patch-2.4.27 linux-2.4.27/fs/xfs/linux/xfs_lrw.c

Next file: linux-2.4.27/fs/xfs/linux/xfs_lrw.h
Previous file: linux-2.4.27/fs/xfs/linux/xfs_linux.h
Back to the patch index
Back to the overall index

diff -urN linux-2.4.26/fs/xfs/linux/xfs_lrw.c linux-2.4.27/fs/xfs/linux/xfs_lrw.c
@@ -1,979 +0,0 @@
-/*
- * Copyright (c) 2000-2003 Silicon Graphics, Inc.  All Rights Reserved.
- *
- * This program is free software; you can redistribute it and/or modify it
- * under the terms of version 2 of the GNU General Public License as
- * published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it would be useful, but
- * WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
- *
- * Further, this software is distributed without any warranty that it is
- * free of the rightful claim of any third person regarding infringement
- * or the like.  Any license provided herein, whether implied or
- * otherwise, applies only to this software file.  Patent licenses, if
- * any, provided herein do not apply to combinations of this program with
- * other software, or any other product whatsoever.
- *
- * You should have received a copy of the GNU General Public License along
- * with this program; if not, write the Free Software Foundation, Inc., 59
- * Temple Place - Suite 330, Boston MA 02111-1307, USA.
- *
- * Contact information: Silicon Graphics, Inc., 1600 Amphitheatre Pkwy,
- * Mountain View, CA  94043, or:
- *
- * http://www.sgi.com
- *
- * For further information regarding this notice, see:
- *
- * http://oss.sgi.com/projects/GenInfo/SGIGPLNoticeExplan/
- */
-/*
- *  fs/xfs/linux/xfs_lrw.c (Linux Read Write stuff)
- *
- */
-
-#include "xfs.h"
-
-#include "xfs_fs.h"
-#include "xfs_inum.h"
-#include "xfs_log.h"
-#include "xfs_trans.h"
-#include "xfs_sb.h"
-#include "xfs_ag.h"
-#include "xfs_dir.h"
-#include "xfs_dir2.h"
-#include "xfs_alloc.h"
-#include "xfs_dmapi.h"
-#include "xfs_quota.h"
-#include "xfs_mount.h"
-#include "xfs_alloc_btree.h"
-#include "xfs_bmap_btree.h"
-#include "xfs_ialloc_btree.h"
-#include "xfs_btree.h"
-#include "xfs_ialloc.h"
-#include "xfs_attr_sf.h"
-#include "xfs_dir_sf.h"
-#include "xfs_dir2_sf.h"
-#include "xfs_dinode.h"
-#include "xfs_inode.h"
-#include "xfs_bmap.h"
-#include "xfs_bit.h"
-#include "xfs_rtalloc.h"
-#include "xfs_error.h"
-#include "xfs_itable.h"
-#include "xfs_rw.h"
-#include "xfs_refcache.h"
-#include "xfs_acl.h"
-#include "xfs_cap.h"
-#include "xfs_mac.h"
-#include "xfs_attr.h"
-#include "xfs_inode_item.h"
-#include "xfs_buf_item.h"
-#include "xfs_utils.h"
-#include "xfs_iomap.h"
-
-#include <linux/capability.h>
-
-
-#if defined(XFS_RW_TRACE)
-void
-xfs_rw_enter_trace(
-	int		tag,
-	xfs_iocore_t	*io,
-	const char	*buf,
-	size_t		size,
-	loff_t		offset,
-	int		ioflags)
-{
-	xfs_inode_t	*ip = XFS_IO_INODE(io);
-
-	if (ip->i_rwtrace == NULL)
-		return;
-	ktrace_enter(ip->i_rwtrace,
-		(void *)(unsigned long)tag,
-		(void *)ip,
-		(void *)((unsigned long)((ip->i_d.di_size >> 32) & 0xffffffff)),
-		(void *)((unsigned long)(ip->i_d.di_size & 0xffffffff)),
-		(void *)(__psint_t)buf,
-		(void *)((unsigned long)size),
-		(void *)((unsigned long)((offset >> 32) & 0xffffffff)),
-		(void *)((unsigned long)(offset & 0xffffffff)),
-		(void *)((unsigned long)ioflags),
-		(void *)((unsigned long)((io->io_new_size >> 32) & 0xffffffff)),
-		(void *)((unsigned long)(io->io_new_size & 0xffffffff)),
-		(void *)NULL,
-		(void *)NULL,
-		(void *)NULL,
-		(void *)NULL,
-		(void *)NULL);
-}
-
-void
-xfs_inval_cached_trace(
-	xfs_iocore_t	*io,
-	xfs_off_t	offset,
-	xfs_off_t	len,
-	xfs_off_t	first,
-	xfs_off_t	last)
-{
-	xfs_inode_t	*ip = XFS_IO_INODE(io);
-
-	if (ip->i_rwtrace == NULL)
-		return;
-	ktrace_enter(ip->i_rwtrace,
-		(void *)(__psint_t)XFS_INVAL_CACHED,
-		(void *)ip,
-		(void *)((unsigned long)((offset >> 32) & 0xffffffff)),
-		(void *)((unsigned long)(offset & 0xffffffff)),
-		(void *)((unsigned long)((len >> 32) & 0xffffffff)),
-		(void *)((unsigned long)(len & 0xffffffff)),
-		(void *)((unsigned long)((first >> 32) & 0xffffffff)),
-		(void *)((unsigned long)(first & 0xffffffff)),
-		(void *)((unsigned long)((last >> 32) & 0xffffffff)),
-		(void *)((unsigned long)(last & 0xffffffff)),
-		(void *)NULL,
-		(void *)NULL,
-		(void *)NULL,
-		(void *)NULL,
-		(void *)NULL,
-		(void *)NULL);
-}
-#endif
-
-/*
- *	xfs_iozero
- *
- *	xfs_iozero clears the specified range of buffer supplied,
- *	and marks all the affected blocks as valid and modified.  If
- *	an affected block is not allocated, it will be allocated.  If
- *	an affected block is not completely overwritten, and is not
- *	valid before the operation, it will be read from disk before
- *	being partially zeroed.
- */
-STATIC int
-xfs_iozero(
-	struct inode		*ip,	/* inode			*/
-	loff_t			pos,	/* offset in file		*/
-	size_t			count,	/* size of data to zero		*/
-	loff_t			end_size)	/* max file size to set */
-{
-	unsigned		bytes;
-	struct page		*page;
-	struct address_space	*mapping;
-	char			*kaddr;
-	int			status;
-
-	mapping = ip->i_mapping;
-	do {
-		unsigned long index, offset;
-
-		offset = (pos & (PAGE_CACHE_SIZE -1)); /* Within page */
-		index = pos >> PAGE_CACHE_SHIFT;
-		bytes = PAGE_CACHE_SIZE - offset;
-		if (bytes > count)
-			bytes = count;
-
-		status = -ENOMEM;
-		page = grab_cache_page(mapping, index);
-		if (!page)
-			break;
-
-		kaddr = kmap(page);
-		status = mapping->a_ops->prepare_write(NULL, page, offset,
-							offset + bytes);
-		if (status) {
-			goto unlock;
-		}
-
-		memset((void *) (kaddr + offset), 0, bytes);
-		flush_dcache_page(page);
-		status = mapping->a_ops->commit_write(NULL, page, offset,
-							offset + bytes);
-		if (!status) {
-			pos += bytes;
-			count -= bytes;
-			if (pos > i_size_read(ip))
-				i_size_write(ip, pos < end_size ? pos : end_size);
-		}
-
-unlock:
-		kunmap(page);
-		unlock_page(page);
-		page_cache_release(page);
-		if (status)
-			break;
-	} while (count);
-
-	return (-status);
-}
-
-/*
- * xfs_inval_cached_pages
- * 
- * This routine is responsible for keeping direct I/O and buffered I/O
- * somewhat coherent.  From here we make sure that we're at least
- * temporarily holding the inode I/O lock exclusively and then call
- * the page cache to flush and invalidate any cached pages.  If there
- * are no cached pages this routine will be very quick.
- */
-void
-xfs_inval_cached_pages(
-	vnode_t		*vp,
-	xfs_iocore_t	*io,
-	xfs_off_t	offset,
-	int		write,
-	int		relock)
-{
-	xfs_mount_t	*mp;
-
-	if (!VN_CACHED(vp)) {
-		return;
-	}
-
-	mp = io->io_mount;
-
-	/*
-	 * We need to get the I/O lock exclusively in order
-	 * to safely invalidate pages and mappings.
-	 */
-	if (relock) {
-		XFS_IUNLOCK(mp, io, XFS_IOLOCK_SHARED);
-		XFS_ILOCK(mp, io, XFS_IOLOCK_EXCL);
-	}
-
-	/* Writing beyond EOF creates a hole that must be zeroed */
-	if (write && (offset > XFS_SIZE(mp, io))) {
-		xfs_fsize_t	isize;
-
-		XFS_ILOCK(mp, io, XFS_ILOCK_EXCL|XFS_EXTSIZE_RD);
-		isize = XFS_SIZE(mp, io);
-		if (offset > isize) {
-			xfs_zero_eof(vp, io, offset, isize, offset);
-		}
-		XFS_IUNLOCK(mp, io, XFS_ILOCK_EXCL|XFS_EXTSIZE_RD);
-	}
-
-	xfs_inval_cached_trace(io, offset, -1, ctooff(offtoct(offset)), -1);
-	VOP_FLUSHINVAL_PAGES(vp, ctooff(offtoct(offset)), -1, FI_REMAPF_LOCKED);
-	if (relock) {
-		XFS_ILOCK_DEMOTE(mp, io, XFS_IOLOCK_EXCL);
-	}
-}
-
-ssize_t			/* bytes read, or (-)  error */
-xfs_read(
-	bhv_desc_t      *bdp,
-	struct file	*file,
-	char		*buf,
-	size_t		size,
-	loff_t		*offset,
-	int		ioflags,
-	cred_t          *credp)
-{
-	ssize_t		ret;
-	xfs_fsize_t	n;
-	xfs_inode_t	*ip;
-	xfs_mount_t	*mp;
-
-	ip = XFS_BHVTOI(bdp);
-	mp = ip->i_mount;
-
-	XFS_STATS_INC(xs_read_calls);
-
-	if (unlikely(ioflags & IO_ISDIRECT)) {
-		if (((__psint_t)buf & BBMASK) ||
-		    (*offset & mp->m_blockmask) ||
-		    (size & mp->m_blockmask)) {
-			if (*offset >= ip->i_d.di_size) {
-				return (0);
-			}
-			return -XFS_ERROR(EINVAL);
-		}
-	}
-
-	n = XFS_MAXIOFFSET(mp) - *offset;
-	if ((n <= 0) || (size == 0))
-		return 0;
-
-	if (n < size)
-		size = n;
-
-	if (XFS_FORCED_SHUTDOWN(mp)) {
-		return -EIO;
-	}
-
-	if (!(ioflags & IO_ISLOCKED))
-		xfs_ilock(ip, XFS_IOLOCK_SHARED);
-
-	if (DM_EVENT_ENABLED(BHV_TO_VNODE(bdp)->v_vfsp, ip, DM_EVENT_READ) &&
-	    !(ioflags & IO_INVIS)) {
-		int error;
-		vrwlock_t locktype = VRWLOCK_READ;
-		int dmflags = FILP_DELAY_FLAG(file) | DM_SEM_FLAG_RD(ioflags);
-
-		error = XFS_SEND_DATA(mp, DM_EVENT_READ, BHV_TO_VNODE(bdp), *offset, size,
-				      dmflags, &locktype);
-		if (error) {
-			if (!(ioflags & IO_ISLOCKED))
-				xfs_iunlock(ip, XFS_IOLOCK_SHARED);
-			return -error;
-		}
-	}
-
-	if (unlikely(ioflags & IO_ISDIRECT)) {
-		xfs_rw_enter_trace(XFS_DIORD_ENTER, &ip->i_iocore,
-					buf, size, *offset, ioflags);
-		ret = do_generic_direct_read(file, buf, size, offset);
-		UPDATE_ATIME(file->f_dentry->d_inode);
-	} else {
-		xfs_rw_enter_trace(XFS_READ_ENTER, &ip->i_iocore,
-					buf, size, *offset, ioflags);
-		ret = generic_file_read(file, buf, size, offset);
-	}
-
-	if (!(ioflags & IO_ISLOCKED))
-		xfs_iunlock(ip, XFS_IOLOCK_SHARED);
-
-	XFS_STATS_ADD(xs_read_bytes, ret);
-
-	if (unlikely(ioflags & IO_INVIS)) {
-		/* generic_file_read updates the atime but we need to
-		 * undo that because this I/O was supposed to be invisible.
-		 */
-		struct inode *inode = LINVFS_GET_IP(BHV_TO_VNODE(bdp));
-		inode->i_atime = ip->i_d.di_atime.t_sec;
-	} else {
-		xfs_ichgtime(ip, XFS_ICHGTIME_ACC);
-	}
-
-	return ret;
-}
-
-/*
- * This routine is called to handle zeroing any space in the last
- * block of the file that is beyond the EOF.  We do this since the
- * size is being increased without writing anything to that block
- * and we don't want anyone to read the garbage on the disk.
- */
-STATIC int				/* error (positive) */
-xfs_zero_last_block(
-	struct inode	*ip,
-	xfs_iocore_t	*io,
-	xfs_off_t	offset,
-	xfs_fsize_t	isize,
-	xfs_fsize_t	end_size)
-{
-	xfs_fileoff_t	last_fsb;
-	xfs_mount_t	*mp;
-	int		nimaps;
-	int		zero_offset;
-	int		zero_len;
-	int		isize_fsb_offset;
-	int		error = 0;
-	xfs_bmbt_irec_t	imap;
-	loff_t		loff;
-	size_t		lsize;
-
-	ASSERT(ismrlocked(io->io_lock, MR_UPDATE) != 0);
-	ASSERT(offset > isize);
-
-	mp = io->io_mount;
-
-	isize_fsb_offset = XFS_B_FSB_OFFSET(mp, isize);
-	if (isize_fsb_offset == 0) {
-		/*
-		 * There are no extra bytes in the last block on disk to
-		 * zero, so return.
-		 */
-		return 0;
-	}
-
-	last_fsb = XFS_B_TO_FSBT(mp, isize);
-	nimaps = 1;
-	error = XFS_BMAPI(mp, NULL, io, last_fsb, 1, 0, NULL, 0, &imap,
-			  &nimaps, NULL);
-	if (error) {
-		return error;
-	}
-	ASSERT(nimaps > 0);
-	/*
-	 * If the block underlying isize is just a hole, then there
-	 * is nothing to zero.
-	 */
-	if (imap.br_startblock == HOLESTARTBLOCK) {
-		return 0;
-	}
-	/*
-	 * Zero the part of the last block beyond the EOF, and write it
-	 * out sync.  We need to drop the ilock while we do this so we
-	 * don't deadlock when the buffer cache calls back to us.
-	 */
-	XFS_IUNLOCK(mp, io, XFS_ILOCK_EXCL| XFS_EXTSIZE_RD);
-	loff = XFS_FSB_TO_B(mp, last_fsb);
-	lsize = XFS_FSB_TO_B(mp, 1);
-
-	zero_offset = isize_fsb_offset;
-	zero_len = mp->m_sb.sb_blocksize - isize_fsb_offset;
-
-	error = xfs_iozero(ip, loff + zero_offset, zero_len, end_size);
-
-	XFS_ILOCK(mp, io, XFS_ILOCK_EXCL|XFS_EXTSIZE_RD);
-	ASSERT(error >= 0);
-	return error;
-}
-
-/*
- * Zero any on disk space between the current EOF and the new,
- * larger EOF.  This handles the normal case of zeroing the remainder
- * of the last block in the file and the unusual case of zeroing blocks
- * out beyond the size of the file.  This second case only happens
- * with fixed size extents and when the system crashes before the inode
- * size was updated but after blocks were allocated.  If fill is set,
- * then any holes in the range are filled and zeroed.  If not, the holes
- * are left alone as holes.
- */
-
-int					/* error (positive) */
-xfs_zero_eof(
-	vnode_t		*vp,
-	xfs_iocore_t	*io,
-	xfs_off_t	offset,		/* starting I/O offset */
-	xfs_fsize_t	isize,		/* current inode size */
-	xfs_fsize_t	end_size)	/* terminal inode size */
-{
-	struct inode	*ip = LINVFS_GET_IP(vp);
-	xfs_fileoff_t	start_zero_fsb;
-	xfs_fileoff_t	end_zero_fsb;
-	xfs_fileoff_t	prev_zero_fsb;
-	xfs_fileoff_t	zero_count_fsb;
-	xfs_fileoff_t	last_fsb;
-	xfs_extlen_t	buf_len_fsb;
-	xfs_extlen_t	prev_zero_count;
-	xfs_mount_t	*mp;
-	int		nimaps;
-	int		error = 0;
-	xfs_bmbt_irec_t	imap;
-	loff_t		loff;
-	size_t		lsize;
-
-	ASSERT(ismrlocked(io->io_lock, MR_UPDATE));
-	ASSERT(ismrlocked(io->io_iolock, MR_UPDATE));
-
-	mp = io->io_mount;
-
-	/*
-	 * First handle zeroing the block on which isize resides.
-	 * We only zero a part of that block so it is handled specially.
-	 */
-	error = xfs_zero_last_block(ip, io, offset, isize, end_size);
-	if (error) {
-		ASSERT(ismrlocked(io->io_lock, MR_UPDATE));
-		ASSERT(ismrlocked(io->io_iolock, MR_UPDATE));
-		return error;
-	}
-
-	/*
-	 * Calculate the range between the new size and the old
-	 * where blocks needing to be zeroed may exist.  To get the
-	 * block where the last byte in the file currently resides,
-	 * we need to subtract one from the size and truncate back
-	 * to a block boundary.  We subtract 1 in case the size is
-	 * exactly on a block boundary.
-	 */
-	last_fsb = isize ? XFS_B_TO_FSBT(mp, isize - 1) : (xfs_fileoff_t)-1;
-	start_zero_fsb = XFS_B_TO_FSB(mp, (xfs_ufsize_t)isize);
-	end_zero_fsb = XFS_B_TO_FSBT(mp, offset - 1);
-	ASSERT((xfs_sfiloff_t)last_fsb < (xfs_sfiloff_t)start_zero_fsb);
-	if (last_fsb == end_zero_fsb) {
-		/*
-		 * The size was only incremented on its last block.
-		 * We took care of that above, so just return.
-		 */
-		return 0;
-	}
-
-	ASSERT(start_zero_fsb <= end_zero_fsb);
-	prev_zero_fsb = NULLFILEOFF;
-	prev_zero_count = 0;
-	while (start_zero_fsb <= end_zero_fsb) {
-		nimaps = 1;
-		zero_count_fsb = end_zero_fsb - start_zero_fsb + 1;
-		error = XFS_BMAPI(mp, NULL, io, start_zero_fsb, zero_count_fsb,
-				  0, NULL, 0, &imap, &nimaps, NULL);
-		if (error) {
-			ASSERT(ismrlocked(io->io_lock, MR_UPDATE));
-			ASSERT(ismrlocked(io->io_iolock, MR_UPDATE));
-			return error;
-		}
-		ASSERT(nimaps > 0);
-
-		if (imap.br_state == XFS_EXT_UNWRITTEN ||
-		    imap.br_startblock == HOLESTARTBLOCK) {
-			/*
-			 * This loop handles initializing pages that were
-			 * partially initialized by the code below this
-			 * loop. It basically zeroes the part of the page
-			 * that sits on a hole and sets the page as P_HOLE
-			 * and calls remapf if it is a mapped file.
-			 */
-			prev_zero_fsb = NULLFILEOFF;
-			prev_zero_count = 0;
-			start_zero_fsb = imap.br_startoff +
-					 imap.br_blockcount;
-			ASSERT(start_zero_fsb <= (end_zero_fsb + 1));
-			continue;
-		}
-
-		/*
-		 * There are blocks in the range requested.
-		 * Zero them a single write at a time.  We actually
-		 * don't zero the entire range returned if it is
-		 * too big and simply loop around to get the rest.
-		 * That is not the most efficient thing to do, but it
-		 * is simple and this path should not be exercised often.
-		 */
-		buf_len_fsb = XFS_FILBLKS_MIN(imap.br_blockcount,
-					      mp->m_writeio_blocks << 8);
-		/*
-		 * Drop the inode lock while we're doing the I/O.
-		 * We'll still have the iolock to protect us.
-		 */
-		XFS_IUNLOCK(mp, io, XFS_ILOCK_EXCL|XFS_EXTSIZE_RD);
-
-		loff = XFS_FSB_TO_B(mp, start_zero_fsb);
-		lsize = XFS_FSB_TO_B(mp, buf_len_fsb);
-
-		error = xfs_iozero(ip, loff, lsize, end_size);
-
-		if (error) {
-			goto out_lock;
-		}
-
-		prev_zero_fsb = start_zero_fsb;
-		prev_zero_count = buf_len_fsb;
-		start_zero_fsb = imap.br_startoff + buf_len_fsb;
-		ASSERT(start_zero_fsb <= (end_zero_fsb + 1));
-
-		XFS_ILOCK(mp, io, XFS_ILOCK_EXCL|XFS_EXTSIZE_RD);
-	}
-
-	return 0;
-
-out_lock:
-
-	XFS_ILOCK(mp, io, XFS_ILOCK_EXCL|XFS_EXTSIZE_RD);
-	ASSERT(error >= 0);
-	return error;
-}
-
-ssize_t				/* bytes written, or (-) error */
-xfs_write(
-	bhv_desc_t      *bdp,
-	struct file	*file,
-	const char	*buf,
-	size_t		size,
-	loff_t		*offset,
-	int		ioflags,
-	cred_t          *credp)
-{
-	xfs_inode_t	*xip;
-	xfs_mount_t	*mp;
-	ssize_t		ret;
-	int		error = 0;
-	xfs_fsize_t     isize, new_size;
-	xfs_fsize_t	n, limit;
-	xfs_iocore_t    *io;
-	vnode_t		*vp;
-	int		iolock;
-	int		eventsent = 0;
-	vrwlock_t	locktype;
-
-	XFS_STATS_INC(xs_write_calls);
-
-	vp = BHV_TO_VNODE(bdp);
-	xip = XFS_BHVTOI(bdp);
-
-	if (size == 0)
-		return 0;
-
-	io = &xip->i_iocore;
-	mp = io->io_mount;
-
-	xfs_check_frozen(mp, bdp, XFS_FREEZE_WRITE);
-
-	if (XFS_FORCED_SHUTDOWN(xip->i_mount)) {
-		return -EIO;
-	}
-
-	if (unlikely(ioflags & IO_ISDIRECT)) {
-		if (((__psint_t)buf & BBMASK) ||
-		    (*offset & mp->m_blockmask) ||
-		    (size  & mp->m_blockmask)) {
-			return XFS_ERROR(-EINVAL);
-		}
-		iolock = XFS_IOLOCK_SHARED;
-		locktype = VRWLOCK_WRITE_DIRECT;
-	} else {
-		if (io->io_flags & XFS_IOCORE_RT)
-			return XFS_ERROR(-EINVAL);
-		iolock = XFS_IOLOCK_EXCL;
-		locktype = VRWLOCK_WRITE;
-	}
-
-	if (ioflags & IO_ISLOCKED)
-		iolock = 0;
-
-	xfs_ilock(xip, XFS_ILOCK_EXCL|iolock);
-
-	isize = xip->i_d.di_size;
-	limit = XFS_MAXIOFFSET(mp);
-
-	if (file->f_flags & O_APPEND)
-		*offset = isize;
-
-start:
-	n = limit - *offset;
-	if (n <= 0) {
-		xfs_iunlock(xip, XFS_ILOCK_EXCL|iolock);
-		return -EFBIG;
-	}
-	if (n < size)
-		size = n;
-
-	new_size = *offset + size;
-	if (new_size > isize) {
-		io->io_new_size = new_size;
-	}
-
-	if ((DM_EVENT_ENABLED(vp->v_vfsp, xip, DM_EVENT_WRITE) &&
-	    !(ioflags & IO_INVIS) && !eventsent)) {
-		loff_t		savedsize = *offset;
-		int dmflags = FILP_DELAY_FLAG(file) | DM_SEM_FLAG_RD(ioflags);
-
-		xfs_iunlock(xip, XFS_ILOCK_EXCL);
-		error = XFS_SEND_DATA(xip->i_mount, DM_EVENT_WRITE, vp,
-				      *offset, size,
-				      dmflags, &locktype);
-		if (error) {
-			if (iolock) xfs_iunlock(xip, iolock);
-			return -error;
-		}
-		xfs_ilock(xip, XFS_ILOCK_EXCL);
-		eventsent = 1;
-
-		/*
-		 * The iolock was dropped and reaquired in XFS_SEND_DATA
-		 * so we have to recheck the size when appending.
-		 * We will only "goto start;" once, since having sent the
-		 * event prevents another call to XFS_SEND_DATA, which is
-		 * what allows the size to change in the first place.
-		 */
-		if ((file->f_flags & O_APPEND) &&
-		    savedsize != xip->i_d.di_size) {
-			*offset = isize = xip->i_d.di_size;
-			goto start;
-		}
-	}
-
-	/*
-	 * If the offset is beyond the size of the file, we have a couple
-	 * of things to do. First, if there is already space allocated
-	 * we need to either create holes or zero the disk or ...
-	 *
-	 * If there is a page where the previous size lands, we need
-	 * to zero it out up to the new size.
-	 */
-
-	if (!(ioflags & IO_ISDIRECT) && (*offset > isize && isize)) {
-		error = xfs_zero_eof(BHV_TO_VNODE(bdp), io, *offset,
-			isize, *offset + size);
-		if (error) {
-			xfs_iunlock(xip, XFS_ILOCK_EXCL|iolock);
-			return(-error);
-		}
-	}
-	xfs_iunlock(xip, XFS_ILOCK_EXCL);
-
-	/*
-	 * If we're writing the file then make sure to clear the
-	 * setuid and setgid bits if the process is not being run
-	 * by root.  This keeps people from modifying setuid and
-	 * setgid binaries.
-	 */
-
-	if (((xip->i_d.di_mode & S_ISUID) ||
-	    ((xip->i_d.di_mode & (S_ISGID | S_IXGRP)) ==
-		(S_ISGID | S_IXGRP))) &&
-	     !capable(CAP_FSETID)) {
-		error = xfs_write_clear_setuid(xip);
-		if (error) {
-			xfs_iunlock(xip, iolock);
-			return -error;
-		}
-	}
-
-
-	if ((ssize_t) size < 0) {
-		ret = -EINVAL;
-		goto error;
-	}
-
-	if (!access_ok(VERIFY_READ, buf, size)) {
-		ret = -EINVAL;
-		goto error;
-	}
-
-retry:
-	if (unlikely(ioflags & IO_ISDIRECT)) {
-		xfs_inval_cached_pages(vp, io, *offset, 1, 1);
-		xfs_rw_enter_trace(XFS_DIOWR_ENTER,
-					io, buf, size, *offset, ioflags);
-		ret = do_generic_direct_write(file, buf, size, offset);
-	} else {
-		xfs_rw_enter_trace(XFS_WRITE_ENTER,
-					io, buf, size, *offset, ioflags);
-		ret = do_generic_file_write(file, buf, size, offset);
-	}
-
-	if (unlikely(ioflags & IO_INVIS)) {
-		/* generic_file_write updates the mtime/ctime but we need
-		 * to undo that because this I/O was supposed to be
-		 * invisible.
-		 */
-		struct inode	*inode = LINVFS_GET_IP(vp);
-		inode->i_mtime = xip->i_d.di_mtime.t_sec;
-		inode->i_ctime = xip->i_d.di_ctime.t_sec;
-	} else {
-		xfs_ichgtime(xip, XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);
-	}
-
-	if ((ret == -ENOSPC) &&
-	    DM_EVENT_ENABLED(vp->v_vfsp, xip, DM_EVENT_NOSPACE) &&
-	    !(ioflags & IO_INVIS)) {
-
-		xfs_rwunlock(bdp, locktype);
-		error = XFS_SEND_NAMESP(xip->i_mount, DM_EVENT_NOSPACE, vp,
-				DM_RIGHT_NULL, vp, DM_RIGHT_NULL, NULL, NULL,
-				0, 0, 0); /* Delay flag intentionally  unused */
-		if (error)
-			return -error;
-		xfs_rwlock(bdp, locktype);
-		*offset = xip->i_d.di_size;
-		goto retry;
-	}
-
-error:
-	if (ret <= 0) {
-		if (iolock)
-			xfs_rwunlock(bdp, locktype);
-		return ret;
-	}
-
-	XFS_STATS_ADD(xs_write_bytes, ret);
-
-	if (*offset > xip->i_d.di_size) {
-		xfs_ilock(xip, XFS_ILOCK_EXCL);
-		if (*offset > xip->i_d.di_size) {
-			struct inode	*inode = LINVFS_GET_IP(vp);
-
-			xip->i_d.di_size = *offset;
-			i_size_write(inode, *offset);
-			xip->i_update_core = 1;
-			xip->i_update_size = 1;
-			mark_inode_dirty_sync(inode);
-		}
-		xfs_iunlock(xip, XFS_ILOCK_EXCL);
-	}
-
-	/* Handle various SYNC-type writes */
-	if ((file->f_flags & O_SYNC) || IS_SYNC(file->f_dentry->d_inode)) {
-
-		/*
-		 * If we're treating this as O_DSYNC and we have not updated the
-		 * size, force the log.
-		 */
-
-		if (!(mp->m_flags & XFS_MOUNT_OSYNCISOSYNC)
-			&& !(xip->i_update_size)) {
-			/*
-			 * If an allocation transaction occurred
-			 * without extending the size, then we have to force
-			 * the log up the proper point to ensure that the
-			 * allocation is permanent.  We can't count on
-			 * the fact that buffered writes lock out direct I/O
-			 * writes - the direct I/O write could have extended
-			 * the size nontransactionally, then finished before
-			 * we started.  xfs_write_file will think that the file
-			 * didn't grow but the update isn't safe unless the
-			 * size change is logged.
-			 *
-			 * Force the log if we've committed a transaction
-			 * against the inode or if someone else has and
-			 * the commit record hasn't gone to disk (e.g.
-			 * the inode is pinned).  This guarantees that
-			 * all changes affecting the inode are permanent
-			 * when we return.
-			 */
-
-			xfs_inode_log_item_t *iip;
-			xfs_lsn_t lsn;
-
-			iip = xip->i_itemp;
-			if (iip && iip->ili_last_lsn) {
-				lsn = iip->ili_last_lsn;
-				xfs_log_force(mp, lsn,
-						XFS_LOG_FORCE | XFS_LOG_SYNC);
-			} else if (xfs_ipincount(xip) > 0) {
-				xfs_log_force(mp, (xfs_lsn_t)0,
-						XFS_LOG_FORCE | XFS_LOG_SYNC);
-			}
-
-		} else {
-			xfs_trans_t	*tp;
-
-			/*
-			 * O_SYNC or O_DSYNC _with_ a size update are handled
-			 * the same way.
-			 *
-			 * If the write was synchronous then we need to make
-			 * sure that the inode modification time is permanent.
-			 * We'll have updated the timestamp above, so here
-			 * we use a synchronous transaction to log the inode.
-			 * It's not fast, but it's necessary.
-			 *
-			 * If this a dsync write and the size got changed
-			 * non-transactionally, then we need to ensure that
-			 * the size change gets logged in a synchronous
-			 * transaction.
-			 */
-
-			tp = xfs_trans_alloc(mp, XFS_TRANS_WRITE_SYNC);
-			if ((error = xfs_trans_reserve(tp, 0,
-						      XFS_SWRITE_LOG_RES(mp),
-						      0, 0, 0))) {
-				/* Transaction reserve failed */
-				xfs_trans_cancel(tp, 0);
-			} else {
-				/* Transaction reserve successful */
-				xfs_ilock(xip, XFS_ILOCK_EXCL);
-				xfs_trans_ijoin(tp, xip, XFS_ILOCK_EXCL);
-				xfs_trans_ihold(tp, xip);
-				xfs_trans_log_inode(tp, xip, XFS_ILOG_CORE);
-				xfs_trans_set_sync(tp);
-				error = xfs_trans_commit(tp, 0, (xfs_lsn_t)0);
-				xfs_iunlock(xip, XFS_ILOCK_EXCL);
-			}
-		}
-	} /* (ioflags & O_SYNC) */
-
-	/*
-	 * If we are coming from an nfsd thread then insert into the
-	 * reference cache.
-	 */
-
-	if (!strcmp(current->comm, "nfsd"))
-		xfs_refcache_insert(xip);
-
-	/* Drop lock this way - the old refcache release is in here */
-	if (iolock)
-		xfs_rwunlock(bdp, locktype);
-
-	return(ret);
-}
-
-/*
- * All xfs metadata buffers except log state machine buffers
- * get this attached as their b_bdstrat callback function.
- * This is so that we can catch a buffer
- * after prematurely unpinning it to forcibly shutdown the filesystem.
- */
-int
-xfs_bdstrat_cb(struct xfs_buf *bp)
-{
-	xfs_mount_t	*mp;
-
-	mp = XFS_BUF_FSPRIVATE3(bp, xfs_mount_t *);
-	if (!XFS_FORCED_SHUTDOWN(mp)) {
-		pagebuf_iorequest(bp);
-		return 0;
-	} else {
-		xfs_buftrace("XFS__BDSTRAT IOERROR", bp);
-		/*
-		 * Metadata write that didn't get logged but
-		 * written delayed anyway. These aren't associated
-		 * with a transaction, and can be ignored.
-		 */
-		if (XFS_BUF_IODONE_FUNC(bp) == NULL &&
-		    (XFS_BUF_ISREAD(bp)) == 0)
-			return (xfs_bioerror_relse(bp));
-		else
-			return (xfs_bioerror(bp));
-	}
-}
-
-
-int
-xfs_bmap(bhv_desc_t	*bdp,
-	xfs_off_t	offset,
-	ssize_t		count,
-	int		flags,
-	xfs_iomap_t	*iomapp,
-	int		*niomaps)
-{
-	xfs_inode_t	*ip = XFS_BHVTOI(bdp);
-	xfs_iocore_t	*io = &ip->i_iocore;
-
-	ASSERT((ip->i_d.di_mode & S_IFMT) == S_IFREG);
-	ASSERT(((ip->i_d.di_flags & XFS_DIFLAG_REALTIME) != 0) ==
-	       ((ip->i_iocore.io_flags & XFS_IOCORE_RT) != 0));
-
-	return xfs_iomap(io, offset, count, flags, iomapp, niomaps);
-}
-
-/*
- * Wrapper around bdstrat so that we can stop data
- * from going to disk in case we are shutting down the filesystem.
- * Typically user data goes thru this path; one of the exceptions
- * is the superblock.
- */
-int
-xfsbdstrat(
-	struct xfs_mount	*mp,
-	struct xfs_buf		*bp)
-{
-	ASSERT(mp);
-	if (!XFS_FORCED_SHUTDOWN(mp)) {
-		/* Grio redirection would go here
-		 * if (XFS_BUF_IS_GRIO(bp)) {
-		 */
-
-		pagebuf_iorequest(bp);
-		return 0;
-	}
-
-	xfs_buftrace("XFSBDSTRAT IOERROR", bp);
-	return (xfs_bioerror_relse(bp));
-}
-
-/*
- * If the underlying (data/log/rt) device is readonly, there are some
- * operations that cannot proceed.
- */
-int
-xfs_dev_is_read_only(
-	xfs_mount_t		*mp,
-	char			*message)
-{
-	if (xfs_readonly_buftarg(mp->m_ddev_targp) ||
-	    xfs_readonly_buftarg(mp->m_logdev_targp) ||
-	    (mp->m_rtdev_targp && xfs_readonly_buftarg(mp->m_rtdev_targp))) {
-		cmn_err(CE_NOTE,
-			"XFS: %s required on read-only device.", message);
-		cmn_err(CE_NOTE,
-			"XFS: write access unavailable, cannot proceed.");
-		return EROFS;
-	}
-	return 0;
-}

FUNET's LINUX-ADM group, linux-adm@nic.funet.fi
TCL-scripts by Sam Shen (who was at: slshen@lbl.gov)