gfs2: Upgrade shared glocks for atime updates (82e938bd) · Commits · 戴 / test

Commit ("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: ("gfs2: Rework read and page fault locking") Cc: stable@vger.kernel.org # v5.8+ Signed-off-by:

Andreas Gruenbacher <agruenba@redhat.com>

fs/gfs2/inode.c

+21 −0

Original line number	Diff line number	Diff line
		@@ -2116,6 +2116,25 @@ loff_t gfs2_seek_hole(struct file *file, loff_t offset)
		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_iops = {
		.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_iops = {
		.fiemap = gfs2_fiemap,
		.get_acl = gfs2_get_acl,
		.set_acl = gfs2_set_acl,
		.update_time = gfs2_update_time,
		.atomic_open = gfs2_atomic_open,
		};

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