[PATCH] Fix IO error reporting on fsync()
authorJan Kara <jack@suse.cz>
Tue, 17 Oct 2006 07:10:19 +0000 (00:10 -0700)
committerLinus Torvalds <torvalds@g5.osdl.org>
Tue, 17 Oct 2006 15:18:46 +0000 (08:18 -0700)
When IO error happens on metadata buffer, buffer is freed from memory and
later fsync() is called, filesystems like ext2 fail to report EIO.  We

solve the problem by introducing a pointer to associated address space into
the buffer_head.  When a buffer is removed from a list of metadata buffers
associated with an address space, IO error is transferred from the buffer to
the address space, so that fsync can later report it.

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
fs/buffer.c
include/linux/buffer_head.h

index f65ef88..35527dc 100644 (file)
@@ -452,6 +452,7 @@ static void end_buffer_async_write(struct buffer_head *bh, int uptodate)
                               bdevname(bh->b_bdev, b));
                }
                set_bit(AS_EIO, &page->mapping->flags);
+               set_buffer_write_io_error(bh);
                clear_buffer_uptodate(bh);
                SetPageError(page);
        }
@@ -571,6 +572,10 @@ EXPORT_SYMBOL(mark_buffer_async_write);
 static inline void __remove_assoc_queue(struct buffer_head *bh)
 {
        list_del_init(&bh->b_assoc_buffers);
+       WARN_ON(!bh->b_assoc_map);
+       if (buffer_write_io_error(bh))
+               set_bit(AS_EIO, &bh->b_assoc_map->flags);
+       bh->b_assoc_map = NULL;
 }
 
 int inode_has_buffers(struct inode *inode)
@@ -669,6 +674,7 @@ void mark_buffer_dirty_inode(struct buffer_head *bh, struct inode *inode)
                spin_lock(&buffer_mapping->private_lock);
                list_move_tail(&bh->b_assoc_buffers,
                                &mapping->private_list);
+               bh->b_assoc_map = mapping;
                spin_unlock(&buffer_mapping->private_lock);
        }
 }
@@ -765,7 +771,7 @@ static int fsync_buffers_list(spinlock_t *lock, struct list_head *list)
        spin_lock(lock);
        while (!list_empty(list)) {
                bh = BH_ENTRY(list->next);
-               list_del_init(&bh->b_assoc_buffers);
+               __remove_assoc_queue(bh);
                if (buffer_dirty(bh) || buffer_locked(bh)) {
                        list_add(&bh->b_assoc_buffers, &tmp);
                        if (buffer_dirty(bh)) {
@@ -786,7 +792,7 @@ static int fsync_buffers_list(spinlock_t *lock, struct list_head *list)
 
        while (!list_empty(&tmp)) {
                bh = BH_ENTRY(tmp.prev);
-               __remove_assoc_queue(bh);
+               list_del_init(&bh->b_assoc_buffers);
                get_bh(bh);
                spin_unlock(lock);
                wait_on_buffer(bh);
@@ -1167,6 +1173,7 @@ void __bforget(struct buffer_head *bh)
 
                spin_lock(&buffer_mapping->private_lock);
                list_del_init(&bh->b_assoc_buffers);
+               bh->b_assoc_map = NULL;
                spin_unlock(&buffer_mapping->private_lock);
        }
        __brelse(bh);
index 131ffd3..5d9fb0e 100644 (file)
@@ -69,6 +69,8 @@ struct buffer_head {
        bh_end_io_t *b_end_io;          /* I/O completion */
        void *b_private;                /* reserved for b_end_io */
        struct list_head b_assoc_buffers; /* associated with another mapping */
+       struct address_space *b_assoc_map;      /* mapping this buffer is
+                                                  associated with */
        atomic_t b_count;               /* users using this buffer_head */
 };