From 3b8249f6178cb2b68b9d683587797270125cc06a Mon Sep 17 00:00:00 2001 From: Steven Whitehouse Date: Fri, 16 Mar 2007 09:40:31 +0000 Subject: [GFS2] Fix bz 224480 and cleanup glock demotion code This patch prevents the printing of a warning message in cases where the fs is functioning normally by handing off responsibility for unlinked, but still open inodes, to another node for eventual deallocation. Also, there is now an improved system for ensuring that such requests to other nodes do not get lost. The callback on the iopen lock is only ever called when i_nlink == 0 and when a node is unable to deallocate it due to it still being in use on another node. When a node receives the callback therefore, it knows that i_nlink must be zero, so we mark it as such (in gfs2_drop_inode) in order that it will then attempt deallocation of the inode itself. As an additional benefit, queuing a demote request no longer requires a memory allocation. This simplifies the code for dealing with gfs2_holders as it removes one special case. There are two new fields in struct gfs2_glock. gl_demote_state is the state which the remote node has requested and gl_demote_time is the time when the request came in. Both fields are only valid when the GLF_DEMOTE flag is set in gl_flags. Signed-off-by: Steven Whitehouse --- fs/gfs2/ops_super.c | 28 +++++++++++++++++++++++++++- 1 file changed, 27 insertions(+), 1 deletion(-) (limited to 'fs/gfs2/ops_super.c') diff --git a/fs/gfs2/ops_super.c b/fs/gfs2/ops_super.c index b89999d3a76..485ce3d4992 100644 --- a/fs/gfs2/ops_super.c +++ b/fs/gfs2/ops_super.c @@ -283,6 +283,31 @@ static int gfs2_remount_fs(struct super_block *sb, int *flags, char *data) return error; } +/** + * gfs2_drop_inode - Drop an inode (test for remote unlink) + * @inode: The inode to drop + * + * If we've received a callback on an iopen lock then its because a + * remote node tried to deallocate the inode but failed due to this node + * still having the inode open. Here we mark the link count zero + * since we know that it must have reached zero if the GLF_DEMOTE flag + * is set on the iopen glock. If we didn't do a disk read since the + * remote node removed the final link then we might otherwise miss + * this event. This check ensures that this node will deallocate the + * inode's blocks, or alternatively pass the baton on to another + * node for later deallocation. + */ +static void gfs2_drop_inode(struct inode *inode) +{ + if (inode->i_private && inode->i_nlink) { + struct gfs2_inode *ip = GFS2_I(inode); + struct gfs2_glock *gl = ip->i_iopen_gh.gh_gl; + if (gl && test_bit(GLF_DEMOTE, &gl->gl_flags)) + clear_nlink(inode); + } + generic_drop_inode(inode); +} + /** * gfs2_clear_inode - Deallocate an inode when VFS is done with it * @inode: The VFS inode @@ -441,7 +466,7 @@ out_unlock: out_uninit: gfs2_holder_uninit(&ip->i_iopen_gh); gfs2_glock_dq_uninit(&gh); - if (error) + if (error && error != GLR_TRYFAILED) fs_warn(sdp, "gfs2_delete_inode: %d\n", error); out: truncate_inode_pages(&inode->i_data, 0); @@ -481,6 +506,7 @@ const struct super_operations gfs2_super_ops = { .statfs = gfs2_statfs, .remount_fs = gfs2_remount_fs, .clear_inode = gfs2_clear_inode, + .drop_inode = gfs2_drop_inode, .show_options = gfs2_show_options, }; -- cgit v1.2.3-18-g5258