Merge branch 'vfs-scale-working' of... (db9effe9) · Commits · 戴 / test

Documentation/filesystems/porting

+4 −4

Original line number	Diff line number	Diff line
		@@ -365,8 +365,8 @@ must be done in the RCU callback.
		[recommended]
		vfs now tries to do path walking in "rcu-walk mode", which avoids
		atomic operations and scalability hazards on dentries and inodes (see
		Documentation/filesystems/path-walk.txt). d_hash and d_compare changes (above)
		are examples of the changes required to support this. For more complex
		Documentation/filesystems/path-lookup.txt). d_hash and d_compare changes
		(above) are examples of the changes required to support this. For more complex
		filesystem callbacks, the vfs drops out of rcu-walk mode before the fs call, so
		no changes are required to the filesystem. However, this is costly and loses
		the benefits of rcu-walk mode. We will begin to add filesystem callbacks that
		@@ -383,8 +383,8 @@ Documentation/filesystems/vfs.txt for more details.

		permission and check_acl are inode permission checks that are called
		on many or all directory inodes on the way down a path walk (to check for
		exec permission). These must now be rcu-walk aware (flags & IPERM_RCU). See
		Documentation/filesystems/vfs.txt for more details.
		exec permission). These must now be rcu-walk aware (flags & IPERM_FLAG_RCU).
		See Documentation/filesystems/vfs.txt for more details.

		--
		[mandatory]

Documentation/filesystems/vfs.txt

+2 −2

Original line number	Diff line number	Diff line
		@@ -415,7 +415,7 @@ otherwise noted.
		permission: called by the VFS to check for access rights on a POSIX-like
		filesystem.

		May be called in rcu-walk mode (flags & IPERM_RCU). If in rcu-walk
		May be called in rcu-walk mode (flags & IPERM_FLAG_RCU). If in rcu-walk
		mode, the filesystem must check the permission without blocking or
		storing to the inode.

fs/namei.c

+24 −4

Original line number	Diff line number	Diff line
		@@ -479,6 +479,14 @@ static int nameidata_dentry_drop_rcu(struct nameidata nd, struct dentry dentry
		struct fs_struct *fs = current->fs;
		struct dentry *parent = nd->path.dentry;

		/*
		* It can be possible to revalidate the dentry that we started
		* the path walk with. force_reval_path may also revalidate the
		* dentry already committed to the nameidata.
		*/
		if (unlikely(parent == dentry))
		return nameidata_drop_rcu(nd);

		BUG_ON(!(nd->flags & LOOKUP_RCU));
		if (nd->root.mnt) {
		spin_lock(&fs->lock);
		@@ -583,6 +591,13 @@ void release_open_intent(struct nameidata *nd)
		fput(nd->intent.open.file);
		}

		/*
		* Call d_revalidate and handle filesystems that request rcu-walk
		* to be dropped. This may be called and return in rcu-walk mode,
		* regardless of success or error. If -ECHILD is returned, the caller
		* must return -ECHILD back up the path walk stack so path walk may
		* be restarted in ref-walk mode.
		*/
		static int d_revalidate(struct dentry dentry, struct nameidata nd)
		{
		int status;
		@@ -673,6 +688,9 @@ force_reval_path(struct path path, struct nameidata nd)
		return 0;

		if (!status) {
		/* Don't d_invalidate in rcu-walk mode */
		if (nameidata_drop_rcu(nd))
		return -ECHILD;
		d_invalidate(dentry);
		status = -ESTALE;
		}
		@@ -2105,12 +2123,14 @@ static struct file do_last(struct nameidata nd, struct path *path,
		dir = nd->path.dentry;
		case LAST_DOT:
		if (need_reval_dot(dir)) {
		error = d_revalidate(nd->path.dentry, nd);
		if (!error)
		error = -ESTALE;
		if (error < 0)
		int status = d_revalidate(nd->path.dentry, nd);
		if (!status)
		status = -ESTALE;
		if (status < 0) {
		error = status;
		goto exit;
		}
		}
		/* fallthrough */
		case LAST_ROOT:
		goto exit;

fs/nfs/dir.c

+5 −1

Original line number	Diff line number	Diff line
		@@ -1406,11 +1406,15 @@ no_open:
		static int nfs_open_revalidate(struct dentry dentry, struct nameidata nd)
		{
		struct dentry *parent = NULL;
		struct inode *inode = dentry->d_inode;
		struct inode *inode;
		struct inode *dir;
		struct nfs_open_context *ctx;
		int openflags, ret = 0;

		if (nd->flags & LOOKUP_RCU)
		return -ECHILD;

		inode = dentry->d_inode;
		if (!is_atomic_open(nd) \|\| d_mountpoint(dentry))
		goto no_open;

include/linux/list_bl.h

+3 −2

Original line number	Diff line number	Diff line
		@@ -16,7 +16,7 @@
		* some fast and compact auxiliary data.
		*/

		#if defined(CONFIG_SMP) \|\| defined(CONFIG_DEBUG_SPINLOCK)
		#if defined(CONFIG_SMP)
		#define LIST_BL_LOCKMASK 1UL
		#else
		#define LIST_BL_LOCKMASK 0UL
		@@ -62,7 +62,8 @@ static inline void hlist_bl_set_first(struct hlist_bl_head *h,
		struct hlist_bl_node *n)
		{
		LIST_BL_BUG_ON((unsigned long)n & LIST_BL_LOCKMASK);
		LIST_BL_BUG_ON(!((unsigned long)h->first & LIST_BL_LOCKMASK));
		LIST_BL_BUG_ON(((unsigned long)h->first & LIST_BL_LOCKMASK) !=
		LIST_BL_LOCKMASK);
		h->first = (struct hlist_bl_node *)((unsigned long)n \| LIST_BL_LOCKMASK);
		}

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