[GFS2] Fix for mmap() bug in readpage
Fix for Red Hat bz 205307. Don't need to lock in readpage if
the higher level code has already grabbed the lock.
Signed-off-by: Russell Cattelan <cattelan@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
diff --git a/fs/gfs2/ops_address.c b/fs/gfs2/ops_address.c
index 6f9ac5e..25d7025 100644
--- a/fs/gfs2/ops_address.c
+++ b/fs/gfs2/ops_address.c
@@ -218,14 +218,16 @@
{
struct gfs2_inode *ip = GFS2_I(page->mapping->host);
struct gfs2_sbd *sdp = GFS2_SB(page->mapping->host);
+ struct gfs2_file *gf = NULL;
struct gfs2_holder gh;
int error;
int do_unlock = 0;
if (likely(file != &gfs2_internal_file_sentinel)) {
if (file) {
- struct gfs2_file *gf = file->private_data;
+ gf = file->private_data;
if (test_bit(GFF_EXLOCK, &gf->f_flags))
+ /* gfs2_sharewrite_nopage has grabbed the ip->i_gl already */
goto skip_lock;
}
gfs2_holder_init(ip->i_gl, LM_ST_SHARED, GL_ATIME|GL_AOP, &gh);
@@ -245,7 +247,8 @@
if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
error = -EIO;
- if (file != &gfs2_internal_file_sentinel) {
+ if (gf && !test_bit(GFF_EXLOCK, &gf->f_flags) &&
+ file != &gfs2_internal_file_sentinel) {
gfs2_glock_dq_m(1, &gh);
gfs2_holder_uninit(&gh);
}