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| author | Abhijith Das <adas@redhat.com> | 2010-07-04 01:33:24 -0400 |
|---|---|---|
| committer | Steven Whitehouse <swhiteho@redhat.com> | 2010-07-15 09:07:16 +0100 |
| commit | 8b4216018bdbfbb1b76150d202b15ee68c38e991 (patch) | |
| tree | c13bd1db68ca135b6362ee8e67e558fe87bfb93c /fs/gfs2/quota.c | |
| parent | b1becbdee776b447f203aa8da9a40488d5a75e1d (diff) | |
| download | linux-8b4216018bdbfbb1b76150d202b15ee68c38e991.tar.bz2 | |
GFS2: BUG in gfs2_adjust_quota
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>
Diffstat (limited to 'fs/gfs2/quota.c')
| -rw-r--r-- | fs/gfs2/quota.c | 8 |
1 files changed, 3 insertions, 5 deletions
diff --git a/fs/gfs2/quota.c b/fs/gfs2/quota.c index 49667d68769e..b256d6f24288 100644 --- a/fs/gfs2/quota.c +++ b/fs/gfs2/quota.c @@ -694,10 +694,8 @@ 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)) @@ -723,7 +721,7 @@ 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; |