From 455486b9ccdd0a1d7432a03302f549b1c917c181 Mon Sep 17 00:00:00 2001 From: David Chinner Date: Thu, 30 Oct 2008 18:03:14 +1100 Subject: [XFS] avoid all reclaimable inodes in xfs_sync_inodes_ag If we are syncing data in xfs_sync_inodes_ag(), the VFS inode must still be referencable as the dirty data state is carried on the VFS inode. hence if we can't get a reference via igrab(), the inode must be in reclaim which implies that it has no dirty data attached. Leave such inodes to the reclaim code to flush the dirty inode state to disk and so avoid attempting to access the VFS inode when it may not exist in xfs_sync_inodes_ag(). Version 4: o don't reference linux inode until after igrab() succeeds Version 3: o converted unlock/rele to an xfs_iput() call. Version 2: o change igrab logic to be more linear o remove initial reclaimable inode check now that we are using igrab() failure to find reclaimable inodes o assert that igrab failure occurs only on reclaimable inodes o clean up inode locking - only grab the iolock if we are doing a SYNC_DELWRI call and we have a dirty inode. SGI-PV: 987246 SGI-Modid: xfs-linux-melb:xfs-kern:32391a Signed-off-by: David Chinner Signed-off-by: Christoph Hellwig Signed-off-by: Peter Leckie Signed-off-by: Lachlan McIlroy --- fs/xfs/linux-2.6/xfs_sync.c | 75 +++++++++++---------------------------------- 1 file changed, 18 insertions(+), 57 deletions(-) (limited to 'fs/xfs/linux-2.6/xfs_sync.c') diff --git a/fs/xfs/linux-2.6/xfs_sync.c b/fs/xfs/linux-2.6/xfs_sync.c index ee1648b179f7..fb5cca3df840 100644 --- a/fs/xfs/linux-2.6/xfs_sync.c +++ b/fs/xfs/linux-2.6/xfs_sync.c @@ -63,25 +63,16 @@ xfs_sync_inodes_ag( int error = 0; int last_error = 0; int fflag = XFS_B_ASYNC; - int lock_flags = XFS_ILOCK_SHARED; if (flags & SYNC_DELWRI) fflag = XFS_B_DELWRI; if (flags & SYNC_WAIT) fflag = 0; /* synchronous overrides all */ - if (flags & SYNC_DELWRI) { - /* - * We need the I/O lock if we're going to call any of - * the flush/inval routines. - */ - lock_flags |= XFS_IOLOCK_SHARED; - } - do { struct inode *inode; - boolean_t inode_refed; xfs_inode_t *ip = NULL; + int lock_flags = XFS_ILOCK_SHARED; /* * use a gang lookup to find the next inode in the tree @@ -109,22 +100,6 @@ xfs_sync_inodes_ag( break; } - /* - * skip inodes in reclaim. Let xfs_syncsub do that for - * us so we don't need to worry. - */ - if (xfs_iflags_test(ip, (XFS_IRECLAIM|XFS_IRECLAIMABLE))) { - read_unlock(&pag->pag_ici_lock); - continue; - } - - /* bad inodes are dealt with elsewhere */ - inode = VFS_I(ip); - if (is_bad_inode(inode)) { - read_unlock(&pag->pag_ici_lock); - continue; - } - /* nothing to sync during shutdown */ if (XFS_FORCED_SHUTDOWN(mp)) { read_unlock(&pag->pag_ici_lock); @@ -132,42 +107,34 @@ xfs_sync_inodes_ag( } /* - * If we can't get a reference on the VFS_I, the inode must be - * in reclaim. If we can get the inode lock without blocking, - * it is safe to flush the inode because we hold the tree lock - * and xfs_iextract will block right now. Hence if we lock the - * inode while holding the tree lock, xfs_ireclaim() is - * guaranteed to block on the inode lock we now hold and hence - * it is safe to reference the inode until we drop the inode - * locks completely. + * If we can't get a reference on the inode, it must be + * in reclaim. Leave it for the reclaim code to flush. */ - inode_refed = B_FALSE; - if (igrab(inode)) { - read_unlock(&pag->pag_ici_lock); - xfs_ilock(ip, lock_flags); - inode_refed = B_TRUE; - } else { - if (!xfs_ilock_nowait(ip, lock_flags)) { - /* leave it to reclaim */ - read_unlock(&pag->pag_ici_lock); - continue; - } + inode = VFS_I(ip); + if (!igrab(inode)) { read_unlock(&pag->pag_ici_lock); + continue; + } + read_unlock(&pag->pag_ici_lock); + + /* bad inodes are dealt with elsewhere */ + if (is_bad_inode(inode)) { + IRELE(ip); + continue; } /* * If we have to flush data or wait for I/O completion - * we need to drop the ilock that we currently hold. - * If we need to drop the lock, insert a marker if we - * have not already done so. + * we need to hold the iolock. */ if ((flags & SYNC_DELWRI) && VN_DIRTY(inode)) { - xfs_iunlock(ip, XFS_ILOCK_SHARED); + xfs_ilock(ip, XFS_IOLOCK_SHARED); + lock_flags |= XFS_IOLOCK_SHARED; error = xfs_flush_pages(ip, 0, -1, fflag, FI_NONE); if (flags & SYNC_IOWAIT) vn_iowait(ip); - xfs_ilock(ip, XFS_ILOCK_SHARED); } + xfs_ilock(ip, XFS_ILOCK_SHARED); if ((flags & SYNC_ATTR) && !xfs_inode_clean(ip)) { if (flags & SYNC_WAIT) { @@ -183,13 +150,7 @@ xfs_sync_inodes_ag( xfs_ifunlock(ip); } } - - if (lock_flags) - xfs_iunlock(ip, lock_flags); - - if (inode_refed) { - IRELE(ip); - } + xfs_iput(ip, lock_flags); if (error) last_error = error; -- cgit v1.2.2