[PATCH v4.1 07/11] xfs: flush eof/cowblocks if we can't reserve quota for inode creation

Darrick J. Wong
2021-01-27T10:22:06Z

From: Darrick J. Wong <djwong@kernel.org>

If an inode creation is unable to reserve enough quota to handle the
modification, try clearing whatever space the filesystem might have been
hanging onto in the hopes of speeding up the filesystem. The flushing
behavior will become particularly important when we add deferred inode
inactivation because that will increase the amount of space that isn't
actively tied to user data.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
---
v4.1: move the retry code to a separate helper to fix the weird return
conventions
---
fs/xfs/xfs_icache.c | 78 ++++++++++++++++++++++++++++------------------
fs/xfs/xfs_icache.h | 2 +
fs/xfs/xfs_inode.c | 17 +++++++++-
fs/xfs/xfs_quota.h | 23 +++++++++++---
fs/xfs/xfs_symlink.c | 9 +++++
fs/xfs/xfs_trans_dquot.c | 48 +++++++++++++++++++++++++++-
6 files changed, 137 insertions(+), 40 deletions(-)

diff --git a/fs/xfs/xfs_icache.c b/fs/xfs/xfs_icache.c
index 7323a1a240bd..ae7888f0e074 100644
--- a/fs/xfs/xfs_icache.c
+++ b/fs/xfs/xfs_icache.c
@@ -1646,60 +1646,78 @@ xfs_start_block_reaping(
}

/*
- * Run cow/eofblocks scans on the quotas applicable to the inode. For inodes
- * with multiple quotas, we don't know exactly which quota caused an allocation
- * failure. We make a best effort by including each quota under low free space
- * conditions (less than 1% free space) in the scan.
+ * Run cow/eofblocks scans on the supplied dquots. We don't know exactly which
+ * quota caused an allocation failure, so we make a best effort by including
+ * each quota under low free space conditions (less than 1% free space) in the
+ * scan.
*/
int
-xfs_blockgc_free_quota(
- struct xfs_inode *ip,
+xfs_blockgc_free_dquots(
+ struct xfs_dquot *udqp,
+ struct xfs_dquot *gdqp,
+ struct xfs_dquot *pdqp,
unsigned int eof_flags)
{
struct xfs_eofblocks eofb = {0};
- struct xfs_dquot *dq;
+ struct xfs_mount *mp = NULL;
bool do_work = false;
int error;

+ if (!udqp && !gdqp && !pdqp)
+ return 0;
+ if (udqp)
+ mp = udqp->q_mount;
+ if (!mp && gdqp)
+ mp = gdqp->q_mount;
+ if (!mp && pdqp)
+ mp = pdqp->q_mount;
+
/*
* Run a scan to free blocks using the union filter to cover all
* applicable quotas in a single scan.
*/
eofb.eof_flags = XFS_EOF_FLAGS_UNION | eof_flags;

- if (XFS_IS_UQUOTA_ENFORCED(ip->i_mount)) {
- dq = xfs_inode_dquot(ip, XFS_DQTYPE_USER);
- if (dq && xfs_dquot_lowsp(dq)) {
- eofb.eof_uid = VFS_I(ip)->i_uid;
- eofb.eof_flags |= XFS_EOF_FLAGS_UID;
- do_work = true;
- }
+ if (XFS_IS_UQUOTA_ENFORCED(mp) && udqp && xfs_dquot_lowsp(udqp)) {
+ eofb.eof_uid = make_kuid(mp->m_super->s_user_ns, udqp->q_id);
+ eofb.eof_flags |= XFS_EOF_FLAGS_UID;
+ do_work = true;
}

- if (XFS_IS_GQUOTA_ENFORCED(ip->i_mount)) {
- dq = xfs_inode_dquot(ip, XFS_DQTYPE_GROUP);
- if (dq && xfs_dquot_lowsp(dq)) {
- eofb.eof_gid = VFS_I(ip)->i_gid;
- eofb.eof_flags |= XFS_EOF_FLAGS_GID;
- do_work = true;
- }
+ if (XFS_IS_UQUOTA_ENFORCED(mp) && gdqp && xfs_dquot_lowsp(gdqp)) {
+ eofb.eof_gid = make_kgid(mp->m_super->s_user_ns, gdqp->q_id);
+ eofb.eof_flags |= XFS_EOF_FLAGS_GID;
+ do_work = true;
}

- if (XFS_IS_PQUOTA_ENFORCED(ip->i_mount)) {
- dq = xfs_inode_dquot(ip, XFS_DQTYPE_PROJ);
- if (dq && xfs_dquot_lowsp(dq)) {
- eofb.eof_prid = ip->i_d.di_projid;
- eofb.eof_flags |= XFS_EOF_FLAGS_PRID;
- do_work = true;
- }
+ if (XFS_IS_PQUOTA_ENFORCED(mp) && pdqp && xfs_dquot_lowsp(pdqp)) {
+ eofb.eof_prid = pdqp->q_id;
+ eofb.eof_flags |= XFS_EOF_FLAGS_PRID;
+ do_work = true;
}

if (!do_work)
return 0;

- error = xfs_icache_free_eofblocks(ip->i_mount, &eofb);
+ error = xfs_icache_free_eofblocks(mp, &eofb);
if (error)
return error;

- return xfs_icache_free_cowblocks(ip->i_mount, &eofb);
+ return xfs_icache_free_cowblocks(mp, &eofb);
+}
+
+/*
+ * Run cow/eofblocks scans on the quotas applicable to the inode. For inodes
+ * with multiple quotas, we don't know exactly which quota caused an allocation
+ * failure. We make a best effort by including each quota under low free space
+ * conditions (less than 1% free space) in the scan.
+ */
+int
+xfs_blockgc_free_quota(
+ struct xfs_inode *ip,
+ unsigned int eof_flags)
+{
+ return xfs_blockgc_free_dquots(xfs_inode_dquot(ip, XFS_DQTYPE_USER),
+ xfs_inode_dquot(ip, XFS_DQTYPE_GROUP),
+ xfs_inode_dquot(ip, XFS_DQTYPE_PROJ), eof_flags);
}
diff --git a/fs/xfs/xfs_icache.h b/fs/xfs/xfs_icache.h
index d64ea8f5c589..5f520de637f6 100644
--- a/fs/xfs/xfs_icache.h
+++ b/fs/xfs/xfs_icache.h
@@ -54,6 +54,8 @@ long xfs_reclaim_inodes_nr(struct xfs_mount *mp, int nr_to_scan);

void xfs_inode_set_reclaim_tag(struct xfs_inode *ip);

+int xfs_blockgc_free_dquots(struct xfs_dquot *udqp, struct xfs_dquot *gdqp,
+ struct xfs_dquot *pdqp, unsigned int eof_flags);
int xfs_blockgc_free_quota(struct xfs_inode *ip, unsigned int eof_flags);

void xfs_inode_set_eofblocks_tag(struct xfs_inode *ip);
diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c
index e909da05cd28..ad4bfe057737 100644
--- a/fs/xfs/xfs_inode.c
+++ b/fs/xfs/xfs_inode.c
@@ -990,6 +990,7 @@ xfs_create(
struct xfs_dquot *gdqp = NULL;
struct xfs_dquot *pdqp = NULL;
struct xfs_trans_res *tres;
+ bool quota_retry = false;
uint resblks;

trace_xfs_create(dp, name);
@@ -1022,6 +1023,7 @@ xfs_create(
* the case we'll drop the one we have and get a more
* appropriate transaction later.
*/
+retry:
error = xfs_trans_alloc(mp, tres, resblks, 0, 0, &tp);
if (error == -ENOSPC) {
/* flush outstanding delalloc blocks and retry */
@@ -1038,9 +1040,14 @@ xfs_create(
* Reserve disk quota and the inode.
*/
error = xfs_trans_reserve_quota_icreate(tp, dp, udqp, gdqp, pdqp,
- resblks);
+ resblks, &quota_retry);
if (error)
goto out_trans_cancel;
+ if (quota_retry) {
+ xfs_trans_cancel_qretry_dquots(tp, dp, udqp, gdqp, pdqp);
+ unlock_dp_on_error = false;
+ goto retry;
+ }

error = xfs_iext_count_may_overflow(dp, XFS_DATA_FORK,
XFS_IEXT_DIR_MANIP_CNT(mp));
@@ -1146,6 +1153,7 @@ xfs_create_tmpfile(
struct xfs_dquot *gdqp = NULL;
struct xfs_dquot *pdqp = NULL;
struct xfs_trans_res *tres;
+ bool quota_retry = false;
uint resblks;

if (XFS_FORCED_SHUTDOWN(mp))
@@ -1165,14 +1173,19 @@ xfs_create_tmpfile(
resblks = XFS_IALLOC_SPACE_RES(mp);
tres = &M_RES(mp)->tr_create_tmpfile;

+retry:
error = xfs_trans_alloc(mp, tres, resblks, 0, 0, &tp);
if (error)
goto out_release_inode;

error = xfs_trans_reserve_quota_icreate(tp, dp, udqp, gdqp, pdqp,
- resblks);
+ resblks, &quota_retry);
if (error)
goto out_trans_cancel;
+ if (quota_retry) {
+ xfs_trans_cancel_qretry_dquots(tp, NULL, udqp, gdqp, pdqp);
+ goto retry;
+ }

error = xfs_dir_ialloc(&tp, dp, mode, 0, 0, prid, &ip);
if (error)
diff --git a/fs/xfs/xfs_quota.h b/fs/xfs/xfs_quota.h
index 321c093459a1..c5bbe7e3e259 100644
--- a/fs/xfs/xfs_quota.h
+++ b/fs/xfs/xfs_quota.h
@@ -87,10 +87,13 @@ int xfs_trans_reserve_quota_nblks(struct xfs_trans *tp, struct xfs_inode *ip,
extern int xfs_trans_reserve_quota_bydquots(struct xfs_trans *,
struct xfs_mount *, struct xfs_dquot *,
struct xfs_dquot *, struct xfs_dquot *, int64_t, long, uint);
-int xfs_trans_reserve_quota_icreate(struct xfs_trans *tp, struct xfs_inode *dp,
- struct xfs_dquot *udqp, struct xfs_dquot *gdqp,
- struct xfs_dquot *pdqp, int64_t nblks);
int xfs_trans_cancel_qretry(struct xfs_trans *tp, struct xfs_inode *ip);
+int xfs_trans_reserve_quota_icreate(struct xfs_trans *tp, struct xfs_inode *dp,
+ struct xfs_dquot *udqp, struct xfs_dquot *gdqp,
+ struct xfs_dquot *pdqp, int64_t nblks, bool *retry);
+int xfs_trans_cancel_qretry_dquots(struct xfs_trans *tp, struct xfs_inode *dp,
+ struct xfs_dquot *udqp, struct xfs_dquot *gdqp,
+ struct xfs_dquot *pdqp);

extern int xfs_qm_vop_dqalloc(struct xfs_inode *, kuid_t, kgid_t,
prid_t, uint, struct xfs_dquot **, struct xfs_dquot **,
@@ -159,7 +162,7 @@ xfs_quota_reserve_blkres(struct xfs_inode *ip, int64_t nblks, bool isrt)
static inline int
xfs_trans_reserve_quota_icreate(struct xfs_trans *tp, struct xfs_inode *dp,
struct xfs_dquot *udqp, struct xfs_dquot *gdqp,
- struct xfs_dquot *pdqp, int64_t nblks)
+ struct xfs_dquot *pdqp, int64_t nblks, bool *retry)
{
return 0;
}
@@ -171,6 +174,18 @@ xfs_trans_cancel_qretry(struct xfs_trans *tp, struct xfs_inode *ip)
return 0;
}

+static inline int
+xfs_trans_cancel_qretry_dquots(
+ struct xfs_trans *tp,
+ struct xfs_inode *dp,
+ struct xfs_dquot *udqp,
+ struct xfs_dquot *gdqp,
+ struct xfs_dquot *pdqp)
+{
+ ASSERT(0);
+ return 0;
+}
+
#define xfs_qm_vop_create_dqattach(tp, ip, u, g, p)
#define xfs_qm_vop_rename_dqattach(it) (0)
#define xfs_qm_vop_chown(tp, ip, old, new) (NULL)
diff --git a/fs/xfs/xfs_symlink.c b/fs/xfs/xfs_symlink.c
index f8bfa51bdeef..c97a3d147bc2 100644
--- a/fs/xfs/xfs_symlink.c
+++ b/fs/xfs/xfs_symlink.c
@@ -159,6 +159,7 @@ xfs_symlink(
struct xfs_dquot *udqp = NULL;
struct xfs_dquot *gdqp = NULL;
struct xfs_dquot *pdqp = NULL;
+ bool quota_retry = false;
uint resblks;

*ipp = NULL;
@@ -197,6 +198,7 @@ xfs_symlink(
fs_blocks = xfs_symlink_blocks(mp, pathlen);
resblks = XFS_SYMLINK_SPACE_RES(mp, link_name->len, fs_blocks);

+retry:
error = xfs_trans_alloc(mp, &M_RES(mp)->tr_symlink, resblks, 0, 0, &tp);
if (error)
goto out_release_inode;
@@ -216,9 +218,14 @@ xfs_symlink(
* Reserve disk quota : blocks and inode.
*/
error = xfs_trans_reserve_quota_icreate(tp, dp, udqp, gdqp, pdqp,
- resblks);
+ resblks, &quota_retry);
if (error)
goto out_trans_cancel;
+ if (quota_retry) {
+ xfs_trans_cancel_qretry_dquots(tp, dp, udqp, gdqp, pdqp);
+ unlock_dp_on_error = false;
+ goto retry;
+ }

error = xfs_iext_count_may_overflow(dp, XFS_DATA_FORK,
XFS_IEXT_DIR_MANIP_CNT(mp));
diff --git a/fs/xfs/xfs_trans_dquot.c b/fs/xfs/xfs_trans_dquot.c
index 4b679b9f2da7..b463047f04c6 100644
--- a/fs/xfs/xfs_trans_dquot.c
+++ b/fs/xfs/xfs_trans_dquot.c
@@ -835,7 +835,17 @@ xfs_trans_cancel_qretry(
return xfs_blockgc_free_quota(ip, 0);
}

-/* Change the quota reservations for an inode creation activity. */
+/*
+ * Change the quota reservations for an inode creation activity. This doesn't
+ * change the actual usage, just the reservation. The caller may hold
+ * ILOCK_EXCL on the inode. If @retry is not a NULL pointer, the caller must
+ * ensure that *retry is set to false before the first time this function is
+ * called.
+ *
+ * If the quota reservation fails because we hit a quota limit (and retry is
+ * not a NULL pointer, and *retry is false), this function will set *retry to
+ * true and return zero.
+ */
int
xfs_trans_reserve_quota_icreate(
struct xfs_trans *tp,
@@ -843,17 +853,49 @@ xfs_trans_reserve_quota_icreate(
struct xfs_dquot *udqp,
struct xfs_dquot *gdqp,
struct xfs_dquot *pdqp,
- int64_t nblks)
+ int64_t nblks,
+ bool *retry)
{
struct xfs_mount *mp = dp->i_mount;
+ int error;

if (!XFS_IS_QUOTA_RUNNING(mp) || !XFS_IS_QUOTA_ON(mp))
return 0;

ASSERT(!xfs_is_quota_inode(&mp->m_sb, dp->i_ino));

- return xfs_trans_reserve_quota_bydquots(tp, dp->i_mount, udqp, gdqp,
+ error = xfs_trans_reserve_quota_bydquots(tp, dp->i_mount, udqp, gdqp,
pdqp, nblks, 1, XFS_QMOPT_RES_REGBLKS);
+ if (retry == NULL)
+ return error;
+ /* We only allow one retry for EDQUOT/ENOSPC. */
+ if (*retry || (error != -EDQUOT && error != -ENOSPC)) {
+ *retry = false;
+ return error;
+ }
+
+ *retry = true;
+ return 0;
+}
+
+/*
+ * Cancel a transaction and try to clear some space so that we can reserve some
+ * quota. When this function returns, the transaction will be cancelled and dp
+ * (if one is supplied) will be unlocked.
+ */
+int
+xfs_trans_cancel_qretry_dquots(
+ struct xfs_trans *tp,
+ struct xfs_inode *dp,
+ struct xfs_dquot *udqp,
+ struct xfs_dquot *gdqp,
+ struct xfs_dquot *pdqp)
+{
+ xfs_trans_cancel(tp);
+ if (dp)
+ xfs_iunlock(dp, XFS_ILOCK_EXCL);
+
+ return xfs_blockgc_free_dquots(udqp, gdqp, pdqp, 0);
}

/*