[PATCH] resierfs: fix reiserfs_invalidatepage race against data=ordered
After a transaction has closed but before it has finished commit, there is a window where data=ordered mode requires invalidatepage to pin pages instead of freeing them. This patch fixes a race between the invalidatepage checks and data=ordered writeback, and it also adds a check to the reiserfs write_ordered_buffers routines to write any anonymous buffers that were dirtied after its first writeback loop. That bug works like this: proc1: transaction closes and a new one starts proc1: write_ordered_buffers starts processing data=ordered list proc1: buffer A is cleaned and written proc2: buffer A is dirtied by another process proc2: File is truncated to zero, page A goes through invalidatepage proc2: reiserfs_invalidatepage sees dirty buffer A with reiserfs journal head, pins it proc1: write_ordered_buffers frees the journal head on buffer A At this point, buffer A stays dirty forever Signed-off-by: Chris Mason <mason@suse.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
parent
ec191574b9
commit
d62b1b87a7
|
@ -2743,6 +2743,7 @@ static int invalidatepage_can_drop(struct inode *inode, struct buffer_head *bh)
|
|||
int ret = 1;
|
||||
struct reiserfs_journal *j = SB_JOURNAL(inode->i_sb);
|
||||
|
||||
lock_buffer(bh);
|
||||
spin_lock(&j->j_dirty_buffers_lock);
|
||||
if (!buffer_mapped(bh)) {
|
||||
goto free_jh;
|
||||
|
@ -2758,7 +2759,7 @@ static int invalidatepage_can_drop(struct inode *inode, struct buffer_head *bh)
|
|||
if (buffer_journaled(bh) || buffer_journal_dirty(bh)) {
|
||||
ret = 0;
|
||||
}
|
||||
} else if (buffer_dirty(bh) || buffer_locked(bh)) {
|
||||
} else if (buffer_dirty(bh)) {
|
||||
struct reiserfs_journal_list *jl;
|
||||
struct reiserfs_jh *jh = bh->b_private;
|
||||
|
||||
|
@ -2784,6 +2785,7 @@ static int invalidatepage_can_drop(struct inode *inode, struct buffer_head *bh)
|
|||
reiserfs_free_jh(bh);
|
||||
}
|
||||
spin_unlock(&j->j_dirty_buffers_lock);
|
||||
unlock_buffer(bh);
|
||||
return ret;
|
||||
}
|
||||
|
||||
|
|
|
@ -877,6 +877,19 @@ static int write_ordered_buffers(spinlock_t * lock,
|
|||
if (!buffer_uptodate(bh)) {
|
||||
ret = -EIO;
|
||||
}
|
||||
/* ugly interaction with invalidatepage here.
|
||||
* reiserfs_invalidate_page will pin any buffer that has a valid
|
||||
* journal head from an older transaction. If someone else sets
|
||||
* our buffer dirty after we write it in the first loop, and
|
||||
* then someone truncates the page away, nobody will ever write
|
||||
* the buffer. We're safe if we write the page one last time
|
||||
* after freeing the journal header.
|
||||
*/
|
||||
if (buffer_dirty(bh) && unlikely(bh->b_page->mapping == NULL)) {
|
||||
spin_unlock(lock);
|
||||
ll_rw_block(WRITE, 1, &bh);
|
||||
spin_lock(lock);
|
||||
}
|
||||
put_bh(bh);
|
||||
cond_resched_lock(lock);
|
||||
}
|
||||
|
|
Loading…
Reference in a new issue