From: Andreas Gruenbacher agruenba@redhat.com
commit 82e938bd5382b322ce81e6cb8fd030987f2da022 upstream.
Commit 20f829999c38 ("gfs2: Rework read and page fault locking") lifted the glock lock taking from the low-level ->readpage and ->readahead address space operations to the higher-level ->read_iter file and ->fault vm operations. The glocks are still taken in LM_ST_SHARED mode only. On filesystems mounted without the noatime option, ->read_iter sometimes needs to update the atime as well, though. Right now, this leads to a failed locking mode assertion in gfs2_dirty_inode.
Fix that by introducing a new update_time inode operation. There, if the glock is held non-exclusively, upgrade it to an exclusive lock.
Reported-by: Alexander Aring aahringo@redhat.com Fixes: 20f829999c38 ("gfs2: Rework read and page fault locking") Cc: stable@vger.kernel.org # v5.8+ Signed-off-by: Andreas Gruenbacher agruenba@redhat.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- fs/gfs2/inode.c | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+)
--- a/fs/gfs2/inode.c +++ b/fs/gfs2/inode.c @@ -2116,6 +2116,25 @@ loff_t gfs2_seek_hole(struct file *file, return vfs_setpos(file, ret, inode->i_sb->s_maxbytes); }
+static int gfs2_update_time(struct inode *inode, struct timespec64 *time, + int flags) +{ + struct gfs2_inode *ip = GFS2_I(inode); + struct gfs2_glock *gl = ip->i_gl; + struct gfs2_holder *gh; + int error; + + gh = gfs2_glock_is_locked_by_me(gl); + if (gh && !gfs2_glock_is_held_excl(gl)) { + gfs2_glock_dq(gh); + gfs2_holder_reinit(LM_ST_EXCLUSIVE, 0, gh); + error = gfs2_glock_nq(gh); + if (error) + return error; + } + return generic_update_time(inode, time, flags); +} + const struct inode_operations gfs2_file_iops = { .permission = gfs2_permission, .setattr = gfs2_setattr, @@ -2124,6 +2143,7 @@ const struct inode_operations gfs2_file_ .fiemap = gfs2_fiemap, .get_acl = gfs2_get_acl, .set_acl = gfs2_set_acl, + .update_time = gfs2_update_time, };
const struct inode_operations gfs2_dir_iops = { @@ -2143,6 +2163,7 @@ const struct inode_operations gfs2_dir_i .fiemap = gfs2_fiemap, .get_acl = gfs2_get_acl, .set_acl = gfs2_set_acl, + .update_time = gfs2_update_time, .atomic_open = gfs2_atomic_open, };