lk/linux-kernel-test
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

[PATCH] resierfs: fix reiserfs_invalidatepage race against data=ordered

Browse Source 
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:
Chris Mason
2006-02-01 03:06:47 -08:00
committed by Linus Torvalds
parent ec191574b9
commit d62b1b87a7
2 changed files with 16 additions and 1 deletions
Download Patch File Download Diff File Expand all files Collapse all files

4
fs/reiserfs/inode.c
View File

@@ -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;
}