| Message ID | 88b8bde4-8c7a-6b44-9478-3ce13ecfab3a@infradead.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | ext2: fix debug reference to ext2_xattr_cache | expand |
On Fri 13-03-20 20:42:05, Randy Dunlap wrote: > From: Randy Dunlap <rdunlap@infradead.org> > > Fix a debug-only build error in ext2/xattr.c: > > When building without extra debugging, (and with another patch that uses > no_printk() instead of <empty> for the ext2-xattr debug-print macros, > this build error happens: > > ../fs/ext2/xattr.c: In function ‘ext2_xattr_cache_insert’: > ../fs/ext2/xattr.c:869:18: error: ‘ext2_xattr_cache’ undeclared (first use in this function); did you mean ‘ext2_xattr_list’? > atomic_read(&ext2_xattr_cache->c_entry_count)); > > Fix by moving struct mb_cache from fs/mbcache.c to <linux/mbcache.h>, > and then using the correct struct name in the debug-print macro. > > This wasn't converted when ext2 xattr cache was changed to use mbcache. > > Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") > Signed-off-by: Randy Dunlap <rdunlap@infradead.org> > Cc: Jan Kara <jack@suse.com> > Cc: Alexander Viro <viro@zeniv.linux.org.uk> > Cc: linux-ext4@vger.kernel.org > Cc: linux-fsdevel@vger.kernel.org Thanks for the patch! I don't think exporting 'struct mb_cache' just for this is reasonable. I've committed a patch which just removes the entry count from the debug message (attached). Honza > --- > This is ancient, from the beginning of git history. > > Or just kill of that print of c_entry_count... > > fs/ext2/xattr.c | 2 +- > fs/mbcache.c | 34 ---------------------------------- > include/linux/mbcache.h | 35 ++++++++++++++++++++++++++++++++++- > 3 files changed, 35 insertions(+), 36 deletions(-) > > --- linux-next-20200313.orig/fs/ext2/xattr.c > +++ linux-next-20200313/fs/ext2/xattr.c > @@ -873,7 +873,7 @@ ext2_xattr_cache_insert(struct mb_cache > if (error) { > if (error == -EBUSY) { > ea_bdebug(bh, "already in cache (%d cache entries)", > - atomic_read(&ext2_xattr_cache->c_entry_count)); > + atomic_read(&cache->c_entry_count)); > error = 0; > } > } else > --- linux-next-20200313.orig/fs/mbcache.c > +++ linux-next-20200313/fs/mbcache.c > @@ -8,40 +8,6 @@ > #include <linux/workqueue.h> > #include <linux/mbcache.h> > > -/* > - * Mbcache is a simple key-value store. Keys need not be unique, however > - * key-value pairs are expected to be unique (we use this fact in > - * mb_cache_entry_delete()). > - * > - * Ext2 and ext4 use this cache for deduplication of extended attribute blocks. > - * Ext4 also uses it for deduplication of xattr values stored in inodes. > - * They use hash of data as a key and provide a value that may represent a > - * block or inode number. That's why keys need not be unique (hash of different > - * data may be the same). However user provided value always uniquely > - * identifies a cache entry. > - * > - * We provide functions for creation and removal of entries, search by key, > - * and a special "delete entry with given key-value pair" operation. Fixed > - * size hash table is used for fast key lookups. > - */ > - > -struct mb_cache { > - /* Hash table of entries */ > - struct hlist_bl_head *c_hash; > - /* log2 of hash table size */ > - int c_bucket_bits; > - /* Maximum entries in cache to avoid degrading hash too much */ > - unsigned long c_max_entries; > - /* Protects c_list, c_entry_count */ > - spinlock_t c_list_lock; > - struct list_head c_list; > - /* Number of entries in cache */ > - unsigned long c_entry_count; > - struct shrinker c_shrink; > - /* Work for shrinking when the cache has too many entries */ > - struct work_struct c_shrink_work; > -}; > - > static struct kmem_cache *mb_entry_cache; > > static unsigned long mb_cache_shrink(struct mb_cache *cache, > --- linux-next-20200313.orig/include/linux/mbcache.h > +++ linux-next-20200313/include/linux/mbcache.h > @@ -8,7 +8,40 @@ > #include <linux/atomic.h> > #include <linux/fs.h> > > -struct mb_cache; > +/* > + * Mbcache is a simple key-value store. Keys need not be unique, however > + * key-value pairs are expected to be unique (we use this fact in > + * mb_cache_entry_delete()). > + * > + * Ext2 and ext4 use this cache for deduplication of extended attribute blocks. > + * Ext4 also uses it for deduplication of xattr values stored in inodes. > + * They use hash of data as a key and provide a value that may represent a > + * block or inode number. That's why keys need not be unique (hash of different > + * data may be the same). However user provided value always uniquely > + * identifies a cache entry. > + * > + * We provide functions for creation and removal of entries, search by key, > + * and a special "delete entry with given key-value pair" operation. Fixed > + * size hash table is used for fast key lookups. > + */ > + > +struct mb_cache { > + /* Hash table of entries */ > + struct hlist_bl_head *c_hash; > + /* log2 of hash table size */ > + int c_bucket_bits; > + /* Maximum entries in cache to avoid degrading hash too much */ > + unsigned long c_max_entries; > + /* Protects c_list, c_entry_count */ > + spinlock_t c_list_lock; > + struct list_head c_list; > + /* Number of entries in cache */ > + unsigned long c_entry_count; > + struct shrinker c_shrink; > + /* Work for shrinking when the cache has too many entries */ > + struct work_struct c_shrink_work; > +}; > + > > struct mb_cache_entry { > /* List of entries in cache - protected by cache->c_list_lock */ >
On 3/17/20 4:47 AM, Jan Kara wrote: > On Fri 13-03-20 20:42:05, Randy Dunlap wrote: >> From: Randy Dunlap <rdunlap@infradead.org> >> >> Fix a debug-only build error in ext2/xattr.c: >> >> When building without extra debugging, (and with another patch that uses >> no_printk() instead of <empty> for the ext2-xattr debug-print macros, >> this build error happens: >> >> ../fs/ext2/xattr.c: In function ‘ext2_xattr_cache_insert’: >> ../fs/ext2/xattr.c:869:18: error: ‘ext2_xattr_cache’ undeclared (first use in this function); did you mean ‘ext2_xattr_list’? >> atomic_read(&ext2_xattr_cache->c_entry_count)); >> >> Fix by moving struct mb_cache from fs/mbcache.c to <linux/mbcache.h>, >> and then using the correct struct name in the debug-print macro. >> >> This wasn't converted when ext2 xattr cache was changed to use mbcache. >> >> Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") >> Signed-off-by: Randy Dunlap <rdunlap@infradead.org> >> Cc: Jan Kara <jack@suse.com> >> Cc: Alexander Viro <viro@zeniv.linux.org.uk> >> Cc: linux-ext4@vger.kernel.org >> Cc: linux-fsdevel@vger.kernel.org > > Thanks for the patch! I don't think exporting 'struct mb_cache' just for > this is reasonable. I've committed a patch which just removes the entry > count from the debug message (attached). > Sure, that's good. I have a patch like that one on my system also. :) > >> --- >> This is ancient, from the beginning of git history. >> >> Or just kill of that print of c_entry_count... >> >> fs/ext2/xattr.c | 2 +- >> fs/mbcache.c | 34 ---------------------------------- >> include/linux/mbcache.h | 35 ++++++++++++++++++++++++++++++++++- >> 3 files changed, 35 insertions(+), 36 deletions(-)
--- linux-next-20200313.orig/fs/ext2/xattr.c +++ linux-next-20200313/fs/ext2/xattr.c @@ -873,7 +873,7 @@ ext2_xattr_cache_insert(struct mb_cache if (error) { if (error == -EBUSY) { ea_bdebug(bh, "already in cache (%d cache entries)", - atomic_read(&ext2_xattr_cache->c_entry_count)); + atomic_read(&cache->c_entry_count)); error = 0; } } else --- linux-next-20200313.orig/fs/mbcache.c +++ linux-next-20200313/fs/mbcache.c @@ -8,40 +8,6 @@ #include <linux/workqueue.h> #include <linux/mbcache.h> -/* - * Mbcache is a simple key-value store. Keys need not be unique, however - * key-value pairs are expected to be unique (we use this fact in - * mb_cache_entry_delete()). - * - * Ext2 and ext4 use this cache for deduplication of extended attribute blocks. - * Ext4 also uses it for deduplication of xattr values stored in inodes. - * They use hash of data as a key and provide a value that may represent a - * block or inode number. That's why keys need not be unique (hash of different - * data may be the same). However user provided value always uniquely - * identifies a cache entry. - * - * We provide functions for creation and removal of entries, search by key, - * and a special "delete entry with given key-value pair" operation. Fixed - * size hash table is used for fast key lookups. - */ - -struct mb_cache { - /* Hash table of entries */ - struct hlist_bl_head *c_hash; - /* log2 of hash table size */ - int c_bucket_bits; - /* Maximum entries in cache to avoid degrading hash too much */ - unsigned long c_max_entries; - /* Protects c_list, c_entry_count */ - spinlock_t c_list_lock; - struct list_head c_list; - /* Number of entries in cache */ - unsigned long c_entry_count; - struct shrinker c_shrink; - /* Work for shrinking when the cache has too many entries */ - struct work_struct c_shrink_work; -}; - static struct kmem_cache *mb_entry_cache; static unsigned long mb_cache_shrink(struct mb_cache *cache, --- linux-next-20200313.orig/include/linux/mbcache.h +++ linux-next-20200313/include/linux/mbcache.h @@ -8,7 +8,40 @@ #include <linux/atomic.h> #include <linux/fs.h> -struct mb_cache; +/* + * Mbcache is a simple key-value store. Keys need not be unique, however + * key-value pairs are expected to be unique (we use this fact in + * mb_cache_entry_delete()). + * + * Ext2 and ext4 use this cache for deduplication of extended attribute blocks. + * Ext4 also uses it for deduplication of xattr values stored in inodes. + * They use hash of data as a key and provide a value that may represent a + * block or inode number. That's why keys need not be unique (hash of different + * data may be the same). However user provided value always uniquely + * identifies a cache entry. + * + * We provide functions for creation and removal of entries, search by key, + * and a special "delete entry with given key-value pair" operation. Fixed + * size hash table is used for fast key lookups. + */ + +struct mb_cache { + /* Hash table of entries */ + struct hlist_bl_head *c_hash; + /* log2 of hash table size */ + int c_bucket_bits; + /* Maximum entries in cache to avoid degrading hash too much */ + unsigned long c_max_entries; + /* Protects c_list, c_entry_count */ + spinlock_t c_list_lock; + struct list_head c_list; + /* Number of entries in cache */ + unsigned long c_entry_count; + struct shrinker c_shrink; + /* Work for shrinking when the cache has too many entries */ + struct work_struct c_shrink_work; +}; + struct mb_cache_entry { /* List of entries in cache - protected by cache->c_list_lock */