ceph: use i_release_count to indicate dir's completeness

Current ceph code tracks directory's completeness in two places.
ceph_readdir() checks i_release_count to decide if it can set the
I_COMPLETE flag in i_ceph_flags. All other places check the I_COMPLETE
flag. This indirection introduces locking complexity.

This patch adds a new variable i_complete_count to ceph_inode_info.
Set i_release_count's value to it when marking a directory complete.
By comparing the two variables, we know if a directory is complete

Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>

1 files changed, 13 insertions, 12 deletions

diff --git a/fs/ceph/dir.c b/fs/ceph/dir.c
index 0c369ac62c07..f02d82b7933e 100644
--- a/fs/ceph/dir.c
+++ b/fs/ceph/dir.c
@@ -107,7 +107,7 @@ static unsigned fpos_off(loff_t p)
  * falling back to a "normal" sync readdir if any dentries in the dir
  * are dropped.
  *
- * I_COMPLETE tells indicates we have all dentries in the dir.  It is
+ * Complete dir indicates that we have all dentries in the dir.  It is
  * defined IFF we hold CEPH_CAP_FILE_SHARED (which will be revoked by
  * the MDS if/when the directory is modified).
  */
@@ -198,8 +198,8 @@ more:
         filp->f_pos++;
 
         /* make sure a dentry wasn't dropped while we didn't have parent lock */
-        if (!ceph_i_test(dir, CEPH_I_COMPLETE)) {
-                dout(" lost I_COMPLETE on %p; falling back to mds\n", dir);
+        if (!ceph_dir_is_complete(dir)) {
+                dout(" lost dir complete on %p; falling back to mds\n", dir);
                 err = -EAGAIN;
                 goto out;
         }
@@ -258,7 +258,7 @@ static int ceph_readdir(struct file *filp, void *dirent, filldir_t filldir)
         if (filp->f_pos == 0) {
                 /* note dir version at start of readdir so we can tell
                  * if any dentries get dropped */
-                fi->dir_release_count = ci->i_release_count;
+                fi->dir_release_count = atomic_read(&ci->i_release_count);
 
                 dout("readdir off 0 -> '.'\n");
                 if (filldir(dirent, ".", 1, ceph_make_fpos(0, 0),
@@ -284,7 +284,7 @@ static int ceph_readdir(struct file *filp, void *dirent, filldir_t filldir)
         if ((filp->f_pos == 2 || fi->dentry) &&
             !ceph_test_mount_opt(fsc, NOASYNCREADDIR) &&
             ceph_snap(inode) != CEPH_SNAPDIR &&
-            (ci->i_ceph_flags & CEPH_I_COMPLETE) &&
+            __ceph_dir_is_complete(ci) &&
             __ceph_caps_issued_mask(ci, CEPH_CAP_FILE_SHARED, 1)) {
                 spin_unlock(&ci->i_ceph_lock);
                 err = __dcache_readdir(filp, dirent, filldir);
@@ -350,7 +350,8 @@ more:
 
                 if (!req->r_did_prepopulate) {
                         dout("readdir !did_prepopulate");
-                        fi->dir_release_count--;    /* preclude I_COMPLETE */
+                        /* preclude from marking dir complete */
+                        fi->dir_release_count--;
                 }
 
                 /* note next offset and last dentry name */
@@ -428,9 +429,9 @@ more:
          * the complete dir contents in our cache.
          */
         spin_lock(&ci->i_ceph_lock);
-        if (ci->i_release_count == fi->dir_release_count) {
+        if (atomic_read(&ci->i_release_count) == fi->dir_release_count) {
                 dout(" marking %p complete\n", inode);
-                ci->i_ceph_flags |= CEPH_I_COMPLETE;
+                __ceph_dir_set_complete(ci, fi->dir_release_count);
                 ci->i_max_offset = filp->f_pos;
         }
         spin_unlock(&ci->i_ceph_lock);
@@ -605,7 +606,7 @@ static struct dentry *ceph_lookup(struct inode *dir, struct dentry *dentry,
                             fsc->mount_options->snapdir_name,
                             dentry->d_name.len) &&
                     !is_root_ceph_dentry(dir, dentry) &&
-                    (ci->i_ceph_flags & CEPH_I_COMPLETE) &&
+                    __ceph_dir_is_complete(ci) &&
                     (__ceph_caps_issued_mask(ci, CEPH_CAP_FILE_SHARED, 1))) {
                         spin_unlock(&ci->i_ceph_lock);
                         dout(" dir %p complete, -ENOENT\n", dir);
@@ -909,7 +910,7 @@ static int ceph_rename(struct inode *old_dir, struct dentry *old_dentry,
                  */
 
                 /* d_move screws up d_subdirs order */
-                ceph_i_clear(new_dir, CEPH_I_COMPLETE);
+                ceph_dir_clear_complete(new_dir);
 
                 d_move(old_dentry, new_dentry);
 
@@ -1079,7 +1080,7 @@ static void ceph_d_prune(struct dentry *dentry)
         if (IS_ROOT(dentry))
                 return;
 
-        /* if we are not hashed, we don't affect I_COMPLETE */
+        /* if we are not hashed, we don't affect dir's completeness */
         if (d_unhashed(dentry))
                 return;
 
@@ -1087,7 +1088,7 @@ static void ceph_d_prune(struct dentry *dentry)
          * we hold d_lock, so d_parent is stable, and d_fsdata is never
          * cleared until d_release
          */
-        ceph_i_clear(dentry->d_parent->d_inode, CEPH_I_COMPLETE);
+        ceph_dir_clear_complete(dentry->d_parent->d_inode);
 }
 
 /*