WSL2-Linux-Kernel/fs/xfs/xfs_bmap_util.c

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53 KiB
C
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/*
* Copyright (c) 2000-2006 Silicon Graphics, Inc.
* Copyright (c) 2012 Red Hat, 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_shared.h"
#include "xfs_format.h"
#include "xfs_log_format.h"
#include "xfs_trans_resv.h"
#include "xfs_bit.h"
#include "xfs_mount.h"
#include "xfs_da_format.h"
#include "xfs_defer.h"
#include "xfs_inode.h"
#include "xfs_btree.h"
#include "xfs_trans.h"
#include "xfs_extfree_item.h"
#include "xfs_alloc.h"
#include "xfs_bmap.h"
#include "xfs_bmap_util.h"
#include "xfs_bmap_btree.h"
#include "xfs_rtalloc.h"
#include "xfs_error.h"
#include "xfs_quota.h"
#include "xfs_trans_space.h"
#include "xfs_trace.h"
#include "xfs_icache.h"
#include "xfs_log.h"
#include "xfs_rmap_btree.h"
#include "xfs_iomap.h"
#include "xfs_reflink.h"
#include "xfs_refcount.h"
/* Kernel only BMAP related definitions and functions */
/*
* Convert the given file system block to a disk block. We have to treat it
* differently based on whether the file is a real time file or not, because the
* bmap code does.
*/
xfs_daddr_t
xfs_fsb_to_db(struct xfs_inode *ip, xfs_fsblock_t fsb)
{
return (XFS_IS_REALTIME_INODE(ip) ? \
(xfs_daddr_t)XFS_FSB_TO_BB((ip)->i_mount, (fsb)) : \
XFS_FSB_TO_DADDR((ip)->i_mount, (fsb)));
}
/*
* Routine to zero an extent on disk allocated to the specific inode.
*
* The VFS functions take a linearised filesystem block offset, so we have to
* convert the sparse xfs fsb to the right format first.
* VFS types are real funky, too.
*/
int
xfs_zero_extent(
struct xfs_inode *ip,
xfs_fsblock_t start_fsb,
xfs_off_t count_fsb)
{
struct xfs_mount *mp = ip->i_mount;
xfs_daddr_t sector = xfs_fsb_to_db(ip, start_fsb);
sector_t block = XFS_BB_TO_FSBT(mp, sector);
return blkdev_issue_zeroout(xfs_find_bdev_for_inode(VFS_I(ip)),
block << (mp->m_super->s_blocksize_bits - 9),
count_fsb << (mp->m_super->s_blocksize_bits - 9),
GFP_NOFS, 0);
}
#ifdef CONFIG_XFS_RT
int
xfs_bmap_rtalloc(
struct xfs_bmalloca *ap) /* bmap alloc argument struct */
{
int error; /* error return value */
xfs_mount_t *mp; /* mount point structure */
xfs_extlen_t prod = 0; /* product factor for allocators */
xfs_extlen_t ralen = 0; /* realtime allocation length */
xfs_extlen_t align; /* minimum allocation alignment */
xfs_rtblock_t rtb;
mp = ap->ip->i_mount;
align = xfs_get_extsz_hint(ap->ip);
prod = align / mp->m_sb.sb_rextsize;
error = xfs_bmap_extsize_align(mp, &ap->got, &ap->prev,
align, 1, ap->eof, 0,
ap->conv, &ap->offset, &ap->length);
if (error)
return error;
ASSERT(ap->length);
ASSERT(ap->length % mp->m_sb.sb_rextsize == 0);
/*
* If the offset & length are not perfectly aligned
* then kill prod, it will just get us in trouble.
*/
if (do_mod(ap->offset, align) || ap->length % align)
prod = 1;
/*
* Set ralen to be the actual requested length in rtextents.
*/
ralen = ap->length / mp->m_sb.sb_rextsize;
/*
* If the old value was close enough to MAXEXTLEN that
* we rounded up to it, cut it back so it's valid again.
* Note that if it's a really large request (bigger than
* MAXEXTLEN), we don't hear about that number, and can't
* adjust the starting point to match it.
*/
if (ralen * mp->m_sb.sb_rextsize >= MAXEXTLEN)
ralen = MAXEXTLEN / mp->m_sb.sb_rextsize;
/*
* Lock out modifications to both the RT bitmap and summary inodes
*/
xfs_ilock(mp->m_rbmip, XFS_ILOCK_EXCL|XFS_ILOCK_RTBITMAP);
xfs_trans_ijoin(ap->tp, mp->m_rbmip, XFS_ILOCK_EXCL);
xfs_ilock(mp->m_rsumip, XFS_ILOCK_EXCL|XFS_ILOCK_RTSUM);
xfs_trans_ijoin(ap->tp, mp->m_rsumip, XFS_ILOCK_EXCL);
/*
* If it's an allocation to an empty file at offset 0,
* pick an extent that will space things out in the rt area.
*/
if (ap->eof && ap->offset == 0) {
xfs_rtblock_t uninitialized_var(rtx); /* realtime extent no */
error = xfs_rtpick_extent(mp, ap->tp, ralen, &rtx);
if (error)
return error;
ap->blkno = rtx * mp->m_sb.sb_rextsize;
} else {
ap->blkno = 0;
}
xfs_bmap_adjacent(ap);
/*
* Realtime allocation, done through xfs_rtallocate_extent.
*/
do_div(ap->blkno, mp->m_sb.sb_rextsize);
rtb = ap->blkno;
ap->length = ralen;
error = xfs_rtallocate_extent(ap->tp, ap->blkno, 1, ap->length,
&ralen, ap->wasdel, prod, &rtb);
if (error)
return error;
ap->blkno = rtb;
if (ap->blkno != NULLFSBLOCK) {
ap->blkno *= mp->m_sb.sb_rextsize;
ralen *= mp->m_sb.sb_rextsize;
ap->length = ralen;
ap->ip->i_d.di_nblocks += ralen;
xfs_trans_log_inode(ap->tp, ap->ip, XFS_ILOG_CORE);
if (ap->wasdel)
ap->ip->i_delayed_blks -= ralen;
/*
* Adjust the disk quota also. This was reserved
* earlier.
*/
xfs_trans_mod_dquot_byino(ap->tp, ap->ip,
ap->wasdel ? XFS_TRANS_DQ_DELRTBCOUNT :
XFS_TRANS_DQ_RTBCOUNT, (long) ralen);
/* Zero the extent if we were asked to do so */
xfs: remote attribute blocks aren't really userdata When adding a new remote attribute, we write the attribute to the new extent before the allocation transaction is committed. This means we cannot reuse busy extents as that violates crash consistency semantics. Hence we currently treat remote attribute extent allocation like userdata because it has the same overwrite ordering constraints as userdata. Unfortunately, this also allows the allocator to incorrectly apply extent size hints to the remote attribute extent allocation. This results in interesting failures, such as transaction block reservation overruns and in-memory inode attribute fork corruption. To fix this, we need to separate the busy extent reuse configuration from the userdata configuration. This changes the definition of XFS_BMAPI_METADATA slightly - it now means that allocation is metadata and reuse of busy extents is acceptible due to the metadata ordering semantics of the journal. If this flag is not set, it means the allocation is that has unordered data writeback, and hence busy extent reuse is not allowed. It no longer implies the allocation is for user data, just that the data write will not be strictly ordered. This matches the semantics for both user data and remote attribute block allocation. As such, This patch changes the "userdata" field to a "datatype" field, and adds a "no busy reuse" flag to the field. When we detect an unordered data extent allocation, we immediately set the no reuse flag. We then set the "user data" flags based on the inode fork we are allocating the extent to. Hence we only set userdata flags on data fork allocations now and consider attribute fork remote extents to be an unordered metadata extent. The result is that remote attribute extents now have the expected allocation semantics, and the data fork allocation behaviour is completely unchanged. It should be noted that there may be other ways to fix this (e.g. use ordered metadata buffers for the remote attribute extent data write) but they are more invasive and difficult to validate both from a design and implementation POV. Hence this patch takes the simple, obvious route to fixing the problem... Reported-and-tested-by: Ross Zwisler <ross.zwisler@linux.intel.com> Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-09-26 01:21:28 +03:00
if (ap->datatype & XFS_ALLOC_USERDATA_ZERO) {
error = xfs_zero_extent(ap->ip, ap->blkno, ap->length);
if (error)
return error;
}
} else {
ap->length = 0;
}
return 0;
}
#endif /* CONFIG_XFS_RT */
/*
* Check if the endoff is outside the last extent. If so the caller will grow
* the allocation to a stripe unit boundary. All offsets are considered outside
* the end of file for an empty fork, so 1 is returned in *eof in that case.
*/
int
xfs_bmap_eof(
struct xfs_inode *ip,
xfs_fileoff_t endoff,
int whichfork,
int *eof)
{
struct xfs_bmbt_irec rec;
int error;
error = xfs_bmap_last_extent(NULL, ip, whichfork, &rec, eof);
if (error || *eof)
return error;
*eof = endoff >= rec.br_startoff + rec.br_blockcount;
return 0;
}
/*
* Extent tree block counting routines.
*/
/*
* Count leaf blocks given a range of extent records. Delayed allocation
* extents are not counted towards the totals.
*/
xfs_extnum_t
xfs_bmap_count_leaves(
struct xfs_ifork *ifp,
xfs_filblks_t *count)
{
struct xfs_iext_cursor icur;
struct xfs_bmbt_irec got;
xfs_extnum_t numrecs = 0;
for_each_xfs_iext(ifp, &icur, &got) {
if (!isnullstartblock(got.br_startblock)) {
*count += got.br_blockcount;
numrecs++;
}
}
return numrecs;
}
/*
* Count leaf blocks given a range of extent records originally
* in btree format.
*/
STATIC void
xfs_bmap_disk_count_leaves(
struct xfs_mount *mp,
struct xfs_btree_block *block,
int numrecs,
xfs_filblks_t *count)
{
int b;
xfs_bmbt_rec_t *frp;
for (b = 1; b <= numrecs; b++) {
frp = XFS_BMBT_REC_ADDR(mp, block, b);
*count += xfs_bmbt_disk_get_blockcount(frp);
}
}
/*
* Recursively walks each level of a btree
* to count total fsblocks in use.
*/
STATIC int
xfs_bmap_count_tree(
struct xfs_mount *mp,
struct xfs_trans *tp,
struct xfs_ifork *ifp,
xfs_fsblock_t blockno,
int levelin,
xfs_extnum_t *nextents,
xfs_filblks_t *count)
{
int error;
struct xfs_buf *bp, *nbp;
int level = levelin;
__be64 *pp;
xfs_fsblock_t bno = blockno;
xfs_fsblock_t nextbno;
struct xfs_btree_block *block, *nextblock;
int numrecs;
error = xfs_btree_read_bufl(mp, tp, bno, 0, &bp, XFS_BMAP_BTREE_REF,
&xfs_bmbt_buf_ops);
if (error)
return error;
*count += 1;
block = XFS_BUF_TO_BLOCK(bp);
if (--level) {
/* Not at node above leaves, count this level of nodes */
nextbno = be64_to_cpu(block->bb_u.l.bb_rightsib);
while (nextbno != NULLFSBLOCK) {
error = xfs_btree_read_bufl(mp, tp, nextbno, 0, &nbp,
XFS_BMAP_BTREE_REF,
&xfs_bmbt_buf_ops);
if (error)
return error;
*count += 1;
nextblock = XFS_BUF_TO_BLOCK(nbp);
nextbno = be64_to_cpu(nextblock->bb_u.l.bb_rightsib);
xfs_trans_brelse(tp, nbp);
}
/* Dive to the next level */
pp = XFS_BMBT_PTR_ADDR(mp, block, 1, mp->m_bmap_dmxr[1]);
bno = be64_to_cpu(*pp);
error = xfs_bmap_count_tree(mp, tp, ifp, bno, level, nextents,
count);
if (error) {
xfs_trans_brelse(tp, bp);
XFS_ERROR_REPORT("xfs_bmap_count_tree(1)",
XFS_ERRLEVEL_LOW, mp);
return -EFSCORRUPTED;
}
xfs_trans_brelse(tp, bp);
} else {
/* count all level 1 nodes and their leaves */
for (;;) {
nextbno = be64_to_cpu(block->bb_u.l.bb_rightsib);
numrecs = be16_to_cpu(block->bb_numrecs);
(*nextents) += numrecs;
xfs_bmap_disk_count_leaves(mp, block, numrecs, count);
xfs_trans_brelse(tp, bp);
if (nextbno == NULLFSBLOCK)
break;
bno = nextbno;
error = xfs_btree_read_bufl(mp, tp, bno, 0, &bp,
XFS_BMAP_BTREE_REF,
&xfs_bmbt_buf_ops);
if (error)
return error;
*count += 1;
block = XFS_BUF_TO_BLOCK(bp);
}
}
return 0;
}
/*
* Count fsblocks of the given fork. Delayed allocation extents are
* not counted towards the totals.
*/
int
xfs_bmap_count_blocks(
struct xfs_trans *tp,
struct xfs_inode *ip,
int whichfork,
xfs_extnum_t *nextents,
xfs_filblks_t *count)
{
struct xfs_mount *mp; /* file system mount structure */
__be64 *pp; /* pointer to block address */
struct xfs_btree_block *block; /* current btree block */
struct xfs_ifork *ifp; /* fork structure */
xfs_fsblock_t bno; /* block # of "block" */
int level; /* btree level, for checking */
int error;
bno = NULLFSBLOCK;
mp = ip->i_mount;
*nextents = 0;
*count = 0;
ifp = XFS_IFORK_PTR(ip, whichfork);
if (!ifp)
return 0;
switch (XFS_IFORK_FORMAT(ip, whichfork)) {
case XFS_DINODE_FMT_EXTENTS:
*nextents = xfs_bmap_count_leaves(ifp, count);
return 0;
case XFS_DINODE_FMT_BTREE:
if (!(ifp->if_flags & XFS_IFEXTENTS)) {
error = xfs_iread_extents(tp, ip, whichfork);
if (error)
return error;
}
/*
* Root level must use BMAP_BROOT_PTR_ADDR macro to get ptr out.
*/
block = ifp->if_broot;
level = be16_to_cpu(block->bb_level);
ASSERT(level > 0);
pp = XFS_BMAP_BROOT_PTR_ADDR(mp, block, 1, ifp->if_broot_bytes);
bno = be64_to_cpu(*pp);
ASSERT(bno != NULLFSBLOCK);
ASSERT(XFS_FSB_TO_AGNO(mp, bno) < mp->m_sb.sb_agcount);
ASSERT(XFS_FSB_TO_AGBNO(mp, bno) < mp->m_sb.sb_agblocks);
error = xfs_bmap_count_tree(mp, tp, ifp, bno, level,
nextents, count);
if (error) {
XFS_ERROR_REPORT("xfs_bmap_count_blocks(2)",
XFS_ERRLEVEL_LOW, mp);
return -EFSCORRUPTED;
}
return 0;
}
return 0;
}
static int
xfs_getbmap_report_one(
struct xfs_inode *ip,
struct getbmapx *bmv,
struct kgetbmap *out,
int64_t bmv_end,
struct xfs_bmbt_irec *got)
{
struct kgetbmap *p = out + bmv->bmv_entries;
bool shared = false, trimmed = false;
int error;
error = xfs_reflink_trim_around_shared(ip, got, &shared, &trimmed);
if (error)
return error;
if (isnullstartblock(got->br_startblock) ||
got->br_startblock == DELAYSTARTBLOCK) {
/*
* Delalloc extents that start beyond EOF can occur due to
* speculative EOF allocation when the delalloc extent is larger
* than the largest freespace extent at conversion time. These
* extents cannot be converted by data writeback, so can exist
* here even if we are not supposed to be finding delalloc
* extents.
*/
if (got->br_startoff < XFS_B_TO_FSB(ip->i_mount, XFS_ISIZE(ip)))
ASSERT((bmv->bmv_iflags & BMV_IF_DELALLOC) != 0);
p->bmv_oflags |= BMV_OF_DELALLOC;
p->bmv_block = -2;
} else {
p->bmv_block = xfs_fsb_to_db(ip, got->br_startblock);
}
if (got->br_state == XFS_EXT_UNWRITTEN &&
(bmv->bmv_iflags & BMV_IF_PREALLOC))
p->bmv_oflags |= BMV_OF_PREALLOC;
if (shared)
p->bmv_oflags |= BMV_OF_SHARED;
p->bmv_offset = XFS_FSB_TO_BB(ip->i_mount, got->br_startoff);
p->bmv_length = XFS_FSB_TO_BB(ip->i_mount, got->br_blockcount);
bmv->bmv_offset = p->bmv_offset + p->bmv_length;
bmv->bmv_length = max(0LL, bmv_end - bmv->bmv_offset);
bmv->bmv_entries++;
return 0;
}
static void
xfs_getbmap_report_hole(
struct xfs_inode *ip,
struct getbmapx *bmv,
struct kgetbmap *out,
int64_t bmv_end,
xfs_fileoff_t bno,
xfs_fileoff_t end)
{
struct kgetbmap *p = out + bmv->bmv_entries;
if (bmv->bmv_iflags & BMV_IF_NO_HOLES)
return;
p->bmv_block = -1;
p->bmv_offset = XFS_FSB_TO_BB(ip->i_mount, bno);
p->bmv_length = XFS_FSB_TO_BB(ip->i_mount, end - bno);
bmv->bmv_offset = p->bmv_offset + p->bmv_length;
bmv->bmv_length = max(0LL, bmv_end - bmv->bmv_offset);
bmv->bmv_entries++;
}
static inline bool
xfs_getbmap_full(
struct getbmapx *bmv)
{
return bmv->bmv_length == 0 || bmv->bmv_entries >= bmv->bmv_count - 1;
}
static bool
xfs_getbmap_next_rec(
struct xfs_bmbt_irec *rec,
xfs_fileoff_t total_end)
{
xfs_fileoff_t end = rec->br_startoff + rec->br_blockcount;
if (end == total_end)
return false;
rec->br_startoff += rec->br_blockcount;
if (!isnullstartblock(rec->br_startblock) &&
rec->br_startblock != DELAYSTARTBLOCK)
rec->br_startblock += rec->br_blockcount;
rec->br_blockcount = total_end - end;
return true;
}
/*
* Get inode's extents as described in bmv, and format for output.
* Calls formatter to fill the user's buffer until all extents
* are mapped, until the passed-in bmv->bmv_count slots have
* been filled, or until the formatter short-circuits the loop,
* if it is tracking filled-in extents on its own.
*/
int /* error code */
xfs_getbmap(
struct xfs_inode *ip,
struct getbmapx *bmv, /* user bmap structure */
struct kgetbmap *out)
{
struct xfs_mount *mp = ip->i_mount;
int iflags = bmv->bmv_iflags;
int whichfork, lock, error = 0;
int64_t bmv_end, max_len;
xfs_fileoff_t bno, first_bno;
struct xfs_ifork *ifp;
struct xfs_bmbt_irec got, rec;
xfs_filblks_t len;
struct xfs_iext_cursor icur;
if (bmv->bmv_iflags & ~BMV_IF_VALID)
return -EINVAL;
#ifndef DEBUG
/* Only allow CoW fork queries if we're debugging. */
if (iflags & BMV_IF_COWFORK)
return -EINVAL;
#endif
if ((iflags & BMV_IF_ATTRFORK) && (iflags & BMV_IF_COWFORK))
return -EINVAL;
if (bmv->bmv_length < -1)
return -EINVAL;
bmv->bmv_entries = 0;
if (bmv->bmv_length == 0)
return 0;
if (iflags & BMV_IF_ATTRFORK)
whichfork = XFS_ATTR_FORK;
else if (iflags & BMV_IF_COWFORK)
whichfork = XFS_COW_FORK;
else
whichfork = XFS_DATA_FORK;
ifp = XFS_IFORK_PTR(ip, whichfork);
xfs_ilock(ip, XFS_IOLOCK_SHARED);
switch (whichfork) {
case XFS_ATTR_FORK:
if (!XFS_IFORK_Q(ip))
goto out_unlock_iolock;
max_len = 1LL << 32;
lock = xfs_ilock_attr_map_shared(ip);
break;
case XFS_COW_FORK:
/* No CoW fork? Just return */
if (!ifp)
goto out_unlock_iolock;
if (xfs_get_cowextsz_hint(ip))
max_len = mp->m_super->s_maxbytes;
else
max_len = XFS_ISIZE(ip);
lock = XFS_ILOCK_SHARED;
xfs_ilock(ip, lock);
break;
case XFS_DATA_FORK:
if (!(iflags & BMV_IF_DELALLOC) &&
(ip->i_delayed_blks || XFS_ISIZE(ip) > ip->i_d.di_size)) {
error = filemap_write_and_wait(VFS_I(ip)->i_mapping);
if (error)
goto out_unlock_iolock;
/*
* Even after flushing the inode, there can still be
* delalloc blocks on the inode beyond EOF due to
* speculative preallocation. These are not removed
* until the release function is called or the inode
* is inactivated. Hence we cannot assert here that
* ip->i_delayed_blks == 0.
*/
}
if (xfs_get_extsz_hint(ip) ||
(ip->i_d.di_flags &
(XFS_DIFLAG_PREALLOC | XFS_DIFLAG_APPEND)))
max_len = mp->m_super->s_maxbytes;
else
max_len = XFS_ISIZE(ip);
lock = xfs_ilock_data_map_shared(ip);
break;
}
switch (XFS_IFORK_FORMAT(ip, whichfork)) {
case XFS_DINODE_FMT_EXTENTS:
case XFS_DINODE_FMT_BTREE:
break;
case XFS_DINODE_FMT_LOCAL:
/* Local format inode forks report no extents. */
goto out_unlock_ilock;
default:
error = -EINVAL;
goto out_unlock_ilock;
}
if (bmv->bmv_length == -1) {
max_len = XFS_FSB_TO_BB(mp, XFS_B_TO_FSB(mp, max_len));
bmv->bmv_length = max(0LL, max_len - bmv->bmv_offset);
}
bmv_end = bmv->bmv_offset + bmv->bmv_length;
first_bno = bno = XFS_BB_TO_FSBT(mp, bmv->bmv_offset);
len = XFS_BB_TO_FSB(mp, bmv->bmv_length);
if (!(ifp->if_flags & XFS_IFEXTENTS)) {
error = xfs_iread_extents(NULL, ip, whichfork);
if (error)
goto out_unlock_ilock;
}
if (!xfs_iext_lookup_extent(ip, ifp, bno, &icur, &got)) {
/*
* Report a whole-file hole if the delalloc flag is set to
* stay compatible with the old implementation.
*/
if (iflags & BMV_IF_DELALLOC)
xfs_getbmap_report_hole(ip, bmv, out, bmv_end, bno,
XFS_B_TO_FSB(mp, XFS_ISIZE(ip)));
goto out_unlock_ilock;
}
while (!xfs_getbmap_full(bmv)) {
xfs_trim_extent(&got, first_bno, len);
/*
* Report an entry for a hole if this extent doesn't directly
* follow the previous one.
*/
if (got.br_startoff > bno) {
xfs_getbmap_report_hole(ip, bmv, out, bmv_end, bno,
got.br_startoff);
if (xfs_getbmap_full(bmv))
break;
}
/*
* In order to report shared extents accurately, we report each
* distinct shared / unshared part of a single bmbt record with
* an individual getbmapx record.
*/
bno = got.br_startoff + got.br_blockcount;
rec = got;
do {
error = xfs_getbmap_report_one(ip, bmv, out, bmv_end,
&rec);
if (error || xfs_getbmap_full(bmv))
goto out_unlock_ilock;
} while (xfs_getbmap_next_rec(&rec, bno));
if (!xfs_iext_next_extent(ifp, &icur, &got)) {
xfs_fileoff_t end = XFS_B_TO_FSB(mp, XFS_ISIZE(ip));
out[bmv->bmv_entries - 1].bmv_oflags |= BMV_OF_LAST;
if (whichfork != XFS_ATTR_FORK && bno < end &&
!xfs_getbmap_full(bmv)) {
xfs_getbmap_report_hole(ip, bmv, out, bmv_end,
bno, end);
}
break;
}
if (bno >= first_bno + len)
break;
}
out_unlock_ilock:
xfs_iunlock(ip, lock);
out_unlock_iolock:
xfs_iunlock(ip, XFS_IOLOCK_SHARED);
return error;
}
/*
* dead simple method of punching delalyed allocation blocks from a range in
* the inode. Walks a block at a time so will be slow, but is only executed in
* rare error cases so the overhead is not critical. This will always punch out
* both the start and end blocks, even if the ranges only partially overlap
* them, so it is up to the caller to ensure that partial blocks are not
* passed in.
*/
int
xfs_bmap_punch_delalloc_range(
struct xfs_inode *ip,
xfs_fileoff_t start_fsb,
xfs_fileoff_t length)
{
xfs_fileoff_t remaining = length;
int error = 0;
ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL));
do {
int done;
xfs_bmbt_irec_t imap;
int nimaps = 1;
xfs_fsblock_t firstblock;
struct xfs_defer_ops dfops;
/*
* Map the range first and check that it is a delalloc extent
* before trying to unmap the range. Otherwise we will be
* trying to remove a real extent (which requires a
* transaction) or a hole, which is probably a bad idea...
*/
error = xfs_bmapi_read(ip, start_fsb, 1, &imap, &nimaps,
XFS_BMAPI_ENTIRE);
if (error) {
/* something screwed, just bail */
if (!XFS_FORCED_SHUTDOWN(ip->i_mount)) {
xfs_alert(ip->i_mount,
"Failed delalloc mapping lookup ino %lld fsb %lld.",
ip->i_ino, start_fsb);
}
break;
}
if (!nimaps) {
/* nothing there */
goto next_block;
}
if (imap.br_startblock != DELAYSTARTBLOCK) {
/* been converted, ignore */
goto next_block;
}
WARN_ON(imap.br_blockcount == 0);
/*
* Note: while we initialise the firstblock/dfops pair, they
* should never be used because blocks should never be
* allocated or freed for a delalloc extent and hence we need
* don't cancel or finish them after the xfs_bunmapi() call.
*/
xfs_defer_init(&dfops, &firstblock);
error = xfs_bunmapi(NULL, ip, start_fsb, 1, 0, 1, &firstblock,
&dfops, &done);
if (error)
break;
ASSERT(!xfs_defer_has_unfinished_work(&dfops));
next_block:
start_fsb++;
remaining--;
} while(remaining > 0);
return error;
}
/*
* Test whether it is appropriate to check an inode for and free post EOF
* blocks. The 'force' parameter determines whether we should also consider
* regular files that are marked preallocated or append-only.
*/
bool
xfs_can_free_eofblocks(struct xfs_inode *ip, bool force)
{
/* prealloc/delalloc exists only on regular files */
if (!S_ISREG(VFS_I(ip)->i_mode))
return false;
/*
* Zero sized files with no cached pages and delalloc blocks will not
* have speculative prealloc/delalloc blocks to remove.
*/
if (VFS_I(ip)->i_size == 0 &&
VFS_I(ip)->i_mapping->nrpages == 0 &&
ip->i_delayed_blks == 0)
return false;
/* If we haven't read in the extent list, then don't do it now. */
if (!(ip->i_df.if_flags & XFS_IFEXTENTS))
return false;
/*
* Do not free real preallocated or append-only files unless the file
* has delalloc blocks and we are forced to remove them.
*/
if (ip->i_d.di_flags & (XFS_DIFLAG_PREALLOC | XFS_DIFLAG_APPEND))
if (!force || ip->i_delayed_blks == 0)
return false;
return true;
}
/*
* This is called to free any blocks beyond eof. The caller must hold
* IOLOCK_EXCL unless we are in the inode reclaim path and have the only
* reference to the inode.
*/
int
xfs_free_eofblocks(
struct xfs_inode *ip)
{
struct xfs_trans *tp;
int error;
xfs_fileoff_t end_fsb;
xfs_fileoff_t last_fsb;
xfs_filblks_t map_len;
int nimaps;
struct xfs_bmbt_irec imap;
struct xfs_mount *mp = ip->i_mount;
/*
* Figure out if there are any blocks beyond the end
* of the file. If not, then there is nothing to do.
*/
end_fsb = XFS_B_TO_FSB(mp, (xfs_ufsize_t)XFS_ISIZE(ip));
last_fsb = XFS_B_TO_FSB(mp, mp->m_super->s_maxbytes);
if (last_fsb <= end_fsb)
return 0;
map_len = last_fsb - end_fsb;
nimaps = 1;
xfs_ilock(ip, XFS_ILOCK_SHARED);
error = xfs_bmapi_read(ip, end_fsb, map_len, &imap, &nimaps, 0);
xfs_iunlock(ip, XFS_ILOCK_SHARED);
/*
* If there are blocks after the end of file, truncate the file to its
* current size to free them up.
*/
if (!error && (nimaps != 0) &&
(imap.br_startblock != HOLESTARTBLOCK ||
ip->i_delayed_blks)) {
/*
* Attach the dquots to the inode up front.
*/
error = xfs_qm_dqattach(ip, 0);
if (error)
return error;
xfs: fix eofblocks race with file extending async dio writes It's possible for post-eof blocks to end up being used for direct I/O writes. dio write performs an upfront unwritten extent allocation, sends the dio and then updates the inode size (if necessary) on write completion. If a file release occurs while a file extending dio write is in flight, it is possible to mistake the post-eof blocks for speculative preallocation and incorrectly truncate them from the inode. This means that the resulting dio write completion can discover a hole and allocate new blocks rather than perform unwritten extent conversion. This requires a strange mix of I/O and is thus not likely to reproduce in real world workloads. It is intermittently reproduced by generic/299. The error manifests as an assert failure due to transaction overrun because the aforementioned write completion transaction has only reserved enough blocks for btree operations: XFS: Assertion failed: tp->t_blk_res_used <= tp->t_blk_res, \ file: fs/xfs//xfs_trans.c, line: 309 The root cause is that xfs_free_eofblocks() uses i_size to truncate post-eof blocks from the inode, but async, file extending direct writes do not update i_size until write completion, long after inode locks are dropped. Therefore, xfs_free_eofblocks() effectively truncates the inode to the incorrect size. Update xfs_free_eofblocks() to serialize against dio similar to how extending writes are serialized against i_size updates before post-eof block zeroing. Specifically, wait on dio while under the iolock. This ensures that dio write completions have updated i_size before post-eof blocks are processed. Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2017-01-28 10:22:57 +03:00
/* wait on dio to ensure i_size has settled */
inode_dio_wait(VFS_I(ip));
error = xfs_trans_alloc(mp, &M_RES(mp)->tr_itruncate, 0, 0, 0,
&tp);
if (error) {
ASSERT(XFS_FORCED_SHUTDOWN(mp));
return error;
}
xfs_ilock(ip, XFS_ILOCK_EXCL);
xfs_trans_ijoin(tp, ip, 0);
/*
* Do not update the on-disk file size. If we update the
* on-disk file size and then the system crashes before the
* contents of the file are flushed to disk then the files
* may be full of holes (ie NULL files bug).
*/
error = xfs_itruncate_extents(&tp, ip, XFS_DATA_FORK,
XFS_ISIZE(ip));
if (error) {
/*
* If we get an error at this point we simply don't
* bother truncating the file.
*/
xfs_trans_cancel(tp);
} else {
error = xfs_trans_commit(tp);
if (!error)
xfs_inode_clear_eofblocks_tag(ip);
}
xfs_iunlock(ip, XFS_ILOCK_EXCL);
}
return error;
}
int
xfs_alloc_file_space(
struct xfs_inode *ip,
xfs_off_t offset,
xfs_off_t len,
int alloc_type)
{
xfs_mount_t *mp = ip->i_mount;
xfs_off_t count;
xfs_filblks_t allocated_fsb;
xfs_filblks_t allocatesize_fsb;
xfs_extlen_t extsz, temp;
xfs_fileoff_t startoffset_fsb;
xfs_fsblock_t firstfsb;
int nimaps;
int quota_flag;
int rt;
xfs_trans_t *tp;
xfs_bmbt_irec_t imaps[1], *imapp;
struct xfs_defer_ops dfops;
uint qblocks, resblks, resrtextents;
int error;
trace_xfs_alloc_file_space(ip);
if (XFS_FORCED_SHUTDOWN(mp))
return -EIO;
error = xfs_qm_dqattach(ip, 0);
if (error)
return error;
if (len <= 0)
return -EINVAL;
rt = XFS_IS_REALTIME_INODE(ip);
extsz = xfs_get_extsz_hint(ip);
count = len;
imapp = &imaps[0];
nimaps = 1;
startoffset_fsb = XFS_B_TO_FSBT(mp, offset);
allocatesize_fsb = XFS_B_TO_FSB(mp, count);
/*
* Allocate file space until done or until there is an error
*/
while (allocatesize_fsb && !error) {
xfs_fileoff_t s, e;
/*
* Determine space reservations for data/realtime.
*/
if (unlikely(extsz)) {
s = startoffset_fsb;
do_div(s, extsz);
s *= extsz;
e = startoffset_fsb + allocatesize_fsb;
if ((temp = do_mod(startoffset_fsb, extsz)))
e += temp;
if ((temp = do_mod(e, extsz)))
e += extsz - temp;
} else {
s = 0;
e = allocatesize_fsb;
}
/*
* The transaction reservation is limited to a 32-bit block
* count, hence we need to limit the number of blocks we are
* trying to reserve to avoid an overflow. We can't allocate
* more than @nimaps extents, and an extent is limited on disk
* to MAXEXTLEN (21 bits), so use that to enforce the limit.
*/
resblks = min_t(xfs_fileoff_t, (e - s), (MAXEXTLEN * nimaps));
if (unlikely(rt)) {
resrtextents = qblocks = resblks;
resrtextents /= mp->m_sb.sb_rextsize;
resblks = XFS_DIOSTRAT_SPACE_RES(mp, 0);
quota_flag = XFS_QMOPT_RES_RTBLKS;
} else {
resrtextents = 0;
resblks = qblocks = XFS_DIOSTRAT_SPACE_RES(mp, resblks);
quota_flag = XFS_QMOPT_RES_REGBLKS;
}
/*
* Allocate and setup the transaction.
*/
error = xfs_trans_alloc(mp, &M_RES(mp)->tr_write, resblks,
resrtextents, 0, &tp);
/*
* Check for running out of space
*/
if (error) {
/*
* Free the transaction structure.
*/
ASSERT(error == -ENOSPC || XFS_FORCED_SHUTDOWN(mp));
break;
}
xfs_ilock(ip, XFS_ILOCK_EXCL);
error = xfs_trans_reserve_quota_nblks(tp, ip, qblocks,
0, quota_flag);
if (error)
goto error1;
xfs_trans_ijoin(tp, ip, 0);
xfs_defer_init(&dfops, &firstfsb);
error = xfs_bmapi_write(tp, ip, startoffset_fsb,
allocatesize_fsb, alloc_type, &firstfsb,
resblks, imapp, &nimaps, &dfops);
if (error)
goto error0;
/*
* Complete the transaction
*/
error = xfs_defer_finish(&tp, &dfops);
if (error)
goto error0;
error = xfs_trans_commit(tp);
xfs_iunlock(ip, XFS_ILOCK_EXCL);
if (error)
break;
allocated_fsb = imapp->br_blockcount;
if (nimaps == 0) {
error = -ENOSPC;
break;
}
startoffset_fsb += allocated_fsb;
allocatesize_fsb -= allocated_fsb;
}
return error;
error0: /* Cancel bmap, unlock inode, unreserve quota blocks, cancel trans */
xfs_defer_cancel(&dfops);
xfs_trans_unreserve_quota_nblks(tp, ip, (long)qblocks, 0, quota_flag);
error1: /* Just cancel transaction */
xfs_trans_cancel(tp);
xfs_iunlock(ip, XFS_ILOCK_EXCL);
return error;
}
static int
xfs_unmap_extent(
struct xfs_inode *ip,
xfs_fileoff_t startoffset_fsb,
xfs_filblks_t len_fsb,
int *done)
{
struct xfs_mount *mp = ip->i_mount;
struct xfs_trans *tp;
struct xfs_defer_ops dfops;
xfs_fsblock_t firstfsb;
uint resblks = XFS_DIOSTRAT_SPACE_RES(mp, 0);
int error;
error = xfs_trans_alloc(mp, &M_RES(mp)->tr_write, resblks, 0, 0, &tp);
if (error) {
ASSERT(error == -ENOSPC || XFS_FORCED_SHUTDOWN(mp));
return error;
}
xfs_ilock(ip, XFS_ILOCK_EXCL);
error = xfs_trans_reserve_quota(tp, mp, ip->i_udquot, ip->i_gdquot,
ip->i_pdquot, resblks, 0, XFS_QMOPT_RES_REGBLKS);
if (error)
goto out_trans_cancel;
xfs_trans_ijoin(tp, ip, 0);
xfs_defer_init(&dfops, &firstfsb);
error = xfs_bunmapi(tp, ip, startoffset_fsb, len_fsb, 0, 2, &firstfsb,
&dfops, done);
if (error)
goto out_bmap_cancel;
xfs_defer_ijoin(&dfops, ip);
error = xfs_defer_finish(&tp, &dfops);
if (error)
goto out_bmap_cancel;
error = xfs_trans_commit(tp);
out_unlock:
xfs_iunlock(ip, XFS_ILOCK_EXCL);
return error;
out_bmap_cancel:
xfs_defer_cancel(&dfops);
out_trans_cancel:
xfs_trans_cancel(tp);
goto out_unlock;
}
static int
xfs_adjust_extent_unmap_boundaries(
struct xfs_inode *ip,
xfs_fileoff_t *startoffset_fsb,
xfs_fileoff_t *endoffset_fsb)
{
struct xfs_mount *mp = ip->i_mount;
struct xfs_bmbt_irec imap;
int nimap, error;
xfs_extlen_t mod = 0;
nimap = 1;
error = xfs_bmapi_read(ip, *startoffset_fsb, 1, &imap, &nimap, 0);
if (error)
return error;
if (nimap && imap.br_startblock != HOLESTARTBLOCK) {
ASSERT(imap.br_startblock != DELAYSTARTBLOCK);
mod = do_mod(imap.br_startblock, mp->m_sb.sb_rextsize);
if (mod)
*startoffset_fsb += mp->m_sb.sb_rextsize - mod;
}
nimap = 1;
error = xfs_bmapi_read(ip, *endoffset_fsb - 1, 1, &imap, &nimap, 0);
if (error)
return error;
if (nimap && imap.br_startblock != HOLESTARTBLOCK) {
ASSERT(imap.br_startblock != DELAYSTARTBLOCK);
mod++;
if (mod && mod != mp->m_sb.sb_rextsize)
*endoffset_fsb -= mod;
}
return 0;
}
static int
xfs_flush_unmap_range(
struct xfs_inode *ip,
xfs_off_t offset,
xfs_off_t len)
{
struct xfs_mount *mp = ip->i_mount;
struct inode *inode = VFS_I(ip);
xfs_off_t rounding, start, end;
int error;
/* wait for the completion of any pending DIOs */
inode_dio_wait(inode);
rounding = max_t(xfs_off_t, 1 << mp->m_sb.sb_blocklog, PAGE_SIZE);
start = round_down(offset, rounding);
end = round_up(offset + len, rounding) - 1;
error = filemap_write_and_wait_range(inode->i_mapping, start, end);
if (error)
return error;
truncate_pagecache_range(inode, start, end);
return 0;
}
int
xfs_free_file_space(
struct xfs_inode *ip,
xfs_off_t offset,
xfs_off_t len)
{
struct xfs_mount *mp = ip->i_mount;
xfs_fileoff_t startoffset_fsb;
xfs_fileoff_t endoffset_fsb;
int done = 0, error;
trace_xfs_free_file_space(ip);
error = xfs_qm_dqattach(ip, 0);
if (error)
return error;
if (len <= 0) /* if nothing being freed */
return 0;
error = xfs_flush_unmap_range(ip, offset, len);
if (error)
return error;
startoffset_fsb = XFS_B_TO_FSB(mp, offset);
endoffset_fsb = XFS_B_TO_FSBT(mp, offset + len);
/*
* Need to zero the stuff we're not freeing, on disk. If it's a RT file
* and we can't use unwritten extents then we actually need to ensure
* to zero the whole extent, otherwise we just need to take of block
* boundaries, and xfs_bunmapi will handle the rest.
*/
if (XFS_IS_REALTIME_INODE(ip) &&
!xfs_sb_version_hasextflgbit(&mp->m_sb)) {
error = xfs_adjust_extent_unmap_boundaries(ip, &startoffset_fsb,
&endoffset_fsb);
if (error)
return error;
}
if (endoffset_fsb > startoffset_fsb) {
while (!done) {
error = xfs_unmap_extent(ip, startoffset_fsb,
endoffset_fsb - startoffset_fsb, &done);
if (error)
return error;
}
}
/*
* Now that we've unmap all full blocks we'll have to zero out any
* partial block at the beginning and/or end. xfs_zero_range is
* smart enough to skip any holes, including those we just created,
* but we must take care not to zero beyond EOF and enlarge i_size.
*/
if (offset >= XFS_ISIZE(ip))
return 0;
if (offset + len > XFS_ISIZE(ip))
len = XFS_ISIZE(ip) - offset;
return xfs_zero_range(ip, offset, len, NULL);
}
xfs: rework zero range to prevent invalid i_size updates The zero range operation is analogous to fallocate with the exception of converting the range to zeroes. E.g., it attempts to allocate zeroed blocks over the range specified by the caller. The XFS implementation kills all delalloc blocks currently over the aligned range, converts the range to allocated zero blocks (unwritten extents) and handles the partial pages at the ends of the range by sending writes through the pagecache. The current implementation suffers from several problems associated with inode size. If the aligned range covers an extending I/O, said I/O is discarded and an inode size update from a previous write never makes it to disk. Further, if an unaligned zero range extends beyond eof, the page write induced for the partial end page can itself increase the inode size, even if the zero range request is not supposed to update i_size (via KEEP_SIZE, similar to an fallocate beyond EOF). The latter behavior not only incorrectly increases the inode size, but can lead to stray delalloc blocks on the inode. Typically, post-eof preallocation blocks are either truncated on release or inode eviction or explicitly written to by xfs_zero_eof() on natural file size extension. If the inode size increases due to zero range, however, associated blocks leak into the address space having never been converted or mapped to pagecache pages. A direct I/O to such an uncovered range cannot convert the extent via writeback and will BUG(). For example: $ xfs_io -fc "pwrite 0 128k" -c "fzero -k 1m 54321" <file> ... $ xfs_io -d -c "pread 128k 128k" <file> <BUG> If the entire delalloc extent happens to not have page coverage whatsoever (e.g., delalloc conversion couldn't find a large enough free space extent), even a full file writeback won't convert what's left of the extent and we'll assert on inode eviction. Rework xfs_zero_file_space() to avoid buffered I/O for partial pages. Use the existing hole punch and prealloc mechanisms as primitives for zero range. This implementation is not efficient nor ideal as we writeback dirty data over the range and remove existing extents rather than convert to unwrittern. The former writeback, however, is currently the only mechanism available to ensure consistency between pagecache and extent state. Even a pagecache truncate/delalloc punch prior to hole punch has lead to inconsistencies due to racing with writeback. This provides a consistent, correct implementation of zero range that survives fsstress/fsx testing without assert failures. The implementation can be optimized from this point forward once the fundamental issue of pagecache and delalloc extent state consistency is addressed. Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2014-10-30 02:35:11 +03:00
/*
* Preallocate and zero a range of a file. This mechanism has the allocation
* semantics of fallocate and in addition converts data in the range to zeroes.
*/
int
xfs_zero_file_space(
struct xfs_inode *ip,
xfs_off_t offset,
xfs_off_t len)
{
struct xfs_mount *mp = ip->i_mount;
xfs: rework zero range to prevent invalid i_size updates The zero range operation is analogous to fallocate with the exception of converting the range to zeroes. E.g., it attempts to allocate zeroed blocks over the range specified by the caller. The XFS implementation kills all delalloc blocks currently over the aligned range, converts the range to allocated zero blocks (unwritten extents) and handles the partial pages at the ends of the range by sending writes through the pagecache. The current implementation suffers from several problems associated with inode size. If the aligned range covers an extending I/O, said I/O is discarded and an inode size update from a previous write never makes it to disk. Further, if an unaligned zero range extends beyond eof, the page write induced for the partial end page can itself increase the inode size, even if the zero range request is not supposed to update i_size (via KEEP_SIZE, similar to an fallocate beyond EOF). The latter behavior not only incorrectly increases the inode size, but can lead to stray delalloc blocks on the inode. Typically, post-eof preallocation blocks are either truncated on release or inode eviction or explicitly written to by xfs_zero_eof() on natural file size extension. If the inode size increases due to zero range, however, associated blocks leak into the address space having never been converted or mapped to pagecache pages. A direct I/O to such an uncovered range cannot convert the extent via writeback and will BUG(). For example: $ xfs_io -fc "pwrite 0 128k" -c "fzero -k 1m 54321" <file> ... $ xfs_io -d -c "pread 128k 128k" <file> <BUG> If the entire delalloc extent happens to not have page coverage whatsoever (e.g., delalloc conversion couldn't find a large enough free space extent), even a full file writeback won't convert what's left of the extent and we'll assert on inode eviction. Rework xfs_zero_file_space() to avoid buffered I/O for partial pages. Use the existing hole punch and prealloc mechanisms as primitives for zero range. This implementation is not efficient nor ideal as we writeback dirty data over the range and remove existing extents rather than convert to unwrittern. The former writeback, however, is currently the only mechanism available to ensure consistency between pagecache and extent state. Even a pagecache truncate/delalloc punch prior to hole punch has lead to inconsistencies due to racing with writeback. This provides a consistent, correct implementation of zero range that survives fsstress/fsx testing without assert failures. The implementation can be optimized from this point forward once the fundamental issue of pagecache and delalloc extent state consistency is addressed. Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2014-10-30 02:35:11 +03:00
uint blksize;
int error;
trace_xfs_zero_file_space(ip);
xfs: rework zero range to prevent invalid i_size updates The zero range operation is analogous to fallocate with the exception of converting the range to zeroes. E.g., it attempts to allocate zeroed blocks over the range specified by the caller. The XFS implementation kills all delalloc blocks currently over the aligned range, converts the range to allocated zero blocks (unwritten extents) and handles the partial pages at the ends of the range by sending writes through the pagecache. The current implementation suffers from several problems associated with inode size. If the aligned range covers an extending I/O, said I/O is discarded and an inode size update from a previous write never makes it to disk. Further, if an unaligned zero range extends beyond eof, the page write induced for the partial end page can itself increase the inode size, even if the zero range request is not supposed to update i_size (via KEEP_SIZE, similar to an fallocate beyond EOF). The latter behavior not only incorrectly increases the inode size, but can lead to stray delalloc blocks on the inode. Typically, post-eof preallocation blocks are either truncated on release or inode eviction or explicitly written to by xfs_zero_eof() on natural file size extension. If the inode size increases due to zero range, however, associated blocks leak into the address space having never been converted or mapped to pagecache pages. A direct I/O to such an uncovered range cannot convert the extent via writeback and will BUG(). For example: $ xfs_io -fc "pwrite 0 128k" -c "fzero -k 1m 54321" <file> ... $ xfs_io -d -c "pread 128k 128k" <file> <BUG> If the entire delalloc extent happens to not have page coverage whatsoever (e.g., delalloc conversion couldn't find a large enough free space extent), even a full file writeback won't convert what's left of the extent and we'll assert on inode eviction. Rework xfs_zero_file_space() to avoid buffered I/O for partial pages. Use the existing hole punch and prealloc mechanisms as primitives for zero range. This implementation is not efficient nor ideal as we writeback dirty data over the range and remove existing extents rather than convert to unwrittern. The former writeback, however, is currently the only mechanism available to ensure consistency between pagecache and extent state. Even a pagecache truncate/delalloc punch prior to hole punch has lead to inconsistencies due to racing with writeback. This provides a consistent, correct implementation of zero range that survives fsstress/fsx testing without assert failures. The implementation can be optimized from this point forward once the fundamental issue of pagecache and delalloc extent state consistency is addressed. Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2014-10-30 02:35:11 +03:00
blksize = 1 << mp->m_sb.sb_blocklog;
/*
xfs: rework zero range to prevent invalid i_size updates The zero range operation is analogous to fallocate with the exception of converting the range to zeroes. E.g., it attempts to allocate zeroed blocks over the range specified by the caller. The XFS implementation kills all delalloc blocks currently over the aligned range, converts the range to allocated zero blocks (unwritten extents) and handles the partial pages at the ends of the range by sending writes through the pagecache. The current implementation suffers from several problems associated with inode size. If the aligned range covers an extending I/O, said I/O is discarded and an inode size update from a previous write never makes it to disk. Further, if an unaligned zero range extends beyond eof, the page write induced for the partial end page can itself increase the inode size, even if the zero range request is not supposed to update i_size (via KEEP_SIZE, similar to an fallocate beyond EOF). The latter behavior not only incorrectly increases the inode size, but can lead to stray delalloc blocks on the inode. Typically, post-eof preallocation blocks are either truncated on release or inode eviction or explicitly written to by xfs_zero_eof() on natural file size extension. If the inode size increases due to zero range, however, associated blocks leak into the address space having never been converted or mapped to pagecache pages. A direct I/O to such an uncovered range cannot convert the extent via writeback and will BUG(). For example: $ xfs_io -fc "pwrite 0 128k" -c "fzero -k 1m 54321" <file> ... $ xfs_io -d -c "pread 128k 128k" <file> <BUG> If the entire delalloc extent happens to not have page coverage whatsoever (e.g., delalloc conversion couldn't find a large enough free space extent), even a full file writeback won't convert what's left of the extent and we'll assert on inode eviction. Rework xfs_zero_file_space() to avoid buffered I/O for partial pages. Use the existing hole punch and prealloc mechanisms as primitives for zero range. This implementation is not efficient nor ideal as we writeback dirty data over the range and remove existing extents rather than convert to unwrittern. The former writeback, however, is currently the only mechanism available to ensure consistency between pagecache and extent state. Even a pagecache truncate/delalloc punch prior to hole punch has lead to inconsistencies due to racing with writeback. This provides a consistent, correct implementation of zero range that survives fsstress/fsx testing without assert failures. The implementation can be optimized from this point forward once the fundamental issue of pagecache and delalloc extent state consistency is addressed. Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2014-10-30 02:35:11 +03:00
* Punch a hole and prealloc the range. We use hole punch rather than
* unwritten extent conversion for two reasons:
*
* 1.) Hole punch handles partial block zeroing for us.
*
* 2.) If prealloc returns ENOSPC, the file range is still zero-valued
* by virtue of the hole punch.
*/
xfs: rework zero range to prevent invalid i_size updates The zero range operation is analogous to fallocate with the exception of converting the range to zeroes. E.g., it attempts to allocate zeroed blocks over the range specified by the caller. The XFS implementation kills all delalloc blocks currently over the aligned range, converts the range to allocated zero blocks (unwritten extents) and handles the partial pages at the ends of the range by sending writes through the pagecache. The current implementation suffers from several problems associated with inode size. If the aligned range covers an extending I/O, said I/O is discarded and an inode size update from a previous write never makes it to disk. Further, if an unaligned zero range extends beyond eof, the page write induced for the partial end page can itself increase the inode size, even if the zero range request is not supposed to update i_size (via KEEP_SIZE, similar to an fallocate beyond EOF). The latter behavior not only incorrectly increases the inode size, but can lead to stray delalloc blocks on the inode. Typically, post-eof preallocation blocks are either truncated on release or inode eviction or explicitly written to by xfs_zero_eof() on natural file size extension. If the inode size increases due to zero range, however, associated blocks leak into the address space having never been converted or mapped to pagecache pages. A direct I/O to such an uncovered range cannot convert the extent via writeback and will BUG(). For example: $ xfs_io -fc "pwrite 0 128k" -c "fzero -k 1m 54321" <file> ... $ xfs_io -d -c "pread 128k 128k" <file> <BUG> If the entire delalloc extent happens to not have page coverage whatsoever (e.g., delalloc conversion couldn't find a large enough free space extent), even a full file writeback won't convert what's left of the extent and we'll assert on inode eviction. Rework xfs_zero_file_space() to avoid buffered I/O for partial pages. Use the existing hole punch and prealloc mechanisms as primitives for zero range. This implementation is not efficient nor ideal as we writeback dirty data over the range and remove existing extents rather than convert to unwrittern. The former writeback, however, is currently the only mechanism available to ensure consistency between pagecache and extent state. Even a pagecache truncate/delalloc punch prior to hole punch has lead to inconsistencies due to racing with writeback. This provides a consistent, correct implementation of zero range that survives fsstress/fsx testing without assert failures. The implementation can be optimized from this point forward once the fundamental issue of pagecache and delalloc extent state consistency is addressed. Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2014-10-30 02:35:11 +03:00
error = xfs_free_file_space(ip, offset, len);
if (error)
goto out;
xfs: rework zero range to prevent invalid i_size updates The zero range operation is analogous to fallocate with the exception of converting the range to zeroes. E.g., it attempts to allocate zeroed blocks over the range specified by the caller. The XFS implementation kills all delalloc blocks currently over the aligned range, converts the range to allocated zero blocks (unwritten extents) and handles the partial pages at the ends of the range by sending writes through the pagecache. The current implementation suffers from several problems associated with inode size. If the aligned range covers an extending I/O, said I/O is discarded and an inode size update from a previous write never makes it to disk. Further, if an unaligned zero range extends beyond eof, the page write induced for the partial end page can itself increase the inode size, even if the zero range request is not supposed to update i_size (via KEEP_SIZE, similar to an fallocate beyond EOF). The latter behavior not only incorrectly increases the inode size, but can lead to stray delalloc blocks on the inode. Typically, post-eof preallocation blocks are either truncated on release or inode eviction or explicitly written to by xfs_zero_eof() on natural file size extension. If the inode size increases due to zero range, however, associated blocks leak into the address space having never been converted or mapped to pagecache pages. A direct I/O to such an uncovered range cannot convert the extent via writeback and will BUG(). For example: $ xfs_io -fc "pwrite 0 128k" -c "fzero -k 1m 54321" <file> ... $ xfs_io -d -c "pread 128k 128k" <file> <BUG> If the entire delalloc extent happens to not have page coverage whatsoever (e.g., delalloc conversion couldn't find a large enough free space extent), even a full file writeback won't convert what's left of the extent and we'll assert on inode eviction. Rework xfs_zero_file_space() to avoid buffered I/O for partial pages. Use the existing hole punch and prealloc mechanisms as primitives for zero range. This implementation is not efficient nor ideal as we writeback dirty data over the range and remove existing extents rather than convert to unwrittern. The former writeback, however, is currently the only mechanism available to ensure consistency between pagecache and extent state. Even a pagecache truncate/delalloc punch prior to hole punch has lead to inconsistencies due to racing with writeback. This provides a consistent, correct implementation of zero range that survives fsstress/fsx testing without assert failures. The implementation can be optimized from this point forward once the fundamental issue of pagecache and delalloc extent state consistency is addressed. Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2014-10-30 02:35:11 +03:00
error = xfs_alloc_file_space(ip, round_down(offset, blksize),
round_up(offset + len, blksize) -
round_down(offset, blksize),
XFS_BMAPI_PREALLOC);
out:
return error;
}
static int
xfs_prepare_shift(
struct xfs_inode *ip,
loff_t offset)
{
int error;
xfs: writeback and inval. file range to be shifted by collapse The collapse range operation currently writes the entire file before starting the collapse to avoid changes in the in-core extent list due to writeback causing the extent count to change. Now that collapse range is fsb based rather than extent index based it can sustain changes in the extent list during the shift sequence without disruption. Modify xfs_collapse_file_space() to writeback and invalidate pages associated with the range of the file to be shifted. xfs_free_file_space() currently has similar behavior, but the space free need only affect the region of the file that is freed and this could change in the future. Also update the comments to reflect the current implementation. We retain the eofblocks trim permanently as a best option for dealing with delalloc extents. We don't shift delalloc extents because this scenario only occurs with post-eof preallocation (since data must be flushed such that the cache can be invalidated and data can be shifted). That means said space must also be initialized before being shifted into the accessible region of the file only to be immediately truncated off as the last part of the collapse. In other words, the eofblocks trim will happen anyways, we just run it first to ensure the file remains in a consistent state throughout the collapse. Finally, detect and fail explicitly in the event of a delalloc extent during the extent shift. The implementation does not support delalloc extents and the caller is expected to prevent this scenario in advance as is done by collapse. Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2014-09-23 09:39:05 +04:00
/*
* Trim eofblocks to avoid shifting uninitialized post-eof preallocation
* into the accessible region of the file.
*/
if (xfs_can_free_eofblocks(ip, true)) {
error = xfs_free_eofblocks(ip);
if (error)
return error;
}
xfs: xfs_file_collapse_range is delalloc challenged If we have delalloc extents on a file before we run a collapse range opertaion, we sync the range that we are going to collapse to convert delalloc extents in that region to real extents to simplify the shift operation. However, the shift operation then assumes that the extent list is not going to change as it iterates over the extent list moving things about. Unfortunately, this isn't true because we can't hold the ILOCK over all the operations. We can prevent new IO from modifying the extent list by holding the IOLOCK, but that doesn't prevent writeback from running.... And when writeback runs, it can convert delalloc extents is the range of the file prior to the region being collapsed, and this changes the indexes of all the extents in the file. That causes the collapse range operation to Go Bad. The right fix is to rewrite the extent shift operation not to be dependent on the extent list not changing across the entire operation, but this is a fairly significant piece of work to do. Hence, as a short-term workaround for the problem, sync the entire file before starting a collapse operation to remove all delalloc ranges from the file and so avoid the problem of concurrent writeback changing the extent list. Diagnosed-and-Reported-by: Brian Foster <bfoster@redhat.com> Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Dave Chinner <david@fromorbit.com>
2014-09-02 06:12:53 +04:00
xfs: writeback and inval. file range to be shifted by collapse The collapse range operation currently writes the entire file before starting the collapse to avoid changes in the in-core extent list due to writeback causing the extent count to change. Now that collapse range is fsb based rather than extent index based it can sustain changes in the extent list during the shift sequence without disruption. Modify xfs_collapse_file_space() to writeback and invalidate pages associated with the range of the file to be shifted. xfs_free_file_space() currently has similar behavior, but the space free need only affect the region of the file that is freed and this could change in the future. Also update the comments to reflect the current implementation. We retain the eofblocks trim permanently as a best option for dealing with delalloc extents. We don't shift delalloc extents because this scenario only occurs with post-eof preallocation (since data must be flushed such that the cache can be invalidated and data can be shifted). That means said space must also be initialized before being shifted into the accessible region of the file only to be immediately truncated off as the last part of the collapse. In other words, the eofblocks trim will happen anyways, we just run it first to ensure the file remains in a consistent state throughout the collapse. Finally, detect and fail explicitly in the event of a delalloc extent during the extent shift. The implementation does not support delalloc extents and the caller is expected to prevent this scenario in advance as is done by collapse. Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2014-09-23 09:39:05 +04:00
/*
* Writeback and invalidate cache for the remainder of the file as we're
* about to shift down every extent from offset to EOF.
xfs: writeback and inval. file range to be shifted by collapse The collapse range operation currently writes the entire file before starting the collapse to avoid changes in the in-core extent list due to writeback causing the extent count to change. Now that collapse range is fsb based rather than extent index based it can sustain changes in the extent list during the shift sequence without disruption. Modify xfs_collapse_file_space() to writeback and invalidate pages associated with the range of the file to be shifted. xfs_free_file_space() currently has similar behavior, but the space free need only affect the region of the file that is freed and this could change in the future. Also update the comments to reflect the current implementation. We retain the eofblocks trim permanently as a best option for dealing with delalloc extents. We don't shift delalloc extents because this scenario only occurs with post-eof preallocation (since data must be flushed such that the cache can be invalidated and data can be shifted). That means said space must also be initialized before being shifted into the accessible region of the file only to be immediately truncated off as the last part of the collapse. In other words, the eofblocks trim will happen anyways, we just run it first to ensure the file remains in a consistent state throughout the collapse. Finally, detect and fail explicitly in the event of a delalloc extent during the extent shift. The implementation does not support delalloc extents and the caller is expected to prevent this scenario in advance as is done by collapse. Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2014-09-23 09:39:05 +04:00
*/
error = filemap_write_and_wait_range(VFS_I(ip)->i_mapping, offset, -1);
xfs: writeback and inval. file range to be shifted by collapse The collapse range operation currently writes the entire file before starting the collapse to avoid changes in the in-core extent list due to writeback causing the extent count to change. Now that collapse range is fsb based rather than extent index based it can sustain changes in the extent list during the shift sequence without disruption. Modify xfs_collapse_file_space() to writeback and invalidate pages associated with the range of the file to be shifted. xfs_free_file_space() currently has similar behavior, but the space free need only affect the region of the file that is freed and this could change in the future. Also update the comments to reflect the current implementation. We retain the eofblocks trim permanently as a best option for dealing with delalloc extents. We don't shift delalloc extents because this scenario only occurs with post-eof preallocation (since data must be flushed such that the cache can be invalidated and data can be shifted). That means said space must also be initialized before being shifted into the accessible region of the file only to be immediately truncated off as the last part of the collapse. In other words, the eofblocks trim will happen anyways, we just run it first to ensure the file remains in a consistent state throughout the collapse. Finally, detect and fail explicitly in the event of a delalloc extent during the extent shift. The implementation does not support delalloc extents and the caller is expected to prevent this scenario in advance as is done by collapse. Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2014-09-23 09:39:05 +04:00
if (error)
return error;
error = invalidate_inode_pages2_range(VFS_I(ip)->i_mapping,
mm, fs: get rid of PAGE_CACHE_* and page_cache_{get,release} macros PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} macros were introduced *long* time ago with promise that one day it will be possible to implement page cache with bigger chunks than PAGE_SIZE. This promise never materialized. And unlikely will. We have many places where PAGE_CACHE_SIZE assumed to be equal to PAGE_SIZE. And it's constant source of confusion on whether PAGE_CACHE_* or PAGE_* constant should be used in a particular case, especially on the border between fs and mm. Global switching to PAGE_CACHE_SIZE != PAGE_SIZE would cause to much breakage to be doable. Let's stop pretending that pages in page cache are special. They are not. The changes are pretty straight-forward: - <foo> << (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>; - <foo> >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>; - PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} -> PAGE_{SIZE,SHIFT,MASK,ALIGN}; - page_cache_get() -> get_page(); - page_cache_release() -> put_page(); This patch contains automated changes generated with coccinelle using script below. For some reason, coccinelle doesn't patch header files. I've called spatch for them manually. The only adjustment after coccinelle is revert of changes to PAGE_CAHCE_ALIGN definition: we are going to drop it later. There are few places in the code where coccinelle didn't reach. I'll fix them manually in a separate patch. Comments and documentation also will be addressed with the separate patch. virtual patch @@ expression E; @@ - E << (PAGE_CACHE_SHIFT - PAGE_SHIFT) + E @@ expression E; @@ - E >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) + E @@ @@ - PAGE_CACHE_SHIFT + PAGE_SHIFT @@ @@ - PAGE_CACHE_SIZE + PAGE_SIZE @@ @@ - PAGE_CACHE_MASK + PAGE_MASK @@ expression E; @@ - PAGE_CACHE_ALIGN(E) + PAGE_ALIGN(E) @@ expression E; @@ - page_cache_get(E) + get_page(E) @@ expression E; @@ - page_cache_release(E) + put_page(E) Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Michal Hocko <mhocko@suse.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-04-01 15:29:47 +03:00
offset >> PAGE_SHIFT, -1);
if (error)
return error;
/*
* Clean out anything hanging around in the cow fork now that
* we've flushed all the dirty data out to disk to avoid having
* CoW extents at the wrong offsets.
*/
if (xfs_is_reflink_inode(ip)) {
error = xfs_reflink_cancel_cow_range(ip, offset, NULLFILEOFF,
true);
if (error)
return error;
}
return 0;
}
/*
* xfs_collapse_file_space()
* This routine frees disk space and shift extent for the given file.
* The first thing we do is to free data blocks in the specified range
* by calling xfs_free_file_space(). It would also sync dirty data
* and invalidate page cache over the region on which collapse range
* is working. And Shift extent records to the left to cover a hole.
* RETURNS:
* 0 on success
* errno on error
*
*/
int
xfs_collapse_file_space(
struct xfs_inode *ip,
xfs_off_t offset,
xfs_off_t len)
{
struct xfs_mount *mp = ip->i_mount;
struct xfs_trans *tp;
int error;
struct xfs_defer_ops dfops;
xfs_fsblock_t first_block;
xfs_fileoff_t stop_fsb = XFS_B_TO_FSB(mp, VFS_I(ip)->i_size);
xfs_fileoff_t next_fsb = XFS_B_TO_FSB(mp, offset + len);
xfs_fileoff_t shift_fsb = XFS_B_TO_FSB(mp, len);
uint resblks = XFS_DIOSTRAT_SPACE_RES(mp, 0);
bool done = false;
ASSERT(xfs_isilocked(ip, XFS_IOLOCK_EXCL));
ASSERT(xfs_isilocked(ip, XFS_MMAPLOCK_EXCL));
trace_xfs_collapse_file_space(ip);
error = xfs_free_file_space(ip, offset, len);
if (error)
return error;
error = xfs_prepare_shift(ip, offset);
if (error)
return error;
while (!error && !done) {
error = xfs_trans_alloc(mp, &M_RES(mp)->tr_write, resblks, 0, 0,
&tp);
if (error)
break;
xfs_ilock(ip, XFS_ILOCK_EXCL);
error = xfs_trans_reserve_quota(tp, mp, ip->i_udquot,
ip->i_gdquot, ip->i_pdquot, resblks, 0,
XFS_QMOPT_RES_REGBLKS);
if (error)
goto out_trans_cancel;
xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
xfs_defer_init(&dfops, &first_block);
error = xfs_bmap_collapse_extents(tp, ip, &next_fsb, shift_fsb,
&done, stop_fsb, &first_block, &dfops);
if (error)
goto out_bmap_cancel;
error = xfs_defer_finish(&tp, &dfops);
if (error)
goto out_bmap_cancel;
error = xfs_trans_commit(tp);
}
return error;
out_bmap_cancel:
xfs_defer_cancel(&dfops);
out_trans_cancel:
xfs_trans_cancel(tp);
return error;
}
/*
* xfs_insert_file_space()
* This routine create hole space by shifting extents for the given file.
* The first thing we do is to sync dirty data and invalidate page cache
* over the region on which insert range is working. And split an extent
* to two extents at given offset by calling xfs_bmap_split_extent.
* And shift all extent records which are laying between [offset,
* last allocated extent] to the right to reserve hole range.
* RETURNS:
* 0 on success
* errno on error
*/
int
xfs_insert_file_space(
struct xfs_inode *ip,
loff_t offset,
loff_t len)
{
struct xfs_mount *mp = ip->i_mount;
struct xfs_trans *tp;
int error;
struct xfs_defer_ops dfops;
xfs_fsblock_t first_block;
xfs_fileoff_t stop_fsb = XFS_B_TO_FSB(mp, offset);
xfs_fileoff_t next_fsb = NULLFSBLOCK;
xfs_fileoff_t shift_fsb = XFS_B_TO_FSB(mp, len);
bool done = false;
ASSERT(xfs_isilocked(ip, XFS_IOLOCK_EXCL));
ASSERT(xfs_isilocked(ip, XFS_MMAPLOCK_EXCL));
trace_xfs_insert_file_space(ip);
error = xfs_prepare_shift(ip, offset);
if (error)
return error;
/*
* The extent shifting code works on extent granularity. So, if stop_fsb
* is not the starting block of extent, we need to split the extent at
* stop_fsb.
*/
error = xfs_bmap_split_extent(ip, stop_fsb);
if (error)
return error;
while (!error && !done) {
error = xfs_trans_alloc(mp, &M_RES(mp)->tr_write, 0, 0, 0,
&tp);
if (error)
break;
xfs_ilock(ip, XFS_ILOCK_EXCL);
xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
xfs_defer_init(&dfops, &first_block);
error = xfs_bmap_insert_extents(tp, ip, &next_fsb, shift_fsb,
&done, stop_fsb, &first_block, &dfops);
if (error)
goto out_bmap_cancel;
error = xfs_defer_finish(&tp, &dfops);
if (error)
goto out_bmap_cancel;
error = xfs_trans_commit(tp);
}
return error;
out_bmap_cancel:
xfs_defer_cancel(&dfops);
xfs_trans_cancel(tp);
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(
struct xfs_inode *ip, /* target inode */
struct xfs_inode *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 we have to use the (expensive) rmap swap method, we can
* handle any number of extents and any format.
*/
if (xfs_sb_version_hasrmapbt(&ip->i_mount->m_sb))
return 0;
/*
* 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_Q(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_Q(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_extent_flush(
struct xfs_inode *ip)
{
int error;
error = filemap_write_and_wait(VFS_I(ip)->i_mapping);
if (error)
return error;
truncate_pagecache_range(VFS_I(ip), 0, -1);
/* Verify O_DIRECT for ftmp */
if (VFS_I(ip)->i_mapping->nrpages)
return -EINVAL;
return 0;
}
/*
* Move extents from one file to another, when rmap is enabled.
*/
STATIC int
xfs_swap_extent_rmap(
struct xfs_trans **tpp,
struct xfs_inode *ip,
struct xfs_inode *tip)
{
struct xfs_bmbt_irec irec;
struct xfs_bmbt_irec uirec;
struct xfs_bmbt_irec tirec;
xfs_fileoff_t offset_fsb;
xfs_fileoff_t end_fsb;
xfs_filblks_t count_fsb;
xfs_fsblock_t firstfsb;
struct xfs_defer_ops dfops;
int error;
xfs_filblks_t ilen;
xfs_filblks_t rlen;
int nimaps;
uint64_t tip_flags2;
/*
* If the source file has shared blocks, we must flag the donor
* file as having shared blocks so that we get the shared-block
* rmap functions when we go to fix up the rmaps. The flags
* will be switch for reals later.
*/
tip_flags2 = tip->i_d.di_flags2;
if (ip->i_d.di_flags2 & XFS_DIFLAG2_REFLINK)
tip->i_d.di_flags2 |= XFS_DIFLAG2_REFLINK;
offset_fsb = 0;
end_fsb = XFS_B_TO_FSB(ip->i_mount, i_size_read(VFS_I(ip)));
count_fsb = (xfs_filblks_t)(end_fsb - offset_fsb);
while (count_fsb) {
/* Read extent from the donor file */
nimaps = 1;
error = xfs_bmapi_read(tip, offset_fsb, count_fsb, &tirec,
&nimaps, 0);
if (error)
goto out;
ASSERT(nimaps == 1);
ASSERT(tirec.br_startblock != DELAYSTARTBLOCK);
trace_xfs_swap_extent_rmap_remap(tip, &tirec);
ilen = tirec.br_blockcount;
/* Unmap the old blocks in the source file. */
while (tirec.br_blockcount) {
xfs_defer_init(&dfops, &firstfsb);
trace_xfs_swap_extent_rmap_remap_piece(tip, &tirec);
/* Read extent from the source file */
nimaps = 1;
error = xfs_bmapi_read(ip, tirec.br_startoff,
tirec.br_blockcount, &irec,
&nimaps, 0);
if (error)
goto out_defer;
ASSERT(nimaps == 1);
ASSERT(tirec.br_startoff == irec.br_startoff);
trace_xfs_swap_extent_rmap_remap_piece(ip, &irec);
/* Trim the extent. */
uirec = tirec;
uirec.br_blockcount = rlen = min_t(xfs_filblks_t,
tirec.br_blockcount,
irec.br_blockcount);
trace_xfs_swap_extent_rmap_remap_piece(tip, &uirec);
/* Remove the mapping from the donor file. */
error = xfs_bmap_unmap_extent((*tpp)->t_mountp, &dfops,
tip, &uirec);
if (error)
goto out_defer;
/* Remove the mapping from the source file. */
error = xfs_bmap_unmap_extent((*tpp)->t_mountp, &dfops,
ip, &irec);
if (error)
goto out_defer;
/* Map the donor file's blocks into the source file. */
error = xfs_bmap_map_extent((*tpp)->t_mountp, &dfops,
ip, &uirec);
if (error)
goto out_defer;
/* Map the source file's blocks into the donor file. */
error = xfs_bmap_map_extent((*tpp)->t_mountp, &dfops,
tip, &irec);
if (error)
goto out_defer;
xfs_defer_ijoin(&dfops, ip);
error = xfs_defer_finish(tpp, &dfops);
if (error)
goto out_defer;
tirec.br_startoff += rlen;
if (tirec.br_startblock != HOLESTARTBLOCK &&
tirec.br_startblock != DELAYSTARTBLOCK)
tirec.br_startblock += rlen;
tirec.br_blockcount -= rlen;
}
/* Roll on... */
count_fsb -= ilen;
offset_fsb += ilen;
}
tip->i_d.di_flags2 = tip_flags2;
return 0;
out_defer:
xfs_defer_cancel(&dfops);
out:
trace_xfs_swap_extent_rmap_error(ip, error, _RET_IP_);
tip->i_d.di_flags2 = tip_flags2;
return error;
}
/* Swap the extents of two files by swapping data forks. */
STATIC int
xfs_swap_extent_forks(
struct xfs_trans *tp,
struct xfs_inode *ip,
struct xfs_inode *tip,
int *src_log_flags,
int *target_log_flags)
{
struct xfs_ifork tempifp, *ifp, *tifp;
xfs_filblks_t aforkblks = 0;
xfs_filblks_t taforkblks = 0;
xfs_extnum_t junk;
uint64_t tmp;
int error;
/*
* 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, &junk,
&aforkblks);
if (error)
return error;
}
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, &junk,
&taforkblks);
if (error)
return error;
}
xfs: swap extents operations for CRC filesystems For CRC enabled filesystems, we can't just swap inode forks from one inode to another when defragmenting a file - the blocks in the inode fork bmap btree contain pointers back to the owner inode. Hence if we are to swap the inode forks we have to atomically modify every block in the btree during the transaction. We are doing an entire fork swap here, so we could create a new transaction item type that indicates we are changing the owner of a certain structure from one value to another. If we combine this with ordered buffer logging to modify all the buffers in the tree, then we can change the buffers in the tree without needing log space for the operation. However, this then requires log recovery to perform the modification of the owner information of the objects/structures in question. This does introduce some interesting ordering details into recovery: we have to make sure that the owner change replay occurs after the change that moves the objects is made, not before. Hence we can't use a separate log item for this as we have no guarantee of strict ordering between multiple items in the log due to the relogging action of asynchronous transaction commits. Hence there is no "generic" method we can use for changing the ownership of arbitrary metadata structures. For inode forks, however, there is a simple method of communicating that the fork contents need the owner rewritten - we can pass a inode log format flag for the fork for the transaction that does a fork swap. This flag will then follow the inode fork through relogging actions so when the swap actually gets replayed the ownership can be changed immediately by log recovery. So that gives us a simple method of "whole fork" exchange between two inodes. This is relatively simple to implement, so it makes sense to do this as an initial implementation to support xfs_fsr on CRC enabled filesytems in the same manner as we do on existing filesystems. This commit introduces the swapext driven functionality, the recovery functionality will be in a separate patch. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2013-08-30 04:23:44 +04:00
/*
xfs: move bmbt owner change to last step of extent swap The extent swap operation currently resets bmbt block owners before the inode forks are swapped. The bmbt buffers are marked as ordered so they do not have to be physically logged in the transaction. This use of ordered buffers is not safe as bmbt buffers may have been previously physically logged. The bmbt owner change algorithm needs to be updated to physically log buffers that are already dirty when/if they are encountered. This means that an extent swap will eventually require multiple rolling transactions to handle large btrees. In addition, all inode related changes must be logged before the bmbt owner change scan begins and can roll the transaction for the first time to preserve fs consistency via log recovery. In preparation for such fixes to the bmbt owner change algorithm, refactor the bmbt scan out of the extent fork swap code to the last operation before the transaction is committed. Update xfs_swap_extent_forks() to only set the inode log flags when an owner change scan is necessary. Update xfs_swap_extents() to trigger the owner change based on the inode log flags. Note that since the owner change now occurs after the extent fork swap, the inode btrees must be fixed up with the inode number of the current inode (similar to log recovery). Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2017-08-29 20:08:39 +03:00
* Btree format (v3) inodes have the inode number stamped in the bmbt
* block headers. We can't start changing the bmbt blocks until the
* inode owner change is logged so recovery does the right thing in the
* event of a crash. Set the owner change log flags now and leave the
* bmbt scan as the last step.
xfs: swap extents operations for CRC filesystems For CRC enabled filesystems, we can't just swap inode forks from one inode to another when defragmenting a file - the blocks in the inode fork bmap btree contain pointers back to the owner inode. Hence if we are to swap the inode forks we have to atomically modify every block in the btree during the transaction. We are doing an entire fork swap here, so we could create a new transaction item type that indicates we are changing the owner of a certain structure from one value to another. If we combine this with ordered buffer logging to modify all the buffers in the tree, then we can change the buffers in the tree without needing log space for the operation. However, this then requires log recovery to perform the modification of the owner information of the objects/structures in question. This does introduce some interesting ordering details into recovery: we have to make sure that the owner change replay occurs after the change that moves the objects is made, not before. Hence we can't use a separate log item for this as we have no guarantee of strict ordering between multiple items in the log due to the relogging action of asynchronous transaction commits. Hence there is no "generic" method we can use for changing the ownership of arbitrary metadata structures. For inode forks, however, there is a simple method of communicating that the fork contents need the owner rewritten - we can pass a inode log format flag for the fork for the transaction that does a fork swap. This flag will then follow the inode fork through relogging actions so when the swap actually gets replayed the ownership can be changed immediately by log recovery. So that gives us a simple method of "whole fork" exchange between two inodes. This is relatively simple to implement, so it makes sense to do this as an initial implementation to support xfs_fsr on CRC enabled filesytems in the same manner as we do on existing filesystems. This commit introduces the swapext driven functionality, the recovery functionality will be in a separate patch. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2013-08-30 04:23:44 +04:00
*/
if (ip->i_d.di_version == 3 &&
xfs: move bmbt owner change to last step of extent swap The extent swap operation currently resets bmbt block owners before the inode forks are swapped. The bmbt buffers are marked as ordered so they do not have to be physically logged in the transaction. This use of ordered buffers is not safe as bmbt buffers may have been previously physically logged. The bmbt owner change algorithm needs to be updated to physically log buffers that are already dirty when/if they are encountered. This means that an extent swap will eventually require multiple rolling transactions to handle large btrees. In addition, all inode related changes must be logged before the bmbt owner change scan begins and can roll the transaction for the first time to preserve fs consistency via log recovery. In preparation for such fixes to the bmbt owner change algorithm, refactor the bmbt scan out of the extent fork swap code to the last operation before the transaction is committed. Update xfs_swap_extent_forks() to only set the inode log flags when an owner change scan is necessary. Update xfs_swap_extents() to trigger the owner change based on the inode log flags. Note that since the owner change now occurs after the extent fork swap, the inode btrees must be fixed up with the inode number of the current inode (similar to log recovery). Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2017-08-29 20:08:39 +03:00
ip->i_d.di_format == XFS_DINODE_FMT_BTREE)
(*target_log_flags) |= XFS_ILOG_DOWNER;
xfs: swap extents operations for CRC filesystems For CRC enabled filesystems, we can't just swap inode forks from one inode to another when defragmenting a file - the blocks in the inode fork bmap btree contain pointers back to the owner inode. Hence if we are to swap the inode forks we have to atomically modify every block in the btree during the transaction. We are doing an entire fork swap here, so we could create a new transaction item type that indicates we are changing the owner of a certain structure from one value to another. If we combine this with ordered buffer logging to modify all the buffers in the tree, then we can change the buffers in the tree without needing log space for the operation. However, this then requires log recovery to perform the modification of the owner information of the objects/structures in question. This does introduce some interesting ordering details into recovery: we have to make sure that the owner change replay occurs after the change that moves the objects is made, not before. Hence we can't use a separate log item for this as we have no guarantee of strict ordering between multiple items in the log due to the relogging action of asynchronous transaction commits. Hence there is no "generic" method we can use for changing the ownership of arbitrary metadata structures. For inode forks, however, there is a simple method of communicating that the fork contents need the owner rewritten - we can pass a inode log format flag for the fork for the transaction that does a fork swap. This flag will then follow the inode fork through relogging actions so when the swap actually gets replayed the ownership can be changed immediately by log recovery. So that gives us a simple method of "whole fork" exchange between two inodes. This is relatively simple to implement, so it makes sense to do this as an initial implementation to support xfs_fsr on CRC enabled filesytems in the same manner as we do on existing filesystems. This commit introduces the swapext driven functionality, the recovery functionality will be in a separate patch. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2013-08-30 04:23:44 +04:00
if (tip->i_d.di_version == 3 &&
xfs: move bmbt owner change to last step of extent swap The extent swap operation currently resets bmbt block owners before the inode forks are swapped. The bmbt buffers are marked as ordered so they do not have to be physically logged in the transaction. This use of ordered buffers is not safe as bmbt buffers may have been previously physically logged. The bmbt owner change algorithm needs to be updated to physically log buffers that are already dirty when/if they are encountered. This means that an extent swap will eventually require multiple rolling transactions to handle large btrees. In addition, all inode related changes must be logged before the bmbt owner change scan begins and can roll the transaction for the first time to preserve fs consistency via log recovery. In preparation for such fixes to the bmbt owner change algorithm, refactor the bmbt scan out of the extent fork swap code to the last operation before the transaction is committed. Update xfs_swap_extent_forks() to only set the inode log flags when an owner change scan is necessary. Update xfs_swap_extents() to trigger the owner change based on the inode log flags. Note that since the owner change now occurs after the extent fork swap, the inode btrees must be fixed up with the inode number of the current inode (similar to log recovery). Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2017-08-29 20:08:39 +03:00
tip->i_d.di_format == XFS_DINODE_FMT_BTREE)
(*src_log_flags) |= XFS_ILOG_DOWNER;
xfs: swap extents operations for CRC filesystems For CRC enabled filesystems, we can't just swap inode forks from one inode to another when defragmenting a file - the blocks in the inode fork bmap btree contain pointers back to the owner inode. Hence if we are to swap the inode forks we have to atomically modify every block in the btree during the transaction. We are doing an entire fork swap here, so we could create a new transaction item type that indicates we are changing the owner of a certain structure from one value to another. If we combine this with ordered buffer logging to modify all the buffers in the tree, then we can change the buffers in the tree without needing log space for the operation. However, this then requires log recovery to perform the modification of the owner information of the objects/structures in question. This does introduce some interesting ordering details into recovery: we have to make sure that the owner change replay occurs after the change that moves the objects is made, not before. Hence we can't use a separate log item for this as we have no guarantee of strict ordering between multiple items in the log due to the relogging action of asynchronous transaction commits. Hence there is no "generic" method we can use for changing the ownership of arbitrary metadata structures. For inode forks, however, there is a simple method of communicating that the fork contents need the owner rewritten - we can pass a inode log format flag for the fork for the transaction that does a fork swap. This flag will then follow the inode fork through relogging actions so when the swap actually gets replayed the ownership can be changed immediately by log recovery. So that gives us a simple method of "whole fork" exchange between two inodes. This is relatively simple to implement, so it makes sense to do this as an initial implementation to support xfs_fsr on CRC enabled filesytems in the same manner as we do on existing filesystems. This commit introduces the swapext driven functionality, the recovery functionality will be in a separate patch. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2013-08-30 04:23:44 +04:00
/*
* 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;
switch (ip->i_d.di_format) {
case XFS_DINODE_FMT_EXTENTS:
(*src_log_flags) |= XFS_ILOG_DEXT;
break;
case XFS_DINODE_FMT_BTREE:
xfs: swap extents operations for CRC filesystems For CRC enabled filesystems, we can't just swap inode forks from one inode to another when defragmenting a file - the blocks in the inode fork bmap btree contain pointers back to the owner inode. Hence if we are to swap the inode forks we have to atomically modify every block in the btree during the transaction. We are doing an entire fork swap here, so we could create a new transaction item type that indicates we are changing the owner of a certain structure from one value to another. If we combine this with ordered buffer logging to modify all the buffers in the tree, then we can change the buffers in the tree without needing log space for the operation. However, this then requires log recovery to perform the modification of the owner information of the objects/structures in question. This does introduce some interesting ordering details into recovery: we have to make sure that the owner change replay occurs after the change that moves the objects is made, not before. Hence we can't use a separate log item for this as we have no guarantee of strict ordering between multiple items in the log due to the relogging action of asynchronous transaction commits. Hence there is no "generic" method we can use for changing the ownership of arbitrary metadata structures. For inode forks, however, there is a simple method of communicating that the fork contents need the owner rewritten - we can pass a inode log format flag for the fork for the transaction that does a fork swap. This flag will then follow the inode fork through relogging actions so when the swap actually gets replayed the ownership can be changed immediately by log recovery. So that gives us a simple method of "whole fork" exchange between two inodes. This is relatively simple to implement, so it makes sense to do this as an initial implementation to support xfs_fsr on CRC enabled filesytems in the same manner as we do on existing filesystems. This commit introduces the swapext driven functionality, the recovery functionality will be in a separate patch. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2013-08-30 04:23:44 +04:00
ASSERT(ip->i_d.di_version < 3 ||
(*src_log_flags & XFS_ILOG_DOWNER));
(*src_log_flags) |= XFS_ILOG_DBROOT;
break;
}
switch (tip->i_d.di_format) {
case XFS_DINODE_FMT_EXTENTS:
(*target_log_flags) |= XFS_ILOG_DEXT;
break;
case XFS_DINODE_FMT_BTREE:
(*target_log_flags) |= XFS_ILOG_DBROOT;
xfs: swap extents operations for CRC filesystems For CRC enabled filesystems, we can't just swap inode forks from one inode to another when defragmenting a file - the blocks in the inode fork bmap btree contain pointers back to the owner inode. Hence if we are to swap the inode forks we have to atomically modify every block in the btree during the transaction. We are doing an entire fork swap here, so we could create a new transaction item type that indicates we are changing the owner of a certain structure from one value to another. If we combine this with ordered buffer logging to modify all the buffers in the tree, then we can change the buffers in the tree without needing log space for the operation. However, this then requires log recovery to perform the modification of the owner information of the objects/structures in question. This does introduce some interesting ordering details into recovery: we have to make sure that the owner change replay occurs after the change that moves the objects is made, not before. Hence we can't use a separate log item for this as we have no guarantee of strict ordering between multiple items in the log due to the relogging action of asynchronous transaction commits. Hence there is no "generic" method we can use for changing the ownership of arbitrary metadata structures. For inode forks, however, there is a simple method of communicating that the fork contents need the owner rewritten - we can pass a inode log format flag for the fork for the transaction that does a fork swap. This flag will then follow the inode fork through relogging actions so when the swap actually gets replayed the ownership can be changed immediately by log recovery. So that gives us a simple method of "whole fork" exchange between two inodes. This is relatively simple to implement, so it makes sense to do this as an initial implementation to support xfs_fsr on CRC enabled filesytems in the same manner as we do on existing filesystems. This commit introduces the swapext driven functionality, the recovery functionality will be in a separate patch. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2013-08-30 04:23:44 +04:00
ASSERT(tip->i_d.di_version < 3 ||
(*target_log_flags & XFS_ILOG_DOWNER));
break;
}
return 0;
}
/*
* Fix up the owners of the bmbt blocks to refer to the current inode. The
* change owner scan attempts to order all modified buffers in the current
* transaction. In the event of ordered buffer failure, the offending buffer is
* physically logged as a fallback and the scan returns -EAGAIN. We must roll
* the transaction in this case to replenish the fallback log reservation and
* restart the scan. This process repeats until the scan completes.
*/
static int
xfs_swap_change_owner(
struct xfs_trans **tpp,
struct xfs_inode *ip,
struct xfs_inode *tmpip)
{
int error;
struct xfs_trans *tp = *tpp;
do {
error = xfs_bmbt_change_owner(tp, ip, XFS_DATA_FORK, ip->i_ino,
NULL);
/* success or fatal error */
if (error != -EAGAIN)
break;
error = xfs_trans_roll(tpp);
if (error)
break;
tp = *tpp;
/*
* Redirty both inodes so they can relog and keep the log tail
* moving forward.
*/
xfs_trans_ijoin(tp, ip, 0);
xfs_trans_ijoin(tp, tmpip, 0);
xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
xfs_trans_log_inode(tp, tmpip, XFS_ILOG_CORE);
} while (true);
return error;
}
int
xfs_swap_extents(
struct xfs_inode *ip, /* target inode */
struct xfs_inode *tip, /* tmp inode */
struct xfs_swapext *sxp)
{
struct xfs_mount *mp = ip->i_mount;
struct xfs_trans *tp;
struct xfs_bstat *sbp = &sxp->sx_stat;
int src_log_flags, target_log_flags;
int error = 0;
int lock_flags;
struct xfs_ifork *cowfp;
uint64_t f;
int resblks = 0;
/*
* Lock the inodes against other IO, page faults and truncate to
* begin with. Then we can ensure the inodes are flushed and have no
* page cache safely. Once we have done this we can take the ilocks and
* do the rest of the checks.
*/
lock_two_nondirectories(VFS_I(ip), VFS_I(tip));
lock_flags = XFS_MMAPLOCK_EXCL;
xfs_lock_two_inodes(ip, XFS_MMAPLOCK_EXCL, tip, XFS_MMAPLOCK_EXCL);
/* Verify that both files have the same format */
if ((VFS_I(ip)->i_mode & S_IFMT) != (VFS_I(tip)->i_mode & S_IFMT)) {
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 = -EINVAL;
goto out_unlock;
}
error = xfs_swap_extent_flush(ip);
if (error)
goto out_unlock;
error = xfs_swap_extent_flush(tip);
if (error)
goto out_unlock;
/*
* Extent "swapping" with rmap requires a permanent reservation and
* a block reservation because it's really just a remap operation
* performed with log redo items!
*/
if (xfs_sb_version_hasrmapbt(&mp->m_sb)) {
/*
* Conceptually this shouldn't affect the shape of either
* bmbt, but since we atomically move extents one by one,
* we reserve enough space to rebuild both trees.
*/
resblks = XFS_SWAP_RMAP_SPACE_RES(mp,
XFS_IFORK_NEXTENTS(ip, XFS_DATA_FORK),
XFS_DATA_FORK) +
XFS_SWAP_RMAP_SPACE_RES(mp,
XFS_IFORK_NEXTENTS(tip, XFS_DATA_FORK),
XFS_DATA_FORK);
}
error = xfs_trans_alloc(mp, &M_RES(mp)->tr_write, resblks, 0, 0, &tp);
if (error)
goto out_unlock;
/*
* Lock and join the inodes to the tansaction so that transaction commit
* or cancel will unlock the inodes from this point onwards.
*/
xfs_lock_two_inodes(ip, XFS_ILOCK_EXCL, tip, XFS_ILOCK_EXCL);
lock_flags |= XFS_ILOCK_EXCL;
xfs_trans_ijoin(tp, ip, 0);
xfs_trans_ijoin(tp, tip, 0);
/* 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 = -EFAULT;
goto out_trans_cancel;
}
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_trans_cancel;
}
/*
* 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 = -EBUSY;
goto out_trans_cancel;
}
/*
* Note the trickiness in setting the log flags - we set the owner log
* flag on the opposite inode (i.e. the inode we are setting the new
* owner to be) because once we swap the forks and log that, log
* recovery is going to see the fork as owned by the swapped inode,
* not the pre-swapped inodes.
*/
src_log_flags = XFS_ILOG_CORE;
target_log_flags = XFS_ILOG_CORE;
if (xfs_sb_version_hasrmapbt(&mp->m_sb))
error = xfs_swap_extent_rmap(&tp, ip, tip);
else
error = xfs_swap_extent_forks(tp, ip, tip, &src_log_flags,
&target_log_flags);
if (error)
goto out_trans_cancel;
/* Do we have to swap reflink flags? */
if ((ip->i_d.di_flags2 & XFS_DIFLAG2_REFLINK) ^
(tip->i_d.di_flags2 & XFS_DIFLAG2_REFLINK)) {
f = ip->i_d.di_flags2 & XFS_DIFLAG2_REFLINK;
ip->i_d.di_flags2 &= ~XFS_DIFLAG2_REFLINK;
ip->i_d.di_flags2 |= tip->i_d.di_flags2 & XFS_DIFLAG2_REFLINK;
tip->i_d.di_flags2 &= ~XFS_DIFLAG2_REFLINK;
tip->i_d.di_flags2 |= f & XFS_DIFLAG2_REFLINK;
}
/* Swap the cow forks. */
if (xfs_sb_version_hasreflink(&mp->m_sb)) {
xfs_extnum_t extnum;
ASSERT(ip->i_cformat == XFS_DINODE_FMT_EXTENTS);
ASSERT(tip->i_cformat == XFS_DINODE_FMT_EXTENTS);
extnum = ip->i_cnextents;
ip->i_cnextents = tip->i_cnextents;
tip->i_cnextents = extnum;
cowfp = ip->i_cowfp;
ip->i_cowfp = tip->i_cowfp;
tip->i_cowfp = cowfp;
if (ip->i_cowfp && ip->i_cnextents)
xfs_inode_set_cowblocks_tag(ip);
else
xfs_inode_clear_cowblocks_tag(ip);
if (tip->i_cowfp && tip->i_cnextents)
xfs_inode_set_cowblocks_tag(tip);
else
xfs_inode_clear_cowblocks_tag(tip);
}
xfs_trans_log_inode(tp, ip, src_log_flags);
xfs_trans_log_inode(tp, tip, target_log_flags);
xfs: move bmbt owner change to last step of extent swap The extent swap operation currently resets bmbt block owners before the inode forks are swapped. The bmbt buffers are marked as ordered so they do not have to be physically logged in the transaction. This use of ordered buffers is not safe as bmbt buffers may have been previously physically logged. The bmbt owner change algorithm needs to be updated to physically log buffers that are already dirty when/if they are encountered. This means that an extent swap will eventually require multiple rolling transactions to handle large btrees. In addition, all inode related changes must be logged before the bmbt owner change scan begins and can roll the transaction for the first time to preserve fs consistency via log recovery. In preparation for such fixes to the bmbt owner change algorithm, refactor the bmbt scan out of the extent fork swap code to the last operation before the transaction is committed. Update xfs_swap_extent_forks() to only set the inode log flags when an owner change scan is necessary. Update xfs_swap_extents() to trigger the owner change based on the inode log flags. Note that since the owner change now occurs after the extent fork swap, the inode btrees must be fixed up with the inode number of the current inode (similar to log recovery). Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2017-08-29 20:08:39 +03:00
/*
* The extent forks have been swapped, but crc=1,rmapbt=0 filesystems
* have inode number owner values in the bmbt blocks that still refer to
* the old inode. Scan each bmbt to fix up the owner values with the
* inode number of the current inode.
*/
if (src_log_flags & XFS_ILOG_DOWNER) {
error = xfs_swap_change_owner(&tp, ip, tip);
xfs: move bmbt owner change to last step of extent swap The extent swap operation currently resets bmbt block owners before the inode forks are swapped. The bmbt buffers are marked as ordered so they do not have to be physically logged in the transaction. This use of ordered buffers is not safe as bmbt buffers may have been previously physically logged. The bmbt owner change algorithm needs to be updated to physically log buffers that are already dirty when/if they are encountered. This means that an extent swap will eventually require multiple rolling transactions to handle large btrees. In addition, all inode related changes must be logged before the bmbt owner change scan begins and can roll the transaction for the first time to preserve fs consistency via log recovery. In preparation for such fixes to the bmbt owner change algorithm, refactor the bmbt scan out of the extent fork swap code to the last operation before the transaction is committed. Update xfs_swap_extent_forks() to only set the inode log flags when an owner change scan is necessary. Update xfs_swap_extents() to trigger the owner change based on the inode log flags. Note that since the owner change now occurs after the extent fork swap, the inode btrees must be fixed up with the inode number of the current inode (similar to log recovery). Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2017-08-29 20:08:39 +03:00
if (error)
goto out_trans_cancel;
}
if (target_log_flags & XFS_ILOG_DOWNER) {
error = xfs_swap_change_owner(&tp, tip, ip);
xfs: move bmbt owner change to last step of extent swap The extent swap operation currently resets bmbt block owners before the inode forks are swapped. The bmbt buffers are marked as ordered so they do not have to be physically logged in the transaction. This use of ordered buffers is not safe as bmbt buffers may have been previously physically logged. The bmbt owner change algorithm needs to be updated to physically log buffers that are already dirty when/if they are encountered. This means that an extent swap will eventually require multiple rolling transactions to handle large btrees. In addition, all inode related changes must be logged before the bmbt owner change scan begins and can roll the transaction for the first time to preserve fs consistency via log recovery. In preparation for such fixes to the bmbt owner change algorithm, refactor the bmbt scan out of the extent fork swap code to the last operation before the transaction is committed. Update xfs_swap_extent_forks() to only set the inode log flags when an owner change scan is necessary. Update xfs_swap_extents() to trigger the owner change based on the inode log flags. Note that since the owner change now occurs after the extent fork swap, the inode btrees must be fixed up with the inode number of the current inode (similar to log recovery). Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2017-08-29 20:08:39 +03:00
if (error)
goto out_trans_cancel;
}
/*
* 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);
trace_xfs_swap_extent_after(ip, 0);
trace_xfs_swap_extent_after(tip, 1);
out_unlock:
xfs_iunlock(ip, lock_flags);
xfs_iunlock(tip, lock_flags);
unlock_two_nondirectories(VFS_I(ip), VFS_I(tip));
return error;
out_trans_cancel:
xfs_trans_cancel(tp);
goto out_unlock;
}