Hi,
I'd just like to ask you to look at autofs4 in the context of this change.
I don't really know what needs to be considered there. If this is a
generally visible dentry that any other users may mount filesystems on,
then this might be difficult to get working here.
I'm not quite sure what games you're playing here with d_mounted... In the
simplest case we might be able to just remove DCACHE_MOUNTED.
Anyway this would be great if we can make it work so I can replace the
member with d_seq for my path walk patches and not bloat dentry. Can you
take a look please if you have a chance?
--
XXX: breaks autofs4, have to work out what it is doing. We can get a mounted
count if needed by counting the hashtable.
---
fs/dcache.c | 1 -
fs/namespace.c | 19 +++++++++++++++----
include/linux/dcache.h | 42 +++++++++++++++++++++---------------------
3 files changed, 36 insertions(+), 26 deletions(-)
Index: linux-2.6/fs/dcache.c
===================================================================
--- linux-2.6.orig/fs/dcache.c
+++ linux-2.6/fs/dcache.c
@@ -1192,7 +1192,6 @@ struct dentry *d_alloc(struct dentry * p
dentry->d_sb = NULL;
dentry->d_op = NULL;
dentry->d_fsdata = NULL;
- dentry->d_mounted = 0;
INIT_HLIST_NODE(&dentry->d_hash);
INIT_LIST_HEAD(&dentry->d_lru);
INIT_LIST_HEAD(&dentry->d_subdirs);
Index: linux-2.6/fs/namespace.c
===================================================================
--- linux-2.6.orig/fs/namespace.c
+++ linux-2.6/fs/namespace.c
@@ -574,6 +574,15 @@ static void __touch_mnt_namespace(struct
}
}
+static void dentry_reset_mounted(struct vfsmount *mnt, struct dentry *dentry)
+{
+ if (!__lookup_mnt(mnt, dentry, 0)) {
+ spin_lock(&dentry->d_lock);
+ dentry->d_flags &= ~DCACHE_MOUNTED;
+ spin_unlock(&dentry->d_lock);
+ }
+}
+
static void detach_mnt(struct vfsmount *mnt, struct path *old_path)
{
old_path->dentry = mnt->mnt_mountpoint;
@@ -582,7 +591,7 @@ static void detach_mnt(struct vfsmount *
mnt->mnt_mountpoint = mnt->mnt_root;
list_del_init(&mnt->mnt_hash);
list_del_init(&mnt->mnt_child);
- old_path->dentry->d_mounted--;
+ dentry_reset_mounted(old_path->mnt, old_path->dentry);
WARN_ON(mnt->mnt_mounted != 1);
mnt->mnt_mounted--;
}
@@ -591,8 +600,10 @@ void mnt_set_mountpoint(struct vfsmount
struct vfsmount *child_mnt)
{
child_mnt->mnt_parent = mntget(mnt);
- child_mnt->mnt_mountpoint = dget(dentry);
- dentry->d_mounted++;
+ spin_lock(&dentry->d_lock);
+ child_mnt->mnt_mountpoint = dget_dlock(dentry);
+ dentry->d_flags |= DCACHE_MOUNTED;
+ spin_unlock(&dentry->d_lock);
}
static void attach_mnt(struct vfsmount *mnt, struct path *path)
@@ -1170,7 +1181,7 @@ void umount_tree(struct vfsmount *mnt, i
p->mnt_mounted--;
if (p->mnt_parent != p) {
p->mnt_parent->mnt_ghosts++;
- p->mnt_mountpoint->d_mounted--;
+ dentry_reset_mounted(p->mnt_parent, p->mnt_mountpoint);
}
change_mnt_propagation(p, MS_PRIVATE);
}
Index: linux-2.6/include/linux/dcache.h
===================================================================
--- linux-2.6.orig/include/linux/dcache.h
+++ linux-2.6/include/linux/dcache.h
@@ -83,14 +83,13 @@ full_name_hash(const unsigned char *name
#ifdef CONFIG_64BIT
#define DNAME_INLINE_LEN_MIN 32 /* 192 bytes */
#else
-#define DNAME_INLINE_LEN_MIN 40 /* 128 bytes */
+#define DNAME_INLINE_LEN_MIN 44 /* 128 bytes */
#endif
struct dentry {
unsigned int d_count; /* protected by d_lock */
unsigned int d_flags; /* protected by d_lock */
spinlock_t d_lock; /* per dentry lock */
- int d_mounted;
struct inode *d_inode; /* Where the name belongs to - NULL is
* negative */
/*
@@ -161,30 +160,31 @@ d_iput: no no yes
/* d_flags entries */
#define DCACHE_AUTOFS_PENDING 0x0001 /* autofs: "under construction" */
-#define DCACHE_NFSFS_RENAMED 0x0002 /* this dentry has been "silly
- * renamed" and has to be
- * deleted on the last dput()
- */
-#define DCACHE_DISCONNECTED 0x0004
- /* 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 endeavour to clear the bit either by discovering that it is
- * connected, or by performing lookup operations. Any filesystem which
- * supports nfsd_operations MUST have a lookup function which, if it finds
- * a directory inode with a DCACHE_DISCONNECTED dentry, will d_move
- * that dentry into place and return that dentry rather than the passed one,
- * typically using d_splice_alias.
- */
+#define DCACHE_NFSFS_RENAMED 0x0002
+ /* this dentry has been "silly renamed" and has to be deleted on the last
+ * dput() */
+
+#define DCACHE_DISCONNECTED 0x0004
+ /* 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
+ * endeavour to clear the bit either by discovering that it is connected,
+ * or by performing lookup operations. Any filesystem which supports
+ * nfsd_operations MUST have a lookup function which, if it finds a
+ * directory inode with a DCACHE_DISCONNECTED dentry, will d_move that
+ * dentry into place and return that dentry rather than the passed one,
+ * typically using d_splice_alias. */
#define DCACHE_REFERENCED 0x0008 /* Recently used, don't discard. */
#define DCACHE_UNHASHED 0x0010
-
-#define DCACHE_INOTIFY_PARENT_WATCHED 0x0020 /* Parent inode is watched by inotify */
+#define DCACHE_INOTIFY_PARENT_WATCHED 0x0020
+ /* Parent inode is watched by inotify */
#define DCACHE_COOKIE 0x0040 /* For use by dcookie subsystem */
+#define DCACHE_FSNOTIFY_PARENT_WATCHED 0x0080
+ /* Parent inode is watched by some fsnotify listener */
-#define DCACHE_FSNOTIFY_PARENT_WATCHED 0x0080 /* Parent inode is watched by some fsnotify listener */
+#define DCACHE_MOUNTED 0x0100 /* is a mountpoint */
extern seqlock_t rename_lock;
@@ -349,7 +349,7 @@ extern void dput(struct dentry *);
static inline int d_mountpoint(struct dentry *dentry)
{
- return dentry->d_mounted;
+ return dentry->d_flags & DCACHE_MOUNTED;
}
extern struct vfsmount *lookup_mnt(struct path *);
--
To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
