kernel-ark/include/linux/mbcache.h
Jan Kara 335e92e8a5 vfs: fix possible deadlock in ext2, ext3, ext4 when using xattrs
mb_cache_entry_alloc() was allocating cache entries with GFP_KERNEL.  But
filesystems are calling this function while holding xattr_sem so possible
recursion into the fs violates locking ordering of xattr_sem and transaction
start / i_mutex for ext2-4.  Change mb_cache_entry_alloc() so that filesystems
can specify desired gfp mask and use GFP_NOFS from all of them.

Signed-off-by: Jan Kara <jack@suse.cz>
Reported-by: Dave Jones <davej@redhat.com>
Cc: <linux-ext4@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-15 19:35:41 -07:00

53 lines
1.5 KiB
C

/*
File: linux/mbcache.h
(C) 2001 by Andreas Gruenbacher, <a.gruenbacher@computer.org>
*/
/* Hardwire the number of additional indexes */
#define MB_CACHE_INDEXES_COUNT 1
struct mb_cache_entry {
struct list_head e_lru_list;
struct mb_cache *e_cache;
unsigned short e_used;
unsigned short e_queued;
struct block_device *e_bdev;
sector_t e_block;
struct list_head e_block_list;
struct {
struct list_head o_list;
unsigned int o_key;
} e_indexes[0];
};
struct mb_cache_op {
int (*free)(struct mb_cache_entry *, gfp_t);
};
/* Functions on caches */
struct mb_cache * mb_cache_create(const char *, struct mb_cache_op *, size_t,
int, int);
void mb_cache_shrink(struct block_device *);
void mb_cache_destroy(struct mb_cache *);
/* Functions on cache entries */
struct mb_cache_entry *mb_cache_entry_alloc(struct mb_cache *, gfp_t);
int mb_cache_entry_insert(struct mb_cache_entry *, struct block_device *,
sector_t, unsigned int[]);
void mb_cache_entry_release(struct mb_cache_entry *);
void mb_cache_entry_free(struct mb_cache_entry *);
struct mb_cache_entry *mb_cache_entry_get(struct mb_cache *,
struct block_device *,
sector_t);
#if !defined(MB_CACHE_INDEXES_COUNT) || (MB_CACHE_INDEXES_COUNT > 0)
struct mb_cache_entry *mb_cache_entry_find_first(struct mb_cache *cache, int,
struct block_device *,
unsigned int);
struct mb_cache_entry *mb_cache_entry_find_next(struct mb_cache_entry *, int,
struct block_device *,
unsigned int);
#endif