From f7b1aa69be138ad9d7d3f31fa56f4c9407f56b6a Mon Sep 17 00:00:00 2001 From: Jan Kara Date: Mon, 20 Jul 2009 12:12:36 +0200 Subject: ocfs2: Fix deadlock on umount In commit ea455f8ab68338ba69f5d3362b342c115bea8e13, we moved the dentry lock put process into ocfs2_wq. This causes problems during umount because ocfs2_wq can drop references to inodes while they are being invalidated by invalidate_inodes() causing all sorts of nasty things (invalidate_inodes() ending in an infinite loop, "Busy inodes after umount" messages etc.). We fix the problem by stopping ocfs2_wq from doing any further releasing of inode references on the superblock being unmounted, wait until it finishes the current round of releasing and finally cleaning up all the references in dentry_lock_list from ocfs2_put_super(). The issue was tracked down by Tao Ma . Signed-off-by: Jan Kara Signed-off-by: Joel Becker --- fs/ocfs2/dcache.c | 35 +++++++++++++++++++++++++++-------- 1 file changed, 27 insertions(+), 8 deletions(-) (limited to 'fs/ocfs2/dcache.c') diff --git a/fs/ocfs2/dcache.c b/fs/ocfs2/dcache.c index b574431a031d..2f28b7de2c8d 100644 --- a/fs/ocfs2/dcache.c +++ b/fs/ocfs2/dcache.c @@ -310,22 +310,19 @@ out_attach: return ret; } -static DEFINE_SPINLOCK(dentry_list_lock); +DEFINE_SPINLOCK(dentry_list_lock); /* We limit the number of dentry locks to drop in one go. We have * this limit so that we don't starve other users of ocfs2_wq. */ #define DL_INODE_DROP_COUNT 64 /* Drop inode references from dentry locks */ -void ocfs2_drop_dl_inodes(struct work_struct *work) +static void __ocfs2_drop_dl_inodes(struct ocfs2_super *osb, int drop_count) { - struct ocfs2_super *osb = container_of(work, struct ocfs2_super, - dentry_lock_work); struct ocfs2_dentry_lock *dl; - int drop_count = DL_INODE_DROP_COUNT; spin_lock(&dentry_list_lock); - while (osb->dentry_lock_list && drop_count--) { + while (osb->dentry_lock_list && (drop_count < 0 || drop_count--)) { dl = osb->dentry_lock_list; osb->dentry_lock_list = dl->dl_next; spin_unlock(&dentry_list_lock); @@ -333,11 +330,32 @@ void ocfs2_drop_dl_inodes(struct work_struct *work) kfree(dl); spin_lock(&dentry_list_lock); } - if (osb->dentry_lock_list) + spin_unlock(&dentry_list_lock); +} + +void ocfs2_drop_dl_inodes(struct work_struct *work) +{ + struct ocfs2_super *osb = container_of(work, struct ocfs2_super, + dentry_lock_work); + + __ocfs2_drop_dl_inodes(osb, DL_INODE_DROP_COUNT); + /* + * Don't queue dropping if umount is in progress. We flush the + * list in ocfs2_dismount_volume + */ + spin_lock(&dentry_list_lock); + if (osb->dentry_lock_list && + !ocfs2_test_osb_flag(osb, OCFS2_OSB_DROP_DENTRY_LOCK_IMMED)) queue_work(ocfs2_wq, &osb->dentry_lock_work); spin_unlock(&dentry_list_lock); } +/* Flush the whole work queue */ +void ocfs2_drop_all_dl_inodes(struct ocfs2_super *osb) +{ + __ocfs2_drop_dl_inodes(osb, -1); +} + /* * ocfs2_dentry_iput() and friends. * @@ -368,7 +386,8 @@ static void ocfs2_drop_dentry_lock(struct ocfs2_super *osb, /* We leave dropping of inode reference to ocfs2_wq as that can * possibly lead to inode deletion which gets tricky */ spin_lock(&dentry_list_lock); - if (!osb->dentry_lock_list) + if (!osb->dentry_lock_list && + !ocfs2_test_osb_flag(osb, OCFS2_OSB_DROP_DENTRY_LOCK_IMMED)) queue_work(ocfs2_wq, &osb->dentry_lock_work); dl->dl_next = osb->dentry_lock_list; osb->dentry_lock_list = dl; -- cgit v1.2.3 From a1b08e75dff3dc18a88444803753e667bb1d126e Mon Sep 17 00:00:00 2001 From: Tao Ma Date: Thu, 27 Aug 2009 14:46:56 +0800 Subject: ocfs2: invalidate dentry if its dentry_lock isn't initialized. In commit a5a0a630922a2f6a774b6dac19f70cb5abd86bb0, when ocfs2_attch_dentry_lock fails, we call an extra iput and reset dentry->d_fsdata to NULL. This resolve a bug, but it isn't completed and the dentry is still there. When we want to use it again, ocfs2_dentry_revalidate doesn't catch it and return true. That make future ocfs2_dentry_lock panic out. One bug is http://oss.oracle.com/bugzilla/show_bug.cgi?id=1162. The resolution is to add a check for dentry->d_fsdata in revalidate process and return false if dentry->d_fsdata is NULL, so that a new ocfs2_lookup will be called again. Signed-off-by: Tao Ma Signed-off-by: Joel Becker --- fs/ocfs2/dcache.c | 11 +++++++++++ 1 file changed, 11 insertions(+) (limited to 'fs/ocfs2/dcache.c') diff --git a/fs/ocfs2/dcache.c b/fs/ocfs2/dcache.c index 2f28b7de2c8d..b4957c7d9fe2 100644 --- a/fs/ocfs2/dcache.c +++ b/fs/ocfs2/dcache.c @@ -85,6 +85,17 @@ static int ocfs2_dentry_revalidate(struct dentry *dentry, goto bail; } + /* + * If the last lookup failed to create dentry lock, let us + * redo it. + */ + if (!dentry->d_fsdata) { + mlog(0, "Inode %llu doesn't have dentry lock, " + "returning false\n", + (unsigned long long)OCFS2_I(inode)->ip_blkno); + goto bail; + } + ret = 1; bail: -- cgit v1.2.3