/*
- * Copyright (c) 2000-2004 Silicon Graphics, Inc. All Rights Reserved.
+ * Copyright (c) 2000-2006 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
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms 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.
+ * 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. See the
+ * GNU General Public License for more details.
*
- * 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/
+ * You should have received a copy of the GNU General Public License
+ * 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"
-
#include "xfs_fs.h"
-#include "xfs_inum.h"
+#include "xfs_bit.h"
#include "xfs_log.h"
+#include "xfs_inum.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_alloc_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_attr_sf.h"
#include "xfs_dinode.h"
#include "xfs_inode.h"
+#include "xfs_ialloc.h"
+#include "xfs_btree.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_acl.h"
-#include "xfs_cap.h"
-#include "xfs_mac.h"
#include "xfs_attr.h"
#include "xfs_buf_item.h"
#include "xfs_trans_space.h"
#include "xfs_utils.h"
#include "xfs_iomap.h"
+#include "xfs_trace.h"
-#if defined(XFS_RW_TRACE)
-void
-xfs_iomap_enter_trace(
- int tag,
- xfs_iocore_t *io,
- xfs_off_t offset,
- ssize_t count)
-{
- xfs_inode_t *ip = XFS_IO_INODE(io);
-
- if (!ip->i_rwtrace)
- 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 *)((unsigned long)((offset >> 32) & 0xffffffff)),
- (void *)((unsigned long)(offset & 0xffffffff)),
- (void *)((unsigned long)count),
- (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 *)NULL,
- (void *)NULL);
-}
-
-void
-xfs_iomap_map_trace(
- int tag,
- xfs_iocore_t *io,
- xfs_off_t offset,
- ssize_t count,
- xfs_iomap_t *iomapp,
- xfs_bmbt_irec_t *imapp,
- int flags)
-{
- xfs_inode_t *ip = XFS_IO_INODE(io);
-
- if (!ip->i_rwtrace)
- 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 *)((unsigned long)((offset >> 32) & 0xffffffff)),
- (void *)((unsigned long)(offset & 0xffffffff)),
- (void *)((unsigned long)count),
- (void *)((unsigned long)flags),
- (void *)((unsigned long)((iomapp->iomap_offset >> 32) & 0xffffffff)),
- (void *)((unsigned long)(iomapp->iomap_offset & 0xffffffff)),
- (void *)((unsigned long)(iomapp->iomap_delta)),
- (void *)((unsigned long)(iomapp->iomap_bsize)),
- (void *)((unsigned long)(iomapp->iomap_bn)),
- (void *)(__psint_t)(imapp->br_startoff),
- (void *)((unsigned long)(imapp->br_blockcount)),
- (void *)(__psint_t)(imapp->br_startblock));
-}
-#else
-#define xfs_iomap_enter_trace(tag, io, offset, count)
-#define xfs_iomap_map_trace(tag, io, offset, count, iomapp, imapp, flags)
-#endif
#define XFS_WRITEIO_ALIGN(mp,off) (((off) >> mp->m_writeio_log) \
<< mp->m_writeio_log)
STATIC int
xfs_imap_to_bmap(
- xfs_iocore_t *io,
+ xfs_inode_t *ip,
xfs_off_t offset,
xfs_bmbt_irec_t *imap,
xfs_iomap_t *iomapp,
int iomaps, /* Number of iomap entries */
int flags)
{
- xfs_mount_t *mp;
- xfs_fsize_t nisize;
+ xfs_mount_t *mp = ip->i_mount;
int pbm;
xfs_fsblock_t start_block;
- mp = io->io_mount;
- nisize = XFS_SIZE(mp, io);
- if (io->io_new_size > nisize)
- nisize = io->io_new_size;
for (pbm = 0; imaps && pbm < iomaps; imaps--, iomapp++, imap++, pbm++) {
iomapp->iomap_offset = XFS_FSB_TO_B(mp, imap->br_startoff);
iomapp->iomap_bsize = XFS_FSB_TO_B(mp, imap->br_blockcount);
iomapp->iomap_flags = flags;
- if (io->io_flags & XFS_IOCORE_RT) {
+ if (XFS_IS_REALTIME_INODE(ip)) {
iomapp->iomap_flags |= IOMAP_REALTIME;
iomapp->iomap_target = mp->m_rtdev_targp;
} else {
iomapp->iomap_bn = IOMAP_DADDR_NULL;
iomapp->iomap_flags |= IOMAP_DELAY;
} else {
- iomapp->iomap_bn = XFS_FSB_TO_DB_IO(io, start_block);
+ iomapp->iomap_bn = xfs_fsb_to_db(ip, start_block);
if (ISUNWRITTEN(imap))
iomapp->iomap_flags |= IOMAP_UNWRITTEN;
}
- if ((iomapp->iomap_offset + iomapp->iomap_bsize) >= nisize) {
- iomapp->iomap_flags |= IOMAP_EOF;
- }
-
offset += iomapp->iomap_bsize - iomapp->iomap_delta;
}
return pbm; /* Return the number filled */
int
xfs_iomap(
- xfs_iocore_t *io,
+ xfs_inode_t *ip,
xfs_off_t offset,
ssize_t count,
int flags,
xfs_iomap_t *iomapp,
int *niomaps)
{
- xfs_mount_t *mp = io->io_mount;
+ xfs_mount_t *mp = ip->i_mount;
xfs_fileoff_t offset_fsb, end_fsb;
int error = 0;
int lockmode = 0;
int bmapi_flags = 0;
int iomap_flags = 0;
+ ASSERT((ip->i_d.di_mode & S_IFMT) == S_IFREG);
+
if (XFS_FORCED_SHUTDOWN(mp))
return XFS_ERROR(EIO);
- switch (flags &
- (BMAPI_READ | BMAPI_WRITE | BMAPI_ALLOCATE |
- BMAPI_UNWRITTEN | BMAPI_DEVICE)) {
+ trace_xfs_iomap_enter(ip, offset, count, flags, NULL);
+
+ switch (flags & (BMAPI_READ | BMAPI_WRITE | BMAPI_ALLOCATE)) {
case BMAPI_READ:
- xfs_iomap_enter_trace(XFS_IOMAP_READ_ENTER, io, offset, count);
- lockmode = XFS_LCK_MAP_SHARED(mp, io);
+ lockmode = xfs_ilock_map_shared(ip);
bmapi_flags = XFS_BMAPI_ENTIRE;
- if (flags & BMAPI_IGNSTATE)
- bmapi_flags |= XFS_BMAPI_IGSTATE;
break;
case BMAPI_WRITE:
- xfs_iomap_enter_trace(XFS_IOMAP_WRITE_ENTER, io, offset, count);
- lockmode = XFS_ILOCK_EXCL|XFS_EXTSIZE_WR;
- bmapi_flags = 0;
- XFS_ILOCK(mp, io, lockmode);
+ lockmode = XFS_ILOCK_EXCL;
+ if (flags & BMAPI_IGNSTATE)
+ bmapi_flags |= XFS_BMAPI_IGSTATE|XFS_BMAPI_ENTIRE;
+ xfs_ilock(ip, lockmode);
break;
case BMAPI_ALLOCATE:
- xfs_iomap_enter_trace(XFS_IOMAP_ALLOC_ENTER, io, offset, count);
- lockmode = XFS_ILOCK_SHARED|XFS_EXTSIZE_RD;
+ lockmode = XFS_ILOCK_SHARED;
bmapi_flags = XFS_BMAPI_ENTIRE;
+
/* Attempt non-blocking lock */
if (flags & BMAPI_TRYLOCK) {
- if (!XFS_ILOCK_NOWAIT(mp, io, lockmode))
+ if (!xfs_ilock_nowait(ip, lockmode))
return XFS_ERROR(EAGAIN);
} else {
- XFS_ILOCK(mp, io, lockmode);
+ xfs_ilock(ip, lockmode);
}
break;
- case BMAPI_UNWRITTEN:
- goto phase2;
- case BMAPI_DEVICE:
- lockmode = XFS_LCK_MAP_SHARED(mp, io);
- iomapp->iomap_target = io->io_flags & XFS_IOCORE_RT ?
- mp->m_rtdev_targp : mp->m_ddev_targp;
- error = 0;
- *niomaps = 1;
- goto out;
default:
BUG();
}
end_fsb = XFS_B_TO_FSB(mp, (xfs_ufsize_t)offset + count);
offset_fsb = XFS_B_TO_FSBT(mp, offset);
- error = XFS_BMAPI(mp, NULL, io, offset_fsb,
+ error = xfs_bmapi(NULL, ip, offset_fsb,
(xfs_filblks_t)(end_fsb - offset_fsb),
bmapi_flags, NULL, 0, &imap,
- &nimaps, NULL);
+ &nimaps, NULL, NULL);
if (error)
goto out;
-phase2:
- switch (flags & (BMAPI_WRITE|BMAPI_ALLOCATE|BMAPI_UNWRITTEN)) {
+ switch (flags & (BMAPI_WRITE|BMAPI_ALLOCATE)) {
case BMAPI_WRITE:
/* If we found an extent, return it */
if (nimaps &&
- (imap.br_startblock != HOLESTARTBLOCK) &&
+ (imap.br_startblock != HOLESTARTBLOCK) &&
(imap.br_startblock != DELAYSTARTBLOCK)) {
- xfs_iomap_map_trace(XFS_IOMAP_WRITE_MAP, io,
- offset, count, iomapp, &imap, flags);
+ trace_xfs_iomap_found(ip, offset, count, flags, &imap);
break;
}
if (flags & (BMAPI_DIRECT|BMAPI_MMAP)) {
- error = XFS_IOMAP_WRITE_DIRECT(mp, io, offset,
- count, flags, &imap, &nimaps, nimaps);
+ error = xfs_iomap_write_direct(ip, offset, count, flags,
+ &imap, &nimaps, nimaps);
} else {
- error = XFS_IOMAP_WRITE_DELAY(mp, io, offset, count,
- flags, &imap, &nimaps);
+ error = xfs_iomap_write_delay(ip, offset, count, flags,
+ &imap, &nimaps);
}
if (!error) {
- xfs_iomap_map_trace(XFS_IOMAP_ALLOC_MAP, io,
- offset, count, iomapp, &imap, flags);
+ trace_xfs_iomap_alloc(ip, offset, count, flags, &imap);
}
iomap_flags = IOMAP_NEW;
break;
case BMAPI_ALLOCATE:
/* If we found an extent, return it */
- XFS_IUNLOCK(mp, io, lockmode);
+ xfs_iunlock(ip, lockmode);
lockmode = 0;
- if (nimaps && !ISNULLSTARTBLOCK(imap.br_startblock)) {
- xfs_iomap_map_trace(XFS_IOMAP_WRITE_MAP, io,
- offset, count, iomapp, &imap, flags);
+ if (nimaps && !isnullstartblock(imap.br_startblock)) {
+ trace_xfs_iomap_found(ip, offset, count, flags, &imap);
break;
}
- error = XFS_IOMAP_WRITE_ALLOCATE(mp, io, offset, count,
+ error = xfs_iomap_write_allocate(ip, offset, count,
&imap, &nimaps);
break;
- case BMAPI_UNWRITTEN:
- lockmode = 0;
- error = XFS_IOMAP_WRITE_UNWRITTEN(mp, io, offset, count);
- nimaps = 0;
- break;
}
if (nimaps) {
- *niomaps = xfs_imap_to_bmap(io, offset, &imap,
+ *niomaps = xfs_imap_to_bmap(ip, offset, &imap,
iomapp, nimaps, *niomaps, iomap_flags);
} else if (niomaps) {
*niomaps = 0;
out:
if (lockmode)
- XFS_IUNLOCK(mp, io, lockmode);
+ xfs_iunlock(ip, lockmode);
return XFS_ERROR(error);
}
+
STATIC int
-xfs_flush_space(
+xfs_iomap_eof_align_last_fsb(
+ xfs_mount_t *mp,
xfs_inode_t *ip,
- int *fsynced,
- int *ioflags)
+ xfs_extlen_t extsize,
+ xfs_fileoff_t *last_fsb)
{
- switch (*fsynced) {
- case 0:
- if (ip->i_delayed_blks) {
- xfs_iunlock(ip, XFS_ILOCK_EXCL);
- xfs_flush_inode(ip);
- xfs_ilock(ip, XFS_ILOCK_EXCL);
- *fsynced = 1;
- } else {
- *ioflags |= BMAPI_SYNC;
- *fsynced = 2;
- }
- return 0;
- case 1:
- *fsynced = 2;
- *ioflags |= BMAPI_SYNC;
- return 0;
- case 2:
- xfs_iunlock(ip, XFS_ILOCK_EXCL);
- xfs_flush_device(ip);
- xfs_ilock(ip, XFS_ILOCK_EXCL);
- *fsynced = 3;
- return 0;
+ xfs_fileoff_t new_last_fsb = 0;
+ xfs_extlen_t align;
+ int eof, error;
+
+ if (XFS_IS_REALTIME_INODE(ip))
+ ;
+ /*
+ * If mounted with the "-o swalloc" option, roundup the allocation
+ * request to a stripe width boundary if the file size is >=
+ * stripe width and we are allocating past the allocation eof.
+ */
+ else if (mp->m_swidth && (mp->m_flags & XFS_MOUNT_SWALLOC) &&
+ (ip->i_size >= XFS_FSB_TO_B(mp, mp->m_swidth)))
+ new_last_fsb = roundup_64(*last_fsb, mp->m_swidth);
+ /*
+ * Roundup the allocation request to a stripe unit (m_dalign) boundary
+ * if the file size is >= stripe unit size, and we are allocating past
+ * the allocation eof.
+ */
+ else if (mp->m_dalign && (ip->i_size >= XFS_FSB_TO_B(mp, mp->m_dalign)))
+ new_last_fsb = roundup_64(*last_fsb, mp->m_dalign);
+
+ /*
+ * Always round up the allocation request to an extent boundary
+ * (when file on a real-time subvolume or has di_extsize hint).
+ */
+ if (extsize) {
+ if (new_last_fsb)
+ align = roundup_64(new_last_fsb, extsize);
+ else
+ align = extsize;
+ new_last_fsb = roundup_64(*last_fsb, align);
+ }
+
+ if (new_last_fsb) {
+ error = xfs_bmap_eof(ip, new_last_fsb, XFS_DATA_FORK, &eof);
+ if (error)
+ return error;
+ if (eof)
+ *last_fsb = new_last_fsb;
}
- return 1;
+ return 0;
+}
+
+STATIC int
+xfs_cmn_err_fsblock_zero(
+ xfs_inode_t *ip,
+ xfs_bmbt_irec_t *imap)
+{
+ xfs_cmn_err(XFS_PTAG_FSBLOCK_ZERO, CE_ALERT, ip->i_mount,
+ "Access to block zero in inode %llu "
+ "start_block: %llx start_off: %llx "
+ "blkcnt: %llx extent-state: %x\n",
+ (unsigned long long)ip->i_ino,
+ (unsigned long long)imap->br_startblock,
+ (unsigned long long)imap->br_startoff,
+ (unsigned long long)imap->br_blockcount,
+ imap->br_state);
+ return EFSCORRUPTED;
}
int
int found)
{
xfs_mount_t *mp = ip->i_mount;
- xfs_iocore_t *io = &ip->i_iocore;
xfs_fileoff_t offset_fsb;
xfs_fileoff_t last_fsb;
- xfs_filblks_t count_fsb;
- xfs_fsize_t isize;
+ xfs_filblks_t count_fsb, resaligned;
xfs_fsblock_t firstfsb;
- int nimaps, maps;
- int error;
+ xfs_extlen_t extsz, temp;
+ int nimaps;
int bmapi_flag;
+ int quota_flag;
int rt;
xfs_trans_t *tp;
- xfs_bmbt_irec_t imap[XFS_WRITE_IMAPS], *imapp;
+ xfs_bmbt_irec_t imap;
xfs_bmap_free_t free_list;
- int aeof;
- xfs_filblks_t datablocks;
+ uint qblocks, resblks, resrtextents;
int committed;
- int numrtextents;
- uint resblks;
+ int error;
/*
* Make sure that the dquots are there. This doesn't hold
* the ilock across a disk read.
*/
- error = XFS_QM_DQATTACH(ip->i_mount, ip, XFS_QMOPT_ILOCKED);
+ error = xfs_qm_dqattach_locked(ip, 0);
if (error)
return XFS_ERROR(error);
- maps = min(XFS_WRITE_IMAPS, *nmaps);
- nimaps = maps;
-
- isize = ip->i_d.di_size;
- aeof = (offset + count) > isize;
-
- if (io->io_new_size > isize)
- isize = io->io_new_size;
+ rt = XFS_IS_REALTIME_INODE(ip);
+ extsz = xfs_get_extsz_hint(ip);
offset_fsb = XFS_B_TO_FSBT(mp, offset);
last_fsb = XFS_B_TO_FSB(mp, ((xfs_ufsize_t)(offset + count)));
+ if ((offset + count) > ip->i_size) {
+ error = xfs_iomap_eof_align_last_fsb(mp, ip, extsz, &last_fsb);
+ if (error)
+ goto error_out;
+ } else {
+ if (found && (ret_imap->br_startblock == HOLESTARTBLOCK))
+ last_fsb = MIN(last_fsb, (xfs_fileoff_t)
+ ret_imap->br_blockcount +
+ ret_imap->br_startoff);
+ }
count_fsb = last_fsb - offset_fsb;
- if (found && (ret_imap->br_startblock == HOLESTARTBLOCK)) {
- xfs_fileoff_t map_last_fsb;
-
- map_last_fsb = ret_imap->br_blockcount + ret_imap->br_startoff;
-
- if (map_last_fsb < last_fsb) {
- last_fsb = map_last_fsb;
- count_fsb = last_fsb - offset_fsb;
- }
- ASSERT(count_fsb > 0);
+ ASSERT(count_fsb > 0);
+
+ resaligned = count_fsb;
+ if (unlikely(extsz)) {
+ if ((temp = do_mod(offset_fsb, extsz)))
+ resaligned += temp;
+ if ((temp = do_mod(resaligned, extsz)))
+ resaligned += extsz - temp;
}
- /*
- * determine if reserving space on
- * the data or realtime partition.
- */
- if ((rt = XFS_IS_REALTIME_INODE(ip))) {
- int sbrtextsize, iprtextsize;
-
- sbrtextsize = mp->m_sb.sb_rextsize;
- iprtextsize =
- ip->i_d.di_extsize ? ip->i_d.di_extsize : sbrtextsize;
- numrtextents = (count_fsb + iprtextsize - 1);
- do_div(numrtextents, sbrtextsize);
- datablocks = 0;
+ if (unlikely(rt)) {
+ resrtextents = qblocks = resaligned;
+ resrtextents /= mp->m_sb.sb_rextsize;
+ resblks = XFS_DIOSTRAT_SPACE_RES(mp, 0);
+ quota_flag = XFS_QMOPT_RES_RTBLKS;
} else {
- datablocks = count_fsb;
- numrtextents = 0;
+ resrtextents = 0;
+ resblks = qblocks = XFS_DIOSTRAT_SPACE_RES(mp, resaligned);
+ quota_flag = XFS_QMOPT_RES_REGBLKS;
}
/*
- * allocate and setup the transaction
+ * Allocate and setup the transaction
*/
xfs_iunlock(ip, XFS_ILOCK_EXCL);
tp = xfs_trans_alloc(mp, XFS_TRANS_DIOSTRAT);
-
- resblks = XFS_DIOSTRAT_SPACE_RES(mp, datablocks);
-
error = xfs_trans_reserve(tp, resblks,
- XFS_WRITE_LOG_RES(mp), numrtextents,
+ XFS_WRITE_LOG_RES(mp), resrtextents,
XFS_TRANS_PERM_LOG_RES,
XFS_WRITE_LOG_COUNT);
-
/*
- * check for running out of space
+ * Check for running out of space, note: need lock to return
*/
if (error)
- /*
- * Free the transaction structure.
- */
xfs_trans_cancel(tp, 0);
-
xfs_ilock(ip, XFS_ILOCK_EXCL);
-
if (error)
- goto error_out; /* Don't return in above if .. trans ..,
- need lock to return */
+ goto error_out;
- if (XFS_TRANS_RESERVE_BLKQUOTA(mp, tp, ip, resblks)) {
- error = (EDQUOT);
+ error = xfs_trans_reserve_quota_nblks(tp, ip, qblocks, 0, quota_flag);
+ if (error)
goto error1;
- }
- nimaps = 1;
- bmapi_flag = XFS_BMAPI_WRITE;
xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
xfs_trans_ihold(tp, ip);
- if (!(flags & BMAPI_MMAP) && (offset < ip->i_d.di_size || rt))
+ bmapi_flag = XFS_BMAPI_WRITE;
+ if ((flags & BMAPI_DIRECT) && (offset < ip->i_size || extsz))
bmapi_flag |= XFS_BMAPI_PREALLOC;
/*
- * issue the bmapi() call to allocate the blocks
+ * Issue the xfs_bmapi() call to allocate the blocks
*/
- XFS_BMAP_INIT(&free_list, &firstfsb);
- imapp = &imap[0];
- error = xfs_bmapi(tp, ip, offset_fsb, count_fsb,
- bmapi_flag, &firstfsb, 0, imapp, &nimaps, &free_list);
- if (error) {
+ xfs_bmap_init(&free_list, &firstfsb);
+ nimaps = 1;
+ error = xfs_bmapi(tp, ip, offset_fsb, count_fsb, bmapi_flag,
+ &firstfsb, 0, &imap, &nimaps, &free_list, NULL);
+ if (error)
goto error0;
- }
/*
- * complete the transaction
+ * Complete the transaction
*/
-
- error = xfs_bmap_finish(&tp, &free_list, firstfsb, &committed);
- if (error) {
+ error = xfs_bmap_finish(&tp, &free_list, &committed);
+ if (error)
goto error0;
- }
+ error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES);
+ if (error)
+ goto error_out;
- error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES, NULL);
- if (error) {
+ /*
+ * Copy any maps to caller's array and return any error.
+ */
+ if (nimaps == 0) {
+ error = ENOSPC;
goto error_out;
}
- /* copy any maps to caller's array and return any error. */
- if (nimaps == 0) {
- error = (ENOSPC);
+ if (!(imap.br_startblock || XFS_IS_REALTIME_INODE(ip))) {
+ error = xfs_cmn_err_fsblock_zero(ip, &imap);
goto error_out;
}
- *ret_imap = imap[0];
+ *ret_imap = imap;
*nmaps = 1;
- if ( !(io->io_flags & XFS_IOCORE_RT) && !ret_imap->br_startblock) {
- cmn_err(CE_PANIC,"Access to block zero: fs <%s> inode: %lld "
- "start_block : %llx start_off : %llx blkcnt : %llx "
- "extent-state : %x \n",
- (ip->i_mount)->m_fsname,
- (long long)ip->i_ino,
- ret_imap->br_startblock, ret_imap->br_startoff,
- ret_imap->br_blockcount,ret_imap->br_state);
- }
return 0;
- error0: /* Cancel bmap, unlock inode, and cancel trans */
+error0: /* Cancel bmap, unlock inode, unreserve quota blocks, cancel trans */
xfs_bmap_cancel(&free_list);
+ xfs_trans_unreserve_quota_nblks(tp, ip, qblocks, 0, quota_flag);
- error1: /* Just cancel transaction */
+error1: /* Just cancel transaction */
xfs_trans_cancel(tp, XFS_TRANS_RELEASE_LOG_RES | XFS_TRANS_ABORT);
*nmaps = 0; /* nothing set-up here */
return XFS_ERROR(error);
}
+/*
+ * If the caller is doing a write at the end of the file, then extend the
+ * allocation out to the file system's write iosize. We clean up any extra
+ * space left over when the file is closed in xfs_inactive().
+ */
+STATIC int
+xfs_iomap_eof_want_preallocate(
+ xfs_mount_t *mp,
+ xfs_inode_t *ip,
+ xfs_off_t offset,
+ size_t count,
+ int ioflag,
+ xfs_bmbt_irec_t *imap,
+ int nimaps,
+ int *prealloc)
+{
+ xfs_fileoff_t start_fsb;
+ xfs_filblks_t count_fsb;
+ xfs_fsblock_t firstblock;
+ int n, error, imaps;
+
+ *prealloc = 0;
+ if ((offset + count) <= ip->i_size)
+ return 0;
+
+ /*
+ * If there are any real blocks past eof, then don't
+ * do any speculative allocation.
+ */
+ start_fsb = XFS_B_TO_FSBT(mp, ((xfs_ufsize_t)(offset + count - 1)));
+ count_fsb = XFS_B_TO_FSB(mp, (xfs_ufsize_t)XFS_MAXIOFFSET(mp));
+ while (count_fsb > 0) {
+ imaps = nimaps;
+ firstblock = NULLFSBLOCK;
+ error = xfs_bmapi(NULL, ip, start_fsb, count_fsb, 0,
+ &firstblock, 0, imap, &imaps, NULL, NULL);
+ if (error)
+ return error;
+ for (n = 0; n < imaps; n++) {
+ if ((imap[n].br_startblock != HOLESTARTBLOCK) &&
+ (imap[n].br_startblock != DELAYSTARTBLOCK))
+ return 0;
+ start_fsb += imap[n].br_blockcount;
+ count_fsb -= imap[n].br_blockcount;
+ }
+ }
+ *prealloc = 1;
+ return 0;
+}
+
int
xfs_iomap_write_delay(
xfs_inode_t *ip,
int *nmaps)
{
xfs_mount_t *mp = ip->i_mount;
- xfs_iocore_t *io = &ip->i_iocore;
xfs_fileoff_t offset_fsb;
xfs_fileoff_t last_fsb;
- xfs_fsize_t isize;
+ xfs_off_t aligned_offset;
+ xfs_fileoff_t ioalign;
xfs_fsblock_t firstblock;
+ xfs_extlen_t extsz;
int nimaps;
- int error;
xfs_bmbt_irec_t imap[XFS_WRITE_IMAPS];
- int aeof;
- int fsynced = 0;
+ int prealloc, flushed = 0;
+ int error;
- ASSERT(ismrlocked(&ip->i_lock, MR_UPDATE) != 0);
+ ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL));
/*
* Make sure that the dquots are there. This doesn't hold
* the ilock across a disk read.
*/
-
- error = XFS_QM_DQATTACH(mp, ip, XFS_QMOPT_ILOCKED);
+ error = xfs_qm_dqattach_locked(ip, 0);
if (error)
return XFS_ERROR(error);
-retry:
- isize = ip->i_d.di_size;
- if (io->io_new_size > isize) {
- isize = io->io_new_size;
- }
-
- aeof = 0;
+ extsz = xfs_get_extsz_hint(ip);
offset_fsb = XFS_B_TO_FSBT(mp, offset);
- last_fsb = XFS_B_TO_FSB(mp, ((xfs_ufsize_t)(offset + count)));
- /*
- * If the caller is doing a write at the end of the file,
- * then extend the allocation (and the buffer used for the write)
- * out to the file system's write iosize. We clean up any extra
- * space left over when the file is closed in xfs_inactive().
- *
- * For sync writes, we are flushing delayed allocate space to
- * try to make additional space available for allocation near
- * the filesystem full boundary - preallocation hurts in that
- * situation, of course.
- */
- if (!(ioflag & BMAPI_SYNC) && ((offset + count) > ip->i_d.di_size)) {
- xfs_off_t aligned_offset;
- xfs_filblks_t count_fsb;
- unsigned int iosize;
- xfs_fileoff_t ioalign;
- int n;
- xfs_fileoff_t start_fsb;
- /*
- * If there are any real blocks past eof, then don't
- * do any speculative allocation.
- */
- start_fsb = XFS_B_TO_FSBT(mp,
- ((xfs_ufsize_t)(offset + count - 1)));
- count_fsb = XFS_B_TO_FSB(mp, (xfs_ufsize_t)XFS_MAXIOFFSET(mp));
- while (count_fsb > 0) {
- nimaps = XFS_WRITE_IMAPS;
- error = XFS_BMAPI(mp, NULL, io, start_fsb, count_fsb,
- 0, &firstblock, 0, imap, &nimaps, NULL);
- if (error) {
- return error;
- }
- for (n = 0; n < nimaps; n++) {
- if ( !(io->io_flags & XFS_IOCORE_RT) &&
- !imap[n].br_startblock) {
- cmn_err(CE_PANIC,"Access to block "
- "zero: fs <%s> inode: %lld "
- "start_block : %llx start_off "
- ": %llx blkcnt : %llx "
- "extent-state : %x \n",
- (ip->i_mount)->m_fsname,
- (long long)ip->i_ino,
- imap[n].br_startblock,
- imap[n].br_startoff,
- imap[n].br_blockcount,
- imap[n].br_state);
- }
- if ((imap[n].br_startblock != HOLESTARTBLOCK) &&
- (imap[n].br_startblock != DELAYSTARTBLOCK)) {
- goto write_map;
- }
- start_fsb += imap[n].br_blockcount;
- count_fsb -= imap[n].br_blockcount;
- }
- }
- iosize = mp->m_writeio_blocks;
+ error = xfs_iomap_eof_want_preallocate(mp, ip, offset, count,
+ ioflag, imap, XFS_WRITE_IMAPS, &prealloc);
+ if (error)
+ return error;
+
+retry:
+ if (prealloc) {
aligned_offset = XFS_WRITEIO_ALIGN(mp, (offset + count - 1));
ioalign = XFS_B_TO_FSBT(mp, aligned_offset);
- last_fsb = ioalign + iosize;
- aeof = 1;
+ last_fsb = ioalign + mp->m_writeio_blocks;
+ } else {
+ last_fsb = XFS_B_TO_FSB(mp, ((xfs_ufsize_t)(offset + count)));
}
-write_map:
- nimaps = XFS_WRITE_IMAPS;
- firstblock = NULLFSBLOCK;
- /*
- * If mounted with the "-o swalloc" option, roundup the allocation
- * request to a stripe width boundary if the file size is >=
- * stripe width and we are allocating past the allocation eof.
- */
- if (!(io->io_flags & XFS_IOCORE_RT) && mp->m_swidth
- && (mp->m_flags & XFS_MOUNT_SWALLOC)
- && (isize >= XFS_FSB_TO_B(mp, mp->m_swidth)) && aeof) {
- int eof;
- xfs_fileoff_t new_last_fsb;
-
- new_last_fsb = roundup_64(last_fsb, mp->m_swidth);
- error = xfs_bmap_eof(ip, new_last_fsb, XFS_DATA_FORK, &eof);
- if (error) {
- return error;
- }
- if (eof) {
- last_fsb = new_last_fsb;
- }
- /*
- * Roundup the allocation request to a stripe unit (m_dalign) boundary
- * if the file size is >= stripe unit size, and we are allocating past
- * the allocation eof.
- */
- } else if (!(io->io_flags & XFS_IOCORE_RT) && mp->m_dalign &&
- (isize >= XFS_FSB_TO_B(mp, mp->m_dalign)) && aeof) {
- int eof;
- xfs_fileoff_t new_last_fsb;
- new_last_fsb = roundup_64(last_fsb, mp->m_dalign);
- error = xfs_bmap_eof(ip, new_last_fsb, XFS_DATA_FORK, &eof);
- if (error) {
- return error;
- }
- if (eof) {
- last_fsb = new_last_fsb;
- }
- /*
- * Round up the allocation request to a real-time extent boundary
- * if the file is on the real-time subvolume.
- */
- } else if (io->io_flags & XFS_IOCORE_RT && aeof) {
- int eof;
- xfs_fileoff_t new_last_fsb;
-
- new_last_fsb = roundup_64(last_fsb, mp->m_sb.sb_rextsize);
- error = XFS_BMAP_EOF(mp, io, new_last_fsb, XFS_DATA_FORK, &eof);
- if (error) {
+ if (prealloc || extsz) {
+ error = xfs_iomap_eof_align_last_fsb(mp, ip, extsz, &last_fsb);
+ if (error)
return error;
- }
- if (eof)
- last_fsb = new_last_fsb;
}
+
+ nimaps = XFS_WRITE_IMAPS;
+ firstblock = NULLFSBLOCK;
error = xfs_bmapi(NULL, ip, offset_fsb,
(xfs_filblks_t)(last_fsb - offset_fsb),
XFS_BMAPI_DELAY | XFS_BMAPI_WRITE |
XFS_BMAPI_ENTIRE, &firstblock, 1, imap,
- &nimaps, NULL);
- /*
- * This can be EDQUOT, if nimaps == 0
- */
- if (error && (error != ENOSPC)) {
+ &nimaps, NULL, NULL);
+ if (error && (error != ENOSPC))
return XFS_ERROR(error);
- }
+
/*
* If bmapi returned us nothing, and if we didn't get back EDQUOT,
- * then we must have run out of space.
+ * then we must have run out of space - flush all other inodes with
+ * delalloc blocks and retry without EOF preallocation.
*/
if (nimaps == 0) {
- xfs_iomap_enter_trace(XFS_IOMAP_WRITE_NOSPACE,
- io, offset, count);
- if (xfs_flush_space(ip, &fsynced, &ioflag))
+ trace_xfs_delalloc_enospc(ip, offset, count);
+ if (flushed)
return XFS_ERROR(ENOSPC);
+ xfs_iunlock(ip, XFS_ILOCK_EXCL);
+ xfs_flush_inodes(ip);
+ xfs_ilock(ip, XFS_ILOCK_EXCL);
+
+ flushed = 1;
error = 0;
+ prealloc = 0;
goto retry;
}
+ if (!(imap[0].br_startblock || XFS_IS_REALTIME_INODE(ip)))
+ return xfs_cmn_err_fsblock_zero(ip, &imap[0]);
+
*ret_imap = imap[0];
*nmaps = 1;
- if ( !(io->io_flags & XFS_IOCORE_RT) && !ret_imap->br_startblock) {
- cmn_err(CE_PANIC,"Access to block zero: fs <%s> inode: %lld "
- "start_block : %llx start_off : %llx blkcnt : %llx "
- "extent-state : %x \n",
- (ip->i_mount)->m_fsname,
- (long long)ip->i_ino,
- ret_imap->br_startblock, ret_imap->br_startoff,
- ret_imap->br_blockcount,ret_imap->br_state);
- }
+
return 0;
}
* the originating callers request.
*
* Called without a lock on the inode.
+ *
+ * We no longer bother to look at the incoming map - all we have to
+ * guarantee is that whatever we allocate fills the required range.
*/
int
xfs_iomap_write_allocate(
int *retmap)
{
xfs_mount_t *mp = ip->i_mount;
- xfs_iocore_t *io = &ip->i_iocore;
xfs_fileoff_t offset_fsb, last_block;
xfs_fileoff_t end_fsb, map_start_fsb;
xfs_fsblock_t first_block;
xfs_bmap_free_t free_list;
xfs_filblks_t count_fsb;
- xfs_bmbt_irec_t imap[XFS_STRAT_WRITE_IMAPS];
+ xfs_bmbt_irec_t imap;
xfs_trans_t *tp;
- int i, nimaps, committed;
+ int nimaps, committed;
int error = 0;
int nres;
/*
* Make sure that the dquots are there.
*/
- if ((error = XFS_QM_DQATTACH(mp, ip, 0)))
+ error = xfs_qm_dqattach(ip, 0);
+ if (error)
return XFS_ERROR(error);
offset_fsb = XFS_B_TO_FSBT(mp, offset);
nimaps = 0;
while (nimaps == 0) {
tp = xfs_trans_alloc(mp, XFS_TRANS_STRAT_WRITE);
+ tp->t_flags |= XFS_TRANS_RESERVE;
nres = XFS_EXTENTADD_SPACE_RES(mp, XFS_DATA_FORK);
error = xfs_trans_reserve(tp, nres,
XFS_WRITE_LOG_RES(mp),
0, XFS_TRANS_PERM_LOG_RES,
XFS_WRITE_LOG_COUNT);
- if (error == ENOSPC) {
- error = xfs_trans_reserve(tp, 0,
- XFS_WRITE_LOG_RES(mp),
- 0,
- XFS_TRANS_PERM_LOG_RES,
- XFS_WRITE_LOG_COUNT);
- }
if (error) {
xfs_trans_cancel(tp, 0);
return XFS_ERROR(error);
xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
xfs_trans_ihold(tp, ip);
- XFS_BMAP_INIT(&free_list, &first_block);
+ xfs_bmap_init(&free_list, &first_block);
- nimaps = XFS_STRAT_WRITE_IMAPS;
/*
- * Ensure we don't go beyond eof - it is possible
- * the extents changed since we did the read call,
- * we dropped the ilock in the interim.
+ * it is possible that the extents have changed since
+ * we did the read call as we dropped the ilock for a
+ * while. We have to be careful about truncates or hole
+ * punchs here - we are not allowed to allocate
+ * non-delalloc blocks here.
+ *
+ * The only protection against truncation is the pages
+ * for the range we are being asked to convert are
+ * locked and hence a truncate will block on them
+ * first.
+ *
+ * As a result, if we go beyond the range we really
+ * need and hit an delalloc extent boundary followed by
+ * a hole while we have excess blocks in the map, we
+ * will fill the hole incorrectly and overrun the
+ * transaction reservation.
+ *
+ * Using a single map prevents this as we are forced to
+ * check each map we look for overlap with the desired
+ * range and abort as soon as we find it. Also, given
+ * that we only return a single map, having one beyond
+ * what we can return is probably a bit silly.
+ *
+ * We also need to check that we don't go beyond EOF;
+ * this is a truncate optimisation as a truncate sets
+ * the new file size before block on the pages we
+ * currently have locked under writeback. Because they
+ * are about to be tossed, we don't need to write them
+ * back....
*/
+ nimaps = 1;
+ end_fsb = XFS_B_TO_FSB(mp, ip->i_size);
+ error = xfs_bmap_last_offset(NULL, ip, &last_block,
+ XFS_DATA_FORK);
+ if (error)
+ goto trans_cancel;
- end_fsb = XFS_B_TO_FSB(mp, ip->i_d.di_size);
- xfs_bmap_last_offset(NULL, ip, &last_block,
- XFS_DATA_FORK);
last_block = XFS_FILEOFF_MAX(last_block, end_fsb);
if ((map_start_fsb + count_fsb) > last_block) {
count_fsb = last_block - map_start_fsb;
/* Go get the actual blocks */
error = xfs_bmapi(tp, ip, map_start_fsb, count_fsb,
XFS_BMAPI_WRITE, &first_block, 1,
- imap, &nimaps, &free_list);
+ &imap, &nimaps, &free_list, NULL);
if (error)
goto trans_cancel;
- error = xfs_bmap_finish(&tp, &free_list,
- first_block, &committed);
+ error = xfs_bmap_finish(&tp, &free_list, &committed);
if (error)
goto trans_cancel;
- error = xfs_trans_commit(tp,
- XFS_TRANS_RELEASE_LOG_RES, NULL);
+ error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES);
if (error)
goto error0;
* See if we were able to allocate an extent that
* covers at least part of the callers request
*/
-
- for (i = 0; i < nimaps; i++) {
- if ( !(io->io_flags & XFS_IOCORE_RT) &&
- !imap[i].br_startblock) {
- cmn_err(CE_PANIC,"Access to block zero: "
- "fs <%s> inode: %lld "
- "start_block : %llx start_off : %llx "
- "blkcnt : %llx extent-state : %x \n",
- (ip->i_mount)->m_fsname,
- (long long)ip->i_ino,
- imap[i].br_startblock,
- imap[i].br_startoff,
- imap[i].br_blockcount,imap[i].br_state);
- }
- if ((offset_fsb >= imap[i].br_startoff) &&
- (offset_fsb < (imap[i].br_startoff +
- imap[i].br_blockcount))) {
- *map = imap[i];
- *retmap = 1;
- XFS_STATS_INC(xs_xstrat_quick);
- return 0;
- }
- count_fsb -= imap[i].br_blockcount;
+ if (!(imap.br_startblock || XFS_IS_REALTIME_INODE(ip)))
+ return xfs_cmn_err_fsblock_zero(ip, &imap);
+
+ if ((offset_fsb >= imap.br_startoff) &&
+ (offset_fsb < (imap.br_startoff +
+ imap.br_blockcount))) {
+ *map = imap;
+ *retmap = 1;
+ XFS_STATS_INC(xs_xstrat_quick);
+ return 0;
}
- /* So far we have not mapped the requested part of the
+ /*
+ * So far we have not mapped the requested part of the
* file, just surrounding data, try again.
*/
- nimaps--;
- map_start_fsb = imap[nimaps].br_startoff +
- imap[nimaps].br_blockcount;
+ count_fsb -= imap.br_blockcount;
+ map_start_fsb = imap.br_startoff + imap.br_blockcount;
}
trans_cancel:
size_t count)
{
xfs_mount_t *mp = ip->i_mount;
- xfs_iocore_t *io = &ip->i_iocore;
- xfs_trans_t *tp;
xfs_fileoff_t offset_fsb;
xfs_filblks_t count_fsb;
xfs_filblks_t numblks_fsb;
- xfs_bmbt_irec_t imap;
+ xfs_fsblock_t firstfsb;
+ int nimaps;
+ xfs_trans_t *tp;
+ xfs_bmbt_irec_t imap;
+ xfs_bmap_free_t free_list;
+ uint resblks;
int committed;
int error;
- int nres;
- int nimaps;
- xfs_fsblock_t firstfsb;
- xfs_bmap_free_t free_list;
- xfs_iomap_enter_trace(XFS_IOMAP_UNWRITTEN,
- &ip->i_iocore, offset, count);
+ trace_xfs_unwritten_convert(ip, offset, count);
offset_fsb = XFS_B_TO_FSBT(mp, offset);
count_fsb = XFS_B_TO_FSB(mp, (xfs_ufsize_t)offset + count);
count_fsb = (xfs_filblks_t)(count_fsb - offset_fsb);
- do {
- nres = XFS_DIOSTRAT_SPACE_RES(mp, 0);
+ /*
+ * Reserve enough blocks in this transaction for two complete extent
+ * btree splits. We may be converting the middle part of an unwritten
+ * extent and in this case we will insert two new extents in the btree
+ * each of which could cause a full split.
+ *
+ * This reservation amount will be used in the first call to
+ * xfs_bmbt_split() to select an AG with enough space to satisfy the
+ * rest of the operation.
+ */
+ resblks = XFS_DIOSTRAT_SPACE_RES(mp, 0) << 1;
+ do {
/*
* set up a transaction to convert the range of extents
* from unwritten to real. Do allocations in a loop until
* we have covered the range passed in.
+ *
+ * Note that we open code the transaction allocation here
+ * to pass KM_NOFS--we can't risk to recursing back into
+ * the filesystem here as we might be asked to write out
+ * the same inode that we complete here and might deadlock
+ * on the iolock.
*/
-
- tp = xfs_trans_alloc(mp, XFS_TRANS_STRAT_WRITE);
- error = xfs_trans_reserve(tp, nres,
+ xfs_wait_for_freeze(mp, SB_FREEZE_TRANS);
+ tp = _xfs_trans_alloc(mp, XFS_TRANS_STRAT_WRITE, KM_NOFS);
+ tp->t_flags |= XFS_TRANS_RESERVE;
+ error = xfs_trans_reserve(tp, resblks,
XFS_WRITE_LOG_RES(mp), 0,
XFS_TRANS_PERM_LOG_RES,
XFS_WRITE_LOG_COUNT);
if (error) {
xfs_trans_cancel(tp, 0);
- goto error0;
+ return XFS_ERROR(error);
}
xfs_ilock(ip, XFS_ILOCK_EXCL);
/*
* Modify the unwritten extent state of the buffer.
*/
- XFS_BMAP_INIT(&free_list, &firstfsb);
+ xfs_bmap_init(&free_list, &firstfsb);
nimaps = 1;
error = xfs_bmapi(tp, ip, offset_fsb, count_fsb,
- XFS_BMAPI_WRITE, &firstfsb,
- 1, &imap, &nimaps, &free_list);
+ XFS_BMAPI_WRITE|XFS_BMAPI_CONVERT, &firstfsb,
+ 1, &imap, &nimaps, &free_list, NULL);
if (error)
goto error_on_bmapi_transaction;
- error = xfs_bmap_finish(&(tp), &(free_list),
- firstfsb, &committed);
+ error = xfs_bmap_finish(&(tp), &(free_list), &committed);
if (error)
goto error_on_bmapi_transaction;
- error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES, NULL);
+ error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES);
xfs_iunlock(ip, XFS_ILOCK_EXCL);
if (error)
- goto error0;
-
- if ( !(io->io_flags & XFS_IOCORE_RT) && !imap.br_startblock) {
- cmn_err(CE_PANIC,"Access to block zero: fs <%s> "
- "inode: %lld start_block : %llx start_off : "
- "%llx blkcnt : %llx extent-state : %x \n",
- (ip->i_mount)->m_fsname,
- (long long)ip->i_ino,
- imap.br_startblock,imap.br_startoff,
- imap.br_blockcount,imap.br_state);
- }
+ return XFS_ERROR(error);
+
+ if (!(imap.br_startblock || XFS_IS_REALTIME_INODE(ip)))
+ return xfs_cmn_err_fsblock_zero(ip, &imap);
if ((numblks_fsb = imap.br_blockcount) == 0) {
/*
xfs_bmap_cancel(&free_list);
xfs_trans_cancel(tp, (XFS_TRANS_RELEASE_LOG_RES | XFS_TRANS_ABORT));
xfs_iunlock(ip, XFS_ILOCK_EXCL);
-error0:
return XFS_ERROR(error);
}
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff