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, 20 insertions, 22 deletions

diff --git a/fs/ceph/super.h b/fs/ceph/super.h
index a04eda714df4..8696be2ff679 100644
--- a/fs/ceph/super.h
+++ b/fs/ceph/super.h
@@ -244,7 +244,8 @@ struct ceph_inode_info {
         u32 i_time_warp_seq;
 
         unsigned i_ceph_flags;
-        unsigned long i_release_count;
+        atomic_t i_release_count;
+        atomic_t i_complete_count;
 
         struct ceph_dir_layout i_dir_layout;
         struct ceph_file_layout i_layout;
@@ -254,7 +255,7 @@ struct ceph_inode_info {
         struct timespec i_rctime;
         u64 i_rbytes, i_rfiles, i_rsubdirs;
         u64 i_files, i_subdirs;
-        u64 i_max_offset;  /* largest readdir offset, set with I_COMPLETE */
+        u64 i_max_offset;  /* largest readdir offset, set with complete dir */
 
         struct rb_root i_fragtree;
         struct mutex i_fragtree_mutex;
@@ -419,38 +420,35 @@ static inline struct inode *ceph_find_inode(struct super_block *sb,
 /*
  * Ceph inode.
  */
-#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 */
 
-static inline void ceph_i_clear(struct inode *inode, unsigned mask)
+static inline void __ceph_dir_set_complete(struct ceph_inode_info *ci,
+                                           int release_count)
 {
-        struct ceph_inode_info *ci = ceph_inode(inode);
-
-        spin_lock(&ci->i_ceph_lock);
-        ci->i_ceph_flags &= ~mask;
-        spin_unlock(&ci->i_ceph_lock);
+        atomic_set(&ci->i_complete_count, release_count);
 }
 
-static inline void ceph_i_set(struct inode *inode, unsigned mask)
+static inline void __ceph_dir_clear_complete(struct ceph_inode_info *ci)
 {
-        struct ceph_inode_info *ci = ceph_inode(inode);
+        atomic_inc(&ci->i_release_count);
+}
 
-        spin_lock(&ci->i_ceph_lock);
-        ci->i_ceph_flags |= mask;
-        spin_unlock(&ci->i_ceph_lock);
+static inline bool __ceph_dir_is_complete(struct ceph_inode_info *ci)
+{
+        return atomic_read(&ci->i_complete_count) ==
+                atomic_read(&ci->i_release_count);
 }
 
-static inline bool ceph_i_test(struct inode *inode, unsigned mask)
+static inline void ceph_dir_clear_complete(struct inode *inode)
 {
-        struct ceph_inode_info *ci = ceph_inode(inode);
-        bool r;
+        __ceph_dir_clear_complete(ceph_inode(inode));
+}
 
-        spin_lock(&ci->i_ceph_lock);
-        r = (ci->i_ceph_flags & mask) == mask;
-        spin_unlock(&ci->i_ceph_lock);
-        return r;
+static inline bool ceph_dir_is_complete(struct inode *inode)
+{
+        return __ceph_dir_is_complete(ceph_inode(inode));
 }
 
 
@@ -565,7 +563,7 @@ struct ceph_file_info {
         u64 next_offset;       /* offset of next chunk (last_name's + 1) */
         char *last_name;       /* last entry in previous chunk */
         struct dentry *dentry; /* next dentry (for dcache readdir) */
-        unsigned long dir_release_count;
+        int dir_release_count;
 
         /* used for -o dirstat read() on directory thing */
         char *dir_info;