linux/fs/xfs/xfs_dquot.c
Mitsuo Hayasaka 20f12d8ac0 xfs: change available ranges of softlimit and hardlimit in quota check
In general, quota allows us to use disk blocks and inodes up to each
limit, that is, they are available if they don't exceed their limitations.
Current xfs sets their available ranges to lower than them except disk
inode quota check. So, this patch changes the ranges to not beyond them.

Signed-off-by: Mitsuo Hayasaka <mitsuo.hayasaka.hu@hitachi.com>
Cc: Ben Myers <bpm@sgi.com>
Cc: Alex Elder <elder@kernel.org>
Cc: Christoph Hellwig <hch@lst.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2012-02-21 10:12:43 -06:00

1243 lines
31 KiB
C

/*
* Copyright (c) 2000-2003 Silicon Graphics, 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_bit.h"
#include "xfs_log.h"
#include "xfs_inum.h"
#include "xfs_trans.h"
#include "xfs_sb.h"
#include "xfs_ag.h"
#include "xfs_alloc.h"
#include "xfs_quota.h"
#include "xfs_mount.h"
#include "xfs_bmap_btree.h"
#include "xfs_inode.h"
#include "xfs_bmap.h"
#include "xfs_rtalloc.h"
#include "xfs_error.h"
#include "xfs_itable.h"
#include "xfs_attr.h"
#include "xfs_buf_item.h"
#include "xfs_trans_space.h"
#include "xfs_trans_priv.h"
#include "xfs_qm.h"
#include "xfs_trace.h"
/*
* Lock order:
*
* ip->i_lock
* qh->qh_lock
* qi->qi_dqlist_lock
* dquot->q_qlock (xfs_dqlock() and friends)
* dquot->q_flush (xfs_dqflock() and friends)
* xfs_Gqm->qm_dqfrlist_lock
*
* If two dquots need to be locked the order is user before group/project,
* otherwise by the lowest id first, see xfs_dqlock2.
*/
#ifdef DEBUG
xfs_buftarg_t *xfs_dqerror_target;
int xfs_do_dqerror;
int xfs_dqreq_num;
int xfs_dqerror_mod = 33;
#endif
static struct lock_class_key xfs_dquot_other_class;
/*
* This is called to free all the memory associated with a dquot
*/
void
xfs_qm_dqdestroy(
xfs_dquot_t *dqp)
{
ASSERT(list_empty(&dqp->q_freelist));
mutex_destroy(&dqp->q_qlock);
kmem_zone_free(xfs_Gqm->qm_dqzone, dqp);
atomic_dec(&xfs_Gqm->qm_totaldquots);
}
/*
* If default limits are in force, push them into the dquot now.
* We overwrite the dquot limits only if they are zero and this
* is not the root dquot.
*/
void
xfs_qm_adjust_dqlimits(
xfs_mount_t *mp,
xfs_disk_dquot_t *d)
{
xfs_quotainfo_t *q = mp->m_quotainfo;
ASSERT(d->d_id);
if (q->qi_bsoftlimit && !d->d_blk_softlimit)
d->d_blk_softlimit = cpu_to_be64(q->qi_bsoftlimit);
if (q->qi_bhardlimit && !d->d_blk_hardlimit)
d->d_blk_hardlimit = cpu_to_be64(q->qi_bhardlimit);
if (q->qi_isoftlimit && !d->d_ino_softlimit)
d->d_ino_softlimit = cpu_to_be64(q->qi_isoftlimit);
if (q->qi_ihardlimit && !d->d_ino_hardlimit)
d->d_ino_hardlimit = cpu_to_be64(q->qi_ihardlimit);
if (q->qi_rtbsoftlimit && !d->d_rtb_softlimit)
d->d_rtb_softlimit = cpu_to_be64(q->qi_rtbsoftlimit);
if (q->qi_rtbhardlimit && !d->d_rtb_hardlimit)
d->d_rtb_hardlimit = cpu_to_be64(q->qi_rtbhardlimit);
}
/*
* Check the limits and timers of a dquot and start or reset timers
* if necessary.
* This gets called even when quota enforcement is OFF, which makes our
* life a little less complicated. (We just don't reject any quota
* reservations in that case, when enforcement is off).
* We also return 0 as the values of the timers in Q_GETQUOTA calls, when
* enforcement's off.
* In contrast, warnings are a little different in that they don't
* 'automatically' get started when limits get exceeded. They do
* get reset to zero, however, when we find the count to be under
* the soft limit (they are only ever set non-zero via userspace).
*/
void
xfs_qm_adjust_dqtimers(
xfs_mount_t *mp,
xfs_disk_dquot_t *d)
{
ASSERT(d->d_id);
#ifdef DEBUG
if (d->d_blk_hardlimit)
ASSERT(be64_to_cpu(d->d_blk_softlimit) <=
be64_to_cpu(d->d_blk_hardlimit));
if (d->d_ino_hardlimit)
ASSERT(be64_to_cpu(d->d_ino_softlimit) <=
be64_to_cpu(d->d_ino_hardlimit));
if (d->d_rtb_hardlimit)
ASSERT(be64_to_cpu(d->d_rtb_softlimit) <=
be64_to_cpu(d->d_rtb_hardlimit));
#endif
if (!d->d_btimer) {
if ((d->d_blk_softlimit &&
(be64_to_cpu(d->d_bcount) >
be64_to_cpu(d->d_blk_softlimit))) ||
(d->d_blk_hardlimit &&
(be64_to_cpu(d->d_bcount) >
be64_to_cpu(d->d_blk_hardlimit)))) {
d->d_btimer = cpu_to_be32(get_seconds() +
mp->m_quotainfo->qi_btimelimit);
} else {
d->d_bwarns = 0;
}
} else {
if ((!d->d_blk_softlimit ||
(be64_to_cpu(d->d_bcount) <=
be64_to_cpu(d->d_blk_softlimit))) &&
(!d->d_blk_hardlimit ||
(be64_to_cpu(d->d_bcount) <=
be64_to_cpu(d->d_blk_hardlimit)))) {
d->d_btimer = 0;
}
}
if (!d->d_itimer) {
if ((d->d_ino_softlimit &&
(be64_to_cpu(d->d_icount) >
be64_to_cpu(d->d_ino_softlimit))) ||
(d->d_ino_hardlimit &&
(be64_to_cpu(d->d_icount) >
be64_to_cpu(d->d_ino_hardlimit)))) {
d->d_itimer = cpu_to_be32(get_seconds() +
mp->m_quotainfo->qi_itimelimit);
} else {
d->d_iwarns = 0;
}
} else {
if ((!d->d_ino_softlimit ||
(be64_to_cpu(d->d_icount) <=
be64_to_cpu(d->d_ino_softlimit))) &&
(!d->d_ino_hardlimit ||
(be64_to_cpu(d->d_icount) <=
be64_to_cpu(d->d_ino_hardlimit)))) {
d->d_itimer = 0;
}
}
if (!d->d_rtbtimer) {
if ((d->d_rtb_softlimit &&
(be64_to_cpu(d->d_rtbcount) >
be64_to_cpu(d->d_rtb_softlimit))) ||
(d->d_rtb_hardlimit &&
(be64_to_cpu(d->d_rtbcount) >
be64_to_cpu(d->d_rtb_hardlimit)))) {
d->d_rtbtimer = cpu_to_be32(get_seconds() +
mp->m_quotainfo->qi_rtbtimelimit);
} else {
d->d_rtbwarns = 0;
}
} else {
if ((!d->d_rtb_softlimit ||
(be64_to_cpu(d->d_rtbcount) <=
be64_to_cpu(d->d_rtb_softlimit))) &&
(!d->d_rtb_hardlimit ||
(be64_to_cpu(d->d_rtbcount) <=
be64_to_cpu(d->d_rtb_hardlimit)))) {
d->d_rtbtimer = 0;
}
}
}
/*
* initialize a buffer full of dquots and log the whole thing
*/
STATIC void
xfs_qm_init_dquot_blk(
xfs_trans_t *tp,
xfs_mount_t *mp,
xfs_dqid_t id,
uint type,
xfs_buf_t *bp)
{
struct xfs_quotainfo *q = mp->m_quotainfo;
xfs_dqblk_t *d;
int curid, i;
ASSERT(tp);
ASSERT(xfs_buf_islocked(bp));
d = bp->b_addr;
/*
* ID of the first dquot in the block - id's are zero based.
*/
curid = id - (id % q->qi_dqperchunk);
ASSERT(curid >= 0);
memset(d, 0, BBTOB(q->qi_dqchunklen));
for (i = 0; i < q->qi_dqperchunk; i++, d++, curid++) {
d->dd_diskdq.d_magic = cpu_to_be16(XFS_DQUOT_MAGIC);
d->dd_diskdq.d_version = XFS_DQUOT_VERSION;
d->dd_diskdq.d_id = cpu_to_be32(curid);
d->dd_diskdq.d_flags = type;
}
xfs_trans_dquot_buf(tp, bp,
(type & XFS_DQ_USER ? XFS_BLF_UDQUOT_BUF :
((type & XFS_DQ_PROJ) ? XFS_BLF_PDQUOT_BUF :
XFS_BLF_GDQUOT_BUF)));
xfs_trans_log_buf(tp, bp, 0, BBTOB(q->qi_dqchunklen) - 1);
}
/*
* Allocate a block and fill it with dquots.
* This is called when the bmapi finds a hole.
*/
STATIC int
xfs_qm_dqalloc(
xfs_trans_t **tpp,
xfs_mount_t *mp,
xfs_dquot_t *dqp,
xfs_inode_t *quotip,
xfs_fileoff_t offset_fsb,
xfs_buf_t **O_bpp)
{
xfs_fsblock_t firstblock;
xfs_bmap_free_t flist;
xfs_bmbt_irec_t map;
int nmaps, error, committed;
xfs_buf_t *bp;
xfs_trans_t *tp = *tpp;
ASSERT(tp != NULL);
trace_xfs_dqalloc(dqp);
/*
* Initialize the bmap freelist prior to calling bmapi code.
*/
xfs_bmap_init(&flist, &firstblock);
xfs_ilock(quotip, XFS_ILOCK_EXCL);
/*
* Return if this type of quotas is turned off while we didn't
* have an inode lock
*/
if (XFS_IS_THIS_QUOTA_OFF(dqp)) {
xfs_iunlock(quotip, XFS_ILOCK_EXCL);
return (ESRCH);
}
xfs_trans_ijoin(tp, quotip, XFS_ILOCK_EXCL);
nmaps = 1;
error = xfs_bmapi_write(tp, quotip, offset_fsb,
XFS_DQUOT_CLUSTER_SIZE_FSB, XFS_BMAPI_METADATA,
&firstblock, XFS_QM_DQALLOC_SPACE_RES(mp),
&map, &nmaps, &flist);
if (error)
goto error0;
ASSERT(map.br_blockcount == XFS_DQUOT_CLUSTER_SIZE_FSB);
ASSERT(nmaps == 1);
ASSERT((map.br_startblock != DELAYSTARTBLOCK) &&
(map.br_startblock != HOLESTARTBLOCK));
/*
* Keep track of the blkno to save a lookup later
*/
dqp->q_blkno = XFS_FSB_TO_DADDR(mp, map.br_startblock);
/* now we can just get the buffer (there's nothing to read yet) */
bp = xfs_trans_get_buf(tp, mp->m_ddev_targp,
dqp->q_blkno,
mp->m_quotainfo->qi_dqchunklen,
0);
error = xfs_buf_geterror(bp);
if (error)
goto error1;
/*
* Make a chunk of dquots out of this buffer and log
* the entire thing.
*/
xfs_qm_init_dquot_blk(tp, mp, be32_to_cpu(dqp->q_core.d_id),
dqp->dq_flags & XFS_DQ_ALLTYPES, bp);
/*
* xfs_bmap_finish() may commit the current transaction and
* start a second transaction if the freelist is not empty.
*
* Since we still want to modify this buffer, we need to
* ensure that the buffer is not released on commit of
* the first transaction and ensure the buffer is added to the
* second transaction.
*
* If there is only one transaction then don't stop the buffer
* from being released when it commits later on.
*/
xfs_trans_bhold(tp, bp);
if ((error = xfs_bmap_finish(tpp, &flist, &committed))) {
goto error1;
}
if (committed) {
tp = *tpp;
xfs_trans_bjoin(tp, bp);
} else {
xfs_trans_bhold_release(tp, bp);
}
*O_bpp = bp;
return 0;
error1:
xfs_bmap_cancel(&flist);
error0:
xfs_iunlock(quotip, XFS_ILOCK_EXCL);
return (error);
}
/*
* Maps a dquot to the buffer containing its on-disk version.
* This returns a ptr to the buffer containing the on-disk dquot
* in the bpp param, and a ptr to the on-disk dquot within that buffer
*/
STATIC int
xfs_qm_dqtobp(
xfs_trans_t **tpp,
xfs_dquot_t *dqp,
xfs_disk_dquot_t **O_ddpp,
xfs_buf_t **O_bpp,
uint flags)
{
xfs_bmbt_irec_t map;
int nmaps = 1, error;
xfs_buf_t *bp;
xfs_inode_t *quotip = XFS_DQ_TO_QIP(dqp);
xfs_mount_t *mp = dqp->q_mount;
xfs_disk_dquot_t *ddq;
xfs_dqid_t id = be32_to_cpu(dqp->q_core.d_id);
xfs_trans_t *tp = (tpp ? *tpp : NULL);
dqp->q_fileoffset = (xfs_fileoff_t)id / mp->m_quotainfo->qi_dqperchunk;
xfs_ilock(quotip, XFS_ILOCK_SHARED);
if (XFS_IS_THIS_QUOTA_OFF(dqp)) {
/*
* Return if this type of quotas is turned off while we
* didn't have the quota inode lock.
*/
xfs_iunlock(quotip, XFS_ILOCK_SHARED);
return ESRCH;
}
/*
* Find the block map; no allocations yet
*/
error = xfs_bmapi_read(quotip, dqp->q_fileoffset,
XFS_DQUOT_CLUSTER_SIZE_FSB, &map, &nmaps, 0);
xfs_iunlock(quotip, XFS_ILOCK_SHARED);
if (error)
return error;
ASSERT(nmaps == 1);
ASSERT(map.br_blockcount == 1);
/*
* Offset of dquot in the (fixed sized) dquot chunk.
*/
dqp->q_bufoffset = (id % mp->m_quotainfo->qi_dqperchunk) *
sizeof(xfs_dqblk_t);
ASSERT(map.br_startblock != DELAYSTARTBLOCK);
if (map.br_startblock == HOLESTARTBLOCK) {
/*
* We don't allocate unless we're asked to
*/
if (!(flags & XFS_QMOPT_DQALLOC))
return ENOENT;
ASSERT(tp);
error = xfs_qm_dqalloc(tpp, mp, dqp, quotip,
dqp->q_fileoffset, &bp);
if (error)
return error;
tp = *tpp;
} else {
trace_xfs_dqtobp_read(dqp);
/*
* store the blkno etc so that we don't have to do the
* mapping all the time
*/
dqp->q_blkno = XFS_FSB_TO_DADDR(mp, map.br_startblock);
error = xfs_trans_read_buf(mp, tp, mp->m_ddev_targp,
dqp->q_blkno,
mp->m_quotainfo->qi_dqchunklen,
0, &bp);
if (error || !bp)
return XFS_ERROR(error);
}
ASSERT(xfs_buf_islocked(bp));
/*
* calculate the location of the dquot inside the buffer.
*/
ddq = bp->b_addr + dqp->q_bufoffset;
/*
* A simple sanity check in case we got a corrupted dquot...
*/
error = xfs_qm_dqcheck(mp, ddq, id, dqp->dq_flags & XFS_DQ_ALLTYPES,
flags & (XFS_QMOPT_DQREPAIR|XFS_QMOPT_DOWARN),
"dqtobp");
if (error) {
if (!(flags & XFS_QMOPT_DQREPAIR)) {
xfs_trans_brelse(tp, bp);
return XFS_ERROR(EIO);
}
}
*O_bpp = bp;
*O_ddpp = ddq;
return (0);
}
/*
* Read in the ondisk dquot using dqtobp() then copy it to an incore version,
* and release the buffer immediately.
*
* If XFS_QMOPT_DQALLOC is set, allocate a dquot on disk if it needed.
*/
int
xfs_qm_dqread(
struct xfs_mount *mp,
xfs_dqid_t id,
uint type,
uint flags,
struct xfs_dquot **O_dqpp)
{
struct xfs_dquot *dqp;
struct xfs_disk_dquot *ddqp;
struct xfs_buf *bp;
struct xfs_trans *tp = NULL;
int error;
int cancelflags = 0;
dqp = kmem_zone_zalloc(xfs_Gqm->qm_dqzone, KM_SLEEP);
dqp->dq_flags = type;
dqp->q_core.d_id = cpu_to_be32(id);
dqp->q_mount = mp;
INIT_LIST_HEAD(&dqp->q_freelist);
mutex_init(&dqp->q_qlock);
init_waitqueue_head(&dqp->q_pinwait);
/*
* Because we want to use a counting completion, complete
* the flush completion once to allow a single access to
* the flush completion without blocking.
*/
init_completion(&dqp->q_flush);
complete(&dqp->q_flush);
/*
* Make sure group quotas have a different lock class than user
* quotas.
*/
if (!(type & XFS_DQ_USER))
lockdep_set_class(&dqp->q_qlock, &xfs_dquot_other_class);
atomic_inc(&xfs_Gqm->qm_totaldquots);
trace_xfs_dqread(dqp);
if (flags & XFS_QMOPT_DQALLOC) {
tp = xfs_trans_alloc(mp, XFS_TRANS_QM_DQALLOC);
error = xfs_trans_reserve(tp, XFS_QM_DQALLOC_SPACE_RES(mp),
XFS_WRITE_LOG_RES(mp) +
/*
* Round the chunklen up to the next multiple
* of 128 (buf log item chunk size)).
*/
BBTOB(mp->m_quotainfo->qi_dqchunklen) - 1 + 128,
0,
XFS_TRANS_PERM_LOG_RES,
XFS_WRITE_LOG_COUNT);
if (error)
goto error1;
cancelflags = XFS_TRANS_RELEASE_LOG_RES;
}
/*
* get a pointer to the on-disk dquot and the buffer containing it
* dqp already knows its own type (GROUP/USER).
*/
error = xfs_qm_dqtobp(&tp, dqp, &ddqp, &bp, flags);
if (error) {
/*
* This can happen if quotas got turned off (ESRCH),
* or if the dquot didn't exist on disk and we ask to
* allocate (ENOENT).
*/
trace_xfs_dqread_fail(dqp);
cancelflags |= XFS_TRANS_ABORT;
goto error1;
}
/* copy everything from disk dquot to the incore dquot */
memcpy(&dqp->q_core, ddqp, sizeof(xfs_disk_dquot_t));
xfs_qm_dquot_logitem_init(dqp);
/*
* Reservation counters are defined as reservation plus current usage
* to avoid having to add every time.
*/
dqp->q_res_bcount = be64_to_cpu(ddqp->d_bcount);
dqp->q_res_icount = be64_to_cpu(ddqp->d_icount);
dqp->q_res_rtbcount = be64_to_cpu(ddqp->d_rtbcount);
/* Mark the buf so that this will stay incore a little longer */
xfs_buf_set_ref(bp, XFS_DQUOT_REF);
/*
* We got the buffer with a xfs_trans_read_buf() (in dqtobp())
* So we need to release with xfs_trans_brelse().
* The strategy here is identical to that of inodes; we lock
* the dquot in xfs_qm_dqget() before making it accessible to
* others. This is because dquots, like inodes, need a good level of
* concurrency, and we don't want to take locks on the entire buffers
* for dquot accesses.
* Note also that the dquot buffer may even be dirty at this point, if
* this particular dquot was repaired. We still aren't afraid to
* brelse it because we have the changes incore.
*/
ASSERT(xfs_buf_islocked(bp));
xfs_trans_brelse(tp, bp);
if (tp) {
error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES);
if (error)
goto error0;
}
*O_dqpp = dqp;
return error;
error1:
if (tp)
xfs_trans_cancel(tp, cancelflags);
error0:
xfs_qm_dqdestroy(dqp);
*O_dqpp = NULL;
return error;
}
/*
* Lookup a dquot in the incore dquot hashtable. We keep two separate
* hashtables for user and group dquots; and, these are global tables
* inside the XQM, not per-filesystem tables.
* The hash chain must be locked by caller, and it is left locked
* on return. Returning dquot is locked.
*/
STATIC int
xfs_qm_dqlookup(
xfs_mount_t *mp,
xfs_dqid_t id,
xfs_dqhash_t *qh,
xfs_dquot_t **O_dqpp)
{
xfs_dquot_t *dqp;
ASSERT(mutex_is_locked(&qh->qh_lock));
/*
* Traverse the hashchain looking for a match
*/
list_for_each_entry(dqp, &qh->qh_list, q_hashlist) {
/*
* We already have the hashlock. We don't need the
* dqlock to look at the id field of the dquot, since the
* id can't be modified without the hashlock anyway.
*/
if (be32_to_cpu(dqp->q_core.d_id) != id || dqp->q_mount != mp)
continue;
trace_xfs_dqlookup_found(dqp);
xfs_dqlock(dqp);
if (dqp->dq_flags & XFS_DQ_FREEING) {
*O_dqpp = NULL;
xfs_dqunlock(dqp);
return -1;
}
dqp->q_nrefs++;
/*
* move the dquot to the front of the hashchain
*/
list_move(&dqp->q_hashlist, &qh->qh_list);
trace_xfs_dqlookup_done(dqp);
*O_dqpp = dqp;
return 0;
}
*O_dqpp = NULL;
return 1;
}
/*
* Given the file system, inode OR id, and type (UDQUOT/GDQUOT), return a
* a locked dquot, doing an allocation (if requested) as needed.
* When both an inode and an id are given, the inode's id takes precedence.
* That is, if the id changes while we don't hold the ilock inside this
* function, the new dquot is returned, not necessarily the one requested
* in the id argument.
*/
int
xfs_qm_dqget(
xfs_mount_t *mp,
xfs_inode_t *ip, /* locked inode (optional) */
xfs_dqid_t id, /* uid/projid/gid depending on type */
uint type, /* XFS_DQ_USER/XFS_DQ_PROJ/XFS_DQ_GROUP */
uint flags, /* DQALLOC, DQSUSER, DQREPAIR, DOWARN */
xfs_dquot_t **O_dqpp) /* OUT : locked incore dquot */
{
xfs_dquot_t *dqp;
xfs_dqhash_t *h;
uint version;
int error;
ASSERT(XFS_IS_QUOTA_RUNNING(mp));
if ((! XFS_IS_UQUOTA_ON(mp) && type == XFS_DQ_USER) ||
(! XFS_IS_PQUOTA_ON(mp) && type == XFS_DQ_PROJ) ||
(! XFS_IS_GQUOTA_ON(mp) && type == XFS_DQ_GROUP)) {
return (ESRCH);
}
h = XFS_DQ_HASH(mp, id, type);
#ifdef DEBUG
if (xfs_do_dqerror) {
if ((xfs_dqerror_target == mp->m_ddev_targp) &&
(xfs_dqreq_num++ % xfs_dqerror_mod) == 0) {
xfs_debug(mp, "Returning error in dqget");
return (EIO);
}
}
ASSERT(type == XFS_DQ_USER ||
type == XFS_DQ_PROJ ||
type == XFS_DQ_GROUP);
if (ip) {
ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL));
if (type == XFS_DQ_USER)
ASSERT(ip->i_udquot == NULL);
else
ASSERT(ip->i_gdquot == NULL);
}
#endif
restart:
mutex_lock(&h->qh_lock);
/*
* Look in the cache (hashtable).
* The chain is kept locked during lookup.
*/
switch (xfs_qm_dqlookup(mp, id, h, O_dqpp)) {
case -1:
XQM_STATS_INC(xqmstats.xs_qm_dquot_dups);
mutex_unlock(&h->qh_lock);
delay(1);
goto restart;
case 0:
XQM_STATS_INC(xqmstats.xs_qm_dqcachehits);
/*
* The dquot was found, moved to the front of the chain,
* taken off the freelist if it was on it, and locked
* at this point. Just unlock the hashchain and return.
*/
ASSERT(*O_dqpp);
ASSERT(XFS_DQ_IS_LOCKED(*O_dqpp));
mutex_unlock(&h->qh_lock);
trace_xfs_dqget_hit(*O_dqpp);
return 0; /* success */
default:
XQM_STATS_INC(xqmstats.xs_qm_dqcachemisses);
break;
}
/*
* Dquot cache miss. We don't want to keep the inode lock across
* a (potential) disk read. Also we don't want to deal with the lock
* ordering between quotainode and this inode. OTOH, dropping the inode
* lock here means dealing with a chown that can happen before
* we re-acquire the lock.
*/
if (ip)
xfs_iunlock(ip, XFS_ILOCK_EXCL);
/*
* Save the hashchain version stamp, and unlock the chain, so that
* we don't keep the lock across a disk read
*/
version = h->qh_version;
mutex_unlock(&h->qh_lock);
error = xfs_qm_dqread(mp, id, type, flags, &dqp);
if (ip)
xfs_ilock(ip, XFS_ILOCK_EXCL);
if (error)
return error;
/*
* Dquot lock comes after hashlock in the lock ordering
*/
if (ip) {
/*
* A dquot could be attached to this inode by now, since
* we had dropped the ilock.
*/
if (type == XFS_DQ_USER) {
if (!XFS_IS_UQUOTA_ON(mp)) {
/* inode stays locked on return */
xfs_qm_dqdestroy(dqp);
return XFS_ERROR(ESRCH);
}
if (ip->i_udquot) {
xfs_qm_dqdestroy(dqp);
dqp = ip->i_udquot;
xfs_dqlock(dqp);
goto dqret;
}
} else {
if (!XFS_IS_OQUOTA_ON(mp)) {
/* inode stays locked on return */
xfs_qm_dqdestroy(dqp);
return XFS_ERROR(ESRCH);
}
if (ip->i_gdquot) {
xfs_qm_dqdestroy(dqp);
dqp = ip->i_gdquot;
xfs_dqlock(dqp);
goto dqret;
}
}
}
/*
* Hashlock comes after ilock in lock order
*/
mutex_lock(&h->qh_lock);
if (version != h->qh_version) {
xfs_dquot_t *tmpdqp;
/*
* Now, see if somebody else put the dquot in the
* hashtable before us. This can happen because we didn't
* keep the hashchain lock. We don't have to worry about
* lock order between the two dquots here since dqp isn't
* on any findable lists yet.
*/
switch (xfs_qm_dqlookup(mp, id, h, &tmpdqp)) {
case 0:
case -1:
/*
* Duplicate found, either in cache or on its way out.
* Just throw away the new dquot and start over.
*/
if (tmpdqp)
xfs_qm_dqput(tmpdqp);
mutex_unlock(&h->qh_lock);
xfs_qm_dqdestroy(dqp);
XQM_STATS_INC(xqmstats.xs_qm_dquot_dups);
goto restart;
default:
break;
}
}
/*
* Put the dquot at the beginning of the hash-chain and mp's list
* LOCK ORDER: hashlock, freelistlock, mplistlock, udqlock, gdqlock ..
*/
ASSERT(mutex_is_locked(&h->qh_lock));
dqp->q_hash = h;
list_add(&dqp->q_hashlist, &h->qh_list);
h->qh_version++;
/*
* Attach this dquot to this filesystem's list of all dquots,
* kept inside the mount structure in m_quotainfo field
*/
mutex_lock(&mp->m_quotainfo->qi_dqlist_lock);
/*
* We return a locked dquot to the caller, with a reference taken
*/
xfs_dqlock(dqp);
dqp->q_nrefs = 1;
list_add(&dqp->q_mplist, &mp->m_quotainfo->qi_dqlist);
mp->m_quotainfo->qi_dquots++;
mutex_unlock(&mp->m_quotainfo->qi_dqlist_lock);
mutex_unlock(&h->qh_lock);
dqret:
ASSERT((ip == NULL) || xfs_isilocked(ip, XFS_ILOCK_EXCL));
trace_xfs_dqget_miss(dqp);
*O_dqpp = dqp;
return (0);
}
/*
* Release a reference to the dquot (decrement ref-count)
* and unlock it. If there is a group quota attached to this
* dquot, carefully release that too without tripping over
* deadlocks'n'stuff.
*/
void
xfs_qm_dqput(
struct xfs_dquot *dqp)
{
struct xfs_dquot *gdqp;
ASSERT(dqp->q_nrefs > 0);
ASSERT(XFS_DQ_IS_LOCKED(dqp));
trace_xfs_dqput(dqp);
recurse:
if (--dqp->q_nrefs > 0) {
xfs_dqunlock(dqp);
return;
}
trace_xfs_dqput_free(dqp);
mutex_lock(&xfs_Gqm->qm_dqfrlist_lock);
if (list_empty(&dqp->q_freelist)) {
list_add_tail(&dqp->q_freelist, &xfs_Gqm->qm_dqfrlist);
xfs_Gqm->qm_dqfrlist_cnt++;
}
mutex_unlock(&xfs_Gqm->qm_dqfrlist_lock);
/*
* If we just added a udquot to the freelist, then we want to release
* the gdquot reference that it (probably) has. Otherwise it'll keep
* the gdquot from getting reclaimed.
*/
gdqp = dqp->q_gdquot;
if (gdqp) {
xfs_dqlock(gdqp);
dqp->q_gdquot = NULL;
}
xfs_dqunlock(dqp);
/*
* If we had a group quota hint, release it now.
*/
if (gdqp) {
dqp = gdqp;
goto recurse;
}
}
/*
* Release a dquot. Flush it if dirty, then dqput() it.
* dquot must not be locked.
*/
void
xfs_qm_dqrele(
xfs_dquot_t *dqp)
{
if (!dqp)
return;
trace_xfs_dqrele(dqp);
xfs_dqlock(dqp);
/*
* We don't care to flush it if the dquot is dirty here.
* That will create stutters that we want to avoid.
* Instead we do a delayed write when we try to reclaim
* a dirty dquot. Also xfs_sync will take part of the burden...
*/
xfs_qm_dqput(dqp);
}
/*
* This is the dquot flushing I/O completion routine. It is called
* from interrupt level when the buffer containing the dquot is
* flushed to disk. It is responsible for removing the dquot logitem
* from the AIL if it has not been re-logged, and unlocking the dquot's
* flush lock. This behavior is very similar to that of inodes..
*/
STATIC void
xfs_qm_dqflush_done(
struct xfs_buf *bp,
struct xfs_log_item *lip)
{
xfs_dq_logitem_t *qip = (struct xfs_dq_logitem *)lip;
xfs_dquot_t *dqp = qip->qli_dquot;
struct xfs_ail *ailp = lip->li_ailp;
/*
* We only want to pull the item from the AIL if its
* location in the log has not changed since we started the flush.
* Thus, we only bother if the dquot's lsn has
* not changed. First we check the lsn outside the lock
* since it's cheaper, and then we recheck while
* holding the lock before removing the dquot from the AIL.
*/
if ((lip->li_flags & XFS_LI_IN_AIL) &&
lip->li_lsn == qip->qli_flush_lsn) {
/* xfs_trans_ail_delete() drops the AIL lock. */
spin_lock(&ailp->xa_lock);
if (lip->li_lsn == qip->qli_flush_lsn)
xfs_trans_ail_delete(ailp, lip);
else
spin_unlock(&ailp->xa_lock);
}
/*
* Release the dq's flush lock since we're done with it.
*/
xfs_dqfunlock(dqp);
}
/*
* Write a modified dquot to disk.
* The dquot must be locked and the flush lock too taken by caller.
* The flush lock will not be unlocked until the dquot reaches the disk,
* but the dquot is free to be unlocked and modified by the caller
* in the interim. Dquot is still locked on return. This behavior is
* identical to that of inodes.
*/
int
xfs_qm_dqflush(
xfs_dquot_t *dqp,
uint flags)
{
struct xfs_mount *mp = dqp->q_mount;
struct xfs_buf *bp;
struct xfs_disk_dquot *ddqp;
int error;
ASSERT(XFS_DQ_IS_LOCKED(dqp));
ASSERT(!completion_done(&dqp->q_flush));
trace_xfs_dqflush(dqp);
/*
* If not dirty, or it's pinned and we are not supposed to block, nada.
*/
if (!XFS_DQ_IS_DIRTY(dqp) ||
((flags & SYNC_TRYLOCK) && atomic_read(&dqp->q_pincount) > 0)) {
xfs_dqfunlock(dqp);
return 0;
}
xfs_qm_dqunpin_wait(dqp);
/*
* This may have been unpinned because the filesystem is shutting
* down forcibly. If that's the case we must not write this dquot
* to disk, because the log record didn't make it to disk!
*/
if (XFS_FORCED_SHUTDOWN(mp)) {
dqp->dq_flags &= ~XFS_DQ_DIRTY;
xfs_dqfunlock(dqp);
return XFS_ERROR(EIO);
}
/*
* Get the buffer containing the on-disk dquot
*/
error = xfs_trans_read_buf(mp, NULL, mp->m_ddev_targp, dqp->q_blkno,
mp->m_quotainfo->qi_dqchunklen, 0, &bp);
if (error) {
ASSERT(error != ENOENT);
xfs_dqfunlock(dqp);
return error;
}
/*
* Calculate the location of the dquot inside the buffer.
*/
ddqp = bp->b_addr + dqp->q_bufoffset;
/*
* A simple sanity check in case we got a corrupted dquot..
*/
error = xfs_qm_dqcheck(mp, &dqp->q_core, be32_to_cpu(ddqp->d_id), 0,
XFS_QMOPT_DOWARN, "dqflush (incore copy)");
if (error) {
xfs_buf_relse(bp);
xfs_dqfunlock(dqp);
xfs_force_shutdown(mp, SHUTDOWN_CORRUPT_INCORE);
return XFS_ERROR(EIO);
}
/* This is the only portion of data that needs to persist */
memcpy(ddqp, &dqp->q_core, sizeof(xfs_disk_dquot_t));
/*
* Clear the dirty field and remember the flush lsn for later use.
*/
dqp->dq_flags &= ~XFS_DQ_DIRTY;
xfs_trans_ail_copy_lsn(mp->m_ail, &dqp->q_logitem.qli_flush_lsn,
&dqp->q_logitem.qli_item.li_lsn);
/*
* Attach an iodone routine so that we can remove this dquot from the
* AIL and release the flush lock once the dquot is synced to disk.
*/
xfs_buf_attach_iodone(bp, xfs_qm_dqflush_done,
&dqp->q_logitem.qli_item);
/*
* If the buffer is pinned then push on the log so we won't
* get stuck waiting in the write for too long.
*/
if (xfs_buf_ispinned(bp)) {
trace_xfs_dqflush_force(dqp);
xfs_log_force(mp, 0);
}
if (flags & SYNC_WAIT)
error = xfs_bwrite(bp);
else
xfs_buf_delwri_queue(bp);
xfs_buf_relse(bp);
trace_xfs_dqflush_done(dqp);
/*
* dqp is still locked, but caller is free to unlock it now.
*/
return error;
}
void
xfs_dqunlock(
xfs_dquot_t *dqp)
{
xfs_dqunlock_nonotify(dqp);
if (dqp->q_logitem.qli_dquot == dqp) {
xfs_trans_unlocked_item(dqp->q_logitem.qli_item.li_ailp,
&dqp->q_logitem.qli_item);
}
}
/*
* Lock two xfs_dquot structures.
*
* To avoid deadlocks we always lock the quota structure with
* the lowerd id first.
*/
void
xfs_dqlock2(
xfs_dquot_t *d1,
xfs_dquot_t *d2)
{
if (d1 && d2) {
ASSERT(d1 != d2);
if (be32_to_cpu(d1->q_core.d_id) >
be32_to_cpu(d2->q_core.d_id)) {
mutex_lock(&d2->q_qlock);
mutex_lock_nested(&d1->q_qlock, XFS_QLOCK_NESTED);
} else {
mutex_lock(&d1->q_qlock);
mutex_lock_nested(&d2->q_qlock, XFS_QLOCK_NESTED);
}
} else if (d1) {
mutex_lock(&d1->q_qlock);
} else if (d2) {
mutex_lock(&d2->q_qlock);
}
}
/*
* Take a dquot out of the mount's dqlist as well as the hashlist. This is
* called via unmount as well as quotaoff, and the purge will always succeed.
*/
void
xfs_qm_dqpurge(
struct xfs_dquot *dqp)
{
struct xfs_mount *mp = dqp->q_mount;
struct xfs_dqhash *qh = dqp->q_hash;
xfs_dqlock(dqp);
/*
* If we're turning off quotas, we have to make sure that, for
* example, we don't delete quota disk blocks while dquots are
* in the process of getting written to those disk blocks.
* This dquot might well be on AIL, and we can't leave it there
* if we're turning off quotas. Basically, we need this flush
* lock, and are willing to block on it.
*/
if (!xfs_dqflock_nowait(dqp)) {
/*
* Block on the flush lock after nudging dquot buffer,
* if it is incore.
*/
xfs_dqflock_pushbuf_wait(dqp);
}
/*
* If we are turning this type of quotas off, we don't care
* about the dirty metadata sitting in this dquot. OTOH, if
* we're unmounting, we do care, so we flush it and wait.
*/
if (XFS_DQ_IS_DIRTY(dqp)) {
int error;
/*
* We don't care about getting disk errors here. We need
* to purge this dquot anyway, so we go ahead regardless.
*/
error = xfs_qm_dqflush(dqp, SYNC_WAIT);
if (error)
xfs_warn(mp, "%s: dquot %p flush failed",
__func__, dqp);
xfs_dqflock(dqp);
}
ASSERT(atomic_read(&dqp->q_pincount) == 0);
ASSERT(XFS_FORCED_SHUTDOWN(mp) ||
!(dqp->q_logitem.qli_item.li_flags & XFS_LI_IN_AIL));
xfs_dqfunlock(dqp);
xfs_dqunlock(dqp);
mutex_lock(&qh->qh_lock);
list_del_init(&dqp->q_hashlist);
qh->qh_version++;
mutex_unlock(&qh->qh_lock);
mutex_lock(&mp->m_quotainfo->qi_dqlist_lock);
list_del_init(&dqp->q_mplist);
mp->m_quotainfo->qi_dqreclaims++;
mp->m_quotainfo->qi_dquots--;
mutex_unlock(&mp->m_quotainfo->qi_dqlist_lock);
/*
* We move dquots to the freelist as soon as their reference count
* hits zero, so it really should be on the freelist here.
*/
mutex_lock(&xfs_Gqm->qm_dqfrlist_lock);
ASSERT(!list_empty(&dqp->q_freelist));
list_del_init(&dqp->q_freelist);
xfs_Gqm->qm_dqfrlist_cnt--;
mutex_unlock(&xfs_Gqm->qm_dqfrlist_lock);
xfs_qm_dqdestroy(dqp);
}
/*
* Give the buffer a little push if it is incore and
* wait on the flush lock.
*/
void
xfs_dqflock_pushbuf_wait(
xfs_dquot_t *dqp)
{
xfs_mount_t *mp = dqp->q_mount;
xfs_buf_t *bp;
/*
* Check to see if the dquot has been flushed delayed
* write. If so, grab its buffer and send it
* out immediately. We'll be able to acquire
* the flush lock when the I/O completes.
*/
bp = xfs_incore(mp->m_ddev_targp, dqp->q_blkno,
mp->m_quotainfo->qi_dqchunklen, XBF_TRYLOCK);
if (!bp)
goto out_lock;
if (XFS_BUF_ISDELAYWRITE(bp)) {
if (xfs_buf_ispinned(bp))
xfs_log_force(mp, 0);
xfs_buf_delwri_promote(bp);
wake_up_process(bp->b_target->bt_task);
}
xfs_buf_relse(bp);
out_lock:
xfs_dqflock(dqp);
}