linux-stable/fs/xfs/xfs_fsops.c
Dave Chinner 2e973b2cd4 xfs: convert remaining mount flags to state flags
The remaining mount flags kept in m_flags are actually runtime state
flags. These change dynamically, so they really should be updated
atomically so we don't potentially lose an update due to racing
modifications.

Convert these remaining flags to be stored in m_opstate and use
atomic bitops to set and clear the flags. This also adds a couple of
simple wrappers for common state checks - read only and shutdown.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
2021-08-19 10:07:13 -07:00

612 lines
15 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (c) 2000-2005 Silicon Graphics, Inc.
* All Rights Reserved.
*/
#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_trans.h"
#include "xfs_error.h"
#include "xfs_alloc.h"
#include "xfs_fsops.h"
#include "xfs_trans_space.h"
#include "xfs_log.h"
#include "xfs_ag.h"
#include "xfs_ag_resv.h"
#include "xfs_trace.h"
/*
* Write new AG headers to disk. Non-transactional, but need to be
* written and completed prior to the growfs transaction being logged.
* To do this, we use a delayed write buffer list and wait for
* submission and IO completion of the list as a whole. This allows the
* IO subsystem to merge all the AG headers in a single AG into a single
* IO and hide most of the latency of the IO from us.
*
* This also means that if we get an error whilst building the buffer
* list to write, we can cancel the entire list without having written
* anything.
*/
static int
xfs_resizefs_init_new_ags(
struct xfs_trans *tp,
struct aghdr_init_data *id,
xfs_agnumber_t oagcount,
xfs_agnumber_t nagcount,
xfs_rfsblock_t delta,
bool *lastag_extended)
{
struct xfs_mount *mp = tp->t_mountp;
xfs_rfsblock_t nb = mp->m_sb.sb_dblocks + delta;
int error;
*lastag_extended = false;
INIT_LIST_HEAD(&id->buffer_list);
for (id->agno = nagcount - 1;
id->agno >= oagcount;
id->agno--, delta -= id->agsize) {
if (id->agno == nagcount - 1)
id->agsize = nb - (id->agno *
(xfs_rfsblock_t)mp->m_sb.sb_agblocks);
else
id->agsize = mp->m_sb.sb_agblocks;
error = xfs_ag_init_headers(mp, id);
if (error) {
xfs_buf_delwri_cancel(&id->buffer_list);
return error;
}
}
error = xfs_buf_delwri_submit(&id->buffer_list);
if (error)
return error;
if (delta) {
*lastag_extended = true;
error = xfs_ag_extend_space(mp, tp, id, delta);
}
return error;
}
/*
* growfs operations
*/
static int
xfs_growfs_data_private(
struct xfs_mount *mp, /* mount point for filesystem */
struct xfs_growfs_data *in) /* growfs data input struct */
{
struct xfs_buf *bp;
int error;
xfs_agnumber_t nagcount;
xfs_agnumber_t nagimax = 0;
xfs_rfsblock_t nb, nb_div, nb_mod;
int64_t delta;
bool lastag_extended;
xfs_agnumber_t oagcount;
struct xfs_trans *tp;
struct aghdr_init_data id = {};
nb = in->newblocks;
error = xfs_sb_validate_fsb_count(&mp->m_sb, nb);
if (error)
return error;
if (nb > mp->m_sb.sb_dblocks) {
error = xfs_buf_read_uncached(mp->m_ddev_targp,
XFS_FSB_TO_BB(mp, nb) - XFS_FSS_TO_BB(mp, 1),
XFS_FSS_TO_BB(mp, 1), 0, &bp, NULL);
if (error)
return error;
xfs_buf_relse(bp);
}
nb_div = nb;
nb_mod = do_div(nb_div, mp->m_sb.sb_agblocks);
nagcount = nb_div + (nb_mod != 0);
if (nb_mod && nb_mod < XFS_MIN_AG_BLOCKS) {
nagcount--;
nb = (xfs_rfsblock_t)nagcount * mp->m_sb.sb_agblocks;
}
delta = nb - mp->m_sb.sb_dblocks;
/*
* Reject filesystems with a single AG because they are not
* supported, and reject a shrink operation that would cause a
* filesystem to become unsupported.
*/
if (delta < 0 && nagcount < 2)
return -EINVAL;
oagcount = mp->m_sb.sb_agcount;
/* allocate the new per-ag structures */
if (nagcount > oagcount) {
error = xfs_initialize_perag(mp, nagcount, &nagimax);
if (error)
return error;
} else if (nagcount < oagcount) {
/* TODO: shrinking the entire AGs hasn't yet completed */
return -EINVAL;
}
error = xfs_trans_alloc(mp, &M_RES(mp)->tr_growdata,
(delta > 0 ? XFS_GROWFS_SPACE_RES(mp) : -delta), 0,
XFS_TRANS_RESERVE, &tp);
if (error)
return error;
if (delta > 0) {
error = xfs_resizefs_init_new_ags(tp, &id, oagcount, nagcount,
delta, &lastag_extended);
} else {
static struct ratelimit_state shrink_warning = \
RATELIMIT_STATE_INIT("shrink_warning", 86400 * HZ, 1);
ratelimit_set_flags(&shrink_warning, RATELIMIT_MSG_ON_RELEASE);
if (__ratelimit(&shrink_warning))
xfs_alert(mp,
"EXPERIMENTAL online shrink feature in use. Use at your own risk!");
error = xfs_ag_shrink_space(mp, &tp, nagcount - 1, -delta);
}
if (error)
goto out_trans_cancel;
/*
* Update changed superblock fields transactionally. These are not
* seen by the rest of the world until the transaction commit applies
* them atomically to the superblock.
*/
if (nagcount > oagcount)
xfs_trans_mod_sb(tp, XFS_TRANS_SB_AGCOUNT, nagcount - oagcount);
if (delta)
xfs_trans_mod_sb(tp, XFS_TRANS_SB_DBLOCKS, delta);
if (id.nfree)
xfs_trans_mod_sb(tp, XFS_TRANS_SB_FDBLOCKS, id.nfree);
/*
* Sync sb counters now to reflect the updated values. This is
* particularly important for shrink because the write verifier
* will fail if sb_fdblocks is ever larger than sb_dblocks.
*/
if (xfs_has_lazysbcount(mp))
xfs_log_sb(tp);
xfs_trans_set_sync(tp);
error = xfs_trans_commit(tp);
if (error)
return error;
/* New allocation groups fully initialized, so update mount struct */
if (nagimax)
mp->m_maxagi = nagimax;
xfs_set_low_space_thresholds(mp);
mp->m_alloc_set_aside = xfs_alloc_set_aside(mp);
if (delta > 0) {
/*
* If we expanded the last AG, free the per-AG reservation
* so we can reinitialize it with the new size.
*/
if (lastag_extended) {
struct xfs_perag *pag;
pag = xfs_perag_get(mp, id.agno);
error = xfs_ag_resv_free(pag);
xfs_perag_put(pag);
if (error)
return error;
}
/*
* Reserve AG metadata blocks. ENOSPC here does not mean there
* was a growfs failure, just that there still isn't space for
* new user data after the grow has been run.
*/
error = xfs_fs_reserve_ag_blocks(mp);
if (error == -ENOSPC)
error = 0;
}
return error;
out_trans_cancel:
xfs_trans_cancel(tp);
return error;
}
static int
xfs_growfs_log_private(
struct xfs_mount *mp, /* mount point for filesystem */
struct xfs_growfs_log *in) /* growfs log input struct */
{
xfs_extlen_t nb;
nb = in->newblocks;
if (nb < XFS_MIN_LOG_BLOCKS || nb < XFS_B_TO_FSB(mp, XFS_MIN_LOG_BYTES))
return -EINVAL;
if (nb == mp->m_sb.sb_logblocks &&
in->isint == (mp->m_sb.sb_logstart != 0))
return -EINVAL;
/*
* Moving the log is hard, need new interfaces to sync
* the log first, hold off all activity while moving it.
* Can have shorter or longer log in the same space,
* or transform internal to external log or vice versa.
*/
return -ENOSYS;
}
static int
xfs_growfs_imaxpct(
struct xfs_mount *mp,
__u32 imaxpct)
{
struct xfs_trans *tp;
int dpct;
int error;
if (imaxpct > 100)
return -EINVAL;
error = xfs_trans_alloc(mp, &M_RES(mp)->tr_growdata,
XFS_GROWFS_SPACE_RES(mp), 0, XFS_TRANS_RESERVE, &tp);
if (error)
return error;
dpct = imaxpct - mp->m_sb.sb_imax_pct;
xfs_trans_mod_sb(tp, XFS_TRANS_SB_IMAXPCT, dpct);
xfs_trans_set_sync(tp);
return xfs_trans_commit(tp);
}
/*
* protected versions of growfs function acquire and release locks on the mount
* point - exported through ioctls: XFS_IOC_FSGROWFSDATA, XFS_IOC_FSGROWFSLOG,
* XFS_IOC_FSGROWFSRT
*/
int
xfs_growfs_data(
struct xfs_mount *mp,
struct xfs_growfs_data *in)
{
int error = 0;
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
if (!mutex_trylock(&mp->m_growlock))
return -EWOULDBLOCK;
/* update imaxpct separately to the physical grow of the filesystem */
if (in->imaxpct != mp->m_sb.sb_imax_pct) {
error = xfs_growfs_imaxpct(mp, in->imaxpct);
if (error)
goto out_error;
}
if (in->newblocks != mp->m_sb.sb_dblocks) {
error = xfs_growfs_data_private(mp, in);
if (error)
goto out_error;
}
/* Post growfs calculations needed to reflect new state in operations */
if (mp->m_sb.sb_imax_pct) {
uint64_t icount = mp->m_sb.sb_dblocks * mp->m_sb.sb_imax_pct;
do_div(icount, 100);
M_IGEO(mp)->maxicount = XFS_FSB_TO_INO(mp, icount);
} else
M_IGEO(mp)->maxicount = 0;
/* Update secondary superblocks now the physical grow has completed */
error = xfs_update_secondary_sbs(mp);
out_error:
/*
* Increment the generation unconditionally, the error could be from
* updating the secondary superblocks, in which case the new size
* is live already.
*/
mp->m_generation++;
mutex_unlock(&mp->m_growlock);
return error;
}
int
xfs_growfs_log(
xfs_mount_t *mp,
struct xfs_growfs_log *in)
{
int error;
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
if (!mutex_trylock(&mp->m_growlock))
return -EWOULDBLOCK;
error = xfs_growfs_log_private(mp, in);
mutex_unlock(&mp->m_growlock);
return error;
}
/*
* exported through ioctl XFS_IOC_FSCOUNTS
*/
void
xfs_fs_counts(
xfs_mount_t *mp,
xfs_fsop_counts_t *cnt)
{
cnt->allocino = percpu_counter_read_positive(&mp->m_icount);
cnt->freeino = percpu_counter_read_positive(&mp->m_ifree);
cnt->freedata = percpu_counter_read_positive(&mp->m_fdblocks) -
mp->m_alloc_set_aside;
spin_lock(&mp->m_sb_lock);
cnt->freertx = mp->m_sb.sb_frextents;
spin_unlock(&mp->m_sb_lock);
}
/*
* exported through ioctl XFS_IOC_SET_RESBLKS & XFS_IOC_GET_RESBLKS
*
* xfs_reserve_blocks is called to set m_resblks
* in the in-core mount table. The number of unused reserved blocks
* is kept in m_resblks_avail.
*
* Reserve the requested number of blocks if available. Otherwise return
* as many as possible to satisfy the request. The actual number
* reserved are returned in outval
*
* A null inval pointer indicates that only the current reserved blocks
* available should be returned no settings are changed.
*/
int
xfs_reserve_blocks(
xfs_mount_t *mp,
uint64_t *inval,
xfs_fsop_resblks_t *outval)
{
int64_t lcounter, delta;
int64_t fdblks_delta = 0;
uint64_t request;
int64_t free;
int error = 0;
/* If inval is null, report current values and return */
if (inval == (uint64_t *)NULL) {
if (!outval)
return -EINVAL;
outval->resblks = mp->m_resblks;
outval->resblks_avail = mp->m_resblks_avail;
return 0;
}
request = *inval;
/*
* With per-cpu counters, this becomes an interesting problem. we need
* to work out if we are freeing or allocation blocks first, then we can
* do the modification as necessary.
*
* We do this under the m_sb_lock so that if we are near ENOSPC, we will
* hold out any changes while we work out what to do. This means that
* the amount of free space can change while we do this, so we need to
* retry if we end up trying to reserve more space than is available.
*/
spin_lock(&mp->m_sb_lock);
/*
* If our previous reservation was larger than the current value,
* then move any unused blocks back to the free pool. Modify the resblks
* counters directly since we shouldn't have any problems unreserving
* space.
*/
if (mp->m_resblks > request) {
lcounter = mp->m_resblks_avail - request;
if (lcounter > 0) { /* release unused blocks */
fdblks_delta = lcounter;
mp->m_resblks_avail -= lcounter;
}
mp->m_resblks = request;
if (fdblks_delta) {
spin_unlock(&mp->m_sb_lock);
error = xfs_mod_fdblocks(mp, fdblks_delta, 0);
spin_lock(&mp->m_sb_lock);
}
goto out;
}
/*
* If the request is larger than the current reservation, reserve the
* blocks before we update the reserve counters. Sample m_fdblocks and
* perform a partial reservation if the request exceeds free space.
*/
error = -ENOSPC;
do {
free = percpu_counter_sum(&mp->m_fdblocks) -
mp->m_alloc_set_aside;
if (free <= 0)
break;
delta = request - mp->m_resblks;
lcounter = free - delta;
if (lcounter < 0)
/* We can't satisfy the request, just get what we can */
fdblks_delta = free;
else
fdblks_delta = delta;
/*
* We'll either succeed in getting space from the free block
* count or we'll get an ENOSPC. If we get a ENOSPC, it means
* things changed while we were calculating fdblks_delta and so
* we should try again to see if there is anything left to
* reserve.
*
* Don't set the reserved flag here - we don't want to reserve
* the extra reserve blocks from the reserve.....
*/
spin_unlock(&mp->m_sb_lock);
error = xfs_mod_fdblocks(mp, -fdblks_delta, 0);
spin_lock(&mp->m_sb_lock);
} while (error == -ENOSPC);
/*
* Update the reserve counters if blocks have been successfully
* allocated.
*/
if (!error && fdblks_delta) {
mp->m_resblks += fdblks_delta;
mp->m_resblks_avail += fdblks_delta;
}
out:
if (outval) {
outval->resblks = mp->m_resblks;
outval->resblks_avail = mp->m_resblks_avail;
}
spin_unlock(&mp->m_sb_lock);
return error;
}
int
xfs_fs_goingdown(
xfs_mount_t *mp,
uint32_t inflags)
{
switch (inflags) {
case XFS_FSOP_GOING_FLAGS_DEFAULT: {
if (!freeze_bdev(mp->m_super->s_bdev)) {
xfs_force_shutdown(mp, SHUTDOWN_FORCE_UMOUNT);
thaw_bdev(mp->m_super->s_bdev);
}
break;
}
case XFS_FSOP_GOING_FLAGS_LOGFLUSH:
xfs_force_shutdown(mp, SHUTDOWN_FORCE_UMOUNT);
break;
case XFS_FSOP_GOING_FLAGS_NOLOGFLUSH:
xfs_force_shutdown(mp,
SHUTDOWN_FORCE_UMOUNT | SHUTDOWN_LOG_IO_ERROR);
break;
default:
return -EINVAL;
}
return 0;
}
/*
* Force a shutdown of the filesystem instantly while keeping the filesystem
* consistent. We don't do an unmount here; just shutdown the shop, make sure
* that absolutely nothing persistent happens to this filesystem after this
* point.
*
* The shutdown state change is atomic, resulting in the first and only the
* first shutdown call processing the shutdown. This means we only shutdown the
* log once as it requires, and we don't spam the logs when multiple concurrent
* shutdowns race to set the shutdown flags.
*/
void
xfs_do_force_shutdown(
struct xfs_mount *mp,
int flags,
char *fname,
int lnnum)
{
int tag;
const char *why;
if (test_and_set_bit(XFS_OPSTATE_SHUTDOWN, &mp->m_opstate))
return;
if (mp->m_sb_bp)
mp->m_sb_bp->b_flags |= XBF_DONE;
if (flags & SHUTDOWN_FORCE_UMOUNT)
xfs_alert(mp, "User initiated shutdown received.");
if (xlog_force_shutdown(mp->m_log, flags)) {
tag = XFS_PTAG_SHUTDOWN_LOGERROR;
why = "Log I/O Error";
} else if (flags & SHUTDOWN_CORRUPT_INCORE) {
tag = XFS_PTAG_SHUTDOWN_CORRUPT;
why = "Corruption of in-memory data";
} else {
tag = XFS_PTAG_SHUTDOWN_IOERROR;
why = "Metadata I/O Error";
}
trace_xfs_force_shutdown(mp, tag, flags, fname, lnnum);
xfs_alert_tag(mp, tag,
"%s (0x%x) detected at %pS (%s:%d). Shutting down filesystem.",
why, flags, __return_address, fname, lnnum);
xfs_alert(mp,
"Please unmount the filesystem and rectify the problem(s)");
if (xfs_error_level >= XFS_ERRLEVEL_HIGH)
xfs_stack_trace();
}
/*
* Reserve free space for per-AG metadata.
*/
int
xfs_fs_reserve_ag_blocks(
struct xfs_mount *mp)
{
xfs_agnumber_t agno;
struct xfs_perag *pag;
int error = 0;
int err2;
mp->m_finobt_nores = false;
for_each_perag(mp, agno, pag) {
err2 = xfs_ag_resv_init(pag, NULL);
if (err2 && !error)
error = err2;
}
if (error && error != -ENOSPC) {
xfs_warn(mp,
"Error %d reserving per-AG metadata reserve pool.", error);
xfs_force_shutdown(mp, SHUTDOWN_CORRUPT_INCORE);
}
return error;
}
/*
* Free space reserved for per-AG metadata.
*/
int
xfs_fs_unreserve_ag_blocks(
struct xfs_mount *mp)
{
xfs_agnumber_t agno;
struct xfs_perag *pag;
int error = 0;
int err2;
for_each_perag(mp, agno, pag) {
err2 = xfs_ag_resv_free(pag);
if (err2 && !error)
error = err2;
}
if (error)
xfs_warn(mp,
"Error %d freeing per-AG metadata reserve pool.", error);
return error;
}