh, "get_write_access");
err = ext4_journal_get_write_access(handle, frame->bh);
if (err)
goto journal_error;
if (levels) {
unsigned icount1 = icount/2, icount2 = icount - icount1;
unsigned hash2 = dx_get_hash(entries + icount1);
dxtrace(printk(KERN_DEBUG "Split index %i/%i\n",
icount1, icount2));
BUFFER_TRACE(frame->bh, "get_write_access"); /* index root */
err = ext4_journal_get_write_access(handle,
frames[0].bh);
if (err)
goto journal_error;
memcpy((char *) entries2, (char *) (entries + icount1),
icount2 * sizeof(struct dx_entry));
dx_set_count(entries, icount1);
dx_set_count(entries2, icount2);
dx_set_limit(entries2, dx_node_limit(dir));
/* Which index block gets the new entry? */
if (at - entries >= icount1) {
frame->at = at = at - entries - icount1 + entries2;
frame->entries = entries = entries2;
swap(frame->bh, bh2);
}
dx_insert_block(frames + 0, hash2, newblock);
dxtrace(dx_show_index("node", frames[1].entries));
dxtrace(dx_show_index("node",
((struct dx_node *) bh2->b_data)->entries));
err = ext4_handle_dirty_dx_node(handle, dir, bh2);
if (err)
goto journal_error;
brelse (bh2);
} else {
dxtrace(printk(KERN_DEBUG
"Creating second level index...\n"));
memcpy((char *) entries2, (char *) entries,
icount * sizeof(struct dx_entry));
dx_set_limit(entries2, dx_node_limit(dir));
/* Set up root */
dx_set_count(entries, 1);
dx_set_block(entries + 0, newblock);
((struct dx_root *) frames[0].bh->b_data)->info.indirect_levels = 1;
/* Add new access path frame */
frame = frames + 1;
frame->at = at = at - entries + entries2;
frame->entries = entries = entries2;
frame->bh = bh2;
err = ext4_journal_get_write_access(handle,
frame->bh);
if (err)
goto journal_error;
}
err = ext4_handle_dirty_dx_node(handle, dir, frames[0].bh);
if (err) {
ext4_std_error(inode->i_sb, err);
goto cleanup;
}
}
de = do_split(handle, dir, &bh, frame, &hinfo, &err);
if (!de)
goto cleanup;
err = add_dirent_to_buf(handle, dentry, inode, de, bh);
goto cleanup;
journal_error:
ext4_std_error(dir->i_sb, err);
cleanup:
brelse(bh);
dx_release(frames);
return err;
}
/*
* ext4_generic_delete_entry deletes a directory entry by merging it
* with the previous entry
*/
int ext4_generic_delete_entry(handle_t *handle,
struct inode *dir,
struct ext4_dir_entry_2 *de_del,
struct buffer_head *bh,
void *entry_buf,
int buf_size,
int csum_size)
{
struct ext4_dir_entry_2 *de, *pde;
unsigned int blocksize = dir->i_sb->s_blocksize;
int i;
i = 0;
pde = NULL;
de = (struct ext4_dir_entry_2 *)entry_buf;
while (i < buf_size - csum_size) {
if (ext4_check_dir_entry(dir, NULL, de, bh,
bh->b_data, bh->b_size, i))
return -EIO;
if (de == de_del) {
if (pde)
pde->rec_len = ext4_rec_len_to_disk(
ext4_rec_len_from_disk(pde->rec_len,
blocksize) +
ext4_rec_len_from_disk(de->rec_len,
blocksize),
blocksize);
else
de->inode = 0;
dir->i_version++;
return 0;
}
i += ext4_rec_len_from_disk(de->rec_len, blocksize);
pde = de;
de = ext4_next_entry(de, blocksize);
}
return -ENOENT;
}
static int ext4_delete_entry(handle_t *handle,
struct inode *dir,
struct ext4_dir_entry_2 *de_del,
struct buffer_head *bh)
{
int err, csum_size = 0;
if (ext4_has_inline_data(dir)) {
int has_inline_data = 1;
err = ext4_delete_inline_entry(handle, dir, de_del, bh,
&has_inline_data);
if (has_inline_data)
return err;
}
if (EXT4_HAS_RO_COMPAT_FEATURE(dir->i_sb,
EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
csum_size = sizeof(struct ext4_dir_entry_tail);
BUFFER_TRACE(bh, "get_write_access");
err = ext4_journal_get_write_access(handle, bh);
if (unlikely(err))
goto out;
err = ext4_generic_delete_entry(handle, dir, de_del,
bh, bh->b_data,
dir->i_sb->s_blocksize, csum_size);
if (err)
goto out;
BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
err = ext4_handle_dirty_dirent_node(handle, dir, bh);
if (unlikely(err))
goto out;
return 0;
out:
if (err != -ENOENT)
ext4_std_error(dir->i_sb, err);
return err;
}
/*
* DIR_NLINK feature is set if 1) nlinks > EXT4_LINK_MAX or 2) nlinks == 2,
* since this indicates that nlinks count was previously 1.
*/
static void ext4_inc_count(handle_t *handle, struct inode *inode)
{
inc_nlink(inode);
if (is_dx(inode) && inode->i_nlink > 1) {
/* limit is 16-bit i_links_count */
if (inode->i_nlink >= EXT4_LINK_MAX || inode->i_nlink == 2) {
set_nlink(inode, 1);
EXT4_SET_RO_COMPAT_FEATURE(inode->i_sb,
EXT4_FEATURE_RO_COMPAT_DIR_NLINK);
}
}
}
/*
* If a directory had nlink == 1, then we should let it be 1. This indicates
* directory has >EXT4_LINK_MAX subdirs.
*/
static void ext4_dec_count(handle_t *handle, struct inode *inode)
{
if (!S_ISDIR(inode->i_mode) || inode->i_nlink > 2)
drop_nlink(inode);
}
static int ext4_add_nondir(handle_t *handle,
struct dentry *dentry, struct inode *inode)
{
int err = ext4_add_entry(handle, dentry, inode);
if (!err) {
ext4_mark_inode_dirty(handle, inode);
unlock_new_inode(inode);
d_instantiate(dentry, inode);
return 0;
}
drop_nlink(inode);
unlock_new_inode(inode);
iput(inode);
return err;
}
/*
* By the time this is called, we already have created
* the directory cache entry for the new file, but it
* is so far negative - it has no inode.
*
* If the create succeeds, we fill in the inode information
* with d_instantiate().
*/
static int ext4_create(struct inode *dir, struct dentry *dentry, umode_t mode,
bool excl)
{
handle_t *handle;
struct inode *inode;
int err, credits, retries = 0;
dquot_initialize(dir);
credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3);
retry:
inode = ext4_new_inode_start_handle(dir, mode, &dentry->d_name, 0,
NULL, EXT4_HT_DIR, credits);
handle = ext4_journal_current_handle();
err = PTR_ERR(inode);
if (!IS_ERR(inode)) {
inode->i_op = &ext4_file_inode_operations;
inode->i_fop = &ext4_file_operations;
ext4_set_aops(inode);
err = ext4_add_nondir(handle, dentry, inode);
if (!err && IS_DIRSYNC(dir))
ext4_handle_sync(handle);
}
if (handle)
ext4_journal_stop(handle);
if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
goto retry;
return err;
}
static int ext4_mknod(struct inode *dir, struct dentry *dentry,
umode_t mode, dev_t rdev)
{
handle_t *handle;
struct inode *inode;
int err, credits, retries = 0;
if (!new_valid_dev(rdev))
return -EINVAL;
dquot_initialize(dir);
credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3);
retry:
inode = ext4_new_inode_start_handle(dir, mode, &dentry->d_name, 0,
NULL, EXT4_HT_DIR, credits);
handle = ext4_journal_current_handle();
err = PTR_ERR(inode);
if (!IS_ERR(inode)) {
init_special_inode(inode, inode->i_mode, rdev);
inode->i_op = &ext4_special_inode_operations;
err = ext4_add_nondir(handle, dentry, inode);
if (!err && IS_DIRSYNC(dir))
ext4_handle_sync(handle);
}
if (handle)
ext4_journal_stop(handle);
if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
goto retry;
return err;
}
static int ext4_tmpfile(struct inode *dir, struct dentry *dentry, umode_t mode)
{
handle_t *handle;
struct inode *inode;
int err, retries = 0;
dquot_initialize(dir);
retry:
inode = ext4_new_inode_start_handle(dir, mode,
NULL, 0, NULL,
EXT4_HT_DIR,
EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb) +
4 + EXT4_XATTR_TRANS_BLOCKS);
handle = ext4_journal_current_handle();
err = PTR_ERR(inode);
if (!IS_ERR(inode)) {
inode->i_op = &ext4_file_inode_operations;
inode->i_fop = &ext4_file_operations;
ext4_set_aops(inode);
d_tmpfile(dentry, inode);
err = ext4_orphan_add(handle, inode);
if (err)
goto err_drop_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_drop_inode:
ext4_journal_stop(handle);
unlock_new_inode(inode);
iput(inode);
return err;
}
struct ext4_dir_entry_2 *ext4_init_dot_dotdot(struct inode *inode,
struct ext4_dir_entry_2 *de,
int blocksize, int csum_size,
unsigned int parent_ino, int dotdot_real_len)
{
de->inode = cpu_to_le32(inode->i_ino);
de->name_len = 1;
de->rec_len = ext4_rec_len_to_disk(EXT4_DIR_REC_LEN(de->name_len),
blocksize);
strcpy(de->name, ".");
ext4_set_de_type(inode->i_sb, de, S_IFDIR);
de = ext4_next_entry(de, blocksize);
de->inode = cpu_to_le32(parent_ino);
de->name_len = 2;
if (!dotdot_real_len)
de->rec_len = ext4_rec_len_to_disk(blocksize -
(csum_size + EXT4_DIR_REC_LEN(1)),
blocksize);
else
de->rec_len = ext4_rec_len_to_disk(
EXT4_DIR_REC_LEN(de->name_len), blocksize);
strcpy(de->name, "..");
ext4_set_de_type(inode->i_sb, de, S_IFDIR);
return ext4_next_entry(de, blocksize);
}
static int ext4_init_new_dir(handle_t *handle, struct inode *dir,
struct inode *inode)
{
struct buffer_head *dir_block = NULL;
struct ext4_dir_entry_2 *de;
struct ext4_dir_entry_tail *t;
ext4_lblk_t block = 0;
unsigned int blocksize = dir->i_sb->s_blocksize;
int csum_size = 0;
int err;
if (EXT4_HAS_RO_COMPAT_FEATURE(dir->i_sb,
EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
csum_size = sizeof(struct ext4_dir_entry_tail);
if (ext4_test_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA)) {
err = ext4_try_create_inline_dir(handle, dir, inode);
if (err < 0 && err != -ENOSPC)
goto out;
if (!err)
goto out;
}
inode->i_size = 0;
dir_block = ext4_append(handle, inode, &block);
if (IS_ERR(dir_block))
return PTR_ERR(dir_block);
BUFFER_TRACE(dir_block, "get_write_access");
err = ext4_journal_get_write_access(handle, dir_block);
if (err)
goto out;
de = (struct ext4_dir_entry_2 *)dir_block->b_data;
ext4_init_dot_dotdot(inode, de, blocksize, csum_size, dir->i_ino, 0);
set_nlink(inode, 2);
if (csum_size) {
t = EXT4_DIRENT_TAIL(dir_block->b_data, blocksize);
initialize_dirent_tail(t, blocksize);
}
BUFFER_TRACE(dir_block, "call ext4_handle_dirty_metadata");
err = ext4_handle_dirty_dirent_node(handle, inode, dir_block);
if (err)
goto out;
set_buffer_verified(dir_block);
out:
brelse(dir_block);
return err;
}
static int ext4_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
{
handle_t *handle;
struct inode *inode;
int err, credits, retries = 0;
if (EXT4_DIR_LINK_MAX(dir))
return -EMLINK;
dquot_initialize(dir);
credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3);
retry:
inode = ext4_new_inode_start_handle(dir, S_IFDIR | mode,
&dentry->d_name,
0, NULL, EXT4_HT_DIR, credits);
handle = ext4_journal_current_handle();
err = PTR_ERR(inode);
if (IS_ERR(inode))
goto out_stop;
inode->i_op = &ext4_dir_inode_operations;
inode->i_fop = &ext4_dir_operations;
err = ext4_init_new_dir(handle, dir, inode);
if (err)
goto out_clear_inode;
err = ext4_mark_inode_dirty(handle, inode);
if (!err)
err = ext4_add_entry(handle, dentry, inode);
if (err) {
out_clear_inode:
clear_nlink(inode);
unlock_new_inode(inode);
ext4_mark_inode_dirty(handle, inode);
iput(inode);
goto out_stop;
}
ext4_inc_count(handle, dir);
ext4_update_dx_flag(dir);
err = ext4_mark_inode_dirty(handle, dir);
if (err)
goto out_clear_inode;
unlock_new_inode(inode);
d_instantiate(dentry, inode);
if (IS_DIRSYNC(dir))
ext4_handle_sync(handle);
out_stop:
if (handle)
ext4_journal_stop(handle);
if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
goto retry;
return err;
}
/*
* routine to check that the specified directory is empty (for rmdir)
*/
static int empty_dir(struct inode *inode)
{
unsigned int offset;
struct buffer_head *bh;
struct ext4_dir_entry_2 *de, *de1;
struct super_block *sb;
int err = 0;
if (ext4_has_inline_data(inode)) {
int has_inline_data = 1;
err = empty_inline_dir(inode, &has_inline_data);
if (has_inline_data)
return err;
}
sb = inode->i_sb;
if (inode->i_size < EXT4_DIR_REC_LEN(1) + EXT4_DIR_REC_LEN(2)) {
EXT4_ERROR_INODE(inode, "invalid size");
return 1;
}
bh = ext4_read_dirblock(inode, 0, EITHER);
if (IS_ERR(bh))
return 1;
de = (struct ext4_dir_entry_2 *) bh->b_data;
de1 = ext4_next_entry(de, sb->s_blocksize);
if (le32_to_cpu(de->inode) != inode->i_ino ||
!le32_to_cpu(de1->inode) ||
strcmp(".", de->name) ||
strcmp("..", de1->name)) {
ext4_warning(inode->i_sb,
"bad directory (dir #%lu) - no `.' or `..'",
inode->i_ino);
brelse(bh);
return 1;
}
offset = ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize) +
ext4_rec_len_from_disk(de1->rec_len, sb->s_blocksize);
de = ext4_next_entry(de1, sb->s_blocksize);
while (offset < inode->i_size) {
if (!bh ||
(void *) de >= (void *) (bh->b_data+sb->s_blocksize)) {
unsigned int lblock;
err = 0;
brelse(bh);
lblock = offset >> EXT4_BLOCK_SIZE_BITS(sb);
bh = ext4_read_dirblock(inode, lblock, EITHER);
if (IS_ERR(bh))
return 1;
de = (struct ext4_dir_entry_2 *) bh->b_data;
}
if (ext4_check_dir_entry(inode, NULL, de, bh,
bh->b_data, bh->b_size, offset)) {
de = (struct ext4_dir_entry_2 *)(bh->b_data +
sb->s_blocksize);
offset = (offset | (sb->s_blocksize - 1)) + 1;
continue;
}
if (le32_to_cpu(de->inode)) {
brelse(bh);
return 0;
}
offset += ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize);
de = ext4_next_entry(de, sb->s_blocksize);
}
brelse(bh);
return 1;
}
/* ext4_orphan_add() links an unlinked or truncated inode into a list of
* such inodes, starting at the superblock, in case we crash before the
* file is closed/deleted, or in case the inode truncate spans multiple
* transactions and the last transaction is not recovered after a crash.
*
* At filesystem recovery time, we walk this list deleting unlinked
* inodes and truncating linked inodes in ext4_orphan_cleanup().
*/
int ext4_orphan_add(handle_t *handle, struct inode *inode)
{
struct super_block *sb = inode->i_sb;
struct ext4_iloc iloc;
int err = 0, rc;
if (!EXT4_SB(sb)->s_journal)
return 0;
mutex_lock(&EXT4_SB(sb)->s_orphan_lock);
if (!list_empty(&EXT4_I(inode)->i_orphan))
goto out_unlock;
/*
* Orphan handling is only valid for files with data blocks
* being truncated, or files being unlinked. Note that we either
* hold i_mutex, or the inode can not be referenced from outside,
* so i_nlink should not be bumped due to race
*/
J_ASSERT((S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
S_ISLNK(inode->i_mode)) || inode->i_nlink == 0);
BUFFER_TRACE(EXT4_SB(sb)->s_sbh, "get_write_access");
err = ext4_journal_get_write_access(handle, EXT4_SB(sb)->s_sbh);
if (err)
goto out_unlock;
err = ext4_reserve_inode_write(handle, inode, &iloc);
if (err)
goto out_unlock;
/*
* Due to previous errors inode may be already a part of on-disk
* orphan list. If so skip on-disk list modification.
*/
if (NEXT_ORPHAN(inode) && NEXT_ORPHAN(inode) <=
(le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count)))
goto mem_insert;
/* Insert this inode at the head of the on-disk orphan list... */
NEXT_ORPHAN(inode) = le32_to_cpu(EXT4_SB(sb)->s_es->s_last_orphan);
EXT4_SB(sb)->s_es->s_last_orphan = cpu_to_le32(inode->i_ino);
err = ext4_handle_dirty_super(handle, sb);
rc = ext4_mark_iloc_dirty(handle, inode, &iloc);
if (!err)
err = rc;
/* Only add to the head of the in-memory list if all the
* previous operations succeeded. If the orphan_add is going to
* fail (possibly taking the journal offline), we can't risk
* leaving the inode on the orphan list: stray orphan-list
* entries can cause panics at unmount time.
*
* This is safe: on error we're going to ignore the orphan list
* anyway on the next recovery. */
mem_insert:
if (!err)
list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
jbd_debug(4, "superblock will point to %lu\n", inode->i_ino);
jbd_debug(4, "orphan inode %lu will point to %d\n",
inode->i_ino, NEXT_ORPHAN(inode));
out_unlock:
mutex_unlock(&EXT4_SB(sb)->s_orphan_lock);
ext4_std_error(inode->i_sb, err);
return err;
}
/*
* ext4_orphan_del() removes an unlinked or truncated inode from the list
* of such inodes stored on disk, because it is finally being cleaned up.
*/
int ext4_orphan_del(handle_t *handle, struct inode *inode)
{
struct list_head *prev;
struct ext4_inode_info *ei = EXT4_I(inode);
struct ext4_sb_info *sbi;
__u32 ino_next;
struct ext4_iloc iloc;
int err = 0;
if ((!EXT4_SB(inode->i_sb)->s_journal) &&
!(EXT4_SB(inode->i_sb)->s_mount_state & EXT4_ORPHAN_FS))
return 0;
mutex_lock(&EXT4_SB(inode->i_sb)->s_orphan_lock);
if (list_empty(&ei->i_orphan))
goto out;
ino_next = NEXT_ORPHAN(inode);
prev = ei->i_orphan.prev;
sbi = EXT4_SB(inode->i_sb);
jbd_debug(4, "remove inode %lu from orphan list\n", inode->i_ino);
list_del_init(&ei->i_orphan);
/* If we're on an error path, we may not have a valid
* transaction handle with which to update the orphan list on
* disk, but we still need to remove the inode from the linked
* list in memory. */
if (!handle)
goto out;
err = ext4_reserve_inode_write(handle, inode, &iloc);
if (err)
goto out_err;
if (prev == &sbi->s_orphan) {
jbd_debug(4, "superblock will point to %u\n", ino_next);
BUFFER_TRACE(sbi->s_sbh, "get_write_access");
err = ext4_journal_get_write_access(handle, sbi->s_sbh);
if (err)
goto out_brelse;
sbi->s_es->s_last_orphan = cpu_to_le32(ino_next);
err = ext4_handle_dirty_super(handle, inode->i_sb);
} else {
struct ext4_iloc iloc2;
struct inode *i_prev =
&list_entry(prev, struct ext4_inode_info, i_orphan)->vfs_inode;
jbd_debug(4, "orphan inode %lu will point to %u\n",
i_prev->i_ino, ino_next);
err = ext4_reserve_inode_write(handle, i_prev, &iloc2);
if (err)
goto out_brelse;
NEXT_ORPHAN(i_prev) = ino_next;
err = ext4_mark_iloc_dirty(handle, i_prev, &iloc2);
}
if (err)
goto out_brelse;
NEXT_ORPHAN(inode) = 0;
err = ext4_mark_iloc_dirty(handle, inode, &iloc);
out_err:
ext4_std_error(inode->i_sb, err);
out:
mutex_unlock(&EXT4_SB(inode->i_sb)->s_orphan_lock);
return err;
out_brelse:
brelse(iloc.bh);
goto out_err;
}
static int ext4_rmdir(struct inode *dir, struct dentry *dentry)
{
int retval;
struct inode *inode;
struct buffer_head *bh;
struct ext4_dir_entry_2 *de;
handle_t *handle = NULL;
/* Initialize quotas before so that eventual writes go in
* separate transaction */
dquot_initialize(dir);
dquot_initialize(dentry->d_inode);
retval = -ENOENT;
bh = ext4_find_entry(dir, &dentry->d_name, &de, NULL);
if (!bh)
goto end_rmdir;
inode = dentry->d_inode;
retval = -EIO;
if (le32_to_cpu(de->inode) != inode->i_ino)
goto end_rmdir;
retval = -ENOTEMPTY;
if (!empty_dir(inode))
goto end_rmdir;
handle = ext4_journal_start(dir, EXT4_HT_DIR,
EXT4_DATA_TRANS_BLOCKS(dir->i_sb));
if (IS_ERR(handle)) {
retval = PTR_ERR(handle);
handle = NULL;
goto end_rmdir;
}
if (IS_DIRSYNC(dir))
ext4_handle_sync(handle);
retval = ext4_delete_entry(handle, dir, de, bh);
if (retval)
goto end_rmdir;
if (!EXT4_DIR_LINK_EMPTY(inode))
ext4_warning(inode->i_sb,
"empty directory has too many links (%d)",
inode->i_nlink);
inode->i_version++;
clear_nlink(inode);
/* There's no need to set i_disksize: the fact that i_nlink is
* zero will ensure that the right thing happens during any
* recovery. */
inode->i_size = 0;
ext4_orphan_add(handle, inode);
inode->i_ctime = dir->i_ctime = dir->i_mtime = ext4_current_time(inode);
ext4_mark_inode_dirty(handle, inode);
ext4_dec_count(handle, dir);
ext4_update_dx_flag(dir);
ext4_mark_inode_dirty(handle, dir);
end_rmdir:
brelse(bh);
if (handle)
ext4_journal_stop(handle);
return retval;
}
static int ext4_unlink(struct inode *dir, struct dentry *dentry)
{
int retval;
struct inode *inode;
struct buffer_head *bh;
struct ext4_dir_entry_2 *de;
handle_t *handle = NULL;
trace_ext4_unlink_enter(dir, dentry);
/* Initialize quotas before so that eventual writes go
* in separate transaction */
dquot_initialize(dir);
dquot_initialize(dentry->d_inode);
retval = -ENOENT;
bh = ext4_find_entry(dir, &dentry->d_name, &de, NULL);
if (!bh)
goto end_unlink;
inode = dentry->d_inode;
retval = -EIO;
if (le32_to_cpu(de->inode) != inode->i_ino)
goto end_unlink;
handle = ext4_journal_start(dir, EXT4_HT_DIR,
EXT4_DATA_TRANS_BLOCKS(dir->i_sb));
if (IS_ERR(handle)) {
retval = PTR_ERR(handle);
handle = NULL;
goto end_unlink;
}
if (IS_DIRSYNC(dir))
ext4_handle_sync(handle);
if (!inode->i_nlink) {
ext4_warning(inode->i_sb,
"Deleting nonexistent file (%lu), %d",
inode->i_ino, inode->i_nlink);
set_nlink(inode, 1);
}
retval = ext4_delete_entry(handle, dir, de, bh);
if (retval)
goto end_unlink;
dir->i_ctime = dir->i_mtime = ext4_current_time(dir);
ext4_update_dx_flag(dir);
ext4_mark_inode_dirty(handle, dir);
drop_nlink(inode);
if (!inode->i_nlink)
ext4_orphan_add(handle, inode);
inode->i_ctime = ext4_current_time(inode);
ext4_mark_inode_dirty(handle, inode);
retval = 0;
end_unlink:
brelse(bh);
if (handle)
ext4_journal_stop(handle);
trace_ext4_unlink_exit(dentry, retval);
return retval;
}
static int ext4_symlink(struct inode *dir,
struct dentry *dentry, const char *symname)
{
handle_t *handle;
struct inode *inode;
int l, err, retries = 0;
int credits;
l = strlen(symname)+1;
if (l > dir->i_sb->s_blocksize)
return -ENAMETOOLONG;
dquot_initialize(dir);
if (l > EXT4_N_BLOCKS * 4) {
/*
* For non-fast symlinks, we just allocate inode and put it on
* orphan list in the first transaction => we need bitmap,
* group descriptor, sb, inode block, quota blocks, and
* possibly selinux xattr blocks.
*/
credits = 4 + EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb) +
EXT4_XATTR_TRANS_BLOCKS;
} else {
/*
* Fast symlink. We have to add entry to directory
* (EXT4_DATA_TRANS_BLOCKS + EXT4_INDEX_EXTRA_TRANS_BLOCKS),
* allocate new inode (bitmap, group descriptor, inode block,
* quota blocks, sb is already counted in previous macros).
*/
credits = EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3;
}
retry:
inode = ext4_new_inode_start_handle(dir, S_IFLNK|S_IRWXUGO,
&dentry->d_name, 0, NULL,
EXT4_HT_DIR, credits);
handle = ext4_journal_current_handle();
err = PTR_ERR(inode);
if (IS_ERR(inode))
goto out_stop;
if (l > EXT4_N_BLOCKS * 4) {
inode->i_op = &ext4_symlink_inode_operations;
ext4_set_aops(inode);
/*
* We cannot call page_symlink() with transaction started
* because it calls into ext4_write_begin() which can wait
* for transaction commit if we are running out of space
* and thus we deadlock. So we have to stop transaction now
* and restart it when symlink contents is written.
*
* To keep fs consistent in case of crash, we have to put inode
* to orphan list in the mean time.
*/
drop_nlink(inode);
err = ext4_orphan_add(handle, inode);
ext4_journal_stop(handle);
if (err)
goto err_drop_inode;
err = __page_symlink(inode, symname, l, 1);
if (err)
goto err_drop_inode;
/*
* Now inode is being linked into dir (EXT4_DATA_TRANS_BLOCKS
* + EXT4_INDEX_EXTRA_TRANS_BLOCKS), inode is also modified
*/
handle = ext4_journal_start(dir, EXT4_HT_DIR,
EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
EXT4_INDEX_EXTRA_TRANS_BLOCKS + 1);
if (IS_ERR(handle)) {
err = PTR_ERR(handle);
goto err_drop_inode;
}
set_nlink(inode, 1);
err = ext4_orphan_del(handle, inode);
if (err) {
ext4_journal_stop(handle);
clear_nlink(inode);
goto err_drop_inode;
}
} else {
/* clear the extent format for fast symlink */
ext4_clear_inode_flag(inode, EXT4_INODE_EXTENTS);
inode->i_op = &ext4_fast_symlink_inode_operations;
memcpy((char *)&EXT4_I(inode)->i_data, symname, l);
inode->i_size = l-1;
}
EXT4_I(inode)->i_disksize = inode->i_size;
err = ext4_add_nondir(handle, dentry, inode);
if (!err && IS_DIRSYNC(dir))
ext4_handle_sync(handle);
out_stop:
if (handle)
ext4_journal_stop(handle);
if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
goto retry;
return err;
err_drop_inode:
unlock_new_inode(inode);
iput(inode);
return err;
}
static int ext4_link(struct dentry *old_dentry,
struct inode *dir, struct dentry *dentry)
{
handle_t *handle;
struct inode *inode = old_dentry->d_inode;
int err, retries = 0;
if (inode->i_nlink >= EXT4_LINK_MAX)
return -EMLINK;
dquot_initialize(dir);
retry:
handle = ext4_journal_start(dir, EXT4_HT_DIR,
(EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
EXT4_INDEX_EXTRA_TRANS_BLOCKS) + 1);
if (IS_ERR(handle))
return PTR_ERR(handle);
if (IS_DIRSYNC(dir))
ext4_handle_sync(handle);
inode->i_ctime = ext4_current_time(inode);
ext4_inc_count(handle, inode);
ihold(inode);
err = ext4_add_entry(handle, dentry, inode);
if (!err) {
ext4_mark_inode_dirty(handle, inode);
/* this can happen only for tmpfile being
* linked the first time
*/
if (inode->i_nlink == 1)
ext4_orphan_del(handle, inode);
d_instantiate(dentry, inode);
} else {
drop_nlink(inode);
iput(inode);
}
ext4_journal_stop(handle);
if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
goto retry;
return err;
}
/*
* Try to find buffer head where contains the parent block.
* It should be the inode block if it is inlined or the 1st block
* if it is a normal dir.
*/
static struct buffer_head *ext4_get_first_dir_block(handle_t *handle,
struct inode *inode,
int *retval,
struct ext4_dir_entry_2 **parent_de,
int *inlined)
{
struct buffer_head *bh;
if (!ext4_has_inline_data(inode)) {
bh = ext4_read_dirblock(inode, 0, EITHER);
if (IS_ERR(bh)) {
*retval = PTR_ERR(bh);
return NULL;
}
*parent_de = ext4_next_entry(
(struct ext4_dir_entry_2 *)bh->b_data,
inode->i_sb->s_blocksize);
return bh;
}
*inlined = 1;
return ext4_get_first_inline_block(inode, parent_de, retval);
}
/*
* Anybody can rename anything with this: the permission checks are left to the
* higher-level routines.
*
* n.b. old_{dentry,inode) refers to the source dentry/inode
* while new_{dentry,inode) refers to the destination dentry/inode
* This comes from rename(const char *oldpath, const char *newpath)
*/
static int ext4_rename(struct inode *old_dir, struct dentry *old_dentry,
struct inode *new_dir, struct dentry *new_dentry)
{
handle_t *handle = NULL;
struct inode *old_inode, *new_inode;
struct buffer_head *old_bh, *new_bh, *dir_bh;
struct ext4_dir_entry_2 *old_de, *new_de;
int retval;
int inlined = 0, new_inlined = 0;
struct ext4_dir_entry_2 *parent_de;
dquot_initialize(old_dir);
dquot_initialize(new_dir);
old_bh = new_bh = dir_bh = NULL;
/* Initialize quotas before so that eventual writes go
* in separate transaction */
if (new_dentry->d_inode)
dquot_initialize(new_dentry->d_inode);
old_bh = ext4_find_entry(old_dir, &old_dentry->d_name, &old_de, NULL);
/*
* Check for inode number is _not_ due to possible IO errors.
* We might rmdir the source, keep it as pwd of some process
* and merrily kill the link to whatever was created under the
* same name. Goodbye sticky bit ;-<
*/
old_inode = old_dentry->d_inode;
retval = -ENOENT;
if (!old_bh || le32_to_cpu(old_de->inode) != old_inode->i_ino)
goto end_rename;
new_inode = new_dentry->d_inode;
new_bh = ext4_find_entry(new_dir, &new_dentry->d_name,
&new_de, &new_inlined);
if (new_bh) {
if (!new_inode) {
brelse(new_bh);
new_bh = NULL;
}
}
if (new_inode && !test_opt(new_dir->i_sb, NO_AUTO_DA_ALLOC))
ext4_alloc_da_blocks(old_inode);
handle = ext4_journal_start(old_dir, EXT4_HT_DIR,
(2 * EXT4_DATA_TRANS_BLOCKS(old_dir->i_sb) +
EXT4_INDEX_EXTRA_TRANS_BLOCKS + 2));
if (IS_ERR(handle))
return PTR_ERR(handle);
if (IS_DIRSYNC(old_dir) || IS_DIRSYNC(new_dir))
ext4_handle_sync(handle);
if (S_ISDIR(old_inode->i_mode)) {
if (new_inode) {
retval = -ENOTEMPTY;
if (!empty_dir(new_inode))
goto end_rename;
}
retval = -EIO;
dir_bh = ext4_get_first_dir_block(handle, old_inode,
&retval, &parent_de,
&inlined);
if (!dir_bh)
goto end_rename;
if (le32_to_cpu(parent_de->inode) != old_dir->i_ino)
goto end_rename;
retval = -EMLINK;
if (!new_inode && new_dir != old_dir &&
EXT4_DIR_LINK_MAX(new_dir))
goto end_rename;
BUFFER_TRACE(dir_bh, "get_write_access");
retval = ext4_journal_get_write_access(handle, dir_bh);
if (retval)
goto end_rename;
}
if (!new_bh) {
retval = ext4_add_entry(handle, new_dentry, old_inode);
if (retval)
goto end_rename;
} else {
BUFFER_TRACE(new_bh, "get write access");
retval = ext4_journal_get_write_access(handle, new_bh);
if (retval)
goto end_rename;
new_de->inode = cpu_to_le32(old_inode->i_ino);
if (EXT4_HAS_INCOMPAT_FEATURE(new_dir->i_sb,
EXT4_FEATURE_INCOMPAT_FILETYPE))
new_de->file_type = old_de->file_type;
new_dir->i_version++;
new_dir->i_ctime = new_dir->i_mtime =
ext4_current_time(new_dir);
ext4_mark_inode_dirty(handle, new_dir);
BUFFER_TRACE(new_bh, "call ext4_handle_dirty_metadata");
if (!new_inlined) {
retval = ext4_handle_dirty_dirent_node(handle,
new_dir, new_bh);
if (unlikely(retval)) {
ext4_std_error(new_dir->i_sb, retval);
goto end_rename;
}
}
brelse(new_bh);
new_bh = NULL;
}
/*
* Like most other Unix systems, set the ctime for inodes on a
* rename.
*/
old_inode->i_ctime = ext4_current_time(old_inode);
ext4_mark_inode_dirty(handle, old_inode);
/*
* ok, that's it
*/
if (le32_to_cpu(old_de->inode) != old_inode->i_ino ||
old_de->name_len != old_dentry->d_name.len ||
strncmp(old_de->name, old_dentry->d_name.name, old_de->name_len) ||
(retval = ext4_delete_entry(handle, old_dir,
old_de, old_bh)) == -ENOENT) {
/* old_de could have moved from under us during htree split, so
* make sure that we are deleting the right entry. We might
* also be pointing to a stale entry in the unused part of
* old_bh so just checking inum and the name isn't enough. */
struct buffer_head *old_bh2;
struct ext4_dir_entry_2 *old_de2;
old_bh2 = ext4_find_entry(old_dir, &old_dentry->d_name,
&old_de2, NULL);
if (old_bh2) {
retval = ext4_delete_entry(handle, old_dir,
old_de2, old_bh2);
brelse(old_bh2);
}
}
if (retval) {
ext4_warning(old_dir->i_sb,
"Deleting old file (%lu), %d, error=%d",
old_dir->i_ino, old_dir->i_nlink, retval);
}
if (new_inode) {
ext4_dec_count(handle, new_inode);
new_inode->i_ctime = ext4_current_time(new_inode);
}
old_dir->i_ctime = old_dir->i_mtime = ext4_current_time(old_dir);
ext4_update_dx_flag(old_dir);
if (dir_bh) {
parent_de->inode = cpu_to_le32(new_dir->i_ino);
BUFFER_TRACE(dir_bh, "call ext4_handle_dirty_metadata");
if (!inlined) {
if (is_dx(old_inode)) {
retval = ext4_handle_dirty_dx_node(handle,
old_inode,
dir_bh);
} else {
retval = ext4_handle_dirty_dirent_node(handle,
old_inode, dir_bh);
}
} else {
retval = ext4_mark_inode_dirty(handle, old_inode);
}
if (retval) {
ext4_std_error(old_dir->i_sb, retval);
goto end_rename;
}
ext4_dec_count(handle, old_dir);
if (new_inode) {
/* checked empty_dir above, can't have another parent,
* ext4_dec_count() won't work for many-linked dirs */
clear_nlink(new_inode);
} else {
ext4_inc_count(handle, new_dir);
ext4_update_dx_flag(new_dir);
ext4_mark_inode_dirty(handle, new_dir);
}
}
ext4_mark_inode_dirty(handle, old_dir);
if (new_inode) {
ext4_mark_inode_dirty(handle, new_inode);
if (!new_inode->i_nlink)
ext4_orphan_add(handle, new_inode);
}
retval = 0;
end_rename:
brelse(dir_bh);
brelse(old_bh);
brelse(new_bh);
if (handle)
ext4_journal_stop(handle);
return retval;
}
/*
* directories can handle most operations...
*/
const struct inode_operations ext4_dir_inode_operations = {
.create = ext4_create,
.lookup = ext4_lookup,
.link = ext4_link,
.unlink = ext4_unlink,
.symlink = ext4_symlink,
.mkdir = ext4_mkdir,
.rmdir = ext4_rmdir,
.mknod = ext4_mknod,
.tmpfile = ext4_tmpfile,
.rename = ext4_rename,
.setattr = ext4_setattr,
.setxattr = generic_setxattr,
.getxattr = generic_getxattr,
.listxattr = ext4_listxattr,
.removexattr = generic_removexattr,
.get_acl = ext4_get_acl,
.fiemap = ext4_fiemap,
};
const struct inode_operations ext4_special_inode_operations = {
.setattr = ext4_setattr,
.setxattr = generic_setxattr,
.getxattr = generic_getxattr,
.listxattr = ext4_listxattr,
.removexattr = generic_removexattr,
.get_acl = ext4_get_acl,
};
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