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linux-pinenote/fs/xfs/xfs_dfrag.c
Eric Sandeen 427d9fe233 xfs: check on-disk (not incore) btree root size in dfrag.c 
xfs_swap_extents_check_format() contains checks to make sure that
original and the temporary files during defrag are compatible;
Gabriel VLASIU ran into a case where xfs_fsr returned EINVAL
because the tests found the btree root to be of size 120,
while the fork offset was only 104; IOW, they overlapped.

However, this is just due to an error in the
xfs_swap_extents_check_format() tests, because it is checking
the in-memory btree root size against the on-disk fork offset.
We should be checking the on-disk sizes in both cases.

This patch adds a new macro to calculate this size, and uses
it in the tests.

With this change, the filesystem image provided by Gabriel
allows for proper file degragmentation.

Reported-by: Gabriel VLASIU <gabriel@vlasiu.net>
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2013-06-20 13:26:09 -05:00

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/*
* 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_log.h"
#include "xfs_trans.h"
#include "xfs_sb.h"
#include "xfs_ag.h"
#include "xfs_mount.h"
#include "xfs_bmap_btree.h"
#include "xfs_alloc_btree.h"
#include "xfs_ialloc_btree.h"
#include "xfs_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"
#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 fd f, tmp;
int error = 0;
/* Pull information for the target fd */
f = fdget((int)sxp->sx_fdtarget);
if (!f.file) {
error = XFS_ERROR(EINVAL);
goto out;
}
if (!(f.file->f_mode & FMODE_WRITE) ||
!(f.file->f_mode & FMODE_READ) ||
(f.file->f_flags & O_APPEND)) {
error = XFS_ERROR(EBADF);
goto out_put_file;
}
tmp = fdget((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_inode(f.file)) ||
IS_SWAPFILE(file_inode(tmp.file))) {
error = XFS_ERROR(EINVAL);
goto out_put_tmp_file;
}
ip = XFS_I(file_inode(f.file));
tip = XFS_I(file_inode(tmp.file));
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:
fdput(tmp);
out_put_file:
fdput(f);
out:
return error;
}
/*
* 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) >
XFS_IFORK_MAXEXT(ip, XFS_DATA_FORK))
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) >
XFS_IFORK_MAXEXT(tip, XFS_DATA_FORK))
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...
*/
if (tip->i_d.di_format == XFS_DINODE_FMT_BTREE) {
if (XFS_IFORK_BOFF(ip) &&
XFS_BMAP_BMDR_SPACE(tip->i_df.if_broot) > XFS_IFORK_BOFF(ip))
return EINVAL;
if (XFS_IFORK_NEXTENTS(tip, XFS_DATA_FORK) <=
XFS_IFORK_MAXEXT(ip, XFS_DATA_FORK))
return EINVAL;
}
/* Reciprocal target->temp btree format checks */
if (ip->i_d.di_format == XFS_DINODE_FMT_BTREE) {
if (XFS_IFORK_BOFF(tip) &&
XFS_BMAP_BMDR_SPACE(ip->i_df.if_broot) > XFS_IFORK_BOFF(tip))
return EINVAL;
if (XFS_IFORK_NEXTENTS(ip, XFS_DATA_FORK) <=
XFS_IFORK_MAXEXT(tip, XFS_DATA_FORK))
return EINVAL;
}
return 0;
}
static int
xfs_swap_extents(
xfs_inode_t *ip, /* target inode */
xfs_inode_t *tip, /* tmp inode */
xfs_swapext_t *sxp)
{
xfs_mount_t *mp = ip->i_mount;
xfs_trans_t *tp;
xfs_bstat_t *sbp = &sxp->sx_stat;
xfs_ifork_t *tempifp, *ifp, *tifp;
int src_log_flags, target_log_flags;
int error = 0;
int aforkblks = 0;
int taforkblks = 0;
__uint64_t tmp;
/*
* We have no way of updating owner information in the BMBT blocks for
* each inode on CRC enabled filesystems, so to avoid corrupting the
* this metadata we simply don't allow extent swaps to occur.
*/
if (xfs_sb_version_hascrc(&mp->m_sb))
return XFS_ERROR(EINVAL);
tempifp = kmem_alloc(sizeof(xfs_ifork_t), KM_MAYFAIL);
if (!tempifp) {
error = XFS_ERROR(ENOMEM);
goto out;
}
/*
* 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;
}
error = -filemap_write_and_wait(VFS_I(tip)->i_mapping);
if (error)
goto out_unlock;
truncate_pagecache_range(VFS_I(tip), 0, -1);
/* 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);
/* check inode formats now that data is flushed */
error = xfs_swap_extents_check_format(ip, tip);
if (error) {
xfs_notice(mp,
"%s: inode 0x%llx format is incompatible for exchanging.",
__func__, 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.
*/
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.
*/
truncate_pagecache_range(VFS_I(ip), 0, -1);
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 */
/*
* 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;
/*
* The extents in the source inode could still contain speculative
* preallocation beyond EOF (e.g. the file is open but not modified
* while defrag is in progress). In that case, we need to copy over the
* number of delalloc blocks the data fork in the source inode is
* tracking beyond EOF so that when the fork is truncated away when the
* temporary inode is unlinked we don't underrun the i_delayed_blks
* counter on that inode.
*/
ASSERT(tip->i_delayed_blks == 0);
tip->i_delayed_blks = ip->i_delayed_blks;
ip->i_delayed_blks = 0;
src_log_flags = 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;
}
src_log_flags |= XFS_ILOG_DEXT;
break;
case XFS_DINODE_FMT_BTREE:
src_log_flags |= XFS_ILOG_DBROOT;
break;
}
target_log_flags = 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;
}
target_log_flags |= XFS_ILOG_DEXT;
break;
case XFS_DINODE_FMT_BTREE:
target_log_flags |= XFS_ILOG_DBROOT;
break;
}
xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL | XFS_IOLOCK_EXCL);
xfs_trans_ijoin(tp, tip, XFS_ILOCK_EXCL | XFS_IOLOCK_EXCL);
xfs_trans_log_inode(tp, ip, src_log_flags);
xfs_trans_log_inode(tp, tip, target_log_flags);
/*
* 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, 0);
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;
}
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