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Diffstat (limited to 'fs/ext4/xattr.c')
-rw-r--r--fs/ext4/xattr.c136
1 files changed, 67 insertions, 69 deletions
diff --git a/fs/ext4/xattr.c b/fs/ext4/xattr.c
index 7c23363ecf19..b310ed81c10e 100644
--- a/fs/ext4/xattr.c
+++ b/fs/ext4/xattr.c
@@ -53,7 +53,7 @@
#include <linux/init.h>
#include <linux/fs.h>
#include <linux/slab.h>
-#include <linux/mbcache.h>
+#include <linux/mbcache2.h>
#include <linux/quotaops.h>
#include "ext4_jbd2.h"
#include "ext4.h"
@@ -80,10 +80,10 @@
# define ea_bdebug(bh, fmt, ...) no_printk(fmt, ##__VA_ARGS__)
#endif
-static void ext4_xattr_cache_insert(struct mb_cache *, struct buffer_head *);
+static void ext4_xattr_cache_insert(struct mb2_cache *, struct buffer_head *);
static struct buffer_head *ext4_xattr_cache_find(struct inode *,
struct ext4_xattr_header *,
- struct mb_cache_entry **);
+ struct mb2_cache_entry **);
static void ext4_xattr_rehash(struct ext4_xattr_header *,
struct ext4_xattr_entry *);
static int ext4_xattr_list(struct dentry *dentry, char *buffer,
@@ -300,7 +300,7 @@ ext4_xattr_block_get(struct inode *inode, int name_index, const char *name,
struct ext4_xattr_entry *entry;
size_t size;
int error;
- struct mb_cache *ext4_mb_cache = EXT4_GET_MB_CACHE(inode);
+ struct mb2_cache *ext4_mb_cache = EXT4_GET_MB_CACHE(inode);
ea_idebug(inode, "name=%d.%s, buffer=%p, buffer_size=%ld",
name_index, name, buffer, (long)buffer_size);
@@ -447,7 +447,7 @@ ext4_xattr_block_list(struct dentry *dentry, char *buffer, size_t buffer_size)
struct inode *inode = d_inode(dentry);
struct buffer_head *bh = NULL;
int error;
- struct mb_cache *ext4_mb_cache = EXT4_GET_MB_CACHE(inode);
+ struct mb2_cache *ext4_mb_cache = EXT4_GET_MB_CACHE(inode);
ea_idebug(inode, "buffer=%p, buffer_size=%ld",
buffer, (long)buffer_size);
@@ -564,11 +564,8 @@ static void
ext4_xattr_release_block(handle_t *handle, struct inode *inode,
struct buffer_head *bh)
{
- struct mb_cache_entry *ce = NULL;
int error = 0;
- struct mb_cache *ext4_mb_cache = EXT4_GET_MB_CACHE(inode);
- ce = mb_cache_entry_get(ext4_mb_cache, bh->b_bdev, bh->b_blocknr);
BUFFER_TRACE(bh, "get_write_access");
error = ext4_journal_get_write_access(handle, bh);
if (error)
@@ -576,9 +573,15 @@ ext4_xattr_release_block(handle_t *handle, struct inode *inode,
lock_buffer(bh);
if (BHDR(bh)->h_refcount == cpu_to_le32(1)) {
+ __u32 hash = le32_to_cpu(BHDR(bh)->h_hash);
+
ea_bdebug(bh, "refcount now=0; freeing");
- if (ce)
- mb_cache_entry_free(ce);
+ /*
+ * This must happen under buffer lock for
+ * ext4_xattr_block_set() to reliably detect freed block
+ */
+ mb2_cache_entry_delete_block(EXT4_GET_MB_CACHE(inode), hash,
+ bh->b_blocknr);
get_bh(bh);
unlock_buffer(bh);
ext4_free_blocks(handle, inode, bh, 0, 1,
@@ -586,8 +589,6 @@ ext4_xattr_release_block(handle_t *handle, struct inode *inode,
EXT4_FREE_BLOCKS_FORGET);
} else {
le32_add_cpu(&BHDR(bh)->h_refcount, -1);
- if (ce)
- mb_cache_entry_release(ce);
/*
* Beware of this ugliness: Releasing of xattr block references
* from different inodes can race and so we have to protect
@@ -800,17 +801,15 @@ ext4_xattr_block_set(handle_t *handle, struct inode *inode,
struct super_block *sb = inode->i_sb;
struct buffer_head *new_bh = NULL;
struct ext4_xattr_search *s = &bs->s;
- struct mb_cache_entry *ce = NULL;
+ struct mb2_cache_entry *ce = NULL;
int error = 0;
- struct mb_cache *ext4_mb_cache = EXT4_GET_MB_CACHE(inode);
+ struct mb2_cache *ext4_mb_cache = EXT4_GET_MB_CACHE(inode);
#define header(x) ((struct ext4_xattr_header *)(x))
if (i->value && i->value_len > sb->s_blocksize)
return -ENOSPC;
if (s->base) {
- ce = mb_cache_entry_get(ext4_mb_cache, bs->bh->b_bdev,
- bs->bh->b_blocknr);
BUFFER_TRACE(bs->bh, "get_write_access");
error = ext4_journal_get_write_access(handle, bs->bh);
if (error)
@@ -818,10 +817,15 @@ ext4_xattr_block_set(handle_t *handle, struct inode *inode,
lock_buffer(bs->bh);
if (header(s->base)->h_refcount == cpu_to_le32(1)) {
- if (ce) {
- mb_cache_entry_free(ce);
- ce = NULL;
- }
+ __u32 hash = le32_to_cpu(BHDR(bs->bh)->h_hash);
+
+ /*
+ * This must happen under buffer lock for
+ * ext4_xattr_block_set() to reliably detect modified
+ * block
+ */
+ mb2_cache_entry_delete_block(ext4_mb_cache, hash,
+ bs->bh->b_blocknr);
ea_bdebug(bs->bh, "modifying in-place");
error = ext4_xattr_set_entry(i, s);
if (!error) {
@@ -845,10 +849,6 @@ ext4_xattr_block_set(handle_t *handle, struct inode *inode,
int offset = (char *)s->here - bs->bh->b_data;
unlock_buffer(bs->bh);
- if (ce) {
- mb_cache_entry_release(ce);
- ce = NULL;
- }
ea_bdebug(bs->bh, "cloning");
s->base = kmalloc(bs->bh->b_size, GFP_NOFS);
error = -ENOMEM;
@@ -903,6 +903,31 @@ inserted:
if (error)
goto cleanup_dquot;
lock_buffer(new_bh);
+ /*
+ * 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)) {
+ /*
+ * Undo everything and check mbcache
+ * again.
+ */
+ unlock_buffer(new_bh);
+ dquot_free_block(inode,
+ EXT4_C2B(EXT4_SB(sb),
+ 1));
+ brelse(new_bh);
+ mb2_cache_entry_put(ext4_mb_cache, ce);
+ ce = NULL;
+ new_bh = NULL;
+ goto inserted;
+ }
le32_add_cpu(&BHDR(new_bh)->h_refcount, 1);
ea_bdebug(new_bh, "reusing; refcount now=%d",
le32_to_cpu(BHDR(new_bh)->h_refcount));
@@ -913,7 +938,8 @@ inserted:
if (error)
goto cleanup_dquot;
}
- mb_cache_entry_release(ce);
+ mb2_cache_entry_touch(ext4_mb_cache, ce);
+ mb2_cache_entry_put(ext4_mb_cache, ce);
ce = NULL;
} else if (bs->bh && s->base == bs->bh->b_data) {
/* We were modifying this block in-place. */
@@ -978,7 +1004,7 @@ getblk_failed:
cleanup:
if (ce)
- mb_cache_entry_release(ce);
+ mb2_cache_entry_put(ext4_mb_cache, ce);
brelse(new_bh);
if (!(bs->bh && s->base == bs->bh->b_data))
kfree(s->base);
@@ -1543,17 +1569,6 @@ cleanup:
}
/*
- * ext4_xattr_put_super()
- *
- * This is called when a file system is unmounted.
- */
-void
-ext4_xattr_put_super(struct super_block *sb)
-{
- mb_cache_shrink(sb->s_bdev);
-}
-
-/*
* ext4_xattr_cache_insert()
*
* Create a new entry in the extended attribute cache, and insert
@@ -1562,28 +1577,18 @@ ext4_xattr_put_super(struct super_block *sb)
* Returns 0, or a negative error number on failure.
*/
static void
-ext4_xattr_cache_insert(struct mb_cache *ext4_mb_cache, struct buffer_head *bh)
+ext4_xattr_cache_insert(struct mb2_cache *ext4_mb_cache, struct buffer_head *bh)
{
__u32 hash = le32_to_cpu(BHDR(bh)->h_hash);
- struct mb_cache_entry *ce;
int error;
- ce = mb_cache_entry_alloc(ext4_mb_cache, GFP_NOFS);
- if (!ce) {
- ea_bdebug(bh, "out of memory");
- return;
- }
- error = mb_cache_entry_insert(ce, bh->b_bdev, bh->b_blocknr, hash);
+ error = mb2_cache_entry_create(ext4_mb_cache, GFP_NOFS, hash,
+ bh->b_blocknr);
if (error) {
- mb_cache_entry_free(ce);
- if (error == -EBUSY) {
+ if (error == -EBUSY)
ea_bdebug(bh, "already in cache");
- error = 0;
- }
- } else {
+ } else
ea_bdebug(bh, "inserting [%x]", (int)hash);
- mb_cache_entry_release(ce);
- }
}
/*
@@ -1636,26 +1641,19 @@ ext4_xattr_cmp(struct ext4_xattr_header *header1,
*/
static struct buffer_head *
ext4_xattr_cache_find(struct inode *inode, struct ext4_xattr_header *header,
- struct mb_cache_entry **pce)
+ struct mb2_cache_entry **pce)
{
__u32 hash = le32_to_cpu(header->h_hash);
- struct mb_cache_entry *ce;
- struct mb_cache *ext4_mb_cache = EXT4_GET_MB_CACHE(inode);
+ struct mb2_cache_entry *ce;
+ struct mb2_cache *ext4_mb_cache = EXT4_GET_MB_CACHE(inode);
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(ext4_mb_cache, inode->i_sb->s_bdev,
- hash);
+ ce = mb2_cache_entry_find_first(ext4_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) {
EXT4_ERROR_INODE(inode, "block %lu read error",
@@ -1671,7 +1669,7 @@ again:
return bh;
}
brelse(bh);
- ce = mb_cache_entry_find_next(ce, inode->i_sb->s_bdev, hash);
+ ce = mb2_cache_entry_find_next(ext4_mb_cache, ce);
}
return NULL;
}
@@ -1746,15 +1744,15 @@ static void ext4_xattr_rehash(struct ext4_xattr_header *header,
#define HASH_BUCKET_BITS 10
-struct mb_cache *
-ext4_xattr_create_cache(char *name)
+struct mb2_cache *
+ext4_xattr_create_cache(void)
{
- return mb_cache_create(name, HASH_BUCKET_BITS);
+ return mb2_cache_create(HASH_BUCKET_BITS);
}
-void ext4_xattr_destroy_cache(struct mb_cache *cache)
+void ext4_xattr_destroy_cache(struct mb2_cache *cache)
{
if (cache)
- mb_cache_destroy(cache);
+ mb2_cache_destroy(cache);
}
generated by cgit v1.2.3 (git 2.25.1) at 2024-06-04 11:38:30 +0000