ceph: use i_ceph_lock instead of i_lock
We have been using i_lock to protect all kinds of data structures in the
ceph_inode_info struct, including lists of inodes that we need to iterate
over while avoiding races with inode destruction. That requires grabbing
a reference to the inode with the list lock protected, but igrab() now
takes i_lock to check the inode flags.
Changing the list lock ordering would be a painful process.
However, using a ceph-specific i_ceph_lock in the ceph inode instead of
i_lock is a simple mechanical change and avoids the ordering constraints
imposed by igrab().
Reported-by: Amon Ott <a.ott@m-privacy.de>
Signed-off-by: Sage Weil <sage@newdream.net>
diff --git a/fs/ceph/dir.c b/fs/ceph/dir.c
index bca3948..3eeb976 100644
--- a/fs/ceph/dir.c
+++ b/fs/ceph/dir.c
@@ -281,18 +281,18 @@
}
/* can we use the dcache? */
- spin_lock(&inode->i_lock);
+ spin_lock(&ci->i_ceph_lock);
if ((filp->f_pos == 2 || fi->dentry) &&
!ceph_test_mount_opt(fsc, NOASYNCREADDIR) &&
ceph_snap(inode) != CEPH_SNAPDIR &&
ceph_dir_test_complete(inode) &&
__ceph_caps_issued_mask(ci, CEPH_CAP_FILE_SHARED, 1)) {
- spin_unlock(&inode->i_lock);
+ spin_unlock(&ci->i_ceph_lock);
err = __dcache_readdir(filp, dirent, filldir);
if (err != -EAGAIN)
return err;
} else {
- spin_unlock(&inode->i_lock);
+ spin_unlock(&ci->i_ceph_lock);
}
if (fi->dentry) {
err = note_last_dentry(fi, fi->dentry->d_name.name,
@@ -428,12 +428,12 @@
* were released during the whole readdir, and we should have
* the complete dir contents in our cache.
*/
- spin_lock(&inode->i_lock);
+ spin_lock(&ci->i_ceph_lock);
if (ci->i_release_count == fi->dir_release_count) {
ceph_dir_set_complete(inode);
ci->i_max_offset = filp->f_pos;
}
- spin_unlock(&inode->i_lock);
+ spin_unlock(&ci->i_ceph_lock);
dout("readdir %p filp %p done.\n", inode, filp);
return 0;
@@ -607,7 +607,7 @@
struct ceph_inode_info *ci = ceph_inode(dir);
struct ceph_dentry_info *di = ceph_dentry(dentry);
- spin_lock(&dir->i_lock);
+ spin_lock(&ci->i_ceph_lock);
dout(" dir %p flags are %d\n", dir, ci->i_ceph_flags);
if (strncmp(dentry->d_name.name,
fsc->mount_options->snapdir_name,
@@ -615,13 +615,13 @@
!is_root_ceph_dentry(dir, dentry) &&
ceph_dir_test_complete(dir) &&
(__ceph_caps_issued_mask(ci, CEPH_CAP_FILE_SHARED, 1))) {
- spin_unlock(&dir->i_lock);
+ spin_unlock(&ci->i_ceph_lock);
dout(" dir %p complete, -ENOENT\n", dir);
d_add(dentry, NULL);
di->lease_shared_gen = ci->i_shared_gen;
return NULL;
}
- spin_unlock(&dir->i_lock);
+ spin_unlock(&ci->i_ceph_lock);
}
op = ceph_snap(dir) == CEPH_SNAPDIR ?
@@ -841,12 +841,12 @@
struct ceph_inode_info *ci = ceph_inode(inode);
int drop = CEPH_CAP_LINK_SHARED | CEPH_CAP_LINK_EXCL;
- spin_lock(&inode->i_lock);
+ spin_lock(&ci->i_ceph_lock);
if (inode->i_nlink == 1) {
drop |= ~(__ceph_caps_wanted(ci) | CEPH_CAP_PIN);
ci->i_ceph_flags |= CEPH_I_NODELAY;
}
- spin_unlock(&inode->i_lock);
+ spin_unlock(&ci->i_ceph_lock);
return drop;
}
@@ -1015,10 +1015,10 @@
struct ceph_dentry_info *di = ceph_dentry(dentry);
int valid = 0;
- spin_lock(&dir->i_lock);
+ spin_lock(&ci->i_ceph_lock);
if (ci->i_shared_gen == di->lease_shared_gen)
valid = __ceph_caps_issued_mask(ci, CEPH_CAP_FILE_SHARED, 1);
- spin_unlock(&dir->i_lock);
+ spin_unlock(&ci->i_ceph_lock);
dout("dir_lease_is_valid dir %p v%u dentry %p v%u = %d\n",
dir, (unsigned)ci->i_shared_gen, dentry,
(unsigned)di->lease_shared_gen, valid);