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-rw-r--r--include/linux/dcache.h103
1 files changed, 96 insertions, 7 deletions
diff --git a/include/linux/dcache.h b/include/linux/dcache.h
index 92c08cf7670e..d8358799c594 100644
--- a/include/linux/dcache.h
+++ b/include/linux/dcache.h
@@ -215,13 +215,16 @@ struct dentry_operations {
#define DCACHE_LRU_LIST 0x00080000
#define DCACHE_ENTRY_TYPE 0x00700000
-#define DCACHE_MISS_TYPE 0x00000000 /* Negative dentry */
-#define DCACHE_DIRECTORY_TYPE 0x00100000 /* Normal directory */
-#define DCACHE_AUTODIR_TYPE 0x00200000 /* Lookupless directory (presumed automount) */
-#define DCACHE_SYMLINK_TYPE 0x00300000 /* Symlink */
-#define DCACHE_FILE_TYPE 0x00400000 /* Other file type */
+#define DCACHE_MISS_TYPE 0x00000000 /* Negative dentry (maybe fallthru to nowhere) */
+#define DCACHE_WHITEOUT_TYPE 0x00100000 /* Whiteout dentry (stop pathwalk) */
+#define DCACHE_DIRECTORY_TYPE 0x00200000 /* Normal directory */
+#define DCACHE_AUTODIR_TYPE 0x00300000 /* Lookupless directory (presumed automount) */
+#define DCACHE_REGULAR_TYPE 0x00400000 /* Regular file type (or fallthru to such) */
+#define DCACHE_SPECIAL_TYPE 0x00500000 /* Other file type (or fallthru to such) */
+#define DCACHE_SYMLINK_TYPE 0x00600000 /* Symlink (or fallthru to such) */
#define DCACHE_MAY_FREE 0x00800000
+#define DCACHE_FALLTHRU 0x01000000 /* Fall through to lower layer */
extern seqlock_t rename_lock;
@@ -423,6 +426,16 @@ static inline unsigned __d_entry_type(const struct dentry *dentry)
return dentry->d_flags & DCACHE_ENTRY_TYPE;
}
+static inline bool d_is_miss(const struct dentry *dentry)
+{
+ return __d_entry_type(dentry) == DCACHE_MISS_TYPE;
+}
+
+static inline bool d_is_whiteout(const struct dentry *dentry)
+{
+ return __d_entry_type(dentry) == DCACHE_WHITEOUT_TYPE;
+}
+
static inline bool d_can_lookup(const struct dentry *dentry)
{
return __d_entry_type(dentry) == DCACHE_DIRECTORY_TYPE;
@@ -443,14 +456,25 @@ static inline bool d_is_symlink(const struct dentry *dentry)
return __d_entry_type(dentry) == DCACHE_SYMLINK_TYPE;
}
+static inline bool d_is_reg(const struct dentry *dentry)
+{
+ return __d_entry_type(dentry) == DCACHE_REGULAR_TYPE;
+}
+
+static inline bool d_is_special(const struct dentry *dentry)
+{
+ return __d_entry_type(dentry) == DCACHE_SPECIAL_TYPE;
+}
+
static inline bool d_is_file(const struct dentry *dentry)
{
- return __d_entry_type(dentry) == DCACHE_FILE_TYPE;
+ return d_is_reg(dentry) || d_is_special(dentry);
}
static inline bool d_is_negative(const struct dentry *dentry)
{
- return __d_entry_type(dentry) == DCACHE_MISS_TYPE;
+ // TODO: check d_is_whiteout(dentry) also.
+ return d_is_miss(dentry);
}
static inline bool d_is_positive(const struct dentry *dentry)
@@ -458,10 +482,75 @@ static inline bool d_is_positive(const struct dentry *dentry)
return !d_is_negative(dentry);
}
+extern void d_set_fallthru(struct dentry *dentry);
+
+static inline bool d_is_fallthru(const struct dentry *dentry)
+{
+ return dentry->d_flags & DCACHE_FALLTHRU;
+}
+
+
extern int sysctl_vfs_cache_pressure;
static inline unsigned long vfs_pressure_ratio(unsigned long val)
{
return mult_frac(val, sysctl_vfs_cache_pressure, 100);
}
+
+/**
+ * d_inode - Get the actual inode of this dentry
+ * @dentry: The dentry to query
+ *
+ * This is the helper normal filesystems should use to get at their own inodes
+ * in their own dentries and ignore the layering superimposed upon them.
+ */
+static inline struct inode *d_inode(const struct dentry *dentry)
+{
+ return dentry->d_inode;
+}
+
+/**
+ * d_inode_rcu - Get the actual inode of this dentry with ACCESS_ONCE()
+ * @dentry: The dentry to query
+ *
+ * This is the helper normal filesystems should use to get at their own inodes
+ * in their own dentries and ignore the layering superimposed upon them.
+ */
+static inline struct inode *d_inode_rcu(const struct dentry *dentry)
+{
+ return ACCESS_ONCE(dentry->d_inode);
+}
+
+/**
+ * d_backing_inode - Get upper or lower inode we should be using
+ * @upper: The upper layer
+ *
+ * This is the helper that should be used to get at the inode that will be used
+ * if this dentry were to be opened as a file. The inode may be on the upper
+ * dentry or it may be on a lower dentry pinned by the upper.
+ *
+ * Normal filesystems should not use this to access their own inodes.
+ */
+static inline struct inode *d_backing_inode(const struct dentry *upper)
+{
+ struct inode *inode = upper->d_inode;
+
+ return inode;
+}
+
+/**
+ * d_backing_dentry - Get upper or lower dentry we should be using
+ * @upper: The upper layer
+ *
+ * This is the helper that should be used to get the dentry of the inode that
+ * will be used if this dentry were opened as a file. It may be the upper
+ * dentry or it may be a lower dentry pinned by the upper.
+ *
+ * Normal filesystems should not use this to access their own dentries.
+ */
+static inline struct dentry *d_backing_dentry(struct dentry *upper)
+{
+ return upper;
+}
+
#endif /* __LINUX_DCACHE_H */