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

542 строки
13 KiB
C

/*
* Copyright (c) 2000-2005 Silicon Graphics, Inc.
* Copyright (c) 2013 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_types.h"
#include "xfs_bit.h"
#include "xfs_log.h"
#include "xfs_trans.h"
#include "xfs_sb.h"
#include "xfs_ag.h"
#include "xfs_mount.h"
#include "xfs_error.h"
#include "xfs_da_btree.h"
#include "xfs_bmap_btree.h"
#include "xfs_dinode.h"
#include "xfs_inode.h"
#include "xfs_alloc.h"
#include "xfs_inode_item.h"
#include "xfs_bmap.h"
#include "xfs_attr.h"
#include "xfs_attr_leaf.h"
#include "xfs_attr_remote.h"
#include "xfs_trans_space.h"
#include "xfs_trace.h"
#include "xfs_cksum.h"
#include "xfs_buf_item.h"
#define ATTR_RMTVALUE_MAPSIZE 1 /* # of map entries at once */
/*
* Each contiguous block has a header, so it is not just a simple attribute
* length to FSB conversion.
*/
static int
xfs_attr3_rmt_blocks(
struct xfs_mount *mp,
int attrlen)
{
int buflen = XFS_ATTR3_RMT_BUF_SPACE(mp,
mp->m_sb.sb_blocksize);
return (attrlen + buflen - 1) / buflen;
}
static bool
xfs_attr3_rmt_verify(
struct xfs_buf *bp)
{
struct xfs_mount *mp = bp->b_target->bt_mount;
struct xfs_attr3_rmt_hdr *rmt = bp->b_addr;
if (!xfs_sb_version_hascrc(&mp->m_sb))
return false;
if (rmt->rm_magic != cpu_to_be32(XFS_ATTR3_RMT_MAGIC))
return false;
if (!uuid_equal(&rmt->rm_uuid, &mp->m_sb.sb_uuid))
return false;
if (bp->b_bn != be64_to_cpu(rmt->rm_blkno))
return false;
if (be32_to_cpu(rmt->rm_offset) +
be32_to_cpu(rmt->rm_bytes) >= XATTR_SIZE_MAX)
return false;
if (rmt->rm_owner == 0)
return false;
return true;
}
static void
xfs_attr3_rmt_read_verify(
struct xfs_buf *bp)
{
struct xfs_mount *mp = bp->b_target->bt_mount;
/* no verification of non-crc buffers */
if (!xfs_sb_version_hascrc(&mp->m_sb))
return;
if (!xfs_verify_cksum(bp->b_addr, BBTOB(bp->b_length),
XFS_ATTR3_RMT_CRC_OFF) ||
!xfs_attr3_rmt_verify(bp)) {
XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp, bp->b_addr);
xfs_buf_ioerror(bp, EFSCORRUPTED);
}
}
static void
xfs_attr3_rmt_write_verify(
struct xfs_buf *bp)
{
struct xfs_mount *mp = bp->b_target->bt_mount;
struct xfs_buf_log_item *bip = bp->b_fspriv;
/* no verification of non-crc buffers */
if (!xfs_sb_version_hascrc(&mp->m_sb))
return;
if (!xfs_attr3_rmt_verify(bp)) {
XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp, bp->b_addr);
xfs_buf_ioerror(bp, EFSCORRUPTED);
return;
}
if (bip) {
struct xfs_attr3_rmt_hdr *rmt = bp->b_addr;
rmt->rm_lsn = cpu_to_be64(bip->bli_item.li_lsn);
}
xfs_update_cksum(bp->b_addr, BBTOB(bp->b_length),
XFS_ATTR3_RMT_CRC_OFF);
}
const struct xfs_buf_ops xfs_attr3_rmt_buf_ops = {
.verify_read = xfs_attr3_rmt_read_verify,
.verify_write = xfs_attr3_rmt_write_verify,
};
static int
xfs_attr3_rmt_hdr_set(
struct xfs_mount *mp,
xfs_ino_t ino,
uint32_t offset,
uint32_t size,
struct xfs_buf *bp)
{
struct xfs_attr3_rmt_hdr *rmt = bp->b_addr;
if (!xfs_sb_version_hascrc(&mp->m_sb))
return 0;
rmt->rm_magic = cpu_to_be32(XFS_ATTR3_RMT_MAGIC);
rmt->rm_offset = cpu_to_be32(offset);
rmt->rm_bytes = cpu_to_be32(size);
uuid_copy(&rmt->rm_uuid, &mp->m_sb.sb_uuid);
rmt->rm_owner = cpu_to_be64(ino);
rmt->rm_blkno = cpu_to_be64(bp->b_bn);
bp->b_ops = &xfs_attr3_rmt_buf_ops;
return sizeof(struct xfs_attr3_rmt_hdr);
}
/*
* Checking of the remote attribute header is split into two parts. the verifier
* does CRC, location and bounds checking, the unpacking function checks the
* attribute parameters and owner.
*/
static bool
xfs_attr3_rmt_hdr_ok(
struct xfs_mount *mp,
xfs_ino_t ino,
uint32_t offset,
uint32_t size,
struct xfs_buf *bp)
{
struct xfs_attr3_rmt_hdr *rmt = bp->b_addr;
if (offset != be32_to_cpu(rmt->rm_offset))
return false;
if (size != be32_to_cpu(rmt->rm_bytes))
return false;
if (ino != be64_to_cpu(rmt->rm_owner))
return false;
/* ok */
return true;
}
/*
* Read the value associated with an attribute from the out-of-line buffer
* that we stored it in.
*/
int
xfs_attr_rmtval_get(
struct xfs_da_args *args)
{
struct xfs_bmbt_irec map[ATTR_RMTVALUE_MAPSIZE];
struct xfs_mount *mp = args->dp->i_mount;
struct xfs_buf *bp;
xfs_daddr_t dblkno;
xfs_dablk_t lblkno = args->rmtblkno;
void *dst = args->value;
int valuelen = args->valuelen;
int nmap;
int error;
int blkcnt;
int i;
int offset = 0;
trace_xfs_attr_rmtval_get(args);
ASSERT(!(args->flags & ATTR_KERNOVAL));
while (valuelen > 0) {
nmap = ATTR_RMTVALUE_MAPSIZE;
error = xfs_bmapi_read(args->dp, (xfs_fileoff_t)lblkno,
args->rmtblkcnt, map, &nmap,
XFS_BMAPI_ATTRFORK);
if (error)
return error;
ASSERT(nmap >= 1);
for (i = 0; (i < nmap) && (valuelen > 0); i++) {
int byte_cnt;
char *src;
ASSERT((map[i].br_startblock != DELAYSTARTBLOCK) &&
(map[i].br_startblock != HOLESTARTBLOCK));
dblkno = XFS_FSB_TO_DADDR(mp, map[i].br_startblock);
blkcnt = XFS_FSB_TO_BB(mp, map[i].br_blockcount);
error = xfs_trans_read_buf(mp, NULL, mp->m_ddev_targp,
dblkno, blkcnt, 0, &bp,
&xfs_attr3_rmt_buf_ops);
if (error)
return error;
byte_cnt = min_t(int, valuelen, BBTOB(bp->b_length));
byte_cnt = XFS_ATTR3_RMT_BUF_SPACE(mp, byte_cnt);
src = bp->b_addr;
if (xfs_sb_version_hascrc(&mp->m_sb)) {
if (!xfs_attr3_rmt_hdr_ok(mp, args->dp->i_ino,
offset, byte_cnt, bp)) {
xfs_alert(mp,
"remote attribute header does not match required off/len/owner (0x%x/Ox%x,0x%llx)",
offset, byte_cnt, args->dp->i_ino);
xfs_buf_relse(bp);
return EFSCORRUPTED;
}
src += sizeof(struct xfs_attr3_rmt_hdr);
}
memcpy(dst, src, byte_cnt);
xfs_buf_relse(bp);
offset += byte_cnt;
dst += byte_cnt;
valuelen -= byte_cnt;
lblkno += map[i].br_blockcount;
}
}
ASSERT(valuelen == 0);
return 0;
}
/*
* Write the value associated with an attribute into the out-of-line buffer
* that we have defined for it.
*/
int
xfs_attr_rmtval_set(
struct xfs_da_args *args)
{
struct xfs_inode *dp = args->dp;
struct xfs_mount *mp = dp->i_mount;
struct xfs_bmbt_irec map;
struct xfs_buf *bp;
xfs_daddr_t dblkno;
xfs_dablk_t lblkno;
xfs_fileoff_t lfileoff = 0;
void *src = args->value;
int blkcnt;
int valuelen;
int nmap;
int error;
int hdrcnt = 0;
bool crcs = xfs_sb_version_hascrc(&mp->m_sb);
int offset = 0;
trace_xfs_attr_rmtval_set(args);
/*
* Find a "hole" in the attribute address space large enough for
* us to drop the new attribute's value into. Because CRC enable
* attributes have headers, we can't just do a straight byte to FSB
* conversion. We calculate the worst case block count in this case
* and we may not need that many, so we have to handle this when
* allocating the blocks below.
*/
if (!crcs)
blkcnt = XFS_B_TO_FSB(mp, args->valuelen);
else
blkcnt = xfs_attr3_rmt_blocks(mp, args->valuelen);
error = xfs_bmap_first_unused(args->trans, args->dp, blkcnt, &lfileoff,
XFS_ATTR_FORK);
if (error)
return error;
/* Start with the attribute data. We'll allocate the rest afterwards. */
if (crcs)
blkcnt = XFS_B_TO_FSB(mp, args->valuelen);
args->rmtblkno = lblkno = (xfs_dablk_t)lfileoff;
args->rmtblkcnt = blkcnt;
/*
* Roll through the "value", allocating blocks on disk as required.
*/
while (blkcnt > 0) {
int committed;
/*
* Allocate a single extent, up to the size of the value.
*/
xfs_bmap_init(args->flist, args->firstblock);
nmap = 1;
error = xfs_bmapi_write(args->trans, dp, (xfs_fileoff_t)lblkno,
blkcnt,
XFS_BMAPI_ATTRFORK | XFS_BMAPI_METADATA,
args->firstblock, args->total, &map, &nmap,
args->flist);
if (!error) {
error = xfs_bmap_finish(&args->trans, args->flist,
&committed);
}
if (error) {
ASSERT(committed);
args->trans = NULL;
xfs_bmap_cancel(args->flist);
return(error);
}
/*
* bmap_finish() may have committed the last trans and started
* a new one. We need the inode to be in all transactions.
*/
if (committed)
xfs_trans_ijoin(args->trans, dp, 0);
ASSERT(nmap == 1);
ASSERT((map.br_startblock != DELAYSTARTBLOCK) &&
(map.br_startblock != HOLESTARTBLOCK));
lblkno += map.br_blockcount;
blkcnt -= map.br_blockcount;
hdrcnt++;
/*
* If we have enough blocks for the attribute data, calculate
* how many extra blocks we need for headers. We might run
* through this multiple times in the case that the additional
* headers in the blocks needed for the data fragments spills
* into requiring more blocks. e.g. for 512 byte blocks, we'll
* spill for another block every 9 headers we require in this
* loop.
*/
if (crcs && blkcnt == 0) {
int total_len;
total_len = args->valuelen +
hdrcnt * sizeof(struct xfs_attr3_rmt_hdr);
blkcnt = XFS_B_TO_FSB(mp, total_len);
blkcnt -= args->rmtblkcnt;
args->rmtblkcnt += blkcnt;
}
/*
* Start the next trans in the chain.
*/
error = xfs_trans_roll(&args->trans, dp);
if (error)
return (error);
}
/*
* Roll through the "value", copying the attribute value to the
* already-allocated blocks. Blocks are written synchronously
* so that we can know they are all on disk before we turn off
* the INCOMPLETE flag.
*/
lblkno = args->rmtblkno;
valuelen = args->valuelen;
while (valuelen > 0) {
int byte_cnt;
char *buf;
/*
* Try to remember where we decided to put the value.
*/
xfs_bmap_init(args->flist, args->firstblock);
nmap = 1;
error = xfs_bmapi_read(dp, (xfs_fileoff_t)lblkno,
args->rmtblkcnt, &map, &nmap,
XFS_BMAPI_ATTRFORK);
if (error)
return(error);
ASSERT(nmap == 1);
ASSERT((map.br_startblock != DELAYSTARTBLOCK) &&
(map.br_startblock != HOLESTARTBLOCK));
dblkno = XFS_FSB_TO_DADDR(mp, map.br_startblock),
blkcnt = XFS_FSB_TO_BB(mp, map.br_blockcount);
bp = xfs_buf_get(mp->m_ddev_targp, dblkno, blkcnt, 0);
if (!bp)
return ENOMEM;
bp->b_ops = &xfs_attr3_rmt_buf_ops;
byte_cnt = BBTOB(bp->b_length);
byte_cnt = XFS_ATTR3_RMT_BUF_SPACE(mp, byte_cnt);
if (valuelen < byte_cnt)
byte_cnt = valuelen;
buf = bp->b_addr;
buf += xfs_attr3_rmt_hdr_set(mp, dp->i_ino, offset,
byte_cnt, bp);
memcpy(buf, src, byte_cnt);
if (byte_cnt < BBTOB(bp->b_length))
xfs_buf_zero(bp, byte_cnt,
BBTOB(bp->b_length) - byte_cnt);
error = xfs_bwrite(bp); /* GROT: NOTE: synchronous write */
xfs_buf_relse(bp);
if (error)
return error;
src += byte_cnt;
valuelen -= byte_cnt;
offset += byte_cnt;
hdrcnt--;
lblkno += map.br_blockcount;
}
ASSERT(valuelen == 0);
ASSERT(hdrcnt == 0);
return 0;
}
/*
* Remove the value associated with an attribute by deleting the
* out-of-line buffer that it is stored on.
*/
int
xfs_attr_rmtval_remove(xfs_da_args_t *args)
{
xfs_mount_t *mp;
xfs_bmbt_irec_t map;
xfs_buf_t *bp;
xfs_daddr_t dblkno;
xfs_dablk_t lblkno;
int valuelen, blkcnt, nmap, error, done, committed;
trace_xfs_attr_rmtval_remove(args);
mp = args->dp->i_mount;
/*
* Roll through the "value", invalidating the attribute value's
* blocks.
*/
lblkno = args->rmtblkno;
valuelen = args->rmtblkcnt;
while (valuelen > 0) {
/*
* Try to remember where we decided to put the value.
*/
nmap = 1;
error = xfs_bmapi_read(args->dp, (xfs_fileoff_t)lblkno,
args->rmtblkcnt, &map, &nmap,
XFS_BMAPI_ATTRFORK);
if (error)
return(error);
ASSERT(nmap == 1);
ASSERT((map.br_startblock != DELAYSTARTBLOCK) &&
(map.br_startblock != HOLESTARTBLOCK));
dblkno = XFS_FSB_TO_DADDR(mp, map.br_startblock),
blkcnt = XFS_FSB_TO_BB(mp, map.br_blockcount);
/*
* If the "remote" value is in the cache, remove it.
*/
bp = xfs_incore(mp->m_ddev_targp, dblkno, blkcnt, XBF_TRYLOCK);
if (bp) {
xfs_buf_stale(bp);
xfs_buf_relse(bp);
bp = NULL;
}
valuelen -= map.br_blockcount;
lblkno += map.br_blockcount;
}
/*
* Keep de-allocating extents until the remote-value region is gone.
*/
lblkno = args->rmtblkno;
blkcnt = args->rmtblkcnt;
done = 0;
while (!done) {
xfs_bmap_init(args->flist, args->firstblock);
error = xfs_bunmapi(args->trans, args->dp, lblkno, blkcnt,
XFS_BMAPI_ATTRFORK | XFS_BMAPI_METADATA,
1, args->firstblock, args->flist,
&done);
if (!error) {
error = xfs_bmap_finish(&args->trans, args->flist,
&committed);
}
if (error) {
ASSERT(committed);
args->trans = NULL;
xfs_bmap_cancel(args->flist);
return error;
}
/*
* bmap_finish() may have committed the last trans and started
* a new one. We need the inode to be in all transactions.
*/
if (committed)
xfs_trans_ijoin(args->trans, args->dp, 0);
/*
* Close out trans and start the next one in the chain.
*/
error = xfs_trans_roll(&args->trans, args->dp);
if (error)
return (error);
}
return(0);
}