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authorSage Weil <sage@newdream.net>2010-03-01 15:16:56 -0800
committerSage Weil <sage@newdream.net>2010-03-01 15:28:02 -0800
commite9964c102312967a4bc1fd501cb628c4a3b19034 (patch)
tree7bccb0c4e29d94baaf8c30e008ec5aebdccf9c57 /fs
parent7af8f1e4aa86720840d3318e4dc225c3c7e5a6d0 (diff)
downloadop-kernel-dev-e9964c102312967a4bc1fd501cb628c4a3b19034.zip
op-kernel-dev-e9964c102312967a4bc1fd501cb628c4a3b19034.tar.gz
ceph: fix flush_dirty_caps race with caps migration
The flush_dirty_caps() used to loop over the first entry of the cap_dirty dirty list on the assumption that after calling ceph_check_caps() it would be removed from the list. This isn't true for caps that are being migrated between MDSs, where we've received the EXPORT but not the IMPORT. Instead, do a safe list iteration, and pin the next inode on the list via the CEPH_I_NOFLUSH flag. Signed-off-by: Sage Weil <sage@newdream.net>
Diffstat (limited to 'fs')
-rw-r--r--fs/ceph/caps.c45
-rw-r--r--fs/ceph/super.h1
2 files changed, 39 insertions, 7 deletions
diff --git a/fs/ceph/caps.c b/fs/ceph/caps.c
index 295b7e54..8b89b91 100644
--- a/fs/ceph/caps.c
+++ b/fs/ceph/caps.c
@@ -1573,6 +1573,11 @@ retry_locked:
}
ack:
+ if (ci->i_ceph_flags & CEPH_I_NOFLUSH) {
+ dout(" skipping %p I_NOFLUSH set\n", inode);
+ continue;
+ }
+
if (session && session != cap->session) {
dout("oops, wrong session %p mutex\n", session);
mutex_unlock(&session->s_mutex);
@@ -1652,6 +1657,10 @@ static int try_flush_caps(struct inode *inode, struct ceph_mds_session *session,
retry:
spin_lock(&inode->i_lock);
+ if (ci->i_ceph_flags & CEPH_I_NOFLUSH) {
+ dout("try_flush_caps skipping %p I_NOFLUSH set\n", inode);
+ goto out;
+ }
if (ci->i_dirty_caps && ci->i_auth_cap) {
struct ceph_cap *cap = ci->i_auth_cap;
int used = __ceph_caps_used(ci);
@@ -2747,16 +2756,38 @@ void ceph_check_delayed_caps(struct ceph_mds_client *mdsc)
*/
void ceph_flush_dirty_caps(struct ceph_mds_client *mdsc)
{
- struct ceph_inode_info *ci;
- struct inode *inode;
+ struct ceph_inode_info *ci, *nci = NULL;
+ struct inode *inode, *ninode = NULL;
+ struct list_head *p, *n;
dout("flush_dirty_caps\n");
spin_lock(&mdsc->cap_dirty_lock);
- while (!list_empty(&mdsc->cap_dirty)) {
- ci = list_first_entry(&mdsc->cap_dirty,
- struct ceph_inode_info,
- i_dirty_item);
- inode = igrab(&ci->vfs_inode);
+ list_for_each_safe(p, n, &mdsc->cap_dirty) {
+ if (nci) {
+ ci = nci;
+ inode = ninode;
+ ci->i_ceph_flags &= ~CEPH_I_NOFLUSH;
+ dout("flush_dirty_caps inode %p (was next inode)\n",
+ inode);
+ } else {
+ ci = list_entry(p, struct ceph_inode_info,
+ i_dirty_item);
+ inode = igrab(&ci->vfs_inode);
+ BUG_ON(!inode);
+ dout("flush_dirty_caps inode %p\n", inode);
+ }
+ if (n != &mdsc->cap_dirty) {
+ nci = list_entry(n, struct ceph_inode_info,
+ i_dirty_item);
+ ninode = igrab(&nci->vfs_inode);
+ BUG_ON(!ninode);
+ nci->i_ceph_flags |= CEPH_I_NOFLUSH;
+ dout("flush_dirty_caps next inode %p, noflush\n",
+ ninode);
+ } else {
+ nci = NULL;
+ ninode = NULL;
+ }
spin_unlock(&mdsc->cap_dirty_lock);
if (inode) {
ceph_check_caps(ci, CHECK_CAPS_NODELAY|CHECK_CAPS_FLUSH,
diff --git a/fs/ceph/super.h b/fs/ceph/super.h
index ff7aaa3..6a778f2 100644
--- a/fs/ceph/super.h
+++ b/fs/ceph/super.h
@@ -289,6 +289,7 @@ struct ceph_inode_xattrs_info {
#define CEPH_I_COMPLETE 1 /* we have complete directory cached */
#define CEPH_I_NODELAY 4 /* do not delay cap release */
#define CEPH_I_FLUSH 8 /* do not delay flush of dirty metadata */
+#define CEPH_I_NOFLUSH 16 /* do not flush dirty caps */
struct ceph_inode_info {
struct ceph_vino i_vino; /* ceph ino + snap */
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