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authorAbhijith Das <adas@redhat.com>2010-07-04 01:33:24 -0400
committerGreg Kroah-Hartman <gregkh@suse.de>2011-05-09 15:55:12 -0700
commit0682ff5eb416867ba128d8e00b05607448d936a6 (patch)
treebf367496e9e3ddc881a5422ec54af1a6ecd125d8 /fs
parenta03167aeee8e456241345b8d6d18b4a64f511a60 (diff)
GFS2: BUG in gfs2_adjust_quota
commit 8b4216018bdbfbb1b76150d202b15ee68c38e991 upstream. HighMem pages on i686 do not get mapped to the buffer_heads and this was causing a NULL pointer dereference when we were trying to memset page buffers to zero. We now use zero_user() that kmaps the page and directly manipulates page data. This patch also fixes a boundary condition that was incorrect. Signed-off-by: Abhi Das <adas@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com> [Adjusted to apply to 2.6.32 by dann frazier <dannf@debian.org>] Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'fs')
-rw-r--r--fs/gfs2/quota.c8
1 files changed, 3 insertions, 5 deletions
diff --git a/fs/gfs2/quota.c b/fs/gfs2/quota.c
index 59c5c98b364d..37af9a980e4d 100644
--- a/fs/gfs2/quota.c
+++ b/fs/gfs2/quota.c
@@ -679,10 +679,8 @@ get_a_page:
if (!buffer_mapped(bh))
goto unlock_out;
/* If it's a newly allocated disk block for quota, zero it */
- if (buffer_new(bh)) {
- memset(bh->b_data, 0, bh->b_size);
- set_buffer_uptodate(bh);
- }
+ if (buffer_new(bh))
+ zero_user(page, pos - blocksize, bh->b_size);
}
if (PageUptodate(page))
@@ -708,7 +706,7 @@ get_a_page:
/* If quota straddles page boundary, we need to update the rest of the
* quota at the beginning of the next page */
- if (offset != 0) { /* first page, offset is closer to PAGE_CACHE_SIZE */
+ if ((offset + sizeof(struct gfs2_quota)) > PAGE_CACHE_SIZE) {
ptr = ptr + nbytes;
nbytes = sizeof(struct gfs2_quota) - nbytes;
offset = 0;