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Commit 7d4fb40a authored by Nathan Scott's avatar Nathan Scott
Browse files

[XFS] Start writeout earlier (on last close) in the case where we have a 


truncate down followed by delayed allocation (buffered writes) - worst
case scenario for the notorious NULL files problem.  This reduces the
window where we are exposed to that problem significantly.

SGI-PV: 917976
SGI-Modid: xfs-linux-melb:xfs-kern:26100a

Signed-off-by: default avatarNathan Scott <nathans@sgi.com>
parent 59c1b082

fs/xfs/linux-2.6/xfs_aops.c

+13 −0
Original line number Diff line number Diff line
@@ -1157,6 +1157,18 @@ out_unlock: 
	return error;

}



STATIC int

xfs_vm_writepages(

	struct address_space	*mapping,

	struct writeback_control *wbc)

{

	struct vnode		*vp = vn_from_inode(mapping->host);



	if (VN_TRUNC(vp))

		VUNTRUNCATE(vp);

	return generic_writepages(mapping, wbc);

}



/*

 * Called to move a page into cleanable state - and from there

 * to be released. Possibly the page is already clean. We always
@@ -1451,6 +1463,7 @@ struct address_space_operations xfs_address_space_operations = { 
	.readpage		= xfs_vm_readpage,

	.readpages		= xfs_vm_readpages,

	.writepage		= xfs_vm_writepage,

	.writepages		= xfs_vm_writepages,

	.sync_page		= block_sync_page,

	.releasepage		= xfs_vm_releasepage,

	.invalidatepage		= xfs_vm_invalidatepage,

fs/xfs/linux-2.6/xfs_file.c

+15 −0
Original line number Diff line number Diff line
@@ -323,6 +323,17 @@ xfs_file_open( 
	return -error;

}



STATIC int

xfs_file_close(

	struct file	*filp)

{

	vnode_t		*vp = vn_from_inode(filp->f_dentry->d_inode);

	int		error;



	VOP_CLOSE(vp, 0, file_count(filp) > 1 ? L_FALSE : L_TRUE, NULL, error);

	return -error;

}



STATIC int

xfs_file_release(

	struct inode	*inode,
@@ -349,6 +360,8 @@ xfs_file_fsync( 


	if (datasync)

		flags |= FSYNC_DATA;

	if (VN_TRUNC(vp))

		VUNTRUNCATE(vp);

	VOP_FSYNC(vp, flags, NULL, (xfs_off_t)0, (xfs_off_t)-1, error);

	return -error;

}
@@ -578,6 +591,7 @@ const struct file_operations xfs_file_operations = { 
#endif

	.mmap		= xfs_file_mmap,

	.open		= xfs_file_open,

	.flush		= xfs_file_close,

	.release	= xfs_file_release,

	.fsync		= xfs_file_fsync,

#ifdef HAVE_FOP_OPEN_EXEC
@@ -602,6 +616,7 @@ const struct file_operations xfs_invis_file_operations = { 
#endif

	.mmap		= xfs_file_mmap,

	.open		= xfs_file_open,

	.flush		= xfs_file_close,

	.release	= xfs_file_release,

	.fsync		= xfs_file_fsync,

};

fs/xfs/linux-2.6/xfs_fs_subr.c

+9 −44
Original line number Diff line number Diff line 
/*

 * Copyright (c) 2000-2002,2005 Silicon Graphics, Inc.

 * Copyright (c) 2000-2002,2005-2006 Silicon Graphics, Inc.

 * All Rights Reserved.

 *

 * This program is free software; you can redistribute it and/or
@@ -15,40 +15,12 @@ 
 * along with this program; if not, write the Free Software Foundation,

 * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

 */



#include "xfs.h"



/*

 * Stub for no-op vnode operations that return error status.

 */

int

fs_noerr(void)

{

	return 0;

}

int  fs_noerr(void) { return 0; }

int  fs_nosys(void) { return ENOSYS; }

void fs_noval(void) { return; }



/*

 * Operation unsupported under this file system.

 */

int

fs_nosys(void)

{

	return ENOSYS;

}



/*

 * Stub for inactive, strategy, and read/write lock/unlock.  Does nothing.

 */

/* ARGSUSED */

void

fs_noval(void)

{

}



/*

 * vnode pcache layer for vnode_tosspages.

 * 'last' parameter unused but left in for IRIX compatibility

 */

void

fs_tosspages(

	bhv_desc_t	*bdp,
@@ -63,11 +35,6 @@ fs_tosspages( 
		truncate_inode_pages(ip->i_mapping, first);

}





/*

 * vnode pcache layer for vnode_flushinval_pages.

 * 'last' parameter unused but left in for IRIX compatibility

 */

void

fs_flushinval_pages(

	bhv_desc_t	*bdp,
@@ -79,16 +46,13 @@ fs_flushinval_pages( 
	struct inode	*ip = vn_to_inode(vp);



	if (VN_CACHED(vp)) {

		if (VN_TRUNC(vp))

			VUNTRUNCATE(vp);

		filemap_write_and_wait(ip->i_mapping);



		truncate_inode_pages(ip->i_mapping, first);

	}

}



/*

 * vnode pcache layer for vnode_flush_pages.

 * 'last' parameter unused but left in for IRIX compatibility

 */

int

fs_flush_pages(

	bhv_desc_t	*bdp,
@@ -100,12 +64,13 @@ fs_flush_pages( 
	vnode_t		*vp = BHV_TO_VNODE(bdp);

	struct inode	*ip = vn_to_inode(vp);



	if (VN_CACHED(vp)) {

	if (VN_DIRTY(vp)) {

		if (VN_TRUNC(vp))

			VUNTRUNCATE(vp);

		filemap_fdatawrite(ip->i_mapping);

		if (flags & XFS_B_ASYNC)

			return 0;

		filemap_fdatawait(ip->i_mapping);

	}



	return 0;

}

fs/xfs/linux-2.6/xfs_vnode.h

+25 −14
Original line number Diff line number Diff line
@@ -56,12 +56,18 @@ typedef xfs_ino_t vnumber_t; 
typedef struct dentry vname_t;

typedef bhv_head_t vn_bhv_head_t;



typedef enum vflags {

	VMODIFIED	= 0x08,	/* XFS inode state possibly differs */

				/* to the Linux inode state. */

	VTRUNCATED	= 0x40,	/* truncated down so flush-on-close */

} vflags_t;



/*

 * MP locking protocols:

 *	v_flag, v_vfsp				VN_LOCK/VN_UNLOCK

 */

typedef struct vnode {

	__u32		v_flag;			/* vnode flags (see below) */

	vflags_t	v_flag;			/* vnode flags (see above) */

	struct vfs	*v_vfsp;		/* ptr to containing VFS */

	vnumber_t	v_number;		/* in-core vnode number */

	vn_bhv_head_t	v_bh;			/* behavior head */
@@ -125,12 +131,6 @@ static inline struct inode *vn_to_inode(struct vnode *vnode) 
	return &vnode->v_inode;

}



/*

 * Vnode flags.

 */

#define VMODIFIED	       0x8	/* XFS inode state possibly differs */

					/* to the Linux inode state.	*/



/*

 * Values for the VOP_RWLOCK and VOP_RWUNLOCK flags parameter.

 */
@@ -162,8 +162,10 @@ typedef enum vchange { 
	VCHANGE_FLAGS_IOEXCL_COUNT	= 4

} vchange_t;



typedef enum { L_FALSE, L_TRUE } lastclose_t;



typedef int	(*vop_open_t)(bhv_desc_t *, struct cred *);

typedef int	(*vop_close_t)(bhv_desc_t *, int, lastclose_t, struct cred *);

typedef ssize_t (*vop_read_t)(bhv_desc_t *, struct kiocb *,

				const struct iovec *, unsigned int,

				loff_t *, int, struct cred *);
@@ -234,6 +236,7 @@ typedef int (*vop_iflush_t)(bhv_desc_t *, int); 
typedef struct vnodeops {

	bhv_position_t  vn_position;    /* position within behavior chain */

	vop_open_t		vop_open;

	vop_close_t		vop_close;

	vop_read_t		vop_read;

	vop_write_t		vop_write;

	vop_sendfile_t		vop_sendfile;
@@ -278,6 +281,10 @@ typedef struct vnodeops { 
 */

#define _VOP_(op, vp)	(*((vnodeops_t *)(vp)->v_fops)->op)



#define VOP_OPEN(vp, cr, rv)						\

	rv = _VOP_(vop_open, vp)((vp)->v_fbhv, cr)

#define VOP_CLOSE(vp, f, last, cr, rv)					\

	rv = _VOP_(vop_close, vp)((vp)->v_fbhv, f, last, cr)

#define VOP_READ(vp,file,iov,segs,offset,ioflags,cr,rv)			\

	rv = _VOP_(vop_read, vp)((vp)->v_fbhv,file,iov,segs,offset,ioflags,cr)

#define VOP_WRITE(vp,file,iov,segs,offset,ioflags,cr,rv)		\
@@ -290,8 +297,6 @@ typedef struct vnodeops { 
	rv = _VOP_(vop_splice_write, vp)((vp)->v_fbhv,f,o,pipe,cnt,fl,iofl,cr)

#define VOP_BMAP(vp,of,sz,rw,b,n,rv)					\

	rv = _VOP_(vop_bmap, vp)((vp)->v_fbhv,of,sz,rw,b,n)

#define VOP_OPEN(vp, cr, rv)						\

	rv = _VOP_(vop_open, vp)((vp)->v_fbhv, cr)

#define VOP_GETATTR(vp, vap, f, cr, rv)					\

	rv = _VOP_(vop_getattr, vp)((vp)->v_fbhv, vap, f, cr)

#define	VOP_SETATTR(vp, vap, f, cr, rv)					\
@@ -556,8 +561,6 @@ static inline struct vnode *vn_grab(struct vnode *vp) 
 */

#define VN_LOCK(vp)		mutex_spinlock(&(vp)->v_lock)

#define VN_UNLOCK(vp, s)	mutex_spinunlock(&(vp)->v_lock, s)

#define VN_FLAGSET(vp,b)	vn_flagset(vp,b)

#define VN_FLAGCLR(vp,b)	vn_flagclr(vp,b)



static __inline__ void vn_flagset(struct vnode *vp, uint flag)

{
@@ -566,13 +569,22 @@ static __inline__ void vn_flagset(struct vnode *vp, uint flag) 
	spin_unlock(&vp->v_lock);

}



static __inline__ void vn_flagclr(struct vnode *vp, uint flag)

static __inline__ uint vn_flagclr(struct vnode *vp, uint flag)

{

	uint	cleared;



	spin_lock(&vp->v_lock);

	cleared = (vp->v_flag & flag);

	vp->v_flag &= ~flag;

	spin_unlock(&vp->v_lock);

	return cleared;

}



#define VMODIFY(vp)	vn_flagset(vp, VMODIFIED)

#define VUNMODIFY(vp)	vn_flagclr(vp, VMODIFIED)

#define VTRUNCATE(vp)	vn_flagset(vp, VTRUNCATED)

#define VUNTRUNCATE(vp)	vn_flagclr(vp, VTRUNCATED)



/*

 * Dealing with bad inodes

 */
@@ -612,8 +624,7 @@ static inline void vn_atime_to_time_t(struct vnode *vp, time_t *tt) 
#define VN_CACHED(vp)	(vn_to_inode(vp)->i_mapping->nrpages)

#define VN_DIRTY(vp)	mapping_tagged(vn_to_inode(vp)->i_mapping, \

					PAGECACHE_TAG_DIRTY)

#define VMODIFY(vp)	VN_FLAGSET(vp, VMODIFIED)

#define VUNMODIFY(vp)	VN_FLAGCLR(vp, VMODIFIED)

#define VN_TRUNC(vp)	((vp)->v_flag & VTRUNCATED)



/*

 * Flags to VOP_SETATTR/VOP_GETATTR.

fs/xfs/xfs_vnodeops.c

+52 −36
Original line number Diff line number Diff line
@@ -16,8 +16,6 @@ 
 * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

 */



#include <linux/capability.h>



#include "xfs.h"

#include "xfs_fs.h"

#include "xfs_types.h"
@@ -58,32 +56,14 @@ 
#include "xfs_log_priv.h"

#include "xfs_mac.h"





/*

 * The maximum pathlen is 1024 bytes. Since the minimum file system

 * blocksize is 512 bytes, we can get a max of 2 extents back from

 * bmapi.

 */

#define SYMLINK_MAPS 2



/*

 * For xfs, we check that the file isn't too big to be opened by this kernel.

 * No other open action is required for regular files.  Devices are handled

 * through the specfs file system, pipes through fifofs.  Device and

 * fifo vnodes are "wrapped" by specfs and fifofs vnodes, respectively,

 * when a new vnode is first looked up or created.

 */

STATIC int

xfs_open(

	bhv_desc_t	*bdp,

	cred_t		*credp)

{

	int		mode;

	vnode_t		*vp;

	xfs_inode_t	*ip;



	vp = BHV_TO_VNODE(bdp);

	ip = XFS_BHVTOI(bdp);

	vnode_t		*vp = BHV_TO_VNODE(bdp);

	xfs_inode_t	*ip = XFS_BHVTOI(bdp);



	if (XFS_FORCED_SHUTDOWN(ip->i_mount))

		return XFS_ERROR(EIO);
@@ -101,6 +81,36 @@ xfs_open( 
	return 0;

}



STATIC int

xfs_close(

	bhv_desc_t	*bdp,

	int		flags,

	lastclose_t	lastclose,

	cred_t		*credp)

{

	vnode_t		*vp = BHV_TO_VNODE(bdp);

	xfs_inode_t	*ip = XFS_BHVTOI(bdp);

	int		error = 0;



	if (XFS_FORCED_SHUTDOWN(ip->i_mount))

		return XFS_ERROR(EIO);



	if (lastclose != L_TRUE || !VN_ISREG(vp))

		return 0;



	/*

	 * If we previously truncated this file and removed old data in

	 * the process, we want to initiate "early" writeout on the last

	 * close.  This is an attempt to combat the notorious NULL files

	 * problem which is particularly noticable from a truncate down,

	 * buffered (re-)write (delalloc), followed by a crash.  What we

	 * are effectively doing here is significantly reducing the time

	 * window where we'd otherwise be exposed to that problem.

	 */

	if (VUNTRUNCATE(vp) && VN_DIRTY(vp) && ip->i_delayed_blks > 0)

		VOP_FLUSH_PAGES(vp, 0, -1, XFS_B_ASYNC, FI_NONE, error);

	return error;

}



/*

 * xfs_getattr
@@ -665,9 +675,17 @@ xfs_setattr( 
					    ((ip->i_d.di_nlink != 0 ||

					      !(mp->m_flags & XFS_MOUNT_WSYNC))

					     ? 1 : 0));

			if (code) {

			if (code)

				goto abort_return;

			}

			/*

			 * Truncated "down", so we're removing references

			 * to old data here - if we now delay flushing for

			 * a long time, we expose ourselves unduly to the

			 * notorious NULL files problem.  So, we mark this

			 * vnode and flush it when the file is closed, and

			 * do not wait the usual (long) time for writeout.

			 */

			VTRUNCATE(vp);

		}

		/*

		 * Have to do this even if the file's size doesn't change.
@@ -936,6 +954,13 @@ xfs_access( 
}





/*

 * The maximum pathlen is 1024 bytes. Since the minimum file system

 * blocksize is 512 bytes, we can get a max of 2 extents back from

 * bmapi.

 */

#define SYMLINK_MAPS 2



/*

 * xfs_readlink

 *
@@ -1470,9 +1495,6 @@ xfs_inactive_symlink_local( 
	return 0;

}



/*

 *

 */

STATIC int

xfs_inactive_attrs(

	xfs_inode_t	*ip,
@@ -1531,10 +1553,10 @@ xfs_release( 


	vp = BHV_TO_VNODE(bdp);

	ip = XFS_BHVTOI(bdp);

	mp = ip->i_mount;



	if (!VN_ISREG(vp) || (ip->i_d.di_mode == 0)) {

	if (!VN_ISREG(vp) || (ip->i_d.di_mode == 0))

		return 0;

	}



	/* If this is a read-only mount, don't do this (would generate I/O) */

	if (vp->v_vfsp->vfs_flag & VFS_RDONLY)
@@ -1546,8 +1568,6 @@ xfs_release( 
		return 0;

#endif



	mp = ip->i_mount;



	if (ip->i_d.di_nlink != 0) {

		if ((((ip->i_d.di_mode & S_IFMT) == S_IFREG) &&

		     ((ip->i_d.di_size > 0) || (VN_CACHED(vp) > 0 ||
@@ -3745,7 +3765,6 @@ xfs_inode_flush( 
	return error;

}





int

xfs_set_dmattrs (

	bhv_desc_t	*bdp,
@@ -3786,10 +3805,6 @@ xfs_set_dmattrs ( 
	return error;

}





/*

 * xfs_reclaim

 */

STATIC int

xfs_reclaim(

	bhv_desc_t	*bdp)
@@ -4645,6 +4660,7 @@ xfs_change_file_space( 
vnodeops_t xfs_vnodeops = {

	BHV_IDENTITY_INIT(VN_BHV_XFS,VNODE_POSITION_XFS),

	.vop_open		= xfs_open,

	.vop_close		= xfs_close,

	.vop_read		= xfs_read,

#ifdef HAVE_SENDFILE

	.vop_sendfile		= xfs_sendfile,