From 26af655233dd486659235f3049959d2f7dafc5a1 Mon Sep 17 00:00:00 2001 From: Dave Chinner Date: Wed, 22 Sep 2010 10:47:20 +1000 Subject: [PATCH] xfs: kill XBF_FS_MANAGED buffers 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 Reviewed-by: Christoph Hellwig Reviewed-by: Alex Elder --- fs/xfs/linux-2.6/xfs_buf.c | 20 ++++------------- fs/xfs/linux-2.6/xfs_buf.h | 4 ---- fs/xfs/xfs_mount.c | 55 ++++++++++++++-------------------------------- 3 files changed, 20 insertions(+), 59 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); } /* -- 2.7.4