xfs: rewrite the filestream allocator using the dentry cache

In Linux we will always be able to find a parent inode for file that are
undergoing I/O.  Use this to simply the file stream allocator by only
keeping track of parent inodes.
Signed-off-by: Christoph Hellwig <hch@lst.de>

fs/xfs/xfs_filestream.h

@@ -20,44 +20,17 @@
 
 struct xfs_mount;
 struct xfs_inode;
-struct xfs_perag;
 struct xfs_bmalloca;
 
-#ifdef XFS_FILESTREAMS_TRACE
-#define XFS_FSTRM_KTRACE_INFO		1
-#define XFS_FSTRM_KTRACE_AGSCAN		2
-#define XFS_FSTRM_KTRACE_AGPICK1	3
-#define XFS_FSTRM_KTRACE_AGPICK2	4
-#define XFS_FSTRM_KTRACE_UPDATE		5
-#define XFS_FSTRM_KTRACE_FREE		6
-#define	XFS_FSTRM_KTRACE_ITEM_LOOKUP	7
-#define	XFS_FSTRM_KTRACE_ASSOCIATE	8
-#define	XFS_FSTRM_KTRACE_MOVEAG		9
-#define	XFS_FSTRM_KTRACE_ORPHAN		10
-
-#define XFS_FSTRM_KTRACE_SIZE	16384
-extern ktrace_t *xfs_filestreams_trace_buf;
-
-#endif
-
-/* allocation selection flags */
-typedef enum xfs_fstrm_alloc {
-	XFS_PICK_USERDATA = 1,
-	XFS_PICK_LOWSPACE = 2,
-} xfs_fstrm_alloc_t;
-
-/* prototypes for filestream.c */
 int xfs_filestream_init(void);
 void xfs_filestream_uninit(void);
 int xfs_filestream_mount(struct xfs_mount *mp);
 void xfs_filestream_unmount(struct xfs_mount *mp);
-xfs_agnumber_t xfs_filestream_lookup_ag(struct xfs_inode *ip);
-int xfs_filestream_associate(struct xfs_inode *dip, struct xfs_inode *ip);
 void xfs_filestream_deassociate(struct xfs_inode *ip);
+xfs_agnumber_t xfs_filestream_lookup_ag(struct xfs_inode *ip);
+int xfs_filestream_associate(struct xfs_inode *dip);
 int xfs_filestream_new_ag(struct xfs_bmalloca *ap, xfs_agnumber_t *agp);
 
-
-/* filestreams for the inode? */
 static inline int
 xfs_inode_is_filestream(
 	struct xfs_inode	*ip)

fs/xfs/xfs_inode.c

@@ -846,9 +846,9 @@ xfs_ialloc(
 
 	/* now we have set up the vfs inode we can associate the filestream */
 	if (filestreams) {
-		error = xfs_filestream_associate(pip, ip);
-		if (error < 0)
-			return -error;
+		error = xfs_filestream_associate(pip);
+		if (error)
+			return error;
 	}
 
 	*ipp = ip;
@@ -1695,16 +1695,6 @@ xfs_release(
 	if (!XFS_FORCED_SHUTDOWN(mp)) {
 		int truncated;
 
-		/*
-		 * If we are using filestreams, and we have an unlinked
-		 * file that we are processing the last close on, then nothing
-		 * will be able to reopen and write to this file. Purge this
-		 * inode from the filestreams cache so that it doesn't delay
-		 * teardown of the inode.
-		 */
-		if ((ip->i_d.di_nlink == 0) && xfs_inode_is_filestream(ip))
-			xfs_filestream_deassociate(ip);
-
 		/*
 		 * If we previously truncated this file and removed old data
 		 * in the process, we want to initiate "early" writeout on
@@ -2661,13 +2651,7 @@ xfs_remove(
 	if (error)
 		goto std_return;
 
-	/*
-	 * If we are using filestreams, kill the stream association.
-	 * If the file is still open it may get a new one but that
-	 * will get killed on last close in xfs_close() so we don't
-	 * have to worry about that.
-	 */
-	if (!is_dir && link_zero && xfs_inode_is_filestream(ip))
+	if (is_dir && xfs_inode_is_filestream(ip))
 		xfs_filestream_deassociate(ip);
 
 	return 0;