linux-sg2042/fs/xfs/xfs_dfrag.c

449 lines
12 KiB
C
Raw Normal View History

/*
* 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 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. See the
* GNU General Public License for more details.
*
* 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_types.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_mount.h"
#include "xfs_bmap_btree.h"
#include "xfs_dinode.h"
#include "xfs_inode.h"
#include "xfs_inode_item.h"
#include "xfs_bmap.h"
#include "xfs_itable.h"
#include "xfs_dfrag.h"
#include "xfs_error.h"
#include "xfs_vnodeops.h"
xfs: event tracing support Convert the old xfs tracing support that could only be used with the out of tree kdb and xfsidbg patches to use the generic event tracer. To use it make sure CONFIG_EVENT_TRACING is enabled and then enable all xfs trace channels by: echo 1 > /sys/kernel/debug/tracing/events/xfs/enable or alternatively enable single events by just doing the same in one event subdirectory, e.g. echo 1 > /sys/kernel/debug/tracing/events/xfs/xfs_ihold/enable or set more complex filters, etc. In Documentation/trace/events.txt all this is desctribed in more detail. To reads the events do a cat /sys/kernel/debug/tracing/trace Compared to the last posting this patch converts the tracing mostly to the one tracepoint per callsite model that other users of the new tracing facility also employ. This allows a very fine-grained control of the tracing, a cleaner output of the traces and also enables the perf tool to use each tracepoint as a virtual performance counter, allowing us to e.g. count how often certain workloads git various spots in XFS. Take a look at http://lwn.net/Articles/346470/ for some examples. Also the btree tracing isn't included at all yet, as it will require additional core tracing features not in mainline yet, I plan to deliver it later. And the really nice thing about this patch is that it actually removes many lines of code while adding this nice functionality: fs/xfs/Makefile | 8 fs/xfs/linux-2.6/xfs_acl.c | 1 fs/xfs/linux-2.6/xfs_aops.c | 52 - fs/xfs/linux-2.6/xfs_aops.h | 2 fs/xfs/linux-2.6/xfs_buf.c | 117 +-- fs/xfs/linux-2.6/xfs_buf.h | 33 fs/xfs/linux-2.6/xfs_fs_subr.c | 3 fs/xfs/linux-2.6/xfs_ioctl.c | 1 fs/xfs/linux-2.6/xfs_ioctl32.c | 1 fs/xfs/linux-2.6/xfs_iops.c | 1 fs/xfs/linux-2.6/xfs_linux.h | 1 fs/xfs/linux-2.6/xfs_lrw.c | 87 -- fs/xfs/linux-2.6/xfs_lrw.h | 45 - fs/xfs/linux-2.6/xfs_super.c | 104 --- fs/xfs/linux-2.6/xfs_super.h | 7 fs/xfs/linux-2.6/xfs_sync.c | 1 fs/xfs/linux-2.6/xfs_trace.c | 75 ++ fs/xfs/linux-2.6/xfs_trace.h | 1369 +++++++++++++++++++++++++++++++++++++++++ fs/xfs/linux-2.6/xfs_vnode.h | 4 fs/xfs/quota/xfs_dquot.c | 110 --- fs/xfs/quota/xfs_dquot.h | 21 fs/xfs/quota/xfs_qm.c | 40 - fs/xfs/quota/xfs_qm_syscalls.c | 4 fs/xfs/support/ktrace.c | 323 --------- fs/xfs/support/ktrace.h | 85 -- fs/xfs/xfs.h | 16 fs/xfs/xfs_ag.h | 14 fs/xfs/xfs_alloc.c | 230 +----- fs/xfs/xfs_alloc.h | 27 fs/xfs/xfs_alloc_btree.c | 1 fs/xfs/xfs_attr.c | 107 --- fs/xfs/xfs_attr.h | 10 fs/xfs/xfs_attr_leaf.c | 14 fs/xfs/xfs_attr_sf.h | 40 - fs/xfs/xfs_bmap.c | 507 +++------------ fs/xfs/xfs_bmap.h | 49 - fs/xfs/xfs_bmap_btree.c | 6 fs/xfs/xfs_btree.c | 5 fs/xfs/xfs_btree_trace.h | 17 fs/xfs/xfs_buf_item.c | 87 -- fs/xfs/xfs_buf_item.h | 20 fs/xfs/xfs_da_btree.c | 3 fs/xfs/xfs_da_btree.h | 7 fs/xfs/xfs_dfrag.c | 2 fs/xfs/xfs_dir2.c | 8 fs/xfs/xfs_dir2_block.c | 20 fs/xfs/xfs_dir2_leaf.c | 21 fs/xfs/xfs_dir2_node.c | 27 fs/xfs/xfs_dir2_sf.c | 26 fs/xfs/xfs_dir2_trace.c | 216 ------ fs/xfs/xfs_dir2_trace.h | 72 -- fs/xfs/xfs_filestream.c | 8 fs/xfs/xfs_fsops.c | 2 fs/xfs/xfs_iget.c | 111 --- fs/xfs/xfs_inode.c | 67 -- fs/xfs/xfs_inode.h | 76 -- fs/xfs/xfs_inode_item.c | 5 fs/xfs/xfs_iomap.c | 85 -- fs/xfs/xfs_iomap.h | 8 fs/xfs/xfs_log.c | 181 +---- fs/xfs/xfs_log_priv.h | 20 fs/xfs/xfs_log_recover.c | 1 fs/xfs/xfs_mount.c | 2 fs/xfs/xfs_quota.h | 8 fs/xfs/xfs_rename.c | 1 fs/xfs/xfs_rtalloc.c | 1 fs/xfs/xfs_rw.c | 3 fs/xfs/xfs_trans.h | 47 + fs/xfs/xfs_trans_buf.c | 62 - fs/xfs/xfs_vnodeops.c | 8 70 files changed, 2151 insertions(+), 2592 deletions(-) Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Alex Elder <aelder@sgi.com>
2009-12-15 07:14:59 +08:00
#include "xfs_trace.h"
static int xfs_swap_extents(
xfs_inode_t *ip, /* target inode */
xfs_inode_t *tip, /* tmp inode */
xfs_swapext_t *sxp);
/*
* ioctl interface for swapext
*/
int
xfs_swapext(
xfs_swapext_t *sxp)
{
xfs_inode_t *ip, *tip;
struct file *file, *tmp_file;
int error = 0;
/* Pull information for the target fd */
file = fget((int)sxp->sx_fdtarget);
if (!file) {
error = XFS_ERROR(EINVAL);
goto out;
}
if (!(file->f_mode & FMODE_WRITE) ||
!(file->f_mode & FMODE_READ) ||
(file->f_flags & O_APPEND)) {
error = XFS_ERROR(EBADF);
goto out_put_file;
}
tmp_file = fget((int)sxp->sx_fdtmp);
if (!tmp_file) {
error = XFS_ERROR(EINVAL);
goto out_put_file;
}
if (!(tmp_file->f_mode & FMODE_WRITE) ||
!(tmp_file->f_mode & FMODE_READ) ||
(tmp_file->f_flags & O_APPEND)) {
error = XFS_ERROR(EBADF);
goto out_put_tmp_file;
}
if (IS_SWAPFILE(file->f_path.dentry->d_inode) ||
IS_SWAPFILE(tmp_file->f_path.dentry->d_inode)) {
error = XFS_ERROR(EINVAL);
goto out_put_tmp_file;
}
ip = XFS_I(file->f_path.dentry->d_inode);
tip = XFS_I(tmp_file->f_path.dentry->d_inode);
if (ip->i_mount != tip->i_mount) {
error = XFS_ERROR(EINVAL);
goto out_put_tmp_file;
}
if (ip->i_ino == tip->i_ino) {
error = XFS_ERROR(EINVAL);
goto out_put_tmp_file;
}
if (XFS_FORCED_SHUTDOWN(ip->i_mount)) {
error = XFS_ERROR(EIO);
goto out_put_tmp_file;
}
error = xfs_swap_extents(ip, tip, sxp);
out_put_tmp_file:
fput(tmp_file);
out_put_file:
fput(file);
out:
return error;
}
xfs: xfs_swap_extents needs to handle dynamic fork offsets When swapping extents, we can corrupt inodes by swapping data forks that are in incompatible formats. This is caused by the two indoes having different fork offsets due to the presence of an attribute fork on an attr2 filesystem. xfs_fsr tries to be smart about setting the fork offset, but the trick it plays only works on attr1 (old fixed format attribute fork) filesystems. Changing the way xfs_fsr sets up the attribute fork will prevent this situation from ever occurring, so in the kernel code we can get by with a preventative fix - check that the data fork in the defragmented inode is in a format valid for the inode it is being swapped into. This will lead to files that will silently and potentially repeatedly fail defragmentation, so issue a warning to the log when this particular failure occurs to let us know that xfs_fsr needs updating/fixing. To help identify how to improve xfs_fsr to avoid this issue, add trace points for the inodes being swapped so that we can determine why the swap was rejected and to confirm that the code is making the right decisions and modifications when swapping forks. A further complication is even when the swap is allowed to proceed when the fork offset is different between the two inodes then value for the maximum number of extents the data fork can hold can be wrong. Make sure these are also set correctly after the swap occurs. Signed-off-by: Dave Chinner <david@fromorbit.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Alex Elder <aelder@sgi.com>
2010-01-14 09:33:54 +08:00
/*
* We need to check that the format of the data fork in the temporary inode is
* valid for the target inode before doing the swap. This is not a problem with
* attr1 because of the fixed fork offset, but attr2 has a dynamically sized
* data fork depending on the space the attribute fork is taking so we can get
* invalid formats on the target inode.
*
* E.g. target has space for 7 extents in extent format, temp inode only has
* space for 6. If we defragment down to 7 extents, then the tmp format is a
* btree, but when swapped it needs to be in extent format. Hence we can't just
* blindly swap data forks on attr2 filesystems.
*
* Note that we check the swap in both directions so that we don't end up with
* a corrupt temporary inode, either.
*
* Note that fixing the way xfs_fsr sets up the attribute fork in the source
* inode will prevent this situation from occurring, so all we do here is
* reject and log the attempt. basically we are putting the responsibility on
* userspace to get this right.
*/
static int
xfs_swap_extents_check_format(
xfs_inode_t *ip, /* target inode */
xfs_inode_t *tip) /* tmp inode */
{
/* Should never get a local format */
if (ip->i_d.di_format == XFS_DINODE_FMT_LOCAL ||
tip->i_d.di_format == XFS_DINODE_FMT_LOCAL)
return EINVAL;
/*
* if the target inode has less extents that then temporary inode then
* why did userspace call us?
*/
if (ip->i_d.di_nextents < tip->i_d.di_nextents)
return EINVAL;
/*
* if the target inode is in extent form and the temp inode is in btree
* form then we will end up with the target inode in the wrong format
* as we already know there are less extents in the temp inode.
*/
if (ip->i_d.di_format == XFS_DINODE_FMT_EXTENTS &&
tip->i_d.di_format == XFS_DINODE_FMT_BTREE)
return EINVAL;
/* Check temp in extent form to max in target */
if (tip->i_d.di_format == XFS_DINODE_FMT_EXTENTS &&
XFS_IFORK_NEXTENTS(tip, XFS_DATA_FORK) > ip->i_df.if_ext_max)
return EINVAL;
/* Check target in extent form to max in temp */
if (ip->i_d.di_format == XFS_DINODE_FMT_EXTENTS &&
XFS_IFORK_NEXTENTS(ip, XFS_DATA_FORK) > tip->i_df.if_ext_max)
return EINVAL;
/*
* If we are in a btree format, check that the temp root block will fit
* in the target and that it has enough extents to be in btree format
* in the target.
*
* Note that we have to be careful to allow btree->extent conversions
* (a common defrag case) which will occur when the temp inode is in
* extent format...
*/
xfs: xfs_swap_extents needs to handle dynamic fork offsets When swapping extents, we can corrupt inodes by swapping data forks that are in incompatible formats. This is caused by the two indoes having different fork offsets due to the presence of an attribute fork on an attr2 filesystem. xfs_fsr tries to be smart about setting the fork offset, but the trick it plays only works on attr1 (old fixed format attribute fork) filesystems. Changing the way xfs_fsr sets up the attribute fork will prevent this situation from ever occurring, so in the kernel code we can get by with a preventative fix - check that the data fork in the defragmented inode is in a format valid for the inode it is being swapped into. This will lead to files that will silently and potentially repeatedly fail defragmentation, so issue a warning to the log when this particular failure occurs to let us know that xfs_fsr needs updating/fixing. To help identify how to improve xfs_fsr to avoid this issue, add trace points for the inodes being swapped so that we can determine why the swap was rejected and to confirm that the code is making the right decisions and modifications when swapping forks. A further complication is even when the swap is allowed to proceed when the fork offset is different between the two inodes then value for the maximum number of extents the data fork can hold can be wrong. Make sure these are also set correctly after the swap occurs. Signed-off-by: Dave Chinner <david@fromorbit.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Alex Elder <aelder@sgi.com>
2010-01-14 09:33:54 +08:00
if (tip->i_d.di_format == XFS_DINODE_FMT_BTREE &&
((XFS_IFORK_BOFF(ip) &&
tip->i_df.if_broot_bytes > XFS_IFORK_BOFF(ip)) ||
XFS_IFORK_NEXTENTS(tip, XFS_DATA_FORK) <= ip->i_df.if_ext_max))
xfs: xfs_swap_extents needs to handle dynamic fork offsets When swapping extents, we can corrupt inodes by swapping data forks that are in incompatible formats. This is caused by the two indoes having different fork offsets due to the presence of an attribute fork on an attr2 filesystem. xfs_fsr tries to be smart about setting the fork offset, but the trick it plays only works on attr1 (old fixed format attribute fork) filesystems. Changing the way xfs_fsr sets up the attribute fork will prevent this situation from ever occurring, so in the kernel code we can get by with a preventative fix - check that the data fork in the defragmented inode is in a format valid for the inode it is being swapped into. This will lead to files that will silently and potentially repeatedly fail defragmentation, so issue a warning to the log when this particular failure occurs to let us know that xfs_fsr needs updating/fixing. To help identify how to improve xfs_fsr to avoid this issue, add trace points for the inodes being swapped so that we can determine why the swap was rejected and to confirm that the code is making the right decisions and modifications when swapping forks. A further complication is even when the swap is allowed to proceed when the fork offset is different between the two inodes then value for the maximum number of extents the data fork can hold can be wrong. Make sure these are also set correctly after the swap occurs. Signed-off-by: Dave Chinner <david@fromorbit.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Alex Elder <aelder@sgi.com>
2010-01-14 09:33:54 +08:00
return EINVAL;
/* Reciprocal target->temp btree format checks */
xfs: xfs_swap_extents needs to handle dynamic fork offsets When swapping extents, we can corrupt inodes by swapping data forks that are in incompatible formats. This is caused by the two indoes having different fork offsets due to the presence of an attribute fork on an attr2 filesystem. xfs_fsr tries to be smart about setting the fork offset, but the trick it plays only works on attr1 (old fixed format attribute fork) filesystems. Changing the way xfs_fsr sets up the attribute fork will prevent this situation from ever occurring, so in the kernel code we can get by with a preventative fix - check that the data fork in the defragmented inode is in a format valid for the inode it is being swapped into. This will lead to files that will silently and potentially repeatedly fail defragmentation, so issue a warning to the log when this particular failure occurs to let us know that xfs_fsr needs updating/fixing. To help identify how to improve xfs_fsr to avoid this issue, add trace points for the inodes being swapped so that we can determine why the swap was rejected and to confirm that the code is making the right decisions and modifications when swapping forks. A further complication is even when the swap is allowed to proceed when the fork offset is different between the two inodes then value for the maximum number of extents the data fork can hold can be wrong. Make sure these are also set correctly after the swap occurs. Signed-off-by: Dave Chinner <david@fromorbit.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Alex Elder <aelder@sgi.com>
2010-01-14 09:33:54 +08:00
if (ip->i_d.di_format == XFS_DINODE_FMT_BTREE &&
((XFS_IFORK_BOFF(tip) &&
ip->i_df.if_broot_bytes > XFS_IFORK_BOFF(tip)) ||
XFS_IFORK_NEXTENTS(ip, XFS_DATA_FORK) <= tip->i_df.if_ext_max))
xfs: xfs_swap_extents needs to handle dynamic fork offsets When swapping extents, we can corrupt inodes by swapping data forks that are in incompatible formats. This is caused by the two indoes having different fork offsets due to the presence of an attribute fork on an attr2 filesystem. xfs_fsr tries to be smart about setting the fork offset, but the trick it plays only works on attr1 (old fixed format attribute fork) filesystems. Changing the way xfs_fsr sets up the attribute fork will prevent this situation from ever occurring, so in the kernel code we can get by with a preventative fix - check that the data fork in the defragmented inode is in a format valid for the inode it is being swapped into. This will lead to files that will silently and potentially repeatedly fail defragmentation, so issue a warning to the log when this particular failure occurs to let us know that xfs_fsr needs updating/fixing. To help identify how to improve xfs_fsr to avoid this issue, add trace points for the inodes being swapped so that we can determine why the swap was rejected and to confirm that the code is making the right decisions and modifications when swapping forks. A further complication is even when the swap is allowed to proceed when the fork offset is different between the two inodes then value for the maximum number of extents the data fork can hold can be wrong. Make sure these are also set correctly after the swap occurs. Signed-off-by: Dave Chinner <david@fromorbit.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Alex Elder <aelder@sgi.com>
2010-01-14 09:33:54 +08:00
return EINVAL;
return 0;
}
static int
xfs_swap_extents(
xfs: xfs_swap_extents needs to handle dynamic fork offsets When swapping extents, we can corrupt inodes by swapping data forks that are in incompatible formats. This is caused by the two indoes having different fork offsets due to the presence of an attribute fork on an attr2 filesystem. xfs_fsr tries to be smart about setting the fork offset, but the trick it plays only works on attr1 (old fixed format attribute fork) filesystems. Changing the way xfs_fsr sets up the attribute fork will prevent this situation from ever occurring, so in the kernel code we can get by with a preventative fix - check that the data fork in the defragmented inode is in a format valid for the inode it is being swapped into. This will lead to files that will silently and potentially repeatedly fail defragmentation, so issue a warning to the log when this particular failure occurs to let us know that xfs_fsr needs updating/fixing. To help identify how to improve xfs_fsr to avoid this issue, add trace points for the inodes being swapped so that we can determine why the swap was rejected and to confirm that the code is making the right decisions and modifications when swapping forks. A further complication is even when the swap is allowed to proceed when the fork offset is different between the two inodes then value for the maximum number of extents the data fork can hold can be wrong. Make sure these are also set correctly after the swap occurs. Signed-off-by: Dave Chinner <david@fromorbit.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Alex Elder <aelder@sgi.com>
2010-01-14 09:33:54 +08:00
xfs_inode_t *ip, /* target inode */
xfs_inode_t *tip, /* tmp inode */
xfs_swapext_t *sxp)
{
xfs_mount_t *mp;
xfs_trans_t *tp;
xfs_bstat_t *sbp = &sxp->sx_stat;
xfs_ifork_t *tempifp, *ifp, *tifp;
int ilf_fields, tilf_fields;
int error = 0;
int aforkblks = 0;
int taforkblks = 0;
__uint64_t tmp;
mp = ip->i_mount;
tempifp = kmem_alloc(sizeof(xfs_ifork_t), KM_MAYFAIL);
if (!tempifp) {
error = XFS_ERROR(ENOMEM);
goto out;
}
sbp = &sxp->sx_stat;
/*
* we have to do two separate lock calls here to keep lockdep
* happy. If we try to get all the locks in one call, lock will
* report false positives when we drop the ILOCK and regain them
* below.
*/
xfs_lock_two_inodes(ip, tip, XFS_IOLOCK_EXCL);
xfs_lock_two_inodes(ip, tip, XFS_ILOCK_EXCL);
/* Verify that both files have the same format */
if ((ip->i_d.di_mode & S_IFMT) != (tip->i_d.di_mode & S_IFMT)) {
error = XFS_ERROR(EINVAL);
goto out_unlock;
}
/* Verify both files are either real-time or non-realtime */
if (XFS_IS_REALTIME_INODE(ip) != XFS_IS_REALTIME_INODE(tip)) {
error = XFS_ERROR(EINVAL);
goto out_unlock;
}
if (VN_CACHED(VFS_I(tip)) != 0) {
error = xfs_flushinval_pages(tip, 0, -1,
FI_REMAPF_LOCKED);
if (error)
goto out_unlock;
}
/* Verify O_DIRECT for ftmp */
if (VN_CACHED(VFS_I(tip)) != 0) {
error = XFS_ERROR(EINVAL);
goto out_unlock;
}
/* Verify all data are being swapped */
if (sxp->sx_offset != 0 ||
sxp->sx_length != ip->i_d.di_size ||
sxp->sx_length != tip->i_d.di_size) {
error = XFS_ERROR(EFAULT);
goto out_unlock;
}
trace_xfs_swap_extent_before(ip, 0);
trace_xfs_swap_extent_before(tip, 1);
xfs: xfs_swap_extents needs to handle dynamic fork offsets When swapping extents, we can corrupt inodes by swapping data forks that are in incompatible formats. This is caused by the two indoes having different fork offsets due to the presence of an attribute fork on an attr2 filesystem. xfs_fsr tries to be smart about setting the fork offset, but the trick it plays only works on attr1 (old fixed format attribute fork) filesystems. Changing the way xfs_fsr sets up the attribute fork will prevent this situation from ever occurring, so in the kernel code we can get by with a preventative fix - check that the data fork in the defragmented inode is in a format valid for the inode it is being swapped into. This will lead to files that will silently and potentially repeatedly fail defragmentation, so issue a warning to the log when this particular failure occurs to let us know that xfs_fsr needs updating/fixing. To help identify how to improve xfs_fsr to avoid this issue, add trace points for the inodes being swapped so that we can determine why the swap was rejected and to confirm that the code is making the right decisions and modifications when swapping forks. A further complication is even when the swap is allowed to proceed when the fork offset is different between the two inodes then value for the maximum number of extents the data fork can hold can be wrong. Make sure these are also set correctly after the swap occurs. Signed-off-by: Dave Chinner <david@fromorbit.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Alex Elder <aelder@sgi.com>
2010-01-14 09:33:54 +08:00
/* check inode formats now that data is flushed */
error = xfs_swap_extents_check_format(ip, tip);
if (error) {
xfs_fs_cmn_err(CE_NOTE, mp,
"%s: inode 0x%llx format is incompatible for exchanging.",
__FILE__, ip->i_ino);
goto out_unlock;
}
/*
* Compare the current change & modify times with that
* passed in. If they differ, we abort this swap.
* This is the mechanism used to ensure the calling
* process that the file was not changed out from
* under it.
*/
2009-10-07 04:29:26 +08:00
if ((sbp->bs_ctime.tv_sec != VFS_I(ip)->i_ctime.tv_sec) ||
(sbp->bs_ctime.tv_nsec != VFS_I(ip)->i_ctime.tv_nsec) ||
(sbp->bs_mtime.tv_sec != VFS_I(ip)->i_mtime.tv_sec) ||
(sbp->bs_mtime.tv_nsec != VFS_I(ip)->i_mtime.tv_nsec)) {
error = XFS_ERROR(EBUSY);
goto out_unlock;
}
/* We need to fail if the file is memory mapped. Once we have tossed
* all existing pages, the page fault will have no option
* but to go to the filesystem for pages. By making the page fault call
* vop_read (or write in the case of autogrow) they block on the iolock
* until we have switched the extents.
*/
if (VN_MAPPED(VFS_I(ip))) {
error = XFS_ERROR(EBUSY);
goto out_unlock;
}
xfs_iunlock(ip, XFS_ILOCK_EXCL);
xfs_iunlock(tip, XFS_ILOCK_EXCL);
/*
* There is a race condition here since we gave up the
* ilock. However, the data fork will not change since
* we have the iolock (locked for truncation too) so we
* are safe. We don't really care if non-io related
* fields change.
*/
xfs_tosspages(ip, 0, -1, FI_REMAPF);
tp = xfs_trans_alloc(mp, XFS_TRANS_SWAPEXT);
if ((error = xfs_trans_reserve(tp, 0,
XFS_ICHANGE_LOG_RES(mp), 0,
0, 0))) {
xfs_iunlock(ip, XFS_IOLOCK_EXCL);
xfs_iunlock(tip, XFS_IOLOCK_EXCL);
xfs_trans_cancel(tp, 0);
goto out;
}
xfs_lock_two_inodes(ip, tip, XFS_ILOCK_EXCL);
/*
* Count the number of extended attribute blocks
*/
if ( ((XFS_IFORK_Q(ip) != 0) && (ip->i_d.di_anextents > 0)) &&
(ip->i_d.di_aformat != XFS_DINODE_FMT_LOCAL)) {
error = xfs_bmap_count_blocks(tp, ip, XFS_ATTR_FORK, &aforkblks);
if (error)
goto out_trans_cancel;
}
if ( ((XFS_IFORK_Q(tip) != 0) && (tip->i_d.di_anextents > 0)) &&
(tip->i_d.di_aformat != XFS_DINODE_FMT_LOCAL)) {
error = xfs_bmap_count_blocks(tp, tip, XFS_ATTR_FORK,
&taforkblks);
if (error)
goto out_trans_cancel;
}
/*
* Swap the data forks of the inodes
*/
ifp = &ip->i_df;
tifp = &tip->i_df;
*tempifp = *ifp; /* struct copy */
*ifp = *tifp; /* struct copy */
*tifp = *tempifp; /* struct copy */
xfs: xfs_swap_extents needs to handle dynamic fork offsets When swapping extents, we can corrupt inodes by swapping data forks that are in incompatible formats. This is caused by the two indoes having different fork offsets due to the presence of an attribute fork on an attr2 filesystem. xfs_fsr tries to be smart about setting the fork offset, but the trick it plays only works on attr1 (old fixed format attribute fork) filesystems. Changing the way xfs_fsr sets up the attribute fork will prevent this situation from ever occurring, so in the kernel code we can get by with a preventative fix - check that the data fork in the defragmented inode is in a format valid for the inode it is being swapped into. This will lead to files that will silently and potentially repeatedly fail defragmentation, so issue a warning to the log when this particular failure occurs to let us know that xfs_fsr needs updating/fixing. To help identify how to improve xfs_fsr to avoid this issue, add trace points for the inodes being swapped so that we can determine why the swap was rejected and to confirm that the code is making the right decisions and modifications when swapping forks. A further complication is even when the swap is allowed to proceed when the fork offset is different between the two inodes then value for the maximum number of extents the data fork can hold can be wrong. Make sure these are also set correctly after the swap occurs. Signed-off-by: Dave Chinner <david@fromorbit.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Alex Elder <aelder@sgi.com>
2010-01-14 09:33:54 +08:00
/*
* Fix the in-memory data fork values that are dependent on the fork
* offset in the inode. We can't assume they remain the same as attr2
* has dynamic fork offsets.
*/
ifp->if_ext_max = XFS_IFORK_SIZE(ip, XFS_DATA_FORK) /
(uint)sizeof(xfs_bmbt_rec_t);
tifp->if_ext_max = XFS_IFORK_SIZE(tip, XFS_DATA_FORK) /
(uint)sizeof(xfs_bmbt_rec_t);
/*
* Fix the on-disk inode values
*/
tmp = (__uint64_t)ip->i_d.di_nblocks;
ip->i_d.di_nblocks = tip->i_d.di_nblocks - taforkblks + aforkblks;
tip->i_d.di_nblocks = tmp + taforkblks - aforkblks;
tmp = (__uint64_t) ip->i_d.di_nextents;
ip->i_d.di_nextents = tip->i_d.di_nextents;
tip->i_d.di_nextents = tmp;
tmp = (__uint64_t) ip->i_d.di_format;
ip->i_d.di_format = tip->i_d.di_format;
tip->i_d.di_format = tmp;
ilf_fields = XFS_ILOG_CORE;
switch(ip->i_d.di_format) {
case XFS_DINODE_FMT_EXTENTS:
/* If the extents fit in the inode, fix the
* pointer. Otherwise it's already NULL or
* pointing to the extent.
*/
if (ip->i_d.di_nextents <= XFS_INLINE_EXTS) {
ifp->if_u1.if_extents =
ifp->if_u2.if_inline_ext;
}
ilf_fields |= XFS_ILOG_DEXT;
break;
case XFS_DINODE_FMT_BTREE:
ilf_fields |= XFS_ILOG_DBROOT;
break;
}
tilf_fields = XFS_ILOG_CORE;
switch(tip->i_d.di_format) {
case XFS_DINODE_FMT_EXTENTS:
/* If the extents fit in the inode, fix the
* pointer. Otherwise it's already NULL or
* pointing to the extent.
*/
if (tip->i_d.di_nextents <= XFS_INLINE_EXTS) {
tifp->if_u1.if_extents =
tifp->if_u2.if_inline_ext;
}
tilf_fields |= XFS_ILOG_DEXT;
break;
case XFS_DINODE_FMT_BTREE:
tilf_fields |= XFS_ILOG_DBROOT;
break;
}
xfs_trans_ijoin_ref(tp, ip, XFS_ILOCK_EXCL | XFS_IOLOCK_EXCL);
xfs_trans_ijoin_ref(tp, tip, XFS_ILOCK_EXCL | XFS_IOLOCK_EXCL);
xfs_trans_log_inode(tp, ip, ilf_fields);
xfs_trans_log_inode(tp, tip, tilf_fields);
/*
* If this is a synchronous mount, make sure that the
* transaction goes to disk before returning to the user.
*/
if (mp->m_flags & XFS_MOUNT_WSYNC)
xfs_trans_set_sync(tp);
error = xfs_trans_commit(tp, XFS_TRANS_SWAPEXT);
trace_xfs_swap_extent_after(ip, 0);
trace_xfs_swap_extent_after(tip, 1);
out:
kmem_free(tempifp);
return error;
out_unlock:
xfs_iunlock(ip, XFS_ILOCK_EXCL | XFS_IOLOCK_EXCL);
xfs_iunlock(tip, XFS_ILOCK_EXCL | XFS_IOLOCK_EXCL);
goto out;
out_trans_cancel:
xfs_trans_cancel(tp, 0);
goto out_unlock;
}