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// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2010 Red Hat, Inc.
* All Rights Reserved.
*/
#include "xfs.h"
#include "xfs_shared.h"
#include "xfs_format.h"
#include "xfs_log_format.h"
#include "xfs_trans_resv.h"
#include "xfs_mount.h"
#include "xfs_btree.h"
#include "xfs_alloc_btree.h"
#include "xfs_alloc.h"
#include "xfs_discard.h"
#include "xfs_error.h"
#include "xfs_extent_busy.h"
#include "xfs_trace.h"
#include "xfs_log.h"
#include "xfs_ag.h"
STATIC int
xfs_trim_extents(
struct xfs_perag *pag,
xfs_daddr_t start,
xfs_daddr_t end,
xfs_daddr_t minlen,
uint64_t *blocks_trimmed)
{
struct xfs_mount *mp = pag->pag_mount;
struct block_device *bdev = mp->m_ddev_targp->bt_bdev;
struct xfs_btree_cur *cur;
struct xfs_buf *agbp;
struct xfs_agf *agf;
int error;
int i;
/*
* Force out the log. This means any transactions that might have freed
* space before we take the AGF buffer lock are now on disk, and the
* volatile disk cache is flushed.
*/
xfs_log_force(mp, XFS_LOG_SYNC);
error = xfs_alloc_read_agf(pag, NULL, 0, &agbp);
if (error)
return error;
agf = agbp->b_addr;
cur = xfs_allocbt_init_cursor(mp, NULL, agbp, pag, XFS_BTNUM_CNT);
/*
* Look up the longest btree in the AGF and start with it.
*/
error = xfs_alloc_lookup_ge(cur, 0, be32_to_cpu(agf->agf_longest), &i);
if (error)
goto out_del_cursor;
/*
* Loop until we are done with all extents that are large
* enough to be worth discarding.
*/
while (i) {
xfs_agblock_t fbno;
xfs_extlen_t flen;
xfs_daddr_t dbno;
xfs_extlen_t dlen;
error = xfs_alloc_get_rec(cur, &fbno, &flen, &i);
if (error)
break;
if (XFS_IS_CORRUPT(mp, i != 1)) {
error = -EFSCORRUPTED;
break;
}
ASSERT(flen <= be32_to_cpu(agf->agf_longest));
/*
* use daddr format for all range/len calculations as that is
* the format the range/len variables are supplied in by
* userspace.
*/
dbno = XFS_AGB_TO_DADDR(mp, pag->pag_agno, fbno);
dlen = XFS_FSB_TO_BB(mp, flen);
/*
* Too small? Give up.
*/
if (dlen < minlen) {
trace_xfs_discard_toosmall(mp, pag->pag_agno, fbno, flen);
break;
}
/*
* If the extent is entirely outside of the range we are
* supposed to discard skip it. Do not bother to trim
* down partially overlapping ranges for now.
*/
if (dbno + dlen < start || dbno > end) {
trace_xfs_discard_exclude(mp, pag->pag_agno, fbno, flen);
goto next_extent;
}
/*
* If any blocks in the range are still busy, skip the
* discard and try again the next time.
*/
if (xfs_extent_busy_search(mp, pag, fbno, flen)) {
trace_xfs_discard_busy(mp, pag->pag_agno, fbno, flen);
goto next_extent;
}
trace_xfs_discard_extent(mp, pag->pag_agno, fbno, flen);
error = blkdev_issue_discard(bdev, dbno, dlen, GFP_NOFS);
if (error)
break;
*blocks_trimmed += flen;
next_extent:
error = xfs_btree_decrement(cur, 0, &i);
if (error)
break;
if (fatal_signal_pending(current)) {
error = -ERESTARTSYS;
break;
}
}
out_del_cursor:
xfs_btree_del_cursor(cur, error);
xfs_buf_relse(agbp);
return error;
}
/*
* trim a range of the filesystem.
*
* Note: the parameters passed from userspace are byte ranges into the
* filesystem which does not match to the format we use for filesystem block
* addressing. FSB addressing is sparse (AGNO|AGBNO), while the incoming format
* is a linear address range. Hence we need to use DADDR based conversions and
* comparisons for determining the correct offset and regions to trim.
*/
int
xfs_ioc_trim(
struct xfs_mount *mp,
struct fstrim_range __user *urange)
{
struct xfs_perag *pag;
unsigned int granularity =
bdev_discard_granularity(mp->m_ddev_targp->bt_bdev);
struct fstrim_range range;
xfs_daddr_t start, end, minlen;
xfs_agnumber_t agno;
uint64_t blocks_trimmed = 0;
int error, last_error = 0;
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
if (!bdev_max_discard_sectors(mp->m_ddev_targp->bt_bdev))
return -EOPNOTSUPP;
/*
* We haven't recovered the log, so we cannot use our bnobt-guided
* storage zapping commands.
*/
if (xfs_has_norecovery(mp))
return -EROFS;
if (copy_from_user(&range, urange, sizeof(range)))
return -EFAULT;
range.minlen = max_t(u64, granularity, range.minlen);
minlen = BTOBB(range.minlen);
/*
* Truncating down the len isn't actually quite correct, but using
* BBTOB would mean we trivially get overflows for values
* of ULLONG_MAX or slightly lower. And ULLONG_MAX is the default
* used by the fstrim application. In the end it really doesn't
* matter as trimming blocks is an advisory interface.
*/
if (range.start >= XFS_FSB_TO_B(mp, mp->m_sb.sb_dblocks) ||
range.minlen > XFS_FSB_TO_B(mp, mp->m_ag_max_usable) ||
range.len < mp->m_sb.sb_blocksize)
return -EINVAL;
start = BTOBB(range.start);
end = start + BTOBBT(range.len) - 1;
if (end > XFS_FSB_TO_BB(mp, mp->m_sb.sb_dblocks) - 1)
end = XFS_FSB_TO_BB(mp, mp->m_sb.sb_dblocks) - 1;
agno = xfs_daddr_to_agno(mp, start);
for_each_perag_range(mp, agno, xfs_daddr_to_agno(mp, end), pag) {
error = xfs_trim_extents(pag, start, end, minlen,
&blocks_trimmed);
if (error) {
last_error = error;
if (error == -ERESTARTSYS) {
xfs_perag_rele(pag);
break;
}
}
}
if (last_error)
return last_error;
range.len = XFS_FSB_TO_B(mp, blocks_trimmed);
if (copy_to_user(urange, &range, sizeof(range)))
return -EFAULT;
return 0;
}
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