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From: Dave Chinner <david@fromorbit.com>
To: xfs@oss.sgi.com
Subject: [PATCH 09/18] xfs: kill XBF_FS_MANAGED buffers
Date: Mon, 27 Sep 2010 11:47:44 +1000	[thread overview]
Message-ID: <1285552073-14663-10-git-send-email-david@fromorbit.com> (raw)
In-Reply-To: <1285552073-14663-1-git-send-email-david@fromorbit.com>

From: Dave Chinner <dchinner@redhat.com>

Filesystem level managed buffers are buffers that have their
lifecycle controlled by the filesystem layer, not the buffer cache.
We currently cache these buffers, which makes cleanup and cache
walking somewhat troublesome. Convert the fs managed buffers to
uncached buffers obtained by via xfs_buf_get_uncached(), and remove
the XBF_FS_MANAGED special cases from the buffer cache.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Alex Elder <aelder@sgi.com>
---
 fs/xfs/linux-2.6/xfs_buf.c |   20 +++------------
 fs/xfs/linux-2.6/xfs_buf.h |    4 ---
 fs/xfs/xfs_mount.c         |   57 +++++++++++++------------------------------
 3 files changed, 21 insertions(+), 60 deletions(-)

diff --git a/fs/xfs/linux-2.6/xfs_buf.c b/fs/xfs/linux-2.6/xfs_buf.c
index d692897..975d658 100644
--- a/fs/xfs/linux-2.6/xfs_buf.c
+++ b/fs/xfs/linux-2.6/xfs_buf.c
@@ -826,8 +826,6 @@ xfs_buf_rele(
 			atomic_inc(&bp->b_hold);
 			spin_unlock(&hash->bh_lock);
 			(*(bp->b_relse)) (bp);
-		} else if (bp->b_flags & XBF_FS_MANAGED) {
-			spin_unlock(&hash->bh_lock);
 		} else {
 			ASSERT(!(bp->b_flags & (XBF_DELWRI|_XBF_DELWRI_Q)));
 			list_del_init(&bp->b_hash_list);
@@ -1433,26 +1431,16 @@ void
 xfs_wait_buftarg(
 	xfs_buftarg_t	*btp)
 {
-	xfs_buf_t	*bp, *n;
 	xfs_bufhash_t	*hash;
 	uint		i;
 
 	for (i = 0; i < (1 << btp->bt_hashshift); i++) {
 		hash = &btp->bt_hash[i];
-again:
 		spin_lock(&hash->bh_lock);
-		list_for_each_entry_safe(bp, n, &hash->bh_list, b_hash_list) {
-			ASSERT(btp == bp->b_target);
-			if (!(bp->b_flags & XBF_FS_MANAGED)) {
-				spin_unlock(&hash->bh_lock);
-				/*
-				 * Catch superblock reference count leaks
-				 * immediately
-				 */
-				BUG_ON(bp->b_bn == 0);
-				delay(100);
-				goto again;
-			}
+		while (!list_empty(&hash->bh_list)) {
+			spin_unlock(&hash->bh_lock);
+			delay(100);
+			spin_lock(&hash->bh_lock);
 		}
 		spin_unlock(&hash->bh_lock);
 	}
diff --git a/fs/xfs/linux-2.6/xfs_buf.h b/fs/xfs/linux-2.6/xfs_buf.h
index def2cea..1f109ce 100644
--- a/fs/xfs/linux-2.6/xfs_buf.h
+++ b/fs/xfs/linux-2.6/xfs_buf.h
@@ -51,7 +51,6 @@ typedef enum {
 #define XBF_DONE	(1 << 5) /* all pages in the buffer uptodate */
 #define XBF_DELWRI	(1 << 6) /* buffer has dirty pages */
 #define XBF_STALE	(1 << 7) /* buffer has been staled, do not find it */
-#define XBF_FS_MANAGED	(1 << 8) /* filesystem controls freeing memory */
 #define XBF_ORDERED	(1 << 11)/* use ordered writes */
 #define XBF_READ_AHEAD	(1 << 12)/* asynchronous read-ahead */
 #define XBF_LOG_BUFFER	(1 << 13)/* this is a buffer used for the log */
@@ -104,7 +103,6 @@ typedef unsigned int xfs_buf_flags_t;
 	{ XBF_DONE,		"DONE" }, \
 	{ XBF_DELWRI,		"DELWRI" }, \
 	{ XBF_STALE,		"STALE" }, \
-	{ XBF_FS_MANAGED,	"FS_MANAGED" }, \
 	{ XBF_ORDERED,		"ORDERED" }, \
 	{ XBF_READ_AHEAD,	"READ_AHEAD" }, \
 	{ XBF_LOCK,		"LOCK" },  	/* should never be set */\
@@ -279,8 +277,6 @@ extern void xfs_buf_terminate(void);
 					XFS_BUF_DONE(bp);	\
 				} while (0)
 
-#define XFS_BUF_UNMANAGE(bp)	((bp)->b_flags &= ~XBF_FS_MANAGED)
-
 #define XFS_BUF_DELAYWRITE(bp)		((bp)->b_flags |= XBF_DELWRI)
 #define XFS_BUF_UNDELAYWRITE(bp)	xfs_buf_delwri_dequeue(bp)
 #define XFS_BUF_ISDELAYWRITE(bp)	((bp)->b_flags & XBF_DELWRI)
diff --git a/fs/xfs/xfs_mount.c b/fs/xfs/xfs_mount.c
index 14fc6e9..fbca293 100644
--- a/fs/xfs/xfs_mount.c
+++ b/fs/xfs/xfs_mount.c
@@ -646,7 +646,6 @@ int
 xfs_readsb(xfs_mount_t *mp, int flags)
 {
 	unsigned int	sector_size;
-	unsigned int	extra_flags;
 	xfs_buf_t	*bp;
 	int		error;
 
@@ -659,28 +658,24 @@ xfs_readsb(xfs_mount_t *mp, int flags)
 	 * access to the superblock.
 	 */
 	sector_size = xfs_getsize_buftarg(mp->m_ddev_targp);
-	extra_flags = XBF_LOCK | XBF_FS_MANAGED | XBF_MAPPED;
 
-	bp = xfs_buf_read(mp->m_ddev_targp, XFS_SB_DADDR, BTOBB(sector_size),
-			  extra_flags);
-	if (!bp || XFS_BUF_ISERROR(bp)) {
-		xfs_fs_mount_cmn_err(flags, "SB read failed");
-		error = bp ? XFS_BUF_GETERROR(bp) : ENOMEM;
-		goto fail;
+reread:
+	bp = xfs_buf_read_uncached(mp, mp->m_ddev_targp,
+					XFS_SB_DADDR, sector_size, 0);
+	if (!bp) {
+		xfs_fs_mount_cmn_err(flags, "SB buffer read failed");
+		return EIO;
 	}
-	ASSERT(XFS_BUF_ISBUSY(bp));
-	ASSERT(XFS_BUF_VALUSEMA(bp) <= 0);
 
 	/*
 	 * Initialize the mount structure from the superblock.
 	 * But first do some basic consistency checking.
 	 */
 	xfs_sb_from_disk(&mp->m_sb, XFS_BUF_TO_SBP(bp));
-
 	error = xfs_mount_validate_sb(mp, &(mp->m_sb), flags);
 	if (error) {
 		xfs_fs_mount_cmn_err(flags, "SB validate failed");
-		goto fail;
+		goto release_buf;
 	}
 
 	/*
@@ -691,7 +686,7 @@ xfs_readsb(xfs_mount_t *mp, int flags)
 			"device supports only %u byte sectors (not %u)",
 			sector_size, mp->m_sb.sb_sectsize);
 		error = ENOSYS;
-		goto fail;
+		goto release_buf;
 	}
 
 	/*
@@ -699,33 +694,20 @@ xfs_readsb(xfs_mount_t *mp, int flags)
 	 * re-read the superblock so the buffer is correctly sized.
 	 */
 	if (sector_size < mp->m_sb.sb_sectsize) {
-		XFS_BUF_UNMANAGE(bp);
 		xfs_buf_relse(bp);
 		sector_size = mp->m_sb.sb_sectsize;
-		bp = xfs_buf_read(mp->m_ddev_targp, XFS_SB_DADDR,
-				  BTOBB(sector_size), extra_flags);
-		if (!bp || XFS_BUF_ISERROR(bp)) {
-			xfs_fs_mount_cmn_err(flags, "SB re-read failed");
-			error = bp ? XFS_BUF_GETERROR(bp) : ENOMEM;
-			goto fail;
-		}
-		ASSERT(XFS_BUF_ISBUSY(bp));
-		ASSERT(XFS_BUF_VALUSEMA(bp) <= 0);
+		goto reread;
 	}
 
 	/* Initialize per-cpu counters */
 	xfs_icsb_reinit_counters(mp);
 
 	mp->m_sb_bp = bp;
-	xfs_buf_relse(bp);
-	ASSERT(XFS_BUF_VALUSEMA(bp) > 0);
+	xfs_buf_unlock(bp);
 	return 0;
 
- fail:
-	if (bp) {
-		XFS_BUF_UNMANAGE(bp);
-		xfs_buf_relse(bp);
-	}
+release_buf:
+	xfs_buf_relse(bp);
 	return error;
 }
 
@@ -2005,18 +1987,13 @@ xfs_getsb(
  */
 void
 xfs_freesb(
-	xfs_mount_t	*mp)
+	struct xfs_mount	*mp)
 {
-	xfs_buf_t	*bp;
+	struct xfs_buf		*bp = mp->m_sb_bp;
 
-	/*
-	 * Use xfs_getsb() so that the buffer will be locked
-	 * when we call xfs_buf_relse().
-	 */
-	bp = xfs_getsb(mp, 0);
-	XFS_BUF_UNMANAGE(bp);
-	xfs_buf_relse(bp);
+	xfs_buf_lock(bp);
 	mp->m_sb_bp = NULL;
+	xfs_buf_relse(bp);
 }
 
 /*
-- 
1.7.1

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  parent reply	other threads:[~2010-09-27  1:47 UTC|newest]

Thread overview: 25+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-09-27  1:47 [PATCH 0/18] xfs: metadata scalability V4 Dave Chinner
2010-09-27  1:47 ` [PATCH 01/18] xfs: force background CIL push under sustained load Dave Chinner
2010-09-27  1:47 ` [PATCH 02/18] xfs: reduce the number of CIL lock round trips during commit Dave Chinner
2010-09-27  1:47 ` [PATCH 03/18] xfs: remove debug assert for per-ag reference counting Dave Chinner
2010-09-27  1:47 ` [PATCH 04/18] xfs: lockless per-ag lookups Dave Chinner
2010-09-27  1:47 ` [PATCH 05/18] xfs: don't use vfs writeback for pure metadata modifications Dave Chinner
2010-09-27  4:53   ` Christoph Hellwig
2010-09-27  1:47 ` [PATCH 06/18] xfs: rename xfs_buf_get_nodaddr to be more appropriate Dave Chinner
2010-09-27  1:47 ` [PATCH 07/18] xfs: introduced uncached buffer read primitve Dave Chinner
2010-09-27  1:47 ` [PATCH 08/18] xfs: store xfs_mount in the buftarg instead of in the xfs_buf Dave Chinner
2010-09-27  1:47 ` Dave Chinner [this message]
2010-09-27  1:47 ` [PATCH 10/18] xfs: use unhashed buffers for size checks Dave Chinner
2010-09-27  1:47 ` [PATCH 11/18] xfs: remove buftarg hash for external devices Dave Chinner
2010-09-27  1:47 ` [PATCH 12/18] xfs: split inode AG walking into separate code for reclaim Dave Chinner
2010-09-27  1:47 ` [PATCH 13/18] xfs: split out inode walk inode grabbing Dave Chinner
2010-09-27 15:58   ` Alex Elder
2010-09-27  1:47 ` [PATCH 14/18] xfs: implement batched inode lookups for AG walking Dave Chinner
2010-09-27 17:50   ` Alex Elder
2010-09-27  1:47 ` [PATCH 15/18] xfs: batch inode reclaim lookup Dave Chinner
2010-09-27  1:47 ` [PATCH 16/18] xfs: serialise inode reclaim within an AG Dave Chinner
2010-09-27  1:47 ` [PATCH 17/18] xfs: convert buffer cache hash to rbtree Dave Chinner
2010-09-27  1:47 ` [PATCH 18/18] xfs: pack xfs_buf structure more tightly Dave Chinner
2010-09-27 17:52 ` [PATCH 0/18] xfs: metadata scalability V4 Alex Elder
2010-09-28  1:42   ` Christoph Hellwig
  -- strict thread matches above, loose matches on Subject: below --
2010-09-24 12:30 [PATCH 0/18] xfs: metadata scalability V3 Dave Chinner
2010-09-24 12:31 ` [PATCH 09/18] xfs: kill XBF_FS_MANAGED buffers Dave Chinner

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