VFS: Put a small type field into struct dentry::d_flags
Put a type field into struct dentry::d_flags to indicate if the dentry is one
of the following types that relate particularly to pathwalk:
Miss (negative dentry)
Directory
"Automount" directory (defective - no i_op->lookup())
Symlink
Other (regular, socket, fifo, device)
The type field is set to one of the first five types on a dentry by calls to
__d_instantiate() and d_obtain_alias() from information in the inode (if one is
given).
The type is cleared by dentry_unlink_inode() when it reconstitutes an existing
dentry as a negative dentry.
Accessors provided are:
d_set_type(dentry, type)
d_is_directory(dentry)
d_is_autodir(dentry)
d_is_symlink(dentry)
d_is_file(dentry)
d_is_negative(dentry)
d_is_positive(dentry)
A bunch of checks in pathname resolution switched to those.
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/include/linux/dcache.h b/include/linux/dcache.h
index 716c376..57e87e7 100644
--- a/include/linux/dcache.h
+++ b/include/linux/dcache.h
@@ -169,13 +169,13 @@
*/
/* d_flags entries */
-#define DCACHE_OP_HASH 0x0001
-#define DCACHE_OP_COMPARE 0x0002
-#define DCACHE_OP_REVALIDATE 0x0004
-#define DCACHE_OP_DELETE 0x0008
-#define DCACHE_OP_PRUNE 0x0010
+#define DCACHE_OP_HASH 0x00000001
+#define DCACHE_OP_COMPARE 0x00000002
+#define DCACHE_OP_REVALIDATE 0x00000004
+#define DCACHE_OP_DELETE 0x00000008
+#define DCACHE_OP_PRUNE 0x00000010
-#define DCACHE_DISCONNECTED 0x0020
+#define DCACHE_DISCONNECTED 0x00000020
/* This dentry is possibly not currently connected to the dcache tree, in
* which case its parent will either be itself, or will have this flag as
* well. nfsd will not use a dentry with this bit set, but will first
@@ -186,30 +186,38 @@
* dentry into place and return that dentry rather than the passed one,
* typically using d_splice_alias. */
-#define DCACHE_REFERENCED 0x0040 /* Recently used, don't discard. */
-#define DCACHE_RCUACCESS 0x0080 /* Entry has ever been RCU-visible */
+#define DCACHE_REFERENCED 0x00000040 /* Recently used, don't discard. */
+#define DCACHE_RCUACCESS 0x00000080 /* Entry has ever been RCU-visible */
-#define DCACHE_CANT_MOUNT 0x0100
-#define DCACHE_GENOCIDE 0x0200
-#define DCACHE_SHRINK_LIST 0x0400
+#define DCACHE_CANT_MOUNT 0x00000100
+#define DCACHE_GENOCIDE 0x00000200
+#define DCACHE_SHRINK_LIST 0x00000400
-#define DCACHE_OP_WEAK_REVALIDATE 0x0800
+#define DCACHE_OP_WEAK_REVALIDATE 0x00000800
-#define DCACHE_NFSFS_RENAMED 0x1000
+#define DCACHE_NFSFS_RENAMED 0x00001000
/* this dentry has been "silly renamed" and has to be deleted on the last
* dput() */
-#define DCACHE_COOKIE 0x2000 /* For use by dcookie subsystem */
-#define DCACHE_FSNOTIFY_PARENT_WATCHED 0x4000
+#define DCACHE_COOKIE 0x00002000 /* For use by dcookie subsystem */
+#define DCACHE_FSNOTIFY_PARENT_WATCHED 0x00004000
/* Parent inode is watched by some fsnotify listener */
-#define DCACHE_MOUNTED 0x10000 /* is a mountpoint */
-#define DCACHE_NEED_AUTOMOUNT 0x20000 /* handle automount on this dir */
-#define DCACHE_MANAGE_TRANSIT 0x40000 /* manage transit from this dirent */
+#define DCACHE_DENTRY_KILLED 0x00008000
+
+#define DCACHE_MOUNTED 0x00010000 /* is a mountpoint */
+#define DCACHE_NEED_AUTOMOUNT 0x00020000 /* handle automount on this dir */
+#define DCACHE_MANAGE_TRANSIT 0x00040000 /* manage transit from this dirent */
#define DCACHE_MANAGED_DENTRY \
(DCACHE_MOUNTED|DCACHE_NEED_AUTOMOUNT|DCACHE_MANAGE_TRANSIT)
-#define DCACHE_LRU_LIST 0x80000
-#define DCACHE_DENTRY_KILLED 0x100000
+#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 */
extern seqlock_t rename_lock;
@@ -394,6 +402,61 @@
return dentry->d_flags & DCACHE_MOUNTED;
}
+/*
+ * Directory cache entry type accessor functions.
+ */
+static inline void __d_set_type(struct dentry *dentry, unsigned type)
+{
+ dentry->d_flags = (dentry->d_flags & ~DCACHE_ENTRY_TYPE) | type;
+}
+
+static inline void __d_clear_type(struct dentry *dentry)
+{
+ __d_set_type(dentry, DCACHE_MISS_TYPE);
+}
+
+static inline void d_set_type(struct dentry *dentry, unsigned type)
+{
+ spin_lock(&dentry->d_lock);
+ __d_set_type(dentry, type);
+ spin_unlock(&dentry->d_lock);
+}
+
+static inline unsigned __d_entry_type(const struct dentry *dentry)
+{
+ return dentry->d_flags & DCACHE_ENTRY_TYPE;
+}
+
+static inline bool d_is_directory(const struct dentry *dentry)
+{
+ return __d_entry_type(dentry) == DCACHE_DIRECTORY_TYPE;
+}
+
+static inline bool d_is_autodir(const struct dentry *dentry)
+{
+ return __d_entry_type(dentry) == DCACHE_AUTODIR_TYPE;
+}
+
+static inline bool d_is_symlink(const struct dentry *dentry)
+{
+ return __d_entry_type(dentry) == DCACHE_SYMLINK_TYPE;
+}
+
+static inline bool d_is_file(const struct dentry *dentry)
+{
+ return __d_entry_type(dentry) == DCACHE_FILE_TYPE;
+}
+
+static inline bool d_is_negative(const struct dentry *dentry)
+{
+ return __d_entry_type(dentry) == DCACHE_MISS_TYPE;
+}
+
+static inline bool d_is_positive(const struct dentry *dentry)
+{
+ return !d_is_negative(dentry);
+}
+
extern int sysctl_vfs_cache_pressure;
static inline unsigned long vfs_pressure_ratio(unsigned long val)