/*
* linux/fs/ext3/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/quotaops.h>
#include "ext3.h"
#include "namei.h"
#include "xattr.h"
#include "acl.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 *ext3_append(handle_t *handle,
struct inode *inode,
u32 *block, int *err)
{
struct buffer_head *bh;
*block = inode->i_size >> inode->i_sb->s_blocksize_bits;
if ((bh = ext3_dir_bread(handle, inode, *block, 1, err))) {
inode->i_size += inode->i_sb->s_blocksize;
EXT3_I(inode)->i_disksize = inode->i_size;
*err = ext3_journal_get_write_access(handle, bh);
if (*err) {
brelse(bh);
bh = NULL;
}
}
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;
};
static inline unsigned dx_get_block (struct dx_entry *entry);
static void dx_set_block (struct dx_entry *entry, unsigned 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 qstr *entry,
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 ext3_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 ext3_dir_entry_2 *dx_move_dirents (char *from, char *to,
struct dx_map_entry *offsets, int count);
static struct ext3_dir_entry_2 *dx_pack_dirents(char *base, unsigned blocksize);
static void dx_insert_block (struct dx_frame *frame, u32 hash, u32 block);
static int ext3_htree_next_block(struct inode *dir, __u32 hash,
struct dx_frame *frame,
struct dx_frame *frames,
__u32 *start_hash);
static struct buffer_head * ext3_dx_find_entry(struct inode *dir,
struct qstr *entry, struct ext3_dir_entry_2 **res_dir,
int *err);
static int ext3_dx_add_entry(handle_t *handle, struct dentry *dentry,
struct inode *inode);
/*
* p is at least 6 bytes before the end of page
*/
static inline struct ext3_dir_entry_2 *
ext3_next_entry(struct ext3_dir_entry_2 *p)
{
return (struct ext3_dir_entry_2 *)((char *)p +
ext3_rec_len_from_disk(p->rec_len));
}
/*
* Future: use high four bits of block for coalesce-on-delete flags
* Mask them off for now.
*/
static inline unsigned dx_get_block (struct dx_entry *entry)
{
return le32_to_cpu(entry->block) & 0x00ffffff;
}
static inline void dx_set_block (struct dx_entry *entry, unsigned 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 - EXT3_DIR_REC_LEN(1) -
EXT3_DIR_REC_LEN(2) - infosize;
return entry_space / sizeof(struct dx_entry);
}
static inline unsigned dx_node_limit (struct inode *dir)
{
unsigned entry_space = dir->i_sb->s_blocksize - EXT3_DIR_REC_LEN(0);
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("%s index ", label);
for (i = 0; i < n; i++)
{
printk("%x->%u ", i? dx_get_hash(entries + i): 0, 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 ext3_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++);
ext3fs_dirhash(de->name, de->name_len, &h);
printk(":%x.%u ", h.hash,
(unsigned) ((char *) de - base));
}
space += EXT3_DIR_REC_LEN(de->name_len);
names++;
}
de = ext3_next_entry(de);
}
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++)
{
u32 block = dx_get_block(entries), 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 = ext3_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 ext3_dir_entry_2 *) bh->b_data, blocksize, 0);
names += stats.names;
space += stats.space;
bcount += stats.bcount;
brelse (bh);
}
if (bcount)
printk("%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 qstr *entry, 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;
if (!(bh = ext3_dir_bread(NULL, dir, 0, 0, err))) {
*err = ERR_BAD_DX_DIR;
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) {
ext3_warning(dir->i_sb, __func__,
"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 += EXT3_SB(dir->i_sb)->s_hash_unsigned;
hinfo->seed = EXT3_SB(dir->i_sb)->s_hash_seed;
if (entry)
ext3fs_dirhash(entry->name, entry->len, hinfo);
hash = hinfo->hash;
if (root->info.unused_flags & 1) {
ext3_warning(dir->i_sb, __func__,
"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) {
ext3_warning(dir->i_sb, __func__,
"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)) {
ext3_warning(dir->i_sb, __func__,
"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)) {
ext3_warning(dir->i_sb, __func__,
"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;
if (!(bh = ext3_dir_bread(NULL, dir, dx_get_block(at), 0, err))) {
*err = ERR_BAD_DX_DIR;
goto fail2;
}
at = entries = ((struct dx_node *) bh->b_data)->entries;
if (dx_get_limit(entries) != dx_node_limit (dir)) {
ext3_warning(dir->i_sb, __func__,
"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)
ext3_warning(dir->i_sb, __func__,
"Corrupt dir inode %ld, 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 ext3_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 err, 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--) {
if (!(bh = ext3_dir_bread(NULL, dir, dx_get_block(p->at),
0, &err)))
return err; /* Failure */
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, int block,
struct dx_hash_info *hinfo,
__u32 start_hash, __u32 start_minor_hash)
{
struct buffer_head *bh;
struct ext3_dir_entry_2 *de, *top;
int err = 0, count = 0;
dxtrace(printk("In htree dirblock_to_tree: block %d\n", block));
if (!(bh = ext3_dir_bread(NULL, dir, block, 0, &err)))
return err;
de = (struct ext3_dir_entry_2 *) bh->b_data;
top = (struct ext3_dir_entry_2 *) ((char *) de +
dir->i_sb->s_blocksize -
EXT3_DIR_REC_LEN(0));
for (; de < top; de = ext3_next_entry(de)) {
if (!ext3_check_dir_entry("htree_dirblock_to_tree", dir, de, bh,
(block<<EXT3_BLOCK_SIZE_BITS(dir->i_sb))
+((char *)de - bh->b_data))) {
/* On error, skip the f_pos to the next block. */
dir_file->f_pos = (dir_file->f_pos |
(dir->i_sb->s_blocksize - 1)) + 1;
brelse (bh);
return count;
}
ext3fs_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 = ext3_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 ext3_htree_fill_tree(struct file *dir_file, __u32 start_hash,
__u32 start_minor_hash, __u32 *next_hash)
{
struct dx_hash_info hinfo;
struct ext3_dir_entry_2 *de;
struct dx_frame frames[2], *frame;
struct inode *dir;
int block, err;
int count = 0;
int ret;
__u32 hashval;
dxtrace(printk("In htree_fill_tree, start hash: %x:%x\n", start_hash,
start_minor_hash));
dir = file_inode(dir_file);
if (!(EXT3_I(dir)->i_flags & EXT3_INDEX_FL)) {
hinfo.hash_version = EXT3_SB(dir->i_sb)->s_def_hash_version;
if (hinfo.hash_version <= DX_HASH_TEA)
hinfo.hash_version +=
EXT3_SB(dir->i_sb)->s_hash_unsigned;
hinfo.seed = EXT3_SB(dir->i_sb)->s_hash_seed;
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, file_inode(dir_file), &hinfo, frames, &err);
if (!frame)
return err;
/* Add '.' and '..' from the htree header */
if (!start_hash && !start_minor_hash) {
de = (struct ext3_dir_entry_2 *) frames[0].bh->b_data;
if ((err = ext3_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 ext3_dir_entry_2 *) frames[0].bh->b_data;
de = ext3_next_entry(de);
if ((err = ext3_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 = ext3_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("Fill tree: returned %d entries, next hash: %x\n",
count, *next_hash));
return count;
errout:
dx_release(frames);
return (err);
}
/*
* 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 ext3_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) {
ext3fs_dirhash(de->name, de->name_len, &h);
map_tail--;
map_tail->hash = h.hash;
map_tail->offs = (u16) ((char *) de - base);
map_tail->size = le16_to_cpu(de->rec_len);
count++;
cond_resched();
}
/* XXX: do we need to check rec_len == 0 case? -Chris */
de = ext3_next_entry(de);
}
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, u32 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);
}
static void ext3_update_dx_flag(struct inode *inode)
{
if (!EXT3_HAS_COMPAT_FEATURE(inode->i_sb,
EXT3_FEATURE_COMPAT_DIR_INDEX))
EXT3_I(inode)->i_flags &= ~EXT3_INDEX_FL;
}
/*
* NOTE! unlike strncmp, ext3_match returns 1 for success, 0 for failure.
*
* `len <= EXT3_NAME_LEN' is guaranteed by caller.
* `de != NULL' is guaranteed by caller.
*/
static inline int ext3_match (int len, const char * const name,
struct ext3_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
*/
static inline int search_dirblock(struct buffer_head * bh,
struct inode *dir,
struct qstr *child,
unsigned long offset,
struct ext3_dir_entry_2 ** res_dir)
{
struct ext3_dir_entry_2 * de;
char * dlimit;
int de_len;
const char *name = child->name;
int namelen = child->len;
de = (struct ext3_dir_entry_2 *) bh->b_data;
dlimit = bh->b_data + dir->i_sb->s_blocksize;
while ((char *) de < dlimit) {
/* this code is executed quadratically often */
/* do minimal checking `by hand' */
if ((char *) de + namelen <= dlimit &&
ext3_match (namelen, name, de)) {
/* found a match - just to be sure, do a full check */
if (!ext3_check_dir_entry("ext3_find_entry",
dir, de, bh, offset))
return -1;
*res_dir = de;
return 1;
}
/* prevent looping on a bad block */
de_len = ext3_rec_len_from_disk(de->rec_len);
if (de_len <= 0)
return -1;
offset += de_len;
de = (struct ext3_dir_entry_2 *) ((char *) de + de_len);
}
return 0;
}
/*
* ext3_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 *ext3_find_entry(struct inode *dir,
struct qstr *entry,
struct ext3_dir_entry_2 **res_dir)
{
struct super_block * sb;
struct buffer_head * bh_use[NAMEI_RA_SIZE];
struct buffer_head * bh, *ret = NULL;
unsigned long start, block, b;
const u8 *name = entry->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;
int nblocks, i, err;
int namelen;
*res_dir = NULL;
sb = dir->i_sb;
namelen = entry->len;
if (namelen > EXT3_NAME_LEN)
return NULL;
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 = ext3_dx_find_entry(dir, entry, 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("ext3_find_entry: dx failed, falling back\n"));
}
nblocks = dir->i_size >> EXT3_BLOCK_SIZE_BITS(sb);
start = EXT3_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 = ext3_getblk(NULL, dir, b++, 0, &err);
bh_use[ra_max] = bh;
if (bh && !bh_uptodate_or_lock(bh)) {
get_bh(bh);
bh->b_end_io = end_buffer_read_sync;
submit_bh(READ | REQ_META | REQ_PRIO,
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 */
ext3_error(sb, __func__, "reading directory #%lu "
"offset %lu", dir->i_ino, block);
brelse(bh);
goto next;
}
i = search_dirblock(bh, dir, entry,
block << EXT3_BLOCK_SIZE_BITS(sb), res_dir);
if (i == 1) {
EXT3_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 >> EXT3_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 * ext3_dx_find_entry(struct inode *dir,
struct qstr *entry, struct ext3_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;
unsigned long block;
int retval;
if (!(frame = dx_probe(entry, dir, &hinfo, frames, err)))
return NULL;
do {
block = dx_get_block(frame->at);
if (!(bh = ext3_dir_bread (NULL, dir, block, 0, err)))
goto errout;
retval = search_dirblock(bh, dir, entry,
block << EXT3_BLOCK_SIZE_BITS(sb),
res_dir);
if (retval == 1) {
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 = ext3_htree_next_block(dir, hinfo.hash, frame,
frames, NULL);
if (retval < 0) {
ext3_warning(sb, __func__,
"error reading index page in directory #%lu",
dir->i_ino);
*err = retval;
goto errout;
}
} while (retval == 1);
*err = -ENOENT;
errout:
dxtrace(printk("%s not found\n", entry->name));
dx_release (frames);
return NULL;
}
static struct dentry *ext3_lookup(struct inode * dir, struct dentry *dentry, unsigned int flags)
{
struct inode * inode;
struct ext3_dir_entry_2 * de;
struct buffer_head * bh;
if (dentry->d_name.len > EXT3_NAME_LEN)
return ERR_PTR(-ENAMETOOLONG);
bh = ext3_find_entry(dir, &dentry->d_name, &de);
inode = NULL;
if (bh) {
unsigned long ino = le32_to_cpu(de->inode);
brelse (bh);
if (!ext3_valid_inum(dir->i_sb, ino)) {
ext3_error(dir->i_sb, "ext3_lookup",
"bad inode number: %lu", ino);
return ERR_PTR(-EIO);
}
inode = ext3_iget(dir->i_sb, ino);
if (inode == ERR_PTR(-ESTALE)) {
ext3_error(dir->i_sb, __func__,
"deleted inode referenced: %lu",
ino);
return ERR_PTR(-EIO);
}
}
return d_splice_alias(inode, dentry);
}
struct dentry *ext3_get_parent(struct dentry *child)
{
unsigned long ino;
struct qstr dotdot = QSTR_INIT("..", 2);
struct ext3_dir_entry_2 * de;
struct buffer_head *bh;
bh = ext3_find_entry(child->d_inode, &dotdot, &de);
if (!bh)
return ERR_PTR(-ENOENT);
ino = le32_to_cpu(de->inode);
brelse(bh);
if (!ext3_valid_inum(child->d_inode->i_sb, ino)) {
ext3_error(child->d_inode->i_sb, "ext3_get_parent",
"bad inode number: %lu", ino);
return ERR_PTR(-EIO);
}
return d_obtain_alias(ext3_iget(child->d_inode->i_sb, ino));
}
#define S_SHIFT 12
static unsigned char ext3_type_by_mode[S_IFMT >> S_SHIFT] = {
[S_IFREG >> S_SHIFT] = EXT3_FT_REG_FILE,
[S_IFDIR >> S_SHIFT] = EXT3_FT_DIR,
[S_IFCHR >> S_SHIFT] = EXT3_FT_CHRDEV,
[S_IFBLK >> S_SHIFT] = EXT3_FT_BLKDEV,
[S_IFIFO >> S_SHIFT] = EXT3_FT_FIFO,
[S_IFSOCK >> S_SHIFT] = EXT3_FT_SOCK,
[S_IFLNK >> S_SHIFT] = EXT3_FT_SYMLINK,
};
static inline void ext3_set_de_type(struct super_block *sb,
struct ext3_dir_entry_2 *de,
umode_t mode) {
if (EXT3_HAS_INCOMPAT_FEATURE(sb, EXT3_FEATURE_INCOMPAT_FILETYPE))
de->file_type = ext3_type_by_mode[(mode & S_IFMT)>>S_SHIFT];
}
/*
* Move count entries from end of map between two memory locations.
* Returns pointer to last entry moved.
*/
static struct ext3_dir_entry_2 *
dx_move_dirents(char *from, char *to, struct dx_map_entry *map, int count)
{
unsigned rec_len = 0;
while (count--) {
struct ext3_dir_entry_2 *de = (struct ext3_dir_entry_2 *) (from + map->offs);
rec_len = EXT3_DIR_REC_LEN(de->name_len);
memcpy (to, de, rec_len);
((struct ext3_dir_entry_2 *) to)->rec_len =
ext3_rec_len_to_disk(rec_len);
de->inode = 0;
map++;
to += rec_len;
}
return (struct ext3_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 ext3_dir_entry_2 *dx_pack_dirents(char *base, unsigned blocksize)
{
struct ext3_dir_entry_2 *next, *to, *prev;
struct ext3_dir_entry_2 *de = (struct ext3_dir_entry_2 *)base;
unsigned rec_len = 0;
prev = to = de;
while ((char *)de < base + blocksize) {
next = ext3_next_entry(de);
if (de->inode && de->name_len) {
rec_len = EXT3_DIR_REC_LEN(de->name_len);
if (de > to)
memmove(to, de, rec_len);
to->rec_len = ext3_rec_len_to_disk(rec_len);
prev = to;
to = (struct ext3_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 ext3_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;
u32 newblock;
u32 hash2;
struct dx_map_entry *map;
char *data1 = (*bh)->b_data, *data2;
unsigned split, move, size;
struct ext3_dir_entry_2 *de = NULL, *de2;
int err = 0, i;
bh2 = ext3_append (handle, dir, &newblock, &err);
if (!(bh2)) {
brelse(*bh);
*bh = NULL;
goto errout;
}
BUFFER_TRACE(*bh, "get_write_access");
err = ext3_journal_get_write_access(handle, *bh);
if (err)
goto journal_error;
BUFFER_TRACE(frame->bh, "get_write_access");
err = ext3_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 ext3_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("Split block %i at %x, %i/%i\n",
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);
de = dx_pack_dirents(data1,blocksize);
de->rec_len = ext3_rec_len_to_disk(data1 + blocksize - (char *) de);
de2->rec_len = ext3_rec_len_to_disk(data2 + blocksize - (char *) de2);
dxtrace(dx_show_leaf (hinfo, (struct ext3_dir_entry_2 *) data1, blocksize, 1));
dxtrace(dx_show_leaf (hinfo, (struct ext3_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 = ext3_journal_dirty_metadata (handle, bh2);
if (err)
goto journal_error;
err = ext3_journal_dirty_metadata (handle, 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;
ext3_std_error(dir->i_sb, err);
errout:
*error = err;
return NULL;
}
/*
* 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.
*
* NOTE! bh is NOT released in the case where ENOSPC is returned. In
* all other cases bh is released.
*/
static int add_dirent_to_buf(handle_t *handle, struct dentry *dentry,
struct inode *inode, struct ext3_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 long offset = 0;
unsigned short reclen;
int nlen, rlen, err;
char *top;
reclen = EXT3_DIR_REC_LEN(namelen);
if (!de) {
de = (struct ext3_dir_entry_2 *)bh->b_data;
top = bh->b_data + dir->i_sb->s_blocksize - reclen;
while ((char *) de <= top) {
if (!ext3_check_dir_entry("ext3_add_entry", dir, de,
bh, offset)) {
brelse (bh);
return -EIO;
}
if (ext3_match (namelen, name, de)) {
brelse (bh);
return -EEXIST;
}
nlen = EXT3_DIR_REC_LEN(de->name_len);
rlen = ext3_rec_len_from_disk(de->rec_len);
if ((de->inode? rlen - nlen: rlen) >= reclen)
break;
de = (struct ext3_dir_entry_2 *)((char *)de + rlen);
offset += rlen;
}
if ((char *) de > top)
return -ENOSPC;
}
BUFFER_TRACE(bh, "get_write_access");
err = ext3_journal_get_write_access(handle, bh);
if (err) {
ext3_std_error(dir->i_sb, err);
brelse(bh);
return err;
}
/* By now the buffer is marked for journaling */
nlen = EXT3_DIR_REC_LEN(de->name_len);
rlen = ext3_rec_len_from_disk(de->rec_len);
if (de->inode) {
struct ext3_dir_entry_2 *de1 = (struct ext3_dir_entry_2 *)((char *)de + nlen);
de1->rec_len = ext3_rec_len_to_disk(rlen - nlen);
de->rec_len = ext3_rec_len_to_disk(nlen);
de = de1;
}
de->file_type = EXT3_FT_UNKNOWN;
if (inode) {
de->inode = cpu_to_le32(inode->i_ino);
ext3_set_de_type(dir->i_sb, de, inode->i_mode);
} else
de->inode = 0;
de->name_len = namelen;
memcpy (de->name, 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
* ext3_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_SEC;
ext3_update_dx_flag(dir);
dir->i_version++;
ext3_mark_inode_dirty(handle, dir);
BUFFER_TRACE(bh, "call ext3_journal_dirty_metadata");
err = ext3_journal_dirty_metadata(handle, bh);
if (err)
ext3_std_error(dir->i_sb, err);
brelse(bh);
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 ext3_dir_entry_2 *de, *de2;
char *data1, *top;
unsigned len;
int retval;
unsigned blocksize;
struct dx_hash_info hinfo;
u32 block;
struct fake_dirent *fde;
blocksize = dir->i_sb->s_blocksize;
dxtrace(printk(KERN_DEBUG "Creating index: inode %lu\n", dir->i_ino));
retval = ext3_journal_get_write_access(handle, bh);
if (retval) {
ext3_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 ext3_dir_entry_2 *)((char *)fde +
ext3_rec_len_from_disk(fde->rec_len));
if ((char *) de >= (((char *) root) + blocksize)) {
ext3_error(dir->i_sb, __func__,
"invalid rec_len for '..' in inode %lu",
dir->i_ino);
brelse(bh);
return -EIO;
}
len = ((char *) root) + blocksize - (char *) de;
bh2 = ext3_append (handle, dir, &block, &retval);
if (!(bh2)) {
brelse(bh);
return retval;
}
EXT3_I(dir)->i_flags |= EXT3_INDEX_FL;
data1 = bh2->b_data;
memcpy (data1, de, len);
de = (struct ext3_dir_entry_2 *) data1;
top = data1 + len;
while ((char *)(de2 = ext3_next_entry(de)) < top)
de = de2;
de->rec_len = ext3_rec_len_to_disk(data1 + blocksize - (char *) de);
/* Initialize the root; the dot dirents already exist */
de = (struct ext3_dir_entry_2 *) (&root->dotdot);
de->rec_len = ext3_rec_len_to_disk(blocksize - EXT3_DIR_REC_LEN(2));
memset (&root->info, 0, sizeof(root->info));
root->info.info_length = sizeof(root->info);
root->info.hash_version = EXT3_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 += EXT3_SB(dir->i_sb)->s_hash_unsigned;
hinfo.seed = EXT3_SB(dir->i_sb)->s_hash_seed;
ext3fs_dirhash(name, namelen, &hinfo);
frame = frames;
frame->entries = entries;
frame->at = entries;
frame->bh = bh;
bh = bh2;
/*
* Mark buffers dirty here so that if do_split() fails we write a
* consistent set of buffers to disk.
*/
ext3_journal_dirty_metadata(handle, frame->bh);
ext3_journal_dirty_metadata(handle, bh);
de = do_split(handle,dir, &bh, frame, &hinfo, &retval);
if (!de) {
ext3_mark_inode_dirty(handle, dir);
dx_release(frames);
return retval;
}
dx_release(frames);
return add_dirent_to_buf(handle, dentry, inode, de, bh);
}
/*
* ext3_add_entry()
*
* adds a file entry to the specified directory, using the same
* semantics as ext3_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 ext3_add_entry (handle_t *handle, struct dentry *dentry,
struct inode *inode)
{
struct inode *dir = dentry->d_parent->d_inode;
struct buffer_head * bh;
struct ext3_dir_entry_2 *de;
struct super_block * sb;
int retval;
int dx_fallback=0;
unsigned blocksize;
u32 block, blocks;
sb = dir->i_sb;
blocksize = sb->s_blocksize;
if (!dentry->d_name.len)
return -EINVAL;
if (is_dx(dir)) {
retval = ext3_dx_add_entry(handle, dentry, inode);
if (!retval || (retval != ERR_BAD_DX_DIR))
return retval;
EXT3_I(dir)->i_flags &= ~EXT3_INDEX_FL;
dx_fallback++;
ext3_mark_inode_dirty(handle, dir);
}
blocks = dir->i_size >> sb->s_blocksize_bits;
for (block = 0; block < blocks; block++) {
if (!(bh = ext3_dir_bread(handle, dir, block, 0, &retval)))
return retval;
retval = add_dirent_to_buf(handle, dentry, inode, NULL, bh);
if (retval != -ENOSPC)
return retval;
if (blocks == 1 && !dx_fallback &&
EXT3_HAS_COMPAT_FEATURE(sb, EXT3_FEATURE_COMPAT_DIR_INDEX))
return make_indexed_dir(handle, dentry, inode, bh);
brelse(bh);
}
bh = ext3_append(handle, dir, &block, &retval);
if (!bh)
return retval;
de = (struct ext3_dir_entry_2 *) bh->b_data;
de->inode = 0;
de->rec_len = ext3_rec_len_to_disk(blocksize);
return add_dirent_to_buf(handle, dentry, inode, de, bh);
}
/*
* Returns 0 for success, or a negative error value
*/
static int ext3_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 ext3_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;
if (!(bh = ext3_dir_bread(handle, dir, dx_get_block(frame->at), 0, &err)))
goto cleanup;
BUFFER_TRACE(bh, "get_write_access");
err = ext3_journal_get_write_access(handle, bh);
if (err)
goto journal_error;
err = add_dirent_to_buf(handle, dentry, inode, NULL, bh);
if (err != -ENOSPC) {
bh = NULL;
goto cleanup;
}
/* Block full, should compress but for now just split */
dxtrace(printk("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)) {
u32 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))) {
ext3_warning(sb, __func__,
"Directory index full!");
err = -ENOSPC;
goto cleanup;
}
bh2 = ext3_append (handle, dir, &newblock, &err);
if (!(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 = ext3_rec_len_to_disk(sb->s_blocksize);
BUFFER_TRACE(frame->bh, "get_write_access");
err = ext3_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("Split index %i/%i\n", icount1, icount2));
BUFFER_TRACE(frame->bh, "get_write_access"); /* index root */
err = ext3_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 = ext3_journal_dirty_metadata(handle, bh2);
if (err)
goto journal_error;
brelse (bh2);
} else {
dxtrace(printk("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 = ext3_journal_get_write_access(handle,
frame->bh);
if (err)
goto journal_error;
}
err = ext3_journal_dirty_metadata(handle, frames[0].bh);
if (err)
goto journal_error;
}
de = do_split(handle, dir, &bh, frame, &hinfo, &err);
if (!de)
goto cleanup;
err = add_dirent_to_buf(handle, dentry, inode, de, bh);
bh = NULL;
goto cleanup;
journal_error:
ext3_std_error(dir->i_sb, err);
cleanup:
if (bh)
brelse(bh);
dx_release(frames);
return err;
}
/*
* ext3_delete_entry deletes a directory entry by merging it with the
* previous entry
*/
static int ext3_delete_entry (handle_t *handle,
struct inode * dir,
struct ext3_dir_entry_2 * de_del,
struct buffer_head * bh)
{
struct ext3_dir_entry_2 * de, * pde;
int i;
i = 0;
pde = NULL;
de = (struct ext3_dir_entry_2 *) bh->b_data;
while (i < bh->b_size) {
if (!ext3_check_dir_entry("ext3_delete_entry", dir, de, bh, i))
return -EIO;
if (de == de_del) {
int err;
BUFFER_TRACE(bh, "get_write_access");
err = ext3_journal_get_write_access(handle, bh);
if (err)
goto journal_error;
if (pde)
pde->rec_len = ext3_rec_len_to_disk(
ext3_rec_len_from_disk(pde->rec_len) +
ext3_rec_len_from_disk(de->rec_len));
else
de->inode = 0;
dir->i_version++;
BUFFER_TRACE(bh, "call ext3_journal_dirty_metadata");
err = ext3_journal_dirty_metadata(handle, bh);
if (err) {
journal_error:
ext3_std_error(dir->i_sb, err);
return err;
}
return 0;
}
i += ext3_rec_len_from_disk(de->rec_len);
pde = de;
de = ext3_next_entry(de);
}
return -ENOENT;
}
static int ext3_add_nondir(handle_t *handle,
struct dentry *dentry, struct inode *inode)
{
int err = ext3_add_entry(handle, dentry, inode);
if (!err) {
ext3_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 ext3_create (struct inode * dir, struct dentry * dentry, umode_t mode,
bool excl)
{
handle_t *handle;
struct inode * inode;
int err, retries = 0;
dquot_initialize(dir);
retry:
handle = ext3_journal_start(dir, EXT3_DATA_TRANS_BLOCKS(dir->i_sb) +
EXT3_INDEX_EXTRA_TRANS_BLOCKS + 3 +
EXT3_MAXQUOTAS_INIT_BLOCKS(dir->i_sb));
if (IS_ERR(handle))
return PTR_ERR(handle);
if (IS_DIRSYNC(dir))
handle->h_sync = 1;
inode = ext3_new_inode (handle, dir, &dentry->d_name, mode);
err = PTR_ERR(inode);
if (!IS_ERR(inode)) {
inode->i_op = &ext3_file_inode_operations;
inode->i_fop = &ext3_file_operations;
ext3_set_aops(inode);
err = ext3_add_nondir(handle, dentry, inode);
}
ext3_journal_stop(handle);
if (err == -ENOSPC && ext3_should_retry_alloc(dir->i_sb, &retries))
goto retry;
return err;
}
static int ext3_mknod (struct inode * dir, struct dentry *dentry,
umode_t mode, dev_t rdev)
{
handle_t *handle;
struct inode *inode;
int err, retries = 0;
if (!new_valid_dev(rdev))
return -EINVAL;
dquot_initialize(dir);
retry:
handle = ext3_journal_start(dir, EXT3_DATA_TRANS_BLOCKS(dir->i_sb) +
EXT3_INDEX_EXTRA_TRANS_BLOCKS + 3 +
EXT3_MAXQUOTAS_INIT_BLOCKS(dir->i_sb));
if (IS_ERR(handle))
return PTR_ERR(handle);
if (IS_DIRSYNC(dir))
handle->h_sync = 1;
inode = ext3_new_inode (handle, dir, &dentry->d_name, mode);
err = PTR_ERR(inode);
if (!IS_ERR(inode)) {
init_special_inode(inode, inode->i_mode, rdev);
#ifdef CONFIG_EXT3_FS_XATTR
inode->i_op = &ext3_special_inode_operations;
#endif
err = ext3_add_nondir(handle, dentry, inode);
}
ext3_journal_stop(handle);
if (err == -ENOSPC && ext3_should_retry_alloc(dir->i_sb, &retries))
goto retry;
return err;
}
static int ext3_mkdir(struct inode * dir, struct dentry * dentry, umode_t mode)
{
handle_t *handle;
struct inode * inode;
struct buffer_head * dir_block = NULL;
struct ext3_dir_entry_2 * de;
int err, retries = 0;
if (dir->i_nlink >= EXT3_LINK_MAX)
return -EMLINK;
dquot_initialize(dir);
retry:
handle = ext3_journal_start(dir, EXT3_DATA_TRANS_BLOCKS(dir->i_sb) +
EXT3_INDEX_EXTRA_TRANS_BLOCKS + 3 +
EXT3_MAXQUOTAS_INIT_BLOCKS(dir->i_sb));
if (IS_ERR(handle))
return PTR_ERR(handle);
if (IS_DIRSYNC(dir))
handle->h_sync = 1;
inode = ext3_new_inode (handle, dir, &dentry->d_name, S_IFDIR | mode);
err = PTR_ERR(inode);
if (IS_ERR(inode))
goto out_stop;
inode->i_op = &ext3_dir_inode_operations;
inode->i_fop = &ext3_dir_operations;
inode->i_size = EXT3_I(inode)->i_disksize = inode->i_sb->s_blocksize;
if (!(dir_block = ext3_dir_bread(handle, inode, 0, 1, &err)))
goto out_clear_inode;
BUFFER_TRACE(dir_block, "get_write_access");
err = ext3_journal_get_write_access(handle, dir_block);
if (err)
goto out_clear_inode;
de = (struct ext3_dir_entry_2 *) dir_block->b_data;
de->inode = cpu_to_le32(inode->i_ino);
de->name_len = 1;
de->rec_len = ext3_rec_len_to_disk(EXT3_DIR_REC_LEN(de->name_len));
strcpy (de->name, ".");
ext3_set_de_type(dir->i_sb, de, S_IFDIR);
de = ext3_next_entry(de);
de->inode = cpu_to_le32(dir->i_ino);
de->rec_len = ext3_rec_len_to_disk(inode->i_sb->s_blocksize -
EXT3_DIR_REC_LEN(1));
de->name_len = 2;
strcpy (de->name, "..");
ext3_set_de_type(dir->i_sb, de, S_IFDIR);
set_nlink(inode, 2);
BUFFER_TRACE(dir_block, "call ext3_journal_dirty_metadata");
err = ext3_journal_dirty_metadata(handle, dir_block);
if (err)
goto out_clear_inode;
err = ext3_mark_inode_dirty(handle, inode);
if (!err)
err = ext3_add_entry (handle, dentry, inode);
if (err) {
out_clear_inode:
clear_nlink(inode);
unlock_new_inode(inode);
ext3_mark_inode_dirty(handle, inode);
iput (inode);
goto out_stop;
}
inc_nlink(dir);
ext3_update_dx_flag(dir);
err = ext3_mark_inode_dirty(handle, dir);
if (err)
goto out_clear_inode;
unlock_new_inode(inode);
d_instantiate(dentry, inode);
out_stop:
brelse(dir_block);
ext3_journal_stop(handle);
if (err == -ENOSPC && ext3_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 long offset;
struct buffer_head * bh;
struct ext3_dir_entry_2 * de, * de1;
struct super_block * sb;
int err = 0;
sb = inode->i_sb;
if (inode->i_size < EXT3_DIR_REC_LEN(1) + EXT3_DIR_REC_LEN(2) ||
!(bh = ext3_dir_bread(NULL, inode, 0, 0, &err))) {
if (err)
ext3_error(inode->i_sb, __func__,
"error %d reading directory #%lu offset 0",
err, inode->i_ino);
else
ext3_warning(inode->i_sb, __func__,
"bad directory (dir #%lu) - no data block",
inode->i_ino);
return 1;
}
de = (struct ext3_dir_entry_2 *) bh->b_data;
de1 = ext3_next_entry(de);
if (le32_to_cpu(de->inode) != inode->i_ino ||
!le32_to_cpu(de1->inode) ||
strcmp (".", de->name) ||
strcmp ("..", de1->name)) {
ext3_warning (inode->i_sb, "empty_dir",
"bad directory (dir #%lu) - no `.' or `..'",
inode->i_ino);
brelse (bh);
return 1;
}
offset = ext3_rec_len_from_disk(de->rec_len) +
ext3_rec_len_from_disk(de1->rec_len);
de = ext3_next_entry(de1);
while (offset < inode->i_size ) {
if (!bh ||
(void *) de >= (void *) (bh->b_data+sb->s_blocksize)) {
err = 0;
brelse (bh);
if (!(bh = ext3_dir_bread (NULL, inode,
offset >> EXT3_BLOCK_SIZE_BITS(sb), 0, &err))) {
if (err)
ext3_error(sb, __func__,
"error %d reading directory"
" #%lu offset %lu",
err, inode->i_ino, offset);
offset += sb->s_blocksize;
continue;
}
de = (struct ext3_dir_entry_2 *) bh->b_data;
}
if (!ext3_check_dir_entry("empty_dir", inode, de, bh, offset)) {
de = (struct ext3_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 += ext3_rec_len_from_disk(de->rec_len);
de = ext3_next_entry(de);
}
brelse (bh);
return 1;
}
/* ext3_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 ext3_orphan_cleanup().
*/
int ext3_orphan_add(handle_t *handle, struct inode *inode)
{
struct super_block *sb = inode->i_sb;
struct ext3_iloc iloc;
int err = 0, rc;
mutex_lock(&EXT3_SB(sb)->s_orphan_lock);
if (!list_empty(&EXT3_I(inode)->i_orphan))
goto out_unlock;
/* Orphan handling is only valid for files with data blocks
* being truncated, or files being unlinked. */
/* @@@ FIXME: Observation from aviro:
* I think I can trigger J_ASSERT in ext3_orphan_add(). We block
* here (on s_orphan_lock), so race with ext3_link() which might bump
* ->i_nlink. For, say it, character device. Not a regular file,
* not a directory, not a symlink and ->i_nlink > 0.
*
* tytso, 4/25/2009: I'm not sure how that could happen;
* shouldn't the fs core protect us from these sort of
* unlink()/link() races?
*/
J_ASSERT ((S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
S_ISLNK(inode->i_mode)) || inode->i_nlink == 0);
BUFFER_TRACE(EXT3_SB(sb)->s_sbh, "get_write_access");
err = ext3_journal_get_write_access(handle, EXT3_SB(sb)->s_sbh);
if (err)
goto out_unlock;
err = ext3_reserve_inode_write(handle, inode, &iloc);
if (err)
goto out_unlock;
/* Insert this inode at the head of the on-disk orphan list... */
NEXT_ORPHAN(inode) = le32_to_cpu(EXT3_SB(sb)->s_es->s_last_orphan);
EXT3_SB(sb)->s_es->s_last_orphan = cpu_to_le32(inode->i_ino);
err = ext3_journal_dirty_metadata(handle, EXT3_SB(sb)->s_sbh);
rc = ext3_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. */
if (!err)
list_add(&EXT3_I(inode)->i_orphan, &EXT3_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(&EXT3_SB(sb)->s_orphan_lock);
ext3_std_error(inode->i_sb, err);
return err;
}
/*
* ext3_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 ext3_orphan_del(handle_t *handle, struct inode *inode)
{
struct list_head *prev;
struct ext3_inode_info *ei = EXT3_I(inode);
struct ext3_sb_info *sbi;
unsigned long ino_next;
struct ext3_iloc iloc;
int err = 0;
mutex_lock(&EXT3_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 = EXT3_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 = ext3_reserve_inode_write(handle, inode, &iloc);
if (err)
goto out_err;
if (prev == &sbi->s_orphan) {
jbd_debug(4, "superblock will point to %lu\n", ino_next);
BUFFER_TRACE(sbi->s_sbh, "get_write_access");
err = ext3_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 = ext3_journal_dirty_metadata(handle, sbi->s_sbh);
} else {
struct ext3_iloc iloc2;
struct inode *i_prev =
&list_entry(prev, struct ext3_inode_info, i_orphan)->vfs_inode;
jbd_debug(4, "orphan inode %lu will point to %lu\n",
i_prev->i_ino, ino_next);
err = ext3_reserve_inode_write(handle, i_prev, &iloc2);
if (err)
goto out_brelse;
NEXT_ORPHAN(i_prev) = ino_next;
err = ext3_mark_iloc_dirty(handle, i_prev, &iloc2);
}
if (err)
goto out_brelse;
NEXT_ORPHAN(inode) = 0;
err = ext3_mark_iloc_dirty(handle, inode, &iloc);
out_err:
ext3_std_error(inode->i_sb, err);
out:
mutex_unlock(&EXT3_SB(inode->i_sb)->s_orphan_lock);
return err;
out_brelse:
brelse(iloc.bh);
goto out_err;
}
static int ext3_rmdir (struct inode * dir, struct dentry *dentry)
{
int retval;
struct inode * inode;
struct buffer_head * bh;
struct ext3_dir_entry_2 * de;
handle_t *handle;
/* Initialize quotas before so that eventual writes go in
* separate transaction */
dquot_initialize(dir);
dquot_initialize(dentry->d_inode);
handle = ext3_journal_start(dir, EXT3_DELETE_TRANS_BLOCKS(dir->i_sb));
if (IS_ERR(handle))
return PTR_ERR(handle);
retval = -ENOENT;
bh = ext3_find_entry(dir, &dentry->d_name, &de);
if (!bh)
goto end_rmdir;
if (IS_DIRSYNC(dir))
handle->h_sync = 1;
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;
retval = ext3_delete_entry(handle, dir, de, bh);
if (retval)
goto end_rmdir;
if (inode->i_nlink != 2)
ext3_warning (inode->i_sb, "ext3_rmdir",
"empty directory has nlink!=2 (%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;
ext3_orphan_add(handle, inode);
inode->i_ctime = dir->i_ctime = dir->i_mtime = CURRENT_TIME_SEC;
ext3_mark_inode_dirty(handle, inode);
drop_nlink(dir);
ext3_update_dx_flag(dir);
ext3_mark_inode_dirty(handle, dir);
end_rmdir:
ext3_journal_stop(handle);
brelse (bh);
return retval;
}
static int ext3_unlink(struct inode * dir, struct dentry *dentry)
{
int retval;
struct inode * inode;
struct buffer_head * bh;
struct ext3_dir_entry_2 * de;
handle_t *handle;
trace_ext3_unlink_enter(dir, dentry);
/* Initialize quotas before so that eventual writes go
* in separate transaction */
dquot_initialize(dir);
dquot_initialize(dentry->d_inode);
handle = ext3_journal_start(dir, EXT3_DELETE_TRANS_BLOCKS(dir->i_sb));
if (IS_ERR(handle))
return PTR_ERR(handle);
if (IS_DIRSYNC(dir))
handle->h_sync = 1;
retval = -ENOENT;
bh = ext3_find_entry(dir, &dentry->d_name, &de);
if (!bh)
goto end_unlink;
inode = dentry->d_inode;
retval = -EIO;
if (le32_to_cpu(de->inode) != inode->i_ino)
goto end_unlink;
if (!inode->i_nlink) {
ext3_warning (inode->i_sb, "ext3_unlink",
"Deleting nonexistent file (%lu), %d",
inode->i_ino, inode->i_nlink);
set_nlink(inode, 1);
}
retval = ext3_delete_entry(handle, dir, de, bh);
if (retval)
goto end_unlink;
dir->i_ctime = dir->i_mtime = CURRENT_TIME_SEC;
ext3_update_dx_flag(dir);
ext3_mark_inode_dirty(handle, dir);
drop_nlink(inode);
if (!inode->i_nlink)
ext3_orphan_add(handle, inode);
inode->i_ctime = dir->i_ctime;
ext3_mark_inode_dirty(handle, inode);
retval = 0;
end_unlink:
ext3_journal_stop(handle);
brelse (bh);
trace_ext3_unlink_exit(dentry, retval);
return retval;
}
static int ext3_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 > EXT3_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 + EXT3_MAXQUOTAS_INIT_BLOCKS(dir->i_sb) +
EXT3_XATTR_TRANS_BLOCKS;
} else {
/*
* Fast symlink. We have to add entry to directory
* (EXT3_DATA_TRANS_BLOCKS + EXT3_INDEX_EXTRA_TRANS_BLOCKS),
* allocate new inode (bitmap, group descriptor, inode block,
* quota blocks, sb is already counted in previous macros).
*/
credits = EXT3_DATA_TRANS_BLOCKS(dir->i_sb) +
EXT3_INDEX_EXTRA_TRANS_BLOCKS + 3 +
EXT3_MAXQUOTAS_INIT_BLOCKS(dir->i_sb);
}
retry:
handle = ext3_journal_start(dir, credits);
if (IS_ERR(handle))
return PTR_ERR(handle);
if (IS_DIRSYNC(dir))
handle->h_sync = 1;
inode = ext3_new_inode (handle, dir, &dentry->d_name, S_IFLNK|S_IRWXUGO);
err = PTR_ERR(inode);
if (IS_ERR(inode))
goto out_stop;
if (l > EXT3_N_BLOCKS * 4) {
inode->i_op = &ext3_symlink_inode_operations;
ext3_set_aops(inode);
/*
* We cannot call page_symlink() with transaction started
* because it calls into ext3_write_begin() which acquires page
* lock which ranks below transaction start (and it can also
* wait for journal commit if we are running out of space). 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 = ext3_orphan_add(handle, inode);
ext3_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 (EXT3_DATA_TRANS_BLOCKS
* + EXT3_INDEX_EXTRA_TRANS_BLOCKS), inode is also modified
*/
handle = ext3_journal_start(dir,
EXT3_DATA_TRANS_BLOCKS(dir->i_sb) +
EXT3_INDEX_EXTRA_TRANS_BLOCKS + 1);
if (IS_ERR(handle)) {
err = PTR_ERR(handle);
goto err_drop_inode;
}
set_nlink(inode, 1);
err = ext3_orphan_del(handle, inode);
if (err) {
ext3_journal_stop(handle);
drop_nlink(inode);
goto err_drop_inode;
}
} else {
inode->i_op = &ext3_fast_symlink_inode_operations;
memcpy((char*)&EXT3_I(inode)->i_data,symname,l);
inode->i_size = l-1;
}
EXT3_I(inode)->i_disksize = inode->i_size;
err = ext3_add_nondir(handle, dentry, inode);
out_stop:
ext3_journal_stop(handle);
if (err == -ENOSPC && ext3_should_retry_alloc(dir->i_sb, &retries))
goto retry;
return err;
err_drop_inode:
unlock_new_inode(inode);
iput(inode);
return err;
}
static int ext3_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 >= EXT3_LINK_MAX)
return -EMLINK;
dquot_initialize(dir);
retry:
handle = ext3_journal_start(dir, EXT3_DATA_TRANS_BLOCKS(dir->i_sb) +
EXT3_INDEX_EXTRA_TRANS_BLOCKS);
if (IS_ERR(handle))
return PTR_ERR(handle);
if (IS_DIRSYNC(dir))
handle->h_sync = 1;
inode->i_ctime = CURRENT_TIME_SEC;
inc_nlink(inode);
ihold(inode);
err = ext3_add_entry(handle, dentry, inode);
if (!err) {
ext3_mark_inode_dirty(handle, inode);
d_instantiate(dentry, inode);
} else {
drop_nlink(inode);
iput(inode);
}
ext3_journal_stop(handle);
if (err == -ENOSPC && ext3_should_retry_alloc(dir->i_sb, &retries))
goto retry;
return err;
}
#define PARENT_INO(buffer) \
(ext3_next_entry((struct ext3_dir_entry_2 *)(buffer))->inode)
/*
* Anybody can rename anything with this: the permission checks are left to the
* higher-level routines.
*/
static int ext3_rename (struct inode * old_dir, struct dentry *old_dentry,
struct inode * new_dir,struct dentry *new_dentry)
{
handle_t *handle;
struct inode * old_inode, * new_inode;
struct buffer_head * old_bh, * new_bh, * dir_bh;
struct ext3_dir_entry_2 * old_de, * new_de;
int retval, flush_file = 0;
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);
handle = ext3_journal_start(old_dir, 2 *
EXT3_DATA_TRANS_BLOCKS(old_dir->i_sb) +
EXT3_INDEX_EXTRA_TRANS_BLOCKS + 2);
if (IS_ERR(handle))
return PTR_ERR(handle);
if (IS_DIRSYNC(old_dir) || IS_DIRSYNC(new_dir))
handle->h_sync = 1;
old_bh = ext3_find_entry(old_dir, &old_dentry->d_name, &old_de);
/*
* 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 = ext3_find_entry(new_dir, &new_dentry->d_name, &new_de);
if (new_bh) {
if (!new_inode) {
brelse (new_bh);
new_bh = NULL;
}
}
if (S_ISDIR(old_inode->i_mode)) {
if (new_inode) {
retval = -ENOTEMPTY;
if (!empty_dir (new_inode))
goto end_rename;
}
retval = -EIO;
dir_bh = ext3_dir_bread(handle, old_inode, 0, 0, &retval);
if (!dir_bh)
goto end_rename;
if (le32_to_cpu(PARENT_INO(dir_bh->b_data)) != old_dir->i_ino)
goto end_rename;
retval = -EMLINK;
if (!new_inode && new_dir!=old_dir &&
new_dir->i_nlink >= EXT3_LINK_MAX)
goto end_rename;
}
if (!new_bh) {
retval = ext3_add_entry (handle, new_dentry, old_inode);
if (retval)
goto end_rename;
} else {
BUFFER_TRACE(new_bh, "get write access");
retval = ext3_journal_get_write_access(handle, new_bh);
if (retval)
goto journal_error;
new_de->inode = cpu_to_le32(old_inode->i_ino);
if (EXT3_HAS_INCOMPAT_FEATURE(new_dir->i_sb,
EXT3_FEATURE_INCOMPAT_FILETYPE))
new_de->file_type = old_de->file_type;
new_dir->i_version++;
new_dir->i_ctime = new_dir->i_mtime = CURRENT_TIME_SEC;
ext3_mark_inode_dirty(handle, new_dir);
BUFFER_TRACE(new_bh, "call ext3_journal_dirty_metadata");
retval = ext3_journal_dirty_metadata(handle, new_bh);
if (retval)
goto journal_error;
brelse(new_bh);
new_bh = NULL;
}
/*
* Like most other Unix systems, set the ctime for inodes on a
* rename.
*/
old_inode->i_ctime = CURRENT_TIME_SEC;
ext3_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 = ext3_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 ext3_dir_entry_2 *old_de2;
old_bh2 = ext3_find_entry(old_dir, &old_dentry->d_name,
&old_de2);
if (old_bh2) {
retval = ext3_delete_entry(handle, old_dir,
old_de2, old_bh2);
brelse(old_bh2);
}
}
if (retval) {
ext3_warning(old_dir->i_sb, "ext3_rename",
"Deleting old file (%lu), %d, error=%d",
old_dir->i_ino, old_dir->i_nlink, retval);
}
if (new_inode) {
drop_nlink(new_inode);
new_inode->i_ctime = CURRENT_TIME_SEC;
}
old_dir->i_ctime = old_dir->i_mtime = CURRENT_TIME_SEC;
ext3_update_dx_flag(old_dir);
if (dir_bh) {
BUFFER_TRACE(dir_bh, "get_write_access");
retval = ext3_journal_get_write_access(handle, dir_bh);
if (retval)
goto journal_error;
PARENT_INO(dir_bh->b_data) = cpu_to_le32(new_dir->i_ino);
BUFFER_TRACE(dir_bh, "call ext3_journal_dirty_metadata");
retval = ext3_journal_dirty_metadata(handle, dir_bh);
if (retval) {
journal_error:
ext3_std_error(new_dir->i_sb, retval);
goto end_rename;
}
drop_nlink(old_dir);
if (new_inode) {
drop_nlink(new_inode);
} else {
inc_nlink(new_dir);
ext3_update_dx_flag(new_dir);
ext3_mark_inode_dirty(handle, new_dir);
}
}
ext3_mark_inode_dirty(handle, old_dir);
if (new_inode) {
ext3_mark_inode_dirty(handle, new_inode);
if (!new_inode->i_nlink)
ext3_orphan_add(handle, new_inode);
if (ext3_should_writeback_data(new_inode))
flush_file = 1;
}
retval = 0;
end_rename:
brelse (dir_bh);
brelse (old_bh);
brelse (new_bh);
ext3_journal_stop(handle);
if (retval == 0 && flush_file)
filemap_flush(old_inode->i_mapping);
return retval;
}
/*
* directories can handle most operations...
*/
const struct inode_operations ext3_dir_inode_operations = {
.create = ext3_create,
.lookup = ext3_lookup,
.link = ext3_link,
.unlink = ext3_unlink,
.symlink = ext3_symlink,
.mkdir = ext3_mkdir,
.rmdir = ext3_rmdir,
.mknod = ext3_mknod,
.rename = ext3_rename,
.setattr = ext3_setattr,
#ifdef CONFIG_EXT3_FS_XATTR
.setxattr = generic_setxattr,
.getxattr = generic_getxattr,
.listxattr = ext3_listxattr,
.removexattr = generic_removexattr,
#endif
.get_acl = ext3_get_acl,
};
const struct inode_operations ext3_special_inode_operations = {
.setattr = ext3_setattr,
#ifdef CONFIG_EXT3_FS_XATTR
.setxattr = generic_setxattr,
.getxattr = generic_getxattr,
.listxattr = ext3_listxattr,
.removexattr = generic_removexattr,
#endif
.get_acl = ext3_get_acl,
};