Merge branch 'for-linus-4.8' of git://git.kernel.org/pub/scm/linux/kernel/git/mason...

[cascardo/linux.git] / fs / ceph / dir.c

diff --git a/fs/ceph/dir.c b/fs/ceph/dir.c
index 6e0fedf..c64a0b7 100644 (file)
--- a/fs/ceph/dir.c
+++ b/fs/ceph/dir.c
@@ -59,7 +59,7 @@ int ceph_init_dentry(struct dentry *dentry)
 
        di->dentry = dentry;
        di->lease_session = NULL;
-       dentry->d_time = jiffies;
+       di->time = jiffies;
        /* avoid reordering d_fsdata setup so that the check above is safe */
        smp_mb();
        dentry->d_fsdata = di;
@@ -1124,7 +1124,7 @@ static int ceph_rename(struct inode *old_dir, struct dentry *old_dentry,
 void ceph_invalidate_dentry_lease(struct dentry *dentry)
 {
        spin_lock(&dentry->d_lock);
-       dentry->d_time = jiffies;
+       ceph_dentry(dentry)->time = jiffies;
        ceph_dentry(dentry)->lease_shared_gen = 0;
        spin_unlock(&dentry->d_lock);
 }
@@ -1133,7 +1133,8 @@ void ceph_invalidate_dentry_lease(struct dentry *dentry)
  * Check if dentry lease is valid.  If not, delete the lease.  Try to
  * renew if the least is more than half up.
  */
-static int dentry_lease_is_valid(struct dentry *dentry)
+static int dentry_lease_is_valid(struct dentry *dentry, unsigned int flags,
+                                struct inode *dir)
 {
        struct ceph_dentry_info *di;
        struct ceph_mds_session *s;
@@ -1141,12 +1142,11 @@ static int dentry_lease_is_valid(struct dentry *dentry)
        u32 gen;
        unsigned long ttl;
        struct ceph_mds_session *session = NULL;
-       struct inode *dir = NULL;
        u32 seq = 0;
 
        spin_lock(&dentry->d_lock);
        di = ceph_dentry(dentry);
-       if (di->lease_session) {
+       if (di && di->lease_session) {
                s = di->lease_session;
                spin_lock(&s->s_gen_ttl_lock);
                gen = s->s_cap_gen;
@@ -1154,17 +1154,24 @@ static int dentry_lease_is_valid(struct dentry *dentry)
                spin_unlock(&s->s_gen_ttl_lock);
 
                if (di->lease_gen == gen &&
-                   time_before(jiffies, dentry->d_time) &&
+                   time_before(jiffies, di->time) &&
                    time_before(jiffies, ttl)) {
                        valid = 1;
                        if (di->lease_renew_after &&
                            time_after(jiffies, di->lease_renew_after)) {
-                               /* we should renew */
-                               dir = d_inode(dentry->d_parent);
-                               session = ceph_get_mds_session(s);
-                               seq = di->lease_seq;
-                               di->lease_renew_after = 0;
-                               di->lease_renew_from = jiffies;
+                               /*
+                                * We should renew. If we're in RCU walk mode
+                                * though, we can't do that so just return
+                                * -ECHILD.
+                                */
+                               if (flags & LOOKUP_RCU) {
+                                       valid = -ECHILD;
+                               } else {
+                                       session = ceph_get_mds_session(s);
+                                       seq = di->lease_seq;
+                                       di->lease_renew_after = 0;
+                                       di->lease_renew_from = jiffies;
+                               }
                        }
                }
        }
@@ -1207,15 +1214,19 @@ static int ceph_d_revalidate(struct dentry *dentry, unsigned int flags)
        struct dentry *parent;
        struct inode *dir;
 
-       if (flags & LOOKUP_RCU)
-               return -ECHILD;
+       if (flags & LOOKUP_RCU) {
+               parent = ACCESS_ONCE(dentry->d_parent);
+               dir = d_inode_rcu(parent);
+               if (!dir)
+                       return -ECHILD;
+       } else {
+               parent = dget_parent(dentry);
+               dir = d_inode(parent);
+       }
 
        dout("d_revalidate %p '%pd' inode %p offset %lld\n", dentry,
             dentry, d_inode(dentry), ceph_dentry(dentry)->offset);
 
-       parent = dget_parent(dentry);
-       dir = d_inode(parent);
-
        /* always trust cached snapped dentries, snapdir dentry */
        if (ceph_snap(dir) != CEPH_NOSNAP) {
                dout("d_revalidate %p '%pd' inode %p is SNAPPED\n", dentry,
@@ -1224,12 +1235,16 @@ static int ceph_d_revalidate(struct dentry *dentry, unsigned int flags)
        } else if (d_really_is_positive(dentry) &&
                   ceph_snap(d_inode(dentry)) == CEPH_SNAPDIR) {
                valid = 1;
-       } else if (dentry_lease_is_valid(dentry) ||
-                  dir_lease_is_valid(dir, dentry)) {
-               if (d_really_is_positive(dentry))
-                       valid = ceph_is_any_caps(d_inode(dentry));
-               else
-                       valid = 1;
+       } else {
+               valid = dentry_lease_is_valid(dentry, flags, dir);
+               if (valid == -ECHILD)
+                       return valid;
+               if (valid || dir_lease_is_valid(dir, dentry)) {
+                       if (d_really_is_positive(dentry))
+                               valid = ceph_is_any_caps(d_inode(dentry));
+                       else
+                               valid = 1;
+               }
        }
 
        if (!valid) {
@@ -1238,6 +1253,9 @@ static int ceph_d_revalidate(struct dentry *dentry, unsigned int flags)
                struct ceph_mds_request *req;
                int op, mask, err;
 
+               if (flags & LOOKUP_RCU)
+                       return -ECHILD;
+
                op = ceph_snap(dir) == CEPH_SNAPDIR ?
                        CEPH_MDS_OP_LOOKUPSNAP : CEPH_MDS_OP_LOOKUP;
                req = ceph_mdsc_create_request(mdsc, op, USE_ANY_MDS);
@@ -1273,7 +1291,8 @@ static int ceph_d_revalidate(struct dentry *dentry, unsigned int flags)
                ceph_dir_clear_complete(dir);
        }
 
-       dput(parent);
+       if (!(flags & LOOKUP_RCU))
+               dput(parent);
        return valid;
 }
 
@@ -1286,10 +1305,14 @@ static void ceph_d_release(struct dentry *dentry)
 
        dout("d_release %p\n", dentry);
        ceph_dentry_lru_del(dentry);
+
+       spin_lock(&dentry->d_lock);
+       dentry->d_fsdata = NULL;
+       spin_unlock(&dentry->d_lock);
+
        if (di->lease_session)
                ceph_put_mds_session(di->lease_session);
        kmem_cache_free(ceph_dentry_cachep, di);
-       dentry->d_fsdata = NULL;
 }
 
 static int ceph_snapdir_d_revalidate(struct dentry *dentry,