From acf7e2444acfaf4c8540603b76d71010eea3fc24 Mon Sep 17 00:00:00 2001 From: Steven Whitehouse Date: Tue, 8 Sep 2009 18:00:30 +0100 Subject: GFS2: Be extra careful about deallocating inodes There is a potential race in the inode deallocation code if two nodes try to deallocate the same inode at the same time. Most of the issue is solved by the iopen locking. There is still a small window which is not covered by the iopen lock. This patches fixes that and also makes the deallocation code more robust in the face of any errors in the rgrp bitmaps, or erroneous iopen callbacks from other nodes. This does introduce one extra disk read, but that is generally not an issue since its the same block that must be written to later in the deallocation process. The total disk accesses therefore stay the same, Signed-off-by: Steven Whitehouse --- fs/gfs2/export.c | 36 ++++-------------------------------- 1 file changed, 4 insertions(+), 32 deletions(-) (limited to 'fs/gfs2/export.c') diff --git a/fs/gfs2/export.c b/fs/gfs2/export.c index 9200ef221716..d15876e9aa26 100644 --- a/fs/gfs2/export.c +++ b/fs/gfs2/export.c @@ -143,17 +143,14 @@ static struct dentry *gfs2_get_parent(struct dentry *child) } static struct dentry *gfs2_get_dentry(struct super_block *sb, - struct gfs2_inum_host *inum) + struct gfs2_inum_host *inum) { struct gfs2_sbd *sdp = sb->s_fs_info; - struct gfs2_holder i_gh, ri_gh, rgd_gh; - struct gfs2_rgrpd *rgd; + struct gfs2_holder i_gh; struct inode *inode; struct dentry *dentry; int error; - /* System files? */ - inode = gfs2_ilookup(sb, inum->no_addr); if (inode) { if (GFS2_I(inode)->i_no_formal_ino != inum->no_formal_ino) { @@ -168,29 +165,11 @@ static struct dentry *gfs2_get_dentry(struct super_block *sb, if (error) return ERR_PTR(error); - error = gfs2_rindex_hold(sdp, &ri_gh); + error = gfs2_check_blk_type(sdp, inum->no_addr, GFS2_BLKST_DINODE); if (error) goto fail; - error = -EINVAL; - rgd = gfs2_blk2rgrpd(sdp, inum->no_addr); - if (!rgd) - goto fail_rindex; - - error = gfs2_glock_nq_init(rgd->rd_gl, LM_ST_SHARED, 0, &rgd_gh); - if (error) - goto fail_rindex; - - error = -ESTALE; - if (gfs2_get_block_type(rgd, inum->no_addr) != GFS2_BLKST_DINODE) - goto fail_rgd; - - gfs2_glock_dq_uninit(&rgd_gh); - gfs2_glock_dq_uninit(&ri_gh); - - inode = gfs2_inode_lookup(sb, DT_UNKNOWN, - inum->no_addr, - 0, 0); + inode = gfs2_inode_lookup(sb, DT_UNKNOWN, inum->no_addr, 0, 0); if (IS_ERR(inode)) { error = PTR_ERR(inode); goto fail; @@ -224,13 +203,6 @@ out_inode: if (!IS_ERR(dentry)) dentry->d_op = &gfs2_dops; return dentry; - -fail_rgd: - gfs2_glock_dq_uninit(&rgd_gh); - -fail_rindex: - gfs2_glock_dq_uninit(&ri_gh); - fail: gfs2_glock_dq_uninit(&i_gh); return ERR_PTR(error); -- cgit v1.2.1