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xfs: implement the GETFSMAP ioctl 

Introduce a new ioctl that uses the reverse mapping btree to return
information about the physical layout of the filesystem.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
zero-colors
Darrick J. Wong 2017-03-28 14:56:37 -07:00
parent fb3c3de2f6
commit e89c041338
12 changed files with 1048 additions and 0 deletions
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1
fs/xfs/Makefile
View File

@ -79,6 +79,7 @@ xfs-y += xfs_aops.o \
xfs_extent_busy.o \
xfs_file.o \
xfs_filestream.o \
xfs_fsmap.o \
xfs_fsops.o \
xfs_globals.o \
xfs_icache.o \

13
fs/xfs/libxfs/xfs_fs.h
View File

@ -92,6 +92,18 @@ struct getbmapx {
#define BMV_OF_LAST 0x4 /* segment is the last in the file */
#define BMV_OF_SHARED 0x8 /* segment shared with another file */
/* fmr_owner special values for FS_IOC_GETFSMAP */
#define XFS_FMR_OWN_FREE FMR_OWN_FREE /* free space */
#define XFS_FMR_OWN_UNKNOWN FMR_OWN_UNKNOWN /* unknown owner */
#define XFS_FMR_OWN_FS FMR_OWNER('X', 1) /* static fs metadata */
#define XFS_FMR_OWN_LOG FMR_OWNER('X', 2) /* journalling log */
#define XFS_FMR_OWN_AG FMR_OWNER('X', 3) /* per-AG metadata */
#define XFS_FMR_OWN_INOBT FMR_OWNER('X', 4) /* inode btree blocks */
#define XFS_FMR_OWN_INODES FMR_OWNER('X', 5) /* inodes */
#define XFS_FMR_OWN_REFC FMR_OWNER('X', 6) /* refcount tree */
#define XFS_FMR_OWN_COW FMR_OWNER('X', 7) /* cow staging */
#define XFS_FMR_OWN_DEFECTIVE FMR_OWNER('X', 8) /* bad blocks */
/*
* Structure for XFS_IOC_FSSETDM.
* For use by backup and restore programs to set the XFS on-disk inode
@ -502,6 +514,7 @@ typedef struct xfs_swapext
#define XFS_IOC_GETBMAPX _IOWR('X', 56, struct getbmap)
#define XFS_IOC_ZERO_RANGE _IOW ('X', 57, struct xfs_flock64)
#define XFS_IOC_FREE_EOFBLOCKS _IOR ('X', 58, struct xfs_fs_eofblocks)
/* XFS_IOC_GETFSMAP ------ hoisted 59 */
/*
* ioctl commands that replace IRIX syssgi()'s

28
fs/xfs/libxfs/xfs_rmap.c
View File

@ -2305,3 +2305,31 @@ xfs_rmap_free_extent(
return __xfs_rmap_add(mp, dfops, XFS_RMAP_FREE, owner,
XFS_DATA_FORK, &bmap);
}
/* Compare rmap records. Returns -1 if a < b, 1 if a > b, and 0 if equal. */
int
xfs_rmap_compare(
const struct xfs_rmap_irec *a,
const struct xfs_rmap_irec *b)
{
__u64 oa;
__u64 ob;
oa = xfs_rmap_irec_offset_pack(a);
ob = xfs_rmap_irec_offset_pack(b);
if (a->rm_startblock < b->rm_startblock)
return -1;
else if (a->rm_startblock > b->rm_startblock)
return 1;
else if (a->rm_owner < b->rm_owner)
return -1;
else if (a->rm_owner > b->rm_owner)
return 1;
else if (oa < ob)
return -1;
else if (oa > ob)
return 1;
else
return 0;
}

2
fs/xfs/libxfs/xfs_rmap.h
View File

@ -214,5 +214,7 @@ int xfs_rmap_find_left_neighbor(struct xfs_btree_cur *cur, xfs_agblock_t bno,
int xfs_rmap_lookup_le_range(struct xfs_btree_cur *cur, xfs_agblock_t bno,
uint64_t owner, uint64_t offset, unsigned int flags,
struct xfs_rmap_irec *irec, int *stat);
int xfs_rmap_compare(const struct xfs_rmap_irec *a,
const struct xfs_rmap_irec *b);
#endif /* __XFS_RMAP_H__ */

756
fs/xfs/xfs_fsmap.c 100644
View File

@ -0,0 +1,756 @@
/*
* Copyright (C) 2017 Oracle. All Rights Reserved.
*
* Author: Darrick J. Wong <darrick.wong@oracle.com>
*
* 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; either version 2
* of the License, or (at your option) any later version.
*
* 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_sb.h"
#include "xfs_mount.h"
#include "xfs_defer.h"
#include "xfs_inode.h"
#include "xfs_trans.h"
#include "xfs_error.h"
#include "xfs_btree.h"
#include "xfs_rmap_btree.h"
#include "xfs_trace.h"
#include "xfs_log.h"
#include "xfs_rmap.h"
#include "xfs_alloc.h"
#include "xfs_bit.h"
#include <linux/fsmap.h>
#include "xfs_fsmap.h"
#include "xfs_refcount.h"
#include "xfs_refcount_btree.h"
/* Convert an xfs_fsmap to an fsmap. */
void
xfs_fsmap_from_internal(
struct fsmap *dest,
struct xfs_fsmap *src)
{
dest->fmr_device = src->fmr_device;
dest->fmr_flags = src->fmr_flags;
dest->fmr_physical = BBTOB(src->fmr_physical);
dest->fmr_owner = src->fmr_owner;
dest->fmr_offset = BBTOB(src->fmr_offset);
dest->fmr_length = BBTOB(src->fmr_length);
dest->fmr_reserved[0] = 0;
dest->fmr_reserved[1] = 0;
dest->fmr_reserved[2] = 0;
}
/* Convert an fsmap to an xfs_fsmap. */
void
xfs_fsmap_to_internal(
struct xfs_fsmap *dest,
struct fsmap *src)
{
dest->fmr_device = src->fmr_device;
dest->fmr_flags = src->fmr_flags;
dest->fmr_physical = BTOBBT(src->fmr_physical);
dest->fmr_owner = src->fmr_owner;
dest->fmr_offset = BTOBBT(src->fmr_offset);
dest->fmr_length = BTOBBT(src->fmr_length);
}
/* Convert an fsmap owner into an rmapbt owner. */
static int
xfs_fsmap_owner_to_rmap(
struct xfs_rmap_irec *dest,
struct xfs_fsmap *src)
{
if (!(src->fmr_flags & FMR_OF_SPECIAL_OWNER)) {
dest->rm_owner = src->fmr_owner;
return 0;
}
switch (src->fmr_owner) {
case 0: /* "lowest owner id possible" */
case -1ULL: /* "highest owner id possible" */
dest->rm_owner = 0;
break;
case XFS_FMR_OWN_FREE:
dest->rm_owner = XFS_RMAP_OWN_NULL;
break;
case XFS_FMR_OWN_UNKNOWN:
dest->rm_owner = XFS_RMAP_OWN_UNKNOWN;
break;
case XFS_FMR_OWN_FS:
dest->rm_owner = XFS_RMAP_OWN_FS;
break;
case XFS_FMR_OWN_LOG:
dest->rm_owner = XFS_RMAP_OWN_LOG;
break;
case XFS_FMR_OWN_AG:
dest->rm_owner = XFS_RMAP_OWN_AG;
break;
case XFS_FMR_OWN_INOBT:
dest->rm_owner = XFS_RMAP_OWN_INOBT;
break;
case XFS_FMR_OWN_INODES:
dest->rm_owner = XFS_RMAP_OWN_INODES;
break;
case XFS_FMR_OWN_REFC:
dest->rm_owner = XFS_RMAP_OWN_REFC;
break;
case XFS_FMR_OWN_COW:
dest->rm_owner = XFS_RMAP_OWN_COW;
break;
case XFS_FMR_OWN_DEFECTIVE: /* not implemented */
/* fall through */
default:
return -EINVAL;
}
return 0;
}
/* Convert an rmapbt owner into an fsmap owner. */
static int
xfs_fsmap_owner_from_rmap(
struct xfs_fsmap *dest,
struct xfs_rmap_irec *src)
{
dest->fmr_flags = 0;
if (!XFS_RMAP_NON_INODE_OWNER(src->rm_owner)) {
dest->fmr_owner = src->rm_owner;
return 0;
}
dest->fmr_flags |= FMR_OF_SPECIAL_OWNER;
switch (src->rm_owner) {
case XFS_RMAP_OWN_FS:
dest->fmr_owner = XFS_FMR_OWN_FS;
break;
case XFS_RMAP_OWN_LOG:
dest->fmr_owner = XFS_FMR_OWN_LOG;
break;
case XFS_RMAP_OWN_AG:
dest->fmr_owner = XFS_FMR_OWN_AG;
break;
case XFS_RMAP_OWN_INOBT:
dest->fmr_owner = XFS_FMR_OWN_INOBT;
break;
case XFS_RMAP_OWN_INODES:
dest->fmr_owner = XFS_FMR_OWN_INODES;
break;
case XFS_RMAP_OWN_REFC:
dest->fmr_owner = XFS_FMR_OWN_REFC;
break;
case XFS_RMAP_OWN_COW:
dest->fmr_owner = XFS_FMR_OWN_COW;
break;
default:
return -EFSCORRUPTED;
}
return 0;
}
/* getfsmap query state */
struct xfs_getfsmap_info {
struct xfs_fsmap_head *head;
xfs_fsmap_format_t formatter; /* formatting fn */
void *format_arg; /* format buffer */
struct xfs_buf *agf_bp; /* AGF, for refcount queries */
xfs_daddr_t next_daddr; /* next daddr we expect */
u64 missing_owner; /* owner of holes */
u32 dev; /* device id */
xfs_agnumber_t agno; /* AG number, if applicable */
struct xfs_rmap_irec low; /* low rmap key */
struct xfs_rmap_irec high; /* high rmap key */
bool last; /* last extent? */
};
/* Associate a device with a getfsmap handler. */
struct xfs_getfsmap_dev {
u32 dev;
int (*fn)(struct xfs_trans *tp,
struct xfs_fsmap *keys,
struct xfs_getfsmap_info *info);
};
/* Compare two getfsmap device handlers. */
static int
xfs_getfsmap_dev_compare(
const void *p1,
const void *p2)
{
const struct xfs_getfsmap_dev *d1 = p1;
const struct xfs_getfsmap_dev *d2 = p2;
return d1->dev - d2->dev;
}
/* Decide if this mapping is shared. */
STATIC int
xfs_getfsmap_is_shared(
struct xfs_trans *tp,
struct xfs_getfsmap_info *info,
struct xfs_rmap_irec *rec,
bool *stat)
{
struct xfs_mount *mp = tp->t_mountp;
struct xfs_btree_cur *cur;
xfs_agblock_t fbno;
xfs_extlen_t flen;
int error;
*stat = false;
if (!xfs_sb_version_hasreflink(&mp->m_sb))
return 0;
/* rt files will have agno set to NULLAGNUMBER */
if (info->agno == NULLAGNUMBER)
return 0;
/* Are there any shared blocks here? */
flen = 0;
cur = xfs_refcountbt_init_cursor(mp, tp, info->agf_bp,
info->agno, NULL);
error = xfs_refcount_find_shared(cur, rec->rm_startblock,
rec->rm_blockcount, &fbno, &flen, false);
xfs_btree_del_cursor(cur, error ? XFS_BTREE_ERROR : XFS_BTREE_NOERROR);
if (error)
return error;
*stat = flen > 0;
return 0;
}
/*
* Format a reverse mapping for getfsmap, having translated rm_startblock
* into the appropriate daddr units.
*/
STATIC int
xfs_getfsmap_helper(
struct xfs_trans *tp,
struct xfs_getfsmap_info *info,
struct xfs_rmap_irec *rec,
xfs_daddr_t rec_daddr)
{
struct xfs_fsmap fmr;
struct xfs_mount *mp = tp->t_mountp;
bool shared;
int error;
if (fatal_signal_pending(current))
return -EINTR;
/*
* Filter out records that start before our startpoint, if the
* caller requested that.
*/
if (xfs_rmap_compare(rec, &info->low) < 0) {
rec_daddr += XFS_FSB_TO_BB(mp, rec->rm_blockcount);
if (info->next_daddr < rec_daddr)
info->next_daddr = rec_daddr;
return XFS_BTREE_QUERY_RANGE_CONTINUE;
}
/* Are we just counting mappings? */
if (info->head->fmh_count == 0) {
if (rec_daddr > info->next_daddr)
info->head->fmh_entries++;
if (info->last)
return XFS_BTREE_QUERY_RANGE_CONTINUE;
info->head->fmh_entries++;
rec_daddr += XFS_FSB_TO_BB(mp, rec->rm_blockcount);
if (info->next_daddr < rec_daddr)
info->next_daddr = rec_daddr;
return XFS_BTREE_QUERY_RANGE_CONTINUE;
}
/*
* If the record starts past the last physical block we saw,
* then we've found a gap. Report the gap as being owned by
* whatever the caller specified is the missing owner.
*/
if (rec_daddr > info->next_daddr) {
if (info->head->fmh_entries >= info->head->fmh_count)
return XFS_BTREE_QUERY_RANGE_ABORT;
fmr.fmr_device = info->dev;
fmr.fmr_physical = info->next_daddr;
fmr.fmr_owner = info->missing_owner;
fmr.fmr_offset = 0;
fmr.fmr_length = rec_daddr - info->next_daddr;
fmr.fmr_flags = FMR_OF_SPECIAL_OWNER;
error = info->formatter(&fmr, info->format_arg);
if (error)
return error;
info->head->fmh_entries++;
}
if (info->last)
goto out;
/* Fill out the extent we found */
if (info->head->fmh_entries >= info->head->fmh_count)
return XFS_BTREE_QUERY_RANGE_ABORT;
trace_xfs_fsmap_mapping(mp, info->dev, info->agno, rec);
fmr.fmr_device = info->dev;
fmr.fmr_physical = rec_daddr;
error = xfs_fsmap_owner_from_rmap(&fmr, rec);
if (error)
return error;
fmr.fmr_offset = XFS_FSB_TO_BB(mp, rec->rm_offset);
fmr.fmr_length = XFS_FSB_TO_BB(mp, rec->rm_blockcount);
if (rec->rm_flags & XFS_RMAP_UNWRITTEN)
fmr.fmr_flags |= FMR_OF_PREALLOC;
if (rec->rm_flags & XFS_RMAP_ATTR_FORK)
fmr.fmr_flags |= FMR_OF_ATTR_FORK;
if (rec->rm_flags & XFS_RMAP_BMBT_BLOCK)
fmr.fmr_flags |= FMR_OF_EXTENT_MAP;
if (fmr.fmr_flags == 0) {
error = xfs_getfsmap_is_shared(tp, info, rec, &shared);
if (error)
return error;
if (shared)
fmr.fmr_flags |= FMR_OF_SHARED;
}
error = info->formatter(&fmr, info->format_arg);
if (error)
return error;
info->head->fmh_entries++;
out:
rec_daddr += XFS_FSB_TO_BB(mp, rec->rm_blockcount);
if (info->next_daddr < rec_daddr)
info->next_daddr = rec_daddr;
return XFS_BTREE_QUERY_RANGE_CONTINUE;
}
/* Transform a rmapbt irec into a fsmap */
STATIC int
xfs_getfsmap_datadev_helper(
struct xfs_btree_cur *cur,
struct xfs_rmap_irec *rec,
void *priv)
{
struct xfs_mount *mp = cur->bc_mp;
struct xfs_getfsmap_info *info = priv;
xfs_fsblock_t fsb;
xfs_daddr_t rec_daddr;
fsb = XFS_AGB_TO_FSB(mp, cur->bc_private.a.agno, rec->rm_startblock);
rec_daddr = XFS_FSB_TO_DADDR(mp, fsb);
return xfs_getfsmap_helper(cur->bc_tp, info, rec, rec_daddr);
}
/* Set rmap flags based on the getfsmap flags */
static void
xfs_getfsmap_set_irec_flags(
struct xfs_rmap_irec *irec,
struct xfs_fsmap *fmr)
{
irec->rm_flags = 0;
if (fmr->fmr_flags & FMR_OF_ATTR_FORK)
irec->rm_flags |= XFS_RMAP_ATTR_FORK;
if (fmr->fmr_flags & FMR_OF_EXTENT_MAP)
irec->rm_flags |= XFS_RMAP_BMBT_BLOCK;
if (fmr->fmr_flags & FMR_OF_PREALLOC)
irec->rm_flags |= XFS_RMAP_UNWRITTEN;
}
/* Execute a getfsmap query against the log device. */
STATIC int
xfs_getfsmap_logdev(
struct xfs_trans *tp,
struct xfs_fsmap *keys,
struct xfs_getfsmap_info *info)
{
struct xfs_mount *mp = tp->t_mountp;
struct xfs_rmap_irec rmap;
int error;
/* Set up search keys */
info->low.rm_startblock = XFS_BB_TO_FSBT(mp, keys[0].fmr_physical);
info->low.rm_offset = XFS_BB_TO_FSBT(mp, keys[0].fmr_offset);
error = xfs_fsmap_owner_to_rmap(&info->low, keys);
if (error)
return error;
info->low.rm_blockcount = 0;
xfs_getfsmap_set_irec_flags(&info->low, &keys[0]);
error = xfs_fsmap_owner_to_rmap(&info->high, keys + 1);
if (error)
return error;
info->high.rm_startblock = -1U;
info->high.rm_owner = ULLONG_MAX;
info->high.rm_offset = ULLONG_MAX;
info->high.rm_blockcount = 0;
info->high.rm_flags = XFS_RMAP_KEY_FLAGS | XFS_RMAP_REC_FLAGS;
info->missing_owner = XFS_FMR_OWN_FREE;
trace_xfs_fsmap_low_key(mp, info->dev, info->agno, &info->low);
trace_xfs_fsmap_high_key(mp, info->dev, info->agno, &info->high);
if (keys[0].fmr_physical > 0)
return 0;
/* Fabricate an rmap entry for the external log device. */
rmap.rm_startblock = 0;
rmap.rm_blockcount = mp->m_sb.sb_logblocks;
rmap.rm_owner = XFS_RMAP_OWN_LOG;
rmap.rm_offset = 0;
rmap.rm_flags = 0;
return xfs_getfsmap_helper(tp, info, &rmap, 0);
}
/* Execute a getfsmap query against the regular data device. */
STATIC int
__xfs_getfsmap_datadev(
struct xfs_trans *tp,
struct xfs_fsmap *keys,
struct xfs_getfsmap_info *info,
int (*query_fn)(struct xfs_trans *,
struct xfs_getfsmap_info *,
struct xfs_btree_cur **,
void *),
void *priv)
{
struct xfs_mount *mp = tp->t_mountp;
struct xfs_btree_cur *bt_cur = NULL;
xfs_fsblock_t start_fsb;
xfs_fsblock_t end_fsb;
xfs_agnumber_t start_ag;
xfs_agnumber_t end_ag;
xfs_daddr_t eofs;
int error = 0;
eofs = XFS_FSB_TO_BB(mp, mp->m_sb.sb_dblocks);
if (keys[0].fmr_physical >= eofs)
return 0;
if (keys[1].fmr_physical >= eofs)
keys[1].fmr_physical = eofs - 1;
start_fsb = XFS_DADDR_TO_FSB(mp, keys[0].fmr_physical);
end_fsb = XFS_DADDR_TO_FSB(mp, keys[1].fmr_physical);
/*
* Convert the fsmap low/high keys to AG based keys. Initialize
* low to the fsmap low key and max out the high key to the end
* of the AG.
*/
info->low.rm_startblock = XFS_FSB_TO_AGBNO(mp, start_fsb);
info->low.rm_offset = XFS_BB_TO_FSBT(mp, keys[0].fmr_offset);
error = xfs_fsmap_owner_to_rmap(&info->low, &keys[0]);
if (error)
return error;
info->low.rm_blockcount = 0;
xfs_getfsmap_set_irec_flags(&info->low, &keys[0]);
info->high.rm_startblock = -1U;
info->high.rm_owner = ULLONG_MAX;
info->high.rm_offset = ULLONG_MAX;
info->high.rm_blockcount = 0;
info->high.rm_flags = XFS_RMAP_KEY_FLAGS | XFS_RMAP_REC_FLAGS;
start_ag = XFS_FSB_TO_AGNO(mp, start_fsb);
end_ag = XFS_FSB_TO_AGNO(mp, end_fsb);
/* Query each AG */
for (info->agno = start_ag; info->agno <= end_ag; info->agno++) {
/*
* Set the AG high key from the fsmap high key if this
* is the last AG that we're querying.
*/
if (info->agno == end_ag) {
info->high.rm_startblock = XFS_FSB_TO_AGBNO(mp,
end_fsb);
info->high.rm_offset = XFS_BB_TO_FSBT(mp,
keys[1].fmr_offset);
error = xfs_fsmap_owner_to_rmap(&info->high, &keys[1]);
if (error)
goto err;
xfs_getfsmap_set_irec_flags(&info->high, &keys[1]);
}
if (bt_cur) {
xfs_btree_del_cursor(bt_cur, XFS_BTREE_NOERROR);
bt_cur = NULL;
xfs_trans_brelse(tp, info->agf_bp);
info->agf_bp = NULL;
}
error = xfs_alloc_read_agf(mp, tp, info->agno, 0,
&info->agf_bp);
if (error)
goto err;
trace_xfs_fsmap_low_key(mp, info->dev, info->agno, &info->low);
trace_xfs_fsmap_high_key(mp, info->dev, info->agno,
&info->high);
error = query_fn(tp, info, &bt_cur, priv);
if (error)
goto err;
/*
* Set the AG low key to the start of the AG prior to
* moving on to the next AG.
*/
if (info->agno == start_ag) {
info->low.rm_startblock = 0;
info->low.rm_owner = 0;
info->low.rm_offset = 0;
info->low.rm_flags = 0;
}
}
/* Report any gap at the end of the AG */
info->last = true;
error = query_fn(tp, info, &bt_cur, priv);
if (error)
goto err;
err:
if (bt_cur)
xfs_btree_del_cursor(bt_cur, error < 0 ? XFS_BTREE_ERROR :
XFS_BTREE_NOERROR);
if (info->agf_bp) {
xfs_trans_brelse(tp, info->agf_bp);
info->agf_bp = NULL;
}
return error;
}
/* Actually query the rmap btree. */
STATIC int
xfs_getfsmap_datadev_rmapbt_query(
struct xfs_trans *tp,
struct xfs_getfsmap_info *info,
struct xfs_btree_cur **curpp,
void *priv)
{
/* Report any gap at the end of the last AG. */
if (info->last)
return xfs_getfsmap_datadev_helper(*curpp, &info->high, info);
/* Allocate cursor for this AG and query_range it. */
*curpp = xfs_rmapbt_init_cursor(tp->t_mountp, tp, info->agf_bp,
info->agno);
return xfs_rmap_query_range(*curpp, &info->low, &info->high,
xfs_getfsmap_datadev_helper, info);
}
/* Execute a getfsmap query against the regular data device rmapbt. */
STATIC int
xfs_getfsmap_datadev_rmapbt(
struct xfs_trans *tp,
struct xfs_fsmap *keys,
struct xfs_getfsmap_info *info)
{
info->missing_owner = XFS_FMR_OWN_FREE;
return __xfs_getfsmap_datadev(tp, keys, info,
xfs_getfsmap_datadev_rmapbt_query, NULL);
}
/* Do we recognize the device? */
STATIC bool
xfs_getfsmap_is_valid_device(
struct xfs_mount *mp,
struct xfs_fsmap *fm)
{
if (fm->fmr_device == 0 || fm->fmr_device == UINT_MAX ||
fm->fmr_device == new_encode_dev(mp->m_ddev_targp->bt_dev))
return true;
if (mp->m_logdev_targp &&
fm->fmr_device == new_encode_dev(mp->m_logdev_targp->bt_dev))
return true;
return false;
}
/* Ensure that the low key is less than the high key. */
STATIC bool
xfs_getfsmap_check_keys(
struct xfs_fsmap *low_key,
struct xfs_fsmap *high_key)
{
if (low_key->fmr_device > high_key->fmr_device)
return false;
if (low_key->fmr_device < high_key->fmr_device)
return true;
if (low_key->fmr_physical > high_key->fmr_physical)
return false;
if (low_key->fmr_physical < high_key->fmr_physical)
return true;
if (low_key->fmr_owner > high_key->fmr_owner)
return false;
if (low_key->fmr_owner < high_key->fmr_owner)
return true;
if (low_key->fmr_offset > high_key->fmr_offset)
return false;
if (low_key->fmr_offset < high_key->fmr_offset)
return true;
return false;
}
#define XFS_GETFSMAP_DEVS 2
/*
* Get filesystem's extents as described in head, and format for
* output. Calls formatter to fill the user's buffer until all
* extents are mapped, until the passed-in head->fmh_count slots have
* been filled, or until the formatter short-circuits the loop, if it
* is tracking filled-in extents on its own.
*
* Key to Confusion
* ----------------
* There are multiple levels of keys and counters at work here:
* xfs_fsmap_head.fmh_keys -- low and high fsmap keys passed in;
* these reflect fs-wide sector addrs.
* dkeys -- fmh_keys used to query each device;
* these are fmh_keys but w/ the low key
* bumped up by fmr_length.
* xfs_getfsmap_info.next_daddr -- next disk addr we expect to see; this
* is how we detect gaps in the fsmap
records and report them.
* xfs_getfsmap_info.low/high -- per-AG low/high keys computed from
* dkeys; used to query the metadata.
*/
int
xfs_getfsmap(
struct xfs_mount *mp,
struct xfs_fsmap_head *head,
xfs_fsmap_format_t formatter,
void *arg)
{
struct xfs_trans *tp = NULL;
struct xfs_fsmap dkeys[2]; /* per-dev keys */
struct xfs_getfsmap_dev handlers[XFS_GETFSMAP_DEVS];
struct xfs_getfsmap_info info = {0};
int i;
int error = 0;
if (!xfs_sb_version_hasrmapbt(&mp->m_sb))
return -EOPNOTSUPP;
if (head->fmh_iflags & ~FMH_IF_VALID)
return -EINVAL;
if (!xfs_getfsmap_is_valid_device(mp, &head->fmh_keys[0]) ||
!xfs_getfsmap_is_valid_device(mp, &head->fmh_keys[1]))
return -EINVAL;
head->fmh_entries = 0;
/* Set up our device handlers. */
memset(handlers, 0, sizeof(handlers));
handlers[0].dev = new_encode_dev(mp->m_ddev_targp->bt_dev);
handlers[0].fn = xfs_getfsmap_datadev_rmapbt;
if (mp->m_logdev_targp != mp->m_ddev_targp) {
handlers[1].dev = new_encode_dev(mp->m_logdev_targp->bt_dev);
handlers[1].fn = xfs_getfsmap_logdev;
}
xfs_sort(handlers, XFS_GETFSMAP_DEVS, sizeof(struct xfs_getfsmap_dev),
xfs_getfsmap_dev_compare);
/*
* To continue where we left off, we allow userspace to use the
* last mapping from a previous call as the low key of the next.
* This is identified by a non-zero length in the low key. We
* have to increment the low key in this scenario to ensure we
* don't return the same mapping again, and instead return the
* very next mapping.
*
* If the low key mapping refers to file data, the same physical
* blocks could be mapped to several other files/offsets.
* According to rmapbt record ordering, the minimal next
* possible record for the block range is the next starting
* offset in the same inode. Therefore, bump the file offset to
* continue the search appropriately. For all other low key
* mapping types (attr blocks, metadata), bump the physical
* offset as there can be no other mapping for the same physical
* block range.
*/
dkeys[0] = head->fmh_keys[0];
if (dkeys[0].fmr_flags & (FMR_OF_SPECIAL_OWNER | FMR_OF_EXTENT_MAP)) {
dkeys[0].fmr_physical += dkeys[0].fmr_length;
dkeys[0].fmr_owner = 0;
if (dkeys[0].fmr_offset)
return -EINVAL;
} else
dkeys[0].fmr_offset += dkeys[0].fmr_length;
dkeys[0].fmr_length = 0;
memset(&dkeys[1], 0xFF, sizeof(struct xfs_fsmap));
if (!xfs_getfsmap_check_keys(dkeys, &head->fmh_keys[1]))
return -EINVAL;
info.next_daddr = head->fmh_keys[0].fmr_physical +
head->fmh_keys[0].fmr_length;
info.formatter = formatter;
info.format_arg = arg;
info.head = head;
/* For each device we support... */
for (i = 0; i < XFS_GETFSMAP_DEVS; i++) {
/* Is this device within the range the user asked for? */
if (!handlers[i].fn)
continue;
if (head->fmh_keys[0].fmr_device > handlers[i].dev)
continue;
if (head->fmh_keys[1].fmr_device < handlers[i].dev)
break;
/*
* If this device number matches the high key, we have
* to pass the high key to the handler to limit the
* query results. If the device number exceeds the
* low key, zero out the low key so that we get
* everything from the beginning.
*/
if (handlers[i].dev == head->fmh_keys[1].fmr_device)
dkeys[1] = head->fmh_keys[1];
if (handlers[i].dev > head->fmh_keys[0].fmr_device)
memset(&dkeys[0], 0, sizeof(struct xfs_fsmap));
error = xfs_trans_alloc_empty(mp, &tp);
if (error)
break;
info.dev = handlers[i].dev;
info.last = false;
info.agno = NULLAGNUMBER;
error = handlers[i].fn(tp, dkeys, &info);
if (error)
break;
xfs_trans_cancel(tp);
tp = NULL;
info.next_daddr = 0;
}
if (tp)
xfs_trans_cancel(tp);
head->fmh_oflags = FMH_OF_DEV_T;
return error;
}

53
fs/xfs/xfs_fsmap.h 100644
View File

@ -0,0 +1,53 @@
/*
* Copyright (C) 2017 Oracle. All Rights Reserved.
*
* Author: Darrick J. Wong <darrick.wong@oracle.com>
*
* 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; either version 2
* of the License, or (at your option) any later version.
*
* 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.
*/
#ifndef __XFS_FSMAP_H__
#define __XFS_FSMAP_H__
struct fsmap;
/* internal fsmap representation */
struct xfs_fsmap {
dev_t fmr_device; /* device id */
uint32_t fmr_flags; /* mapping flags */
uint64_t fmr_physical; /* device offset of segment */
uint64_t fmr_owner; /* owner id */
xfs_fileoff_t fmr_offset; /* file offset of segment */
xfs_filblks_t fmr_length; /* length of segment, blocks */
};
struct xfs_fsmap_head {
uint32_t fmh_iflags; /* control flags */
uint32_t fmh_oflags; /* output flags */
unsigned int fmh_count; /* # of entries in array incl. input */
unsigned int fmh_entries; /* # of entries filled in (output). */
struct xfs_fsmap fmh_keys[2]; /* low and high keys */
};
void xfs_fsmap_from_internal(struct fsmap *dest, struct xfs_fsmap *src);
void xfs_fsmap_to_internal(struct xfs_fsmap *dest, struct fsmap *src);
/* fsmap to userspace formatter - copy to user & advance pointer */
typedef int (*xfs_fsmap_format_t)(struct xfs_fsmap *, void *);
int xfs_getfsmap(struct xfs_mount *mp, struct xfs_fsmap_head *head,
xfs_fsmap_format_t formatter, void *arg);
#endif /* __XFS_FSMAP_H__ */

84
fs/xfs/xfs_ioctl.c
View File

@ -41,6 +41,9 @@
#include "xfs_trans.h"
#include "xfs_pnfs.h"
#include "xfs_acl.h"
#include "xfs_btree.h"
#include <linux/fsmap.h>
#include "xfs_fsmap.h"
#include <linux/capability.h>
#include <linux/cred.h>
@ -1609,6 +1612,84 @@ xfs_ioc_getbmapx(
return 0;
}
struct getfsmap_info {
struct xfs_mount *mp;
struct fsmap __user *data;
__u32 last_flags;
};
STATIC int
xfs_getfsmap_format(struct xfs_fsmap *xfm, void *priv)
{
struct getfsmap_info *info = priv;
struct fsmap fm;
trace_xfs_getfsmap_mapping(info->mp, xfm);
info->last_flags = xfm->fmr_flags;
xfs_fsmap_from_internal(&fm, xfm);
if (copy_to_user(info->data, &fm, sizeof(struct fsmap)))
return -EFAULT;
info->data++;
return 0;
}
STATIC int
xfs_ioc_getfsmap(
struct xfs_inode *ip,
void __user *arg)
{
struct getfsmap_info info = {0};
struct xfs_fsmap_head xhead = {0};
struct fsmap_head head;
bool aborted = false;
int error;
if (copy_from_user(&head, arg, sizeof(struct fsmap_head)))
return -EFAULT;
if (memchr_inv(head.fmh_reserved, 0, sizeof(head.fmh_reserved)) ||
memchr_inv(head.fmh_keys[0].fmr_reserved, 0,
sizeof(head.fmh_keys[0].fmr_reserved)) ||
memchr_inv(head.fmh_keys[1].fmr_reserved, 0,
sizeof(head.fmh_keys[1].fmr_reserved)))
return -EINVAL;
xhead.fmh_iflags = head.fmh_iflags;
xhead.fmh_count = head.fmh_count;
xfs_fsmap_to_internal(&xhead.fmh_keys[0], &head.fmh_keys[0]);
xfs_fsmap_to_internal(&xhead.fmh_keys[1], &head.fmh_keys[1]);
trace_xfs_getfsmap_low_key(ip->i_mount, &xhead.fmh_keys[0]);
trace_xfs_getfsmap_high_key(ip->i_mount, &xhead.fmh_keys[1]);
info.mp = ip->i_mount;
info.data = ((__force struct fsmap_head *)arg)->fmh_recs;
error = xfs_getfsmap(ip->i_mount, &xhead, xfs_getfsmap_format, &info);
if (error == XFS_BTREE_QUERY_RANGE_ABORT) {
error = 0;
aborted = true;
} else if (error)
return error;
/* If we didn't abort, set the "last" flag in the last fmx */
if (!aborted && xhead.fmh_entries) {
info.data--;
info.last_flags |= FMR_OF_LAST;
if (copy_to_user(&info.data->fmr_flags, &info.last_flags,
sizeof(info.last_flags)))
return -EFAULT;
}
/* copy back header */
head.fmh_entries = xhead.fmh_entries;
head.fmh_oflags = xhead.fmh_oflags;
if (copy_to_user(arg, &head, sizeof(struct fsmap_head)))
return -EFAULT;
return 0;
}
int
xfs_ioc_swapext(
xfs_swapext_t *sxp)
@ -1789,6 +1870,9 @@ xfs_file_ioctl(
case XFS_IOC_GETBMAPX:
return xfs_ioc_getbmapx(ip, arg);
case FS_IOC_GETFSMAP:
return xfs_ioc_getfsmap(ip, arg);
case XFS_IOC_FD_TO_HANDLE:
case XFS_IOC_PATH_TO_HANDLE:
case XFS_IOC_PATH_TO_FSHANDLE: {

2
fs/xfs/xfs_ioctl32.c
View File

@ -20,6 +20,7 @@
#include <linux/mount.h>
#include <linux/slab.h>
#include <linux/uaccess.h>
#include <linux/fsmap.h>
#include "xfs.h"
#include "xfs_fs.h"
#include "xfs_format.h"
@ -554,6 +555,7 @@ xfs_file_compat_ioctl(
case XFS_IOC_GOINGDOWN:
case XFS_IOC_ERROR_INJECTION:
case XFS_IOC_ERROR_CLEARALL:
case FS_IOC_GETFSMAP:
return xfs_file_ioctl(filp, cmd, p);
#ifndef BROKEN_X86_ALIGNMENT
/* These are handled fine if no alignment issues */

1
fs/xfs/xfs_trace.c
View File

@ -47,6 +47,7 @@
#include "xfs_inode_item.h"
#include "xfs_bmap_btree.h"
#include "xfs_filestream.h"
#include "xfs_fsmap.h"
/*
* We include this last to have the helpers above available for the trace

84
fs/xfs/xfs_trace.h
View File

@ -40,6 +40,8 @@ struct xfs_inode_log_format;
struct xfs_bmbt_irec;
struct xfs_btree_cur;
struct xfs_refcount_irec;
struct xfs_fsmap;
struct xfs_rmap_irec;
DECLARE_EVENT_CLASS(xfs_attr_list_class,
TP_PROTO(struct xfs_attr_list_context *ctx),
@ -3267,6 +3269,88 @@ DEFINE_INODE_IREC_EVENT(xfs_swap_extent_rmap_remap);
DEFINE_INODE_IREC_EVENT(xfs_swap_extent_rmap_remap_piece);
DEFINE_INODE_ERROR_EVENT(xfs_swap_extent_rmap_error);
/* fsmap traces */
DECLARE_EVENT_CLASS(xfs_fsmap_class,
TP_PROTO(struct xfs_mount *mp, u32 keydev, xfs_agnumber_t agno,
struct xfs_rmap_irec *rmap),
TP_ARGS(mp, keydev, agno, rmap),
TP_STRUCT__entry(
__field(dev_t, dev)
__field(dev_t, keydev)
__field(xfs_agnumber_t, agno)
__field(xfs_fsblock_t, bno)
__field(xfs_filblks_t, len)
__field(__uint64_t, owner)
__field(__uint64_t, offset)
__field(unsigned int, flags)
),
TP_fast_assign(
__entry->dev = mp->m_super->s_dev;
__entry->keydev = new_decode_dev(keydev);
__entry->agno = agno;
__entry->bno = rmap->rm_startblock;
__entry->len = rmap->rm_blockcount;
__entry->owner = rmap->rm_owner;
__entry->offset = rmap->rm_offset;
__entry->flags = rmap->rm_flags;
),
TP_printk("dev %d:%d keydev %d:%d agno %u bno %llu len %llu owner %lld offset %llu flags 0x%x\n",
MAJOR(__entry->dev), MINOR(__entry->dev),
MAJOR(__entry->keydev), MINOR(__entry->keydev),
__entry->agno,
__entry->bno,
__entry->len,
__entry->owner,
__entry->offset,
__entry->flags)
)
#define DEFINE_FSMAP_EVENT(name) \
DEFINE_EVENT(xfs_fsmap_class, name, \
TP_PROTO(struct xfs_mount *mp, u32 keydev, xfs_agnumber_t agno, \
struct xfs_rmap_irec *rmap), \
TP_ARGS(mp, keydev, agno, rmap))
DEFINE_FSMAP_EVENT(xfs_fsmap_low_key);
DEFINE_FSMAP_EVENT(xfs_fsmap_high_key);
DEFINE_FSMAP_EVENT(xfs_fsmap_mapping);
DECLARE_EVENT_CLASS(xfs_getfsmap_class,
TP_PROTO(struct xfs_mount *mp, struct xfs_fsmap *fsmap),
TP_ARGS(mp, fsmap),
TP_STRUCT__entry(
__field(dev_t, dev)
__field(dev_t, keydev)
__field(xfs_daddr_t, block)
__field(xfs_daddr_t, len)
__field(__uint64_t, owner)
__field(__uint64_t, offset)
__field(__uint64_t, flags)
),
TP_fast_assign(
__entry->dev = mp->m_super->s_dev;
__entry->keydev = new_decode_dev(fsmap->fmr_device);
__entry->block = fsmap->fmr_physical;
__entry->len = fsmap->fmr_length;
__entry->owner = fsmap->fmr_owner;
__entry->offset = fsmap->fmr_offset;
__entry->flags = fsmap->fmr_flags;
),
TP_printk("dev %d:%d keydev %d:%d block %llu len %llu owner %lld offset %llu flags 0x%llx\n",
MAJOR(__entry->dev), MINOR(__entry->dev),
MAJOR(__entry->keydev), MINOR(__entry->keydev),
__entry->block,
__entry->len,
__entry->owner,
__entry->offset,
__entry->flags)
)
#define DEFINE_GETFSMAP_EVENT(name) \
DEFINE_EVENT(xfs_getfsmap_class, name, \
TP_PROTO(struct xfs_mount *mp, struct xfs_fsmap *fsmap), \
TP_ARGS(mp, fsmap))
DEFINE_GETFSMAP_EVENT(xfs_getfsmap_low_key);
DEFINE_GETFSMAP_EVENT(xfs_getfsmap_high_key);
DEFINE_GETFSMAP_EVENT(xfs_getfsmap_mapping);
#endif /* _TRACE_XFS_H */
#undef TRACE_INCLUDE_PATH

22
fs/xfs/xfs_trans.c
View File

@ -262,6 +262,28 @@ xfs_trans_alloc(
return 0;
}
/*
* Create an empty transaction with no reservation. This is a defensive
* mechanism for routines that query metadata without actually modifying
* them -- if the metadata being queried is somehow cross-linked (think a
* btree block pointer that points higher in the tree), we risk deadlock.
* However, blocks grabbed as part of a transaction can be re-grabbed.
* The verifiers will notice the corrupt block and the operation will fail
* back to userspace without deadlocking.
*
* Note the zero-length reservation; this transaction MUST be cancelled
* without any dirty data.
*/
int
xfs_trans_alloc_empty(
struct xfs_mount *mp,
struct xfs_trans **tpp)
{
struct xfs_trans_res resv = {0};
return xfs_trans_alloc(mp, &resv, 0, 0, XFS_TRANS_NO_WRITECOUNT, tpp);
}
/*
* Record the indicated change to the given field for application
* to the file system's superblock when the transaction commits.

2
fs/xfs/xfs_trans.h
View File

@ -158,6 +158,8 @@ typedef struct xfs_trans {
int xfs_trans_alloc(struct xfs_mount *mp, struct xfs_trans_res *resp,
uint blocks, uint rtextents, uint flags,
struct xfs_trans **tpp);
int xfs_trans_alloc_empty(struct xfs_mount *mp,
struct xfs_trans **tpp);
void xfs_trans_mod_sb(xfs_trans_t *, uint, int64_t);
struct xfs_buf *xfs_trans_get_buf_map(struct xfs_trans *tp,