static int ext2_xattr_set2(struct inode *, struct buffer_head *,
struct ext2_xattr_header *);
-static int ext2_xattr_cache_insert(struct buffer_head *);
+static int ext2_xattr_cache_insert(struct mb_cache *, struct buffer_head *);
static struct buffer_head *ext2_xattr_cache_find(struct inode *,
struct ext2_xattr_header *);
static void ext2_xattr_rehash(struct ext2_xattr_header *,
struct ext2_xattr_entry *);
-static struct mb_cache *ext2_xattr_cache;
-
static const struct xattr_handler *ext2_xattr_handler_map[] = {
[EXT2_XATTR_INDEX_USER] = &ext2_xattr_user_handler,
#ifdef CONFIG_EXT2_FS_POSIX_ACL
size_t name_len, size;
char *end;
int error;
+ struct mb_cache *ext2_mb_cache = EXT2_SB(inode->i_sb)->s_mb_cache;
ea_idebug(inode, "name=%d.%s, buffer=%p, buffer_size=%ld",
name_index, name, buffer, (long)buffer_size);
goto found;
entry = next;
}
- if (ext2_xattr_cache_insert(bh))
+ if (ext2_xattr_cache_insert(ext2_mb_cache, bh))
ea_idebug(inode, "cache insert failed");
error = -ENODATA;
goto cleanup;
le16_to_cpu(entry->e_value_offs) + size > inode->i_sb->s_blocksize)
goto bad_block;
- if (ext2_xattr_cache_insert(bh))
+ if (ext2_xattr_cache_insert(ext2_mb_cache, bh))
ea_idebug(inode, "cache insert failed");
if (buffer) {
error = -ERANGE;
char *end;
size_t rest = buffer_size;
int error;
+ struct mb_cache *ext2_mb_cache = EXT2_SB(inode->i_sb)->s_mb_cache;
ea_idebug(inode, "buffer=%p, buffer_size=%ld",
buffer, (long)buffer_size);
goto bad_block;
entry = next;
}
- if (ext2_xattr_cache_insert(bh))
+ if (ext2_xattr_cache_insert(ext2_mb_cache, bh))
ea_idebug(inode, "cache insert failed");
/* list the attribute names */
/* Here we know that we can set the new attribute. */
if (header) {
- struct mb_cache_entry *ce;
-
/* assert(header == HDR(bh)); */
- ce = mb_cache_entry_get(ext2_xattr_cache, bh->b_bdev,
- bh->b_blocknr);
lock_buffer(bh);
if (header->h_refcount == cpu_to_le32(1)) {
+ __u32 hash = le32_to_cpu(header->h_hash);
+
ea_bdebug(bh, "modifying in-place");
- if (ce)
- mb_cache_entry_free(ce);
+ /*
+ * This must happen under buffer lock for
+ * ext2_xattr_set2() to reliably detect modified block
+ */
+ mb_cache_entry_delete_block(EXT2_SB(sb)->s_mb_cache,
+ hash, bh->b_blocknr);
+
/* keep the buffer locked while modifying it. */
} else {
int offset;
- if (ce)
- mb_cache_entry_release(ce);
unlock_buffer(bh);
ea_bdebug(bh, "cloning");
header = kmalloc(bh->b_size, GFP_KERNEL);
struct super_block *sb = inode->i_sb;
struct buffer_head *new_bh = NULL;
int error;
+ struct mb_cache *ext2_mb_cache = EXT2_SB(sb)->s_mb_cache;
if (header) {
new_bh = ext2_xattr_cache_find(inode, header);
don't need to change the reference count. */
new_bh = old_bh;
get_bh(new_bh);
- ext2_xattr_cache_insert(new_bh);
+ ext2_xattr_cache_insert(ext2_mb_cache, new_bh);
} else {
/* We need to allocate a new block */
ext2_fsblk_t goal = ext2_group_first_block_no(sb,
memcpy(new_bh->b_data, header, new_bh->b_size);
set_buffer_uptodate(new_bh);
unlock_buffer(new_bh);
- ext2_xattr_cache_insert(new_bh);
+ ext2_xattr_cache_insert(ext2_mb_cache, new_bh);
ext2_xattr_update_super_block(sb);
}
error = 0;
if (old_bh && old_bh != new_bh) {
- struct mb_cache_entry *ce;
-
/*
* If there was an old block and we are no longer using it,
* release the old block.
*/
- ce = mb_cache_entry_get(ext2_xattr_cache, old_bh->b_bdev,
- old_bh->b_blocknr);
lock_buffer(old_bh);
if (HDR(old_bh)->h_refcount == cpu_to_le32(1)) {
+ __u32 hash = le32_to_cpu(HDR(old_bh)->h_hash);
+
+ /*
+ * This must happen under buffer lock for
+ * ext2_xattr_set2() to reliably detect freed block
+ */
+ mb_cache_entry_delete_block(ext2_mb_cache,
+ hash, old_bh->b_blocknr);
/* Free the old block. */
- if (ce)
- mb_cache_entry_free(ce);
ea_bdebug(old_bh, "freeing");
ext2_free_blocks(inode, old_bh->b_blocknr, 1);
mark_inode_dirty(inode);
} else {
/* Decrement the refcount only. */
le32_add_cpu(&HDR(old_bh)->h_refcount, -1);
- if (ce)
- mb_cache_entry_release(ce);
dquot_free_block_nodirty(inode, 1);
mark_inode_dirty(inode);
mark_buffer_dirty(old_bh);
ext2_xattr_delete_inode(struct inode *inode)
{
struct buffer_head *bh = NULL;
- struct mb_cache_entry *ce;
down_write(&EXT2_I(inode)->xattr_sem);
if (!EXT2_I(inode)->i_file_acl)
EXT2_I(inode)->i_file_acl);
goto cleanup;
}
- ce = mb_cache_entry_get(ext2_xattr_cache, bh->b_bdev, bh->b_blocknr);
lock_buffer(bh);
if (HDR(bh)->h_refcount == cpu_to_le32(1)) {
- if (ce)
- mb_cache_entry_free(ce);
+ __u32 hash = le32_to_cpu(HDR(bh)->h_hash);
+
+ /*
+ * This must happen under buffer lock for ext2_xattr_set2() to
+ * reliably detect freed block
+ */
+ mb_cache_entry_delete_block(EXT2_SB(inode->i_sb)->s_mb_cache,
+ hash, bh->b_blocknr);
ext2_free_blocks(inode, EXT2_I(inode)->i_file_acl, 1);
get_bh(bh);
bforget(bh);
unlock_buffer(bh);
} else {
le32_add_cpu(&HDR(bh)->h_refcount, -1);
- if (ce)
- mb_cache_entry_release(ce);
ea_bdebug(bh, "refcount now=%d",
le32_to_cpu(HDR(bh)->h_refcount));
unlock_buffer(bh);
up_write(&EXT2_I(inode)->xattr_sem);
}
-/*
- * ext2_xattr_put_super()
- *
- * This is called when a file system is unmounted.
- */
-void
-ext2_xattr_put_super(struct super_block *sb)
-{
- mb_cache_shrink(sb->s_bdev);
-}
-
-
/*
* ext2_xattr_cache_insert()
*
* Returns 0, or a negative error number on failure.
*/
static int
-ext2_xattr_cache_insert(struct buffer_head *bh)
+ext2_xattr_cache_insert(struct mb_cache *cache, struct buffer_head *bh)
{
__u32 hash = le32_to_cpu(HDR(bh)->h_hash);
- struct mb_cache_entry *ce;
int error;
- ce = mb_cache_entry_alloc(ext2_xattr_cache, GFP_NOFS);
- if (!ce)
- return -ENOMEM;
- error = mb_cache_entry_insert(ce, bh->b_bdev, bh->b_blocknr, hash);
+ error = mb_cache_entry_create(cache, GFP_NOFS, hash, bh->b_blocknr, 1);
if (error) {
- mb_cache_entry_free(ce);
if (error == -EBUSY) {
ea_bdebug(bh, "already in cache (%d cache entries)",
atomic_read(&ext2_xattr_cache->c_entry_count));
error = 0;
}
- } else {
- ea_bdebug(bh, "inserting [%x] (%d cache entries)", (int)hash,
- atomic_read(&ext2_xattr_cache->c_entry_count));
- mb_cache_entry_release(ce);
- }
+ } else
+ ea_bdebug(bh, "inserting [%x]", (int)hash);
return error;
}
{
__u32 hash = le32_to_cpu(header->h_hash);
struct mb_cache_entry *ce;
+ struct mb_cache *ext2_mb_cache = EXT2_SB(inode->i_sb)->s_mb_cache;
if (!header->h_hash)
return NULL; /* never share */
ea_idebug(inode, "looking for cached blocks [%x]", (int)hash);
again:
- ce = mb_cache_entry_find_first(ext2_xattr_cache, inode->i_sb->s_bdev,
- hash);
+ ce = mb_cache_entry_find_first(ext2_mb_cache, hash);
while (ce) {
struct buffer_head *bh;
- if (IS_ERR(ce)) {
- if (PTR_ERR(ce) == -EAGAIN)
- goto again;
- break;
- }
-
bh = sb_bread(inode->i_sb, ce->e_block);
if (!bh) {
ext2_error(inode->i_sb, "ext2_xattr_cache_find",
inode->i_ino, (unsigned long) ce->e_block);
} else {
lock_buffer(bh);
- if (le32_to_cpu(HDR(bh)->h_refcount) >
+ /*
+ * We have to be careful about races with freeing or
+ * rehashing of xattr block. Once we hold buffer lock
+ * xattr block's state is stable so we can check
+ * whether the block got freed / rehashed or not.
+ * Since we unhash mbcache entry under buffer lock when
+ * freeing / rehashing xattr block, checking whether
+ * entry is still hashed is reliable.
+ */
+ if (hlist_bl_unhashed(&ce->e_hash_list)) {
+ mb_cache_entry_put(ext2_mb_cache, ce);
+ unlock_buffer(bh);
+ brelse(bh);
+ goto again;
+ } else if (le32_to_cpu(HDR(bh)->h_refcount) >
EXT2_XATTR_REFCOUNT_MAX) {
ea_idebug(inode, "block %ld refcount %d>%d",
(unsigned long) ce->e_block,
} else if (!ext2_xattr_cmp(header, HDR(bh))) {
ea_bdebug(bh, "b_count=%d",
atomic_read(&(bh->b_count)));
- mb_cache_entry_release(ce);
+ mb_cache_entry_touch(ext2_mb_cache, ce);
+ mb_cache_entry_put(ext2_mb_cache, ce);
return bh;
}
unlock_buffer(bh);
brelse(bh);
}
- ce = mb_cache_entry_find_next(ce, inode->i_sb->s_bdev, hash);
+ ce = mb_cache_entry_find_next(ext2_mb_cache, ce);
}
return NULL;
}
#undef BLOCK_HASH_SHIFT
-int __init
-init_ext2_xattr(void)
+#define HASH_BUCKET_BITS 10
+
+struct mb_cache *ext2_xattr_create_cache(void)
{
- ext2_xattr_cache = mb_cache_create("ext2_xattr", 6);
- if (!ext2_xattr_cache)
- return -ENOMEM;
- return 0;
+ return mb_cache_create(HASH_BUCKET_BITS);
}
-void
-exit_ext2_xattr(void)
+void ext2_xattr_destroy_cache(struct mb_cache *cache)
{
- mb_cache_destroy(ext2_xattr_cache);
+ if (cache)
+ mb_cache_destroy(cache);
}
projects / cascardo / linux.git / blobdiff