ceph: rework dcache readdir
Previously our dcache readdir code relies on that child dentries in
directory dentry's d_subdir list are sorted by dentry's offset in
descending order. When adding dentries to the dcache, if a dentry
already exists, our readdir code moves it to head of directory
dentry's d_subdir list. This design relies on dcache internals.
Al Viro suggests using ncpfs's approach: keeping array of pointers
to dentries in page cache of directory inode. the validity of those
pointers are presented by directory inode's complete and ordered
flags. When a dentry gets pruned, we clear directory inode's complete
flag in the d_prune() callback. Before moving a dentry to other
directory, we clear the ordered flag for both old and new directory.
Signed-off-by: Yan, Zheng <zyan@redhat.com>
diff --git a/fs/ceph/super.h b/fs/ceph/super.h
index 4415e97..860cc016 100644
--- a/fs/ceph/super.h
+++ b/fs/ceph/super.h
@@ -282,9 +282,9 @@
u32 i_time_warp_seq;
unsigned i_ceph_flags;
- int i_ordered_count;
- atomic_t i_release_count;
- atomic_t i_complete_count;
+ atomic64_t i_release_count;
+ atomic64_t i_ordered_count;
+ atomic64_t i_complete_seq[2];
struct ceph_dir_layout i_dir_layout;
struct ceph_file_layout i_layout;
@@ -471,30 +471,36 @@
static inline void __ceph_dir_set_complete(struct ceph_inode_info *ci,
- int release_count, int ordered_count)
+ long long release_count,
+ long long ordered_count)
{
- atomic_set(&ci->i_complete_count, release_count);
- if (ci->i_ordered_count == ordered_count)
- ci->i_ceph_flags |= CEPH_I_DIR_ORDERED;
- else
- ci->i_ceph_flags &= ~CEPH_I_DIR_ORDERED;
+ smp_mb__before_atomic();
+ atomic64_set(&ci->i_complete_seq[0], release_count);
+ atomic64_set(&ci->i_complete_seq[1], ordered_count);
}
static inline void __ceph_dir_clear_complete(struct ceph_inode_info *ci)
{
- atomic_inc(&ci->i_release_count);
+ atomic64_inc(&ci->i_release_count);
+}
+
+static inline void __ceph_dir_clear_ordered(struct ceph_inode_info *ci)
+{
+ atomic64_inc(&ci->i_ordered_count);
}
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);
+ return atomic64_read(&ci->i_complete_seq[0]) ==
+ atomic64_read(&ci->i_release_count);
}
static inline bool __ceph_dir_is_complete_ordered(struct ceph_inode_info *ci)
{
- return __ceph_dir_is_complete(ci) &&
- (ci->i_ceph_flags & CEPH_I_DIR_ORDERED);
+ return atomic64_read(&ci->i_complete_seq[0]) ==
+ atomic64_read(&ci->i_release_count) &&
+ atomic64_read(&ci->i_complete_seq[1]) ==
+ atomic64_read(&ci->i_ordered_count);
}
static inline void ceph_dir_clear_complete(struct inode *inode)
@@ -504,20 +510,13 @@
static inline void ceph_dir_clear_ordered(struct inode *inode)
{
- struct ceph_inode_info *ci = ceph_inode(inode);
- spin_lock(&ci->i_ceph_lock);
- ci->i_ordered_count++;
- ci->i_ceph_flags &= ~CEPH_I_DIR_ORDERED;
- spin_unlock(&ci->i_ceph_lock);
+ __ceph_dir_clear_ordered(ceph_inode(inode));
}
static inline bool ceph_dir_is_complete_ordered(struct inode *inode)
{
- struct ceph_inode_info *ci = ceph_inode(inode);
- bool ret;
- spin_lock(&ci->i_ceph_lock);
- ret = __ceph_dir_is_complete_ordered(ci);
- spin_unlock(&ci->i_ceph_lock);
+ bool ret = __ceph_dir_is_complete_ordered(ceph_inode(inode));
+ smp_rmb();
return ret;
}
@@ -636,16 +635,20 @@
unsigned offset; /* offset of last chunk, adjusted for . and .. */
unsigned 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) */
- int dir_release_count;
- int dir_ordered_count;
+ long long dir_release_count;
+ long long dir_ordered_count;
+ int readdir_cache_idx;
/* used for -o dirstat read() on directory thing */
char *dir_info;
int dir_info_len;
};
-
+struct ceph_readdir_cache_control {
+ struct page *page;
+ struct dentry **dentries;
+ int index;
+};
/*
* A "snap realm" describes a subset of the file hierarchy sharing
@@ -944,6 +947,7 @@
extern void ceph_invalidate_dentry_lease(struct dentry *dentry);
extern unsigned ceph_dentry_hash(struct inode *dir, struct dentry *dn);
extern struct inode *ceph_get_dentry_parent_inode(struct dentry *dentry);
+extern void ceph_readdir_cache_release(struct ceph_readdir_cache_control *ctl);
/*
* our d_ops vary depending on whether the inode is live,
