| Message ID | 152401917977.11465.9543981144688523511.stgit@magnolia (mailing list archive) |
|---|---|
| State | Deferred, archived |
| Headers | show |
On Tue, Apr 17, 2018 at 07:39:39PM -0700, Darrick J. Wong wrote: > From: Darrick J. Wong <darrick.wong@oracle.com> > > Create a new QMOPT flag to signal that we've already locked the quota > inode. This will be used by the quota scrub code refactoring to avoid > dropping the quota ip lock during scrub. The flag is incompatible with > the DQALLOC flag because dquot allocation creates a transaction, and we > shouldn't be doing that with the ILOCK held. > > Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> > --- > fs/xfs/libxfs/xfs_quota_defs.h | 2 ++ > fs/xfs/xfs_dquot.c | 32 ++++++++++++++++++++------------ > 2 files changed, 22 insertions(+), 12 deletions(-) > > > diff --git a/fs/xfs/libxfs/xfs_quota_defs.h b/fs/xfs/libxfs/xfs_quota_defs.h > index bb1b13a..cfc9938 100644 > --- a/fs/xfs/libxfs/xfs_quota_defs.h > +++ b/fs/xfs/libxfs/xfs_quota_defs.h > @@ -107,6 +107,8 @@ typedef uint16_t xfs_qwarncnt_t; > * to a single function. None of these XFS_QMOPT_* flags are meant to have > * persistent values (ie. their values can and will change between versions) > */ > +/* Quota ip already locked. Cannot be used with DQALLOC. */ > +#define XFS_QMOPT_QUOTIP_LOCKED 0x0000001 > #define XFS_QMOPT_DQALLOC 0x0000002 /* alloc dquot ondisk if needed */ > #define XFS_QMOPT_UQUOTA 0x0000004 /* user dquot requested */ > #define XFS_QMOPT_PQUOTA 0x0000008 /* project dquot requested */ > diff --git a/fs/xfs/xfs_dquot.c b/fs/xfs/xfs_dquot.c > index a7daef9..ed2e37c 100644 > --- a/fs/xfs/xfs_dquot.c > +++ b/fs/xfs/xfs_dquot.c > @@ -417,18 +417,20 @@ xfs_qm_dqtobp( > struct xfs_mount *mp = dqp->q_mount; > xfs_dqid_t id = be32_to_cpu(dqp->q_core.d_id); > struct xfs_trans *tp = (tpp ? *tpp : NULL); > - uint lock_mode; > + uint lock_mode = 0; > > quotip = xfs_quota_inode(dqp->q_mount, dqp->dq_flags); > dqp->q_fileoffset = (xfs_fileoff_t)id / mp->m_quotainfo->qi_dqperchunk; > > - lock_mode = xfs_ilock_data_map_shared(quotip); > + if (!(flags & XFS_QMOPT_QUOTIP_LOCKED)) > + lock_mode = xfs_ilock_data_map_shared(quotip); > if (!xfs_this_quota_on(dqp->q_mount, dqp->dq_flags)) { > /* > * Return if this type of quotas is turned off while we > * didn't have the quota inode lock. > */ > - xfs_iunlock(quotip, lock_mode); > + if (lock_mode) > + xfs_iunlock(quotip, lock_mode); > return -ESRCH; > } > > @@ -438,7 +440,8 @@ xfs_qm_dqtobp( > error = xfs_bmapi_read(quotip, dqp->q_fileoffset, > XFS_DQUOT_CLUSTER_SIZE_FSB, &map, &nmaps, 0); > > - xfs_iunlock(quotip, lock_mode); > + if (lock_mode) > + xfs_iunlock(quotip, lock_mode); > if (error) > return error; > > @@ -458,7 +461,7 @@ xfs_qm_dqtobp( > */ > if (!(flags & XFS_QMOPT_DQALLOC)) > return -ENOENT; > - > + ASSERT(!(flags & XFS_QMOPT_QUOTIP_LOCKED)); > ASSERT(tp); > error = xfs_qm_dqalloc(tpp, mp, dqp, quotip, > dqp->q_fileoffset, &bp); > @@ -553,6 +556,7 @@ xfs_qm_dqread( > trace_xfs_dqread(dqp); > > if (flags & XFS_QMOPT_DQALLOC) { > + ASSERT(!(flags & XFS_QMOPT_QUOTIP_LOCKED)); Perhaps we should just have an explicit check for both flags above and return with -EINVAL if necessary? > error = xfs_trans_alloc(mp, &M_RES(mp)->tr_qm_dqalloc, > XFS_QM_DQALLOC_SPACE_RES(mp), 0, 0, &tp); > if (error) > @@ -634,11 +638,12 @@ static int > xfs_dq_get_next_id( > struct xfs_mount *mp, > uint type, > - xfs_dqid_t *id) > + xfs_dqid_t *id, > + uint flags) > { > struct xfs_inode *quotip = xfs_quota_inode(mp, type); > xfs_dqid_t next_id = *id + 1; /* simple advance */ > - uint lock_flags; > + uint lock_flags = 0; > struct xfs_bmbt_irec got; > struct xfs_iext_cursor cur; > xfs_fsblock_t start; > @@ -657,7 +662,8 @@ xfs_dq_get_next_id( > /* Nope, next_id is now past the current chunk, so find the next one */ > start = (xfs_fsblock_t)next_id / mp->m_quotainfo->qi_dqperchunk; > > - lock_flags = xfs_ilock_data_map_shared(quotip); > + if (!(flags & XFS_QMOPT_QUOTIP_LOCKED)) > + lock_flags = xfs_ilock_data_map_shared(quotip); > if (!(quotip->i_df.if_flags & XFS_IFEXTENTS)) { > error = xfs_iread_extents(NULL, quotip, XFS_DATA_FORK); > if (error) > @@ -673,7 +679,8 @@ xfs_dq_get_next_id( > error = -ENOENT; > } > > - xfs_iunlock(quotip, lock_flags); > + if (lock_flags) > + xfs_iunlock(quotip, lock_flags); > > return error; > } > @@ -733,7 +740,8 @@ xfs_qm_dqget( Earlier code in this function drops/reacquires the ip ILOCK with a note in the comment around lock ordering with the quota inode. Assuming an inode is passed, is that lock cycle safe if the caller also has the quotip held locked? Brian > if (XFS_IS_DQUOT_UNINITIALIZED(dqp)) { > xfs_dqunlock(dqp); > mutex_unlock(&qi->qi_tree_lock); > - error = xfs_dq_get_next_id(mp, type, &id); > + error = xfs_dq_get_next_id(mp, type, &id, > + flags); > if (error) > return error; > goto restart; > @@ -768,7 +776,7 @@ xfs_qm_dqget( > > /* If we are asked to find next active id, keep looking */ > if (error == -ENOENT && (flags & XFS_QMOPT_DQNEXT)) { > - error = xfs_dq_get_next_id(mp, type, &id); > + error = xfs_dq_get_next_id(mp, type, &id, flags); > if (!error) > goto restart; > } > @@ -827,7 +835,7 @@ xfs_qm_dqget( > if (flags & XFS_QMOPT_DQNEXT) { > if (XFS_IS_DQUOT_UNINITIALIZED(dqp)) { > xfs_qm_dqput(dqp); > - error = xfs_dq_get_next_id(mp, type, &id); > + error = xfs_dq_get_next_id(mp, type, &id, flags); > if (error) > return error; > goto restart; > > -- > To unsubscribe from this list: send the line "unsubscribe linux-xfs" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-xfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Wed, Apr 18, 2018 at 11:33:17AM -0400, Brian Foster wrote: > On Tue, Apr 17, 2018 at 07:39:39PM -0700, Darrick J. Wong wrote: > > From: Darrick J. Wong <darrick.wong@oracle.com> > > > > Create a new QMOPT flag to signal that we've already locked the quota > > inode. This will be used by the quota scrub code refactoring to avoid > > dropping the quota ip lock during scrub. The flag is incompatible with > > the DQALLOC flag because dquot allocation creates a transaction, and we > > shouldn't be doing that with the ILOCK held. > > > > Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> > > --- > > fs/xfs/libxfs/xfs_quota_defs.h | 2 ++ > > fs/xfs/xfs_dquot.c | 32 ++++++++++++++++++++------------ > > 2 files changed, 22 insertions(+), 12 deletions(-) > > > > > > diff --git a/fs/xfs/libxfs/xfs_quota_defs.h b/fs/xfs/libxfs/xfs_quota_defs.h > > index bb1b13a..cfc9938 100644 > > --- a/fs/xfs/libxfs/xfs_quota_defs.h > > +++ b/fs/xfs/libxfs/xfs_quota_defs.h > > @@ -107,6 +107,8 @@ typedef uint16_t xfs_qwarncnt_t; > > * to a single function. None of these XFS_QMOPT_* flags are meant to have > > * persistent values (ie. their values can and will change between versions) > > */ > > +/* Quota ip already locked. Cannot be used with DQALLOC. */ > > +#define XFS_QMOPT_QUOTIP_LOCKED 0x0000001 > > #define XFS_QMOPT_DQALLOC 0x0000002 /* alloc dquot ondisk if needed */ > > #define XFS_QMOPT_UQUOTA 0x0000004 /* user dquot requested */ > > #define XFS_QMOPT_PQUOTA 0x0000008 /* project dquot requested */ > > diff --git a/fs/xfs/xfs_dquot.c b/fs/xfs/xfs_dquot.c > > index a7daef9..ed2e37c 100644 > > --- a/fs/xfs/xfs_dquot.c > > +++ b/fs/xfs/xfs_dquot.c > > @@ -417,18 +417,20 @@ xfs_qm_dqtobp( > > struct xfs_mount *mp = dqp->q_mount; > > xfs_dqid_t id = be32_to_cpu(dqp->q_core.d_id); > > struct xfs_trans *tp = (tpp ? *tpp : NULL); > > - uint lock_mode; > > + uint lock_mode = 0; > > > > quotip = xfs_quota_inode(dqp->q_mount, dqp->dq_flags); > > dqp->q_fileoffset = (xfs_fileoff_t)id / mp->m_quotainfo->qi_dqperchunk; > > > > - lock_mode = xfs_ilock_data_map_shared(quotip); > > + if (!(flags & XFS_QMOPT_QUOTIP_LOCKED)) > > + lock_mode = xfs_ilock_data_map_shared(quotip); > > if (!xfs_this_quota_on(dqp->q_mount, dqp->dq_flags)) { > > /* > > * Return if this type of quotas is turned off while we > > * didn't have the quota inode lock. > > */ > > - xfs_iunlock(quotip, lock_mode); > > + if (lock_mode) > > + xfs_iunlock(quotip, lock_mode); > > return -ESRCH; > > } > > > > @@ -438,7 +440,8 @@ xfs_qm_dqtobp( > > error = xfs_bmapi_read(quotip, dqp->q_fileoffset, > > XFS_DQUOT_CLUSTER_SIZE_FSB, &map, &nmaps, 0); > > > > - xfs_iunlock(quotip, lock_mode); > > + if (lock_mode) > > + xfs_iunlock(quotip, lock_mode); > > if (error) > > return error; > > > > @@ -458,7 +461,7 @@ xfs_qm_dqtobp( > > */ > > if (!(flags & XFS_QMOPT_DQALLOC)) > > return -ENOENT; > > - > > + ASSERT(!(flags & XFS_QMOPT_QUOTIP_LOCKED)); > > ASSERT(tp); > > error = xfs_qm_dqalloc(tpp, mp, dqp, quotip, > > dqp->q_fileoffset, &bp); > > @@ -553,6 +556,7 @@ xfs_qm_dqread( > > trace_xfs_dqread(dqp); > > > > if (flags & XFS_QMOPT_DQALLOC) { > > + ASSERT(!(flags & XFS_QMOPT_QUOTIP_LOCKED)); > > Perhaps we should just have an explicit check for both flags above and > return with -EINVAL if necessary? Sounds like a good idea. > > error = xfs_trans_alloc(mp, &M_RES(mp)->tr_qm_dqalloc, > > XFS_QM_DQALLOC_SPACE_RES(mp), 0, 0, &tp); > > if (error) > > @@ -634,11 +638,12 @@ static int > > xfs_dq_get_next_id( > > struct xfs_mount *mp, > > uint type, > > - xfs_dqid_t *id) > > + xfs_dqid_t *id, > > + uint flags) > > { > > struct xfs_inode *quotip = xfs_quota_inode(mp, type); > > xfs_dqid_t next_id = *id + 1; /* simple advance */ > > - uint lock_flags; > > + uint lock_flags = 0; > > struct xfs_bmbt_irec got; > > struct xfs_iext_cursor cur; > > xfs_fsblock_t start; > > @@ -657,7 +662,8 @@ xfs_dq_get_next_id( > > /* Nope, next_id is now past the current chunk, so find the next one */ > > start = (xfs_fsblock_t)next_id / mp->m_quotainfo->qi_dqperchunk; > > > > - lock_flags = xfs_ilock_data_map_shared(quotip); > > + if (!(flags & XFS_QMOPT_QUOTIP_LOCKED)) > > + lock_flags = xfs_ilock_data_map_shared(quotip); > > if (!(quotip->i_df.if_flags & XFS_IFEXTENTS)) { > > error = xfs_iread_extents(NULL, quotip, XFS_DATA_FORK); > > if (error) > > @@ -673,7 +679,8 @@ xfs_dq_get_next_id( > > error = -ENOENT; > > } > > > > - xfs_iunlock(quotip, lock_flags); > > + if (lock_flags) > > + xfs_iunlock(quotip, lock_flags); > > > > return error; > > } > > @@ -733,7 +740,8 @@ xfs_qm_dqget( > > Earlier code in this function drops/reacquires the ip ILOCK with a note > in the comment around lock ordering with the quota inode. Assuming an > inode is passed, is that lock cycle safe if the caller also has the > quotip held locked? I'm not sure; for the case that I want to support (iterate dquots without a specific file inode in mind) I don't need (ip != NULL) at all. So my answer is that I don't want to support this scenario at all. :) Ok, so at the top of _dqget, add: if (flags & _QUOTIP_LOCKED) { ASSERT(ip == NULL); ASSERT(!(flags & _DQALLOC)); if (ip || (flags & DQALLOC)) return -EINVAL; } --D > > Brian > > > if (XFS_IS_DQUOT_UNINITIALIZED(dqp)) { > > xfs_dqunlock(dqp); > > mutex_unlock(&qi->qi_tree_lock); > > - error = xfs_dq_get_next_id(mp, type, &id); > > + error = xfs_dq_get_next_id(mp, type, &id, > > + flags); > > if (error) > > return error; > > goto restart; > > @@ -768,7 +776,7 @@ xfs_qm_dqget( > > > > /* If we are asked to find next active id, keep looking */ > > if (error == -ENOENT && (flags & XFS_QMOPT_DQNEXT)) { > > - error = xfs_dq_get_next_id(mp, type, &id); > > + error = xfs_dq_get_next_id(mp, type, &id, flags); > > if (!error) > > goto restart; > > } > > @@ -827,7 +835,7 @@ xfs_qm_dqget( > > if (flags & XFS_QMOPT_DQNEXT) { > > if (XFS_IS_DQUOT_UNINITIALIZED(dqp)) { > > xfs_qm_dqput(dqp); > > - error = xfs_dq_get_next_id(mp, type, &id); > > + error = xfs_dq_get_next_id(mp, type, &id, flags); > > if (error) > > return error; > > goto restart; > > > > -- > > To unsubscribe from this list: send the line "unsubscribe linux-xfs" in > > the body of a message to majordomo@vger.kernel.org > > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- > To unsubscribe from this list: send the line "unsubscribe linux-xfs" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-xfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Wed, Apr 18, 2018 at 09:55:11AM -0700, Darrick J. Wong wrote: > On Wed, Apr 18, 2018 at 11:33:17AM -0400, Brian Foster wrote: > > On Tue, Apr 17, 2018 at 07:39:39PM -0700, Darrick J. Wong wrote: > > > From: Darrick J. Wong <darrick.wong@oracle.com> > > > > > > Create a new QMOPT flag to signal that we've already locked the quota > > > inode. This will be used by the quota scrub code refactoring to avoid > > > dropping the quota ip lock during scrub. The flag is incompatible with > > > the DQALLOC flag because dquot allocation creates a transaction, and we > > > shouldn't be doing that with the ILOCK held. > > > > > > Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> > > > --- > > > fs/xfs/libxfs/xfs_quota_defs.h | 2 ++ > > > fs/xfs/xfs_dquot.c | 32 ++++++++++++++++++++------------ > > > 2 files changed, 22 insertions(+), 12 deletions(-) > > > > > > > > > diff --git a/fs/xfs/libxfs/xfs_quota_defs.h b/fs/xfs/libxfs/xfs_quota_defs.h > > > index bb1b13a..cfc9938 100644 > > > --- a/fs/xfs/libxfs/xfs_quota_defs.h > > > +++ b/fs/xfs/libxfs/xfs_quota_defs.h > > > @@ -107,6 +107,8 @@ typedef uint16_t xfs_qwarncnt_t; > > > * to a single function. None of these XFS_QMOPT_* flags are meant to have > > > * persistent values (ie. their values can and will change between versions) > > > */ > > > +/* Quota ip already locked. Cannot be used with DQALLOC. */ > > > +#define XFS_QMOPT_QUOTIP_LOCKED 0x0000001 > > > #define XFS_QMOPT_DQALLOC 0x0000002 /* alloc dquot ondisk if needed */ > > > #define XFS_QMOPT_UQUOTA 0x0000004 /* user dquot requested */ > > > #define XFS_QMOPT_PQUOTA 0x0000008 /* project dquot requested */ > > > diff --git a/fs/xfs/xfs_dquot.c b/fs/xfs/xfs_dquot.c > > > index a7daef9..ed2e37c 100644 > > > --- a/fs/xfs/xfs_dquot.c > > > +++ b/fs/xfs/xfs_dquot.c > > > @@ -417,18 +417,20 @@ xfs_qm_dqtobp( > > > struct xfs_mount *mp = dqp->q_mount; > > > xfs_dqid_t id = be32_to_cpu(dqp->q_core.d_id); > > > struct xfs_trans *tp = (tpp ? *tpp : NULL); > > > - uint lock_mode; > > > + uint lock_mode = 0; > > > > > > quotip = xfs_quota_inode(dqp->q_mount, dqp->dq_flags); > > > dqp->q_fileoffset = (xfs_fileoff_t)id / mp->m_quotainfo->qi_dqperchunk; > > > > > > - lock_mode = xfs_ilock_data_map_shared(quotip); > > > + if (!(flags & XFS_QMOPT_QUOTIP_LOCKED)) > > > + lock_mode = xfs_ilock_data_map_shared(quotip); > > > if (!xfs_this_quota_on(dqp->q_mount, dqp->dq_flags)) { > > > /* > > > * Return if this type of quotas is turned off while we > > > * didn't have the quota inode lock. > > > */ > > > - xfs_iunlock(quotip, lock_mode); > > > + if (lock_mode) > > > + xfs_iunlock(quotip, lock_mode); > > > return -ESRCH; > > > } > > > > > > @@ -438,7 +440,8 @@ xfs_qm_dqtobp( > > > error = xfs_bmapi_read(quotip, dqp->q_fileoffset, > > > XFS_DQUOT_CLUSTER_SIZE_FSB, &map, &nmaps, 0); > > > > > > - xfs_iunlock(quotip, lock_mode); > > > + if (lock_mode) > > > + xfs_iunlock(quotip, lock_mode); > > > if (error) > > > return error; > > > > > > @@ -458,7 +461,7 @@ xfs_qm_dqtobp( > > > */ > > > if (!(flags & XFS_QMOPT_DQALLOC)) > > > return -ENOENT; > > > - > > > + ASSERT(!(flags & XFS_QMOPT_QUOTIP_LOCKED)); > > > ASSERT(tp); > > > error = xfs_qm_dqalloc(tpp, mp, dqp, quotip, > > > dqp->q_fileoffset, &bp); > > > @@ -553,6 +556,7 @@ xfs_qm_dqread( > > > trace_xfs_dqread(dqp); > > > > > > if (flags & XFS_QMOPT_DQALLOC) { > > > + ASSERT(!(flags & XFS_QMOPT_QUOTIP_LOCKED)); > > > > Perhaps we should just have an explicit check for both flags above and > > return with -EINVAL if necessary? > > Sounds like a good idea. > > > > error = xfs_trans_alloc(mp, &M_RES(mp)->tr_qm_dqalloc, > > > XFS_QM_DQALLOC_SPACE_RES(mp), 0, 0, &tp); > > > if (error) > > > @@ -634,11 +638,12 @@ static int > > > xfs_dq_get_next_id( > > > struct xfs_mount *mp, > > > uint type, > > > - xfs_dqid_t *id) > > > + xfs_dqid_t *id, > > > + uint flags) > > > { > > > struct xfs_inode *quotip = xfs_quota_inode(mp, type); > > > xfs_dqid_t next_id = *id + 1; /* simple advance */ > > > - uint lock_flags; > > > + uint lock_flags = 0; > > > struct xfs_bmbt_irec got; > > > struct xfs_iext_cursor cur; > > > xfs_fsblock_t start; > > > @@ -657,7 +662,8 @@ xfs_dq_get_next_id( > > > /* Nope, next_id is now past the current chunk, so find the next one */ > > > start = (xfs_fsblock_t)next_id / mp->m_quotainfo->qi_dqperchunk; > > > > > > - lock_flags = xfs_ilock_data_map_shared(quotip); > > > + if (!(flags & XFS_QMOPT_QUOTIP_LOCKED)) > > > + lock_flags = xfs_ilock_data_map_shared(quotip); > > > if (!(quotip->i_df.if_flags & XFS_IFEXTENTS)) { > > > error = xfs_iread_extents(NULL, quotip, XFS_DATA_FORK); > > > if (error) > > > @@ -673,7 +679,8 @@ xfs_dq_get_next_id( > > > error = -ENOENT; > > > } > > > > > > - xfs_iunlock(quotip, lock_flags); > > > + if (lock_flags) > > > + xfs_iunlock(quotip, lock_flags); > > > > > > return error; > > > } > > > @@ -733,7 +740,8 @@ xfs_qm_dqget( > > > > Earlier code in this function drops/reacquires the ip ILOCK with a note > > in the comment around lock ordering with the quota inode. Assuming an > > inode is passed, is that lock cycle safe if the caller also has the > > quotip held locked? > > I'm not sure; for the case that I want to support (iterate dquots > without a specific file inode in mind) I don't need (ip != NULL) at all. > So my answer is that I don't want to support this scenario at all. :) > Ok, works for me. > Ok, so at the top of _dqget, add: > > if (flags & _QUOTIP_LOCKED) { > ASSERT(ip == NULL); > ASSERT(!(flags & _DQALLOC)); > if (ip || (flags & DQALLOC)) > return -EINVAL; > } > It might be better to split the DQALLOC part off to xfs_qm_dqread() since it is not static and that's where we act on the dqalloc flag. Brian > --D > > > > > Brian > > > > > if (XFS_IS_DQUOT_UNINITIALIZED(dqp)) { > > > xfs_dqunlock(dqp); > > > mutex_unlock(&qi->qi_tree_lock); > > > - error = xfs_dq_get_next_id(mp, type, &id); > > > + error = xfs_dq_get_next_id(mp, type, &id, > > > + flags); > > > if (error) > > > return error; > > > goto restart; > > > @@ -768,7 +776,7 @@ xfs_qm_dqget( > > > > > > /* If we are asked to find next active id, keep looking */ > > > if (error == -ENOENT && (flags & XFS_QMOPT_DQNEXT)) { > > > - error = xfs_dq_get_next_id(mp, type, &id); > > > + error = xfs_dq_get_next_id(mp, type, &id, flags); > > > if (!error) > > > goto restart; > > > } > > > @@ -827,7 +835,7 @@ xfs_qm_dqget( > > > if (flags & XFS_QMOPT_DQNEXT) { > > > if (XFS_IS_DQUOT_UNINITIALIZED(dqp)) { > > > xfs_qm_dqput(dqp); > > > - error = xfs_dq_get_next_id(mp, type, &id); > > > + error = xfs_dq_get_next_id(mp, type, &id, flags); > > > if (error) > > > return error; > > > goto restart; > > > > > > -- > > > To unsubscribe from this list: send the line "unsubscribe linux-xfs" in > > > the body of a message to majordomo@vger.kernel.org > > > More majordomo info at http://vger.kernel.org/majordomo-info.html > > -- > > To unsubscribe from this list: send the line "unsubscribe linux-xfs" in > > the body of a message to majordomo@vger.kernel.org > > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- > To unsubscribe from this list: send the line "unsubscribe linux-xfs" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-xfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Tue, Apr 17, 2018 at 07:39:39PM -0700, Darrick J. Wong wrote: > From: Darrick J. Wong <darrick.wong@oracle.com> > > Create a new QMOPT flag to signal that we've already locked the quota > inode. This will be used by the quota scrub code refactoring to avoid > dropping the quota ip lock during scrub. The flag is incompatible with > the DQALLOC flag because dquot allocation creates a transaction, and we > shouldn't be doing that with the ILOCK held. Locked flag are always a sign for code smell. And this already is pretty smelly code before that flag is added. I think someone (i.e. either you or me :)) needs to do a major refactoring here first. -- To unsubscribe from this list: send the line "unsubscribe linux-xfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Thu, Apr 19, 2018 at 01:32:24AM -0700, Christoph Hellwig wrote: > On Tue, Apr 17, 2018 at 07:39:39PM -0700, Darrick J. Wong wrote: > > From: Darrick J. Wong <darrick.wong@oracle.com> > > > > Create a new QMOPT flag to signal that we've already locked the quota > > inode. This will be used by the quota scrub code refactoring to avoid > > dropping the quota ip lock during scrub. The flag is incompatible with > > the DQALLOC flag because dquot allocation creates a transaction, and we > > shouldn't be doing that with the ILOCK held. > > Locked flag are always a sign for code smell. And this already is > pretty smelly code before that flag is added. I think someone (i.e. > either you or me :)) needs to do a major refactoring here first. Bleh... ok, I marched through that swamp and refactored all that goopy dqget crud into a ton of smaller helper functions that only do one thing, killed off QMOPT_NEXT, and renamed DQALLOC to make it obvious it's for dqget only. So now we have... xfs_qm_dqget (get dquot based on id/type, can take XFS_DQGET_DQALLOC to allocate if not present) xfs_qm_dqget_inode (get dquot based on inode/type, contains all the locking and looping mess to one function, can take _DQALLOC) xfs_qm_dqget_next (get this or the next higher dquot, no DQALLOC allowed here, contain all the NEXT looping mess to this function) xfs_qm_dqread (read dquot from disk and return incore dquot, do not check in radix tree, no longer takes DQALLOC) xfs_qm_dqiterate (iterate all the dquots for the given quota type) I also cleaned out a bunch of unnecessary parameters and other junk, and refactored mount time quotacheck so that it doesn't need to ILOCK_EXCL every inode in the system. In theory that should be fine because we only needed ILOCK_EXCL to make sure nobody can chown/chproj the inode on us, which shouldn't be happening during mount. As a bonus I realized that scrub and repair don't actually need to maintain the ilock once they're done fixing all of the things that can cause dqget to fail, so the ILOCKED flag goes away entirely. Will have a revised megaseries out on the list ideally some time before LSF starts... though it did add another 12 patches to the review queue. :P --D > -- > To unsubscribe from this list: send the line "unsubscribe linux-xfs" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-xfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/fs/xfs/libxfs/xfs_quota_defs.h b/fs/xfs/libxfs/xfs_quota_defs.h index bb1b13a..cfc9938 100644 --- a/fs/xfs/libxfs/xfs_quota_defs.h +++ b/fs/xfs/libxfs/xfs_quota_defs.h @@ -107,6 +107,8 @@ typedef uint16_t xfs_qwarncnt_t; * to a single function. None of these XFS_QMOPT_* flags are meant to have * persistent values (ie. their values can and will change between versions) */ +/* Quota ip already locked. Cannot be used with DQALLOC. */ +#define XFS_QMOPT_QUOTIP_LOCKED 0x0000001 #define XFS_QMOPT_DQALLOC 0x0000002 /* alloc dquot ondisk if needed */ #define XFS_QMOPT_UQUOTA 0x0000004 /* user dquot requested */ #define XFS_QMOPT_PQUOTA 0x0000008 /* project dquot requested */ diff --git a/fs/xfs/xfs_dquot.c b/fs/xfs/xfs_dquot.c index a7daef9..ed2e37c 100644 --- a/fs/xfs/xfs_dquot.c +++ b/fs/xfs/xfs_dquot.c @@ -417,18 +417,20 @@ xfs_qm_dqtobp( struct xfs_mount *mp = dqp->q_mount; xfs_dqid_t id = be32_to_cpu(dqp->q_core.d_id); struct xfs_trans *tp = (tpp ? *tpp : NULL); - uint lock_mode; + uint lock_mode = 0; quotip = xfs_quota_inode(dqp->q_mount, dqp->dq_flags); dqp->q_fileoffset = (xfs_fileoff_t)id / mp->m_quotainfo->qi_dqperchunk; - lock_mode = xfs_ilock_data_map_shared(quotip); + if (!(flags & XFS_QMOPT_QUOTIP_LOCKED)) + lock_mode = xfs_ilock_data_map_shared(quotip); if (!xfs_this_quota_on(dqp->q_mount, dqp->dq_flags)) { /* * Return if this type of quotas is turned off while we * didn't have the quota inode lock. */ - xfs_iunlock(quotip, lock_mode); + if (lock_mode) + xfs_iunlock(quotip, lock_mode); return -ESRCH; } @@ -438,7 +440,8 @@ xfs_qm_dqtobp( error = xfs_bmapi_read(quotip, dqp->q_fileoffset, XFS_DQUOT_CLUSTER_SIZE_FSB, &map, &nmaps, 0); - xfs_iunlock(quotip, lock_mode); + if (lock_mode) + xfs_iunlock(quotip, lock_mode); if (error) return error; @@ -458,7 +461,7 @@ xfs_qm_dqtobp( */ if (!(flags & XFS_QMOPT_DQALLOC)) return -ENOENT; - + ASSERT(!(flags & XFS_QMOPT_QUOTIP_LOCKED)); ASSERT(tp); error = xfs_qm_dqalloc(tpp, mp, dqp, quotip, dqp->q_fileoffset, &bp); @@ -553,6 +556,7 @@ xfs_qm_dqread( trace_xfs_dqread(dqp); if (flags & XFS_QMOPT_DQALLOC) { + ASSERT(!(flags & XFS_QMOPT_QUOTIP_LOCKED)); error = xfs_trans_alloc(mp, &M_RES(mp)->tr_qm_dqalloc, XFS_QM_DQALLOC_SPACE_RES(mp), 0, 0, &tp); if (error) @@ -634,11 +638,12 @@ static int xfs_dq_get_next_id( struct xfs_mount *mp, uint type, - xfs_dqid_t *id) + xfs_dqid_t *id, + uint flags) { struct xfs_inode *quotip = xfs_quota_inode(mp, type); xfs_dqid_t next_id = *id + 1; /* simple advance */ - uint lock_flags; + uint lock_flags = 0; struct xfs_bmbt_irec got; struct xfs_iext_cursor cur; xfs_fsblock_t start; @@ -657,7 +662,8 @@ xfs_dq_get_next_id( /* Nope, next_id is now past the current chunk, so find the next one */ start = (xfs_fsblock_t)next_id / mp->m_quotainfo->qi_dqperchunk; - lock_flags = xfs_ilock_data_map_shared(quotip); + if (!(flags & XFS_QMOPT_QUOTIP_LOCKED)) + lock_flags = xfs_ilock_data_map_shared(quotip); if (!(quotip->i_df.if_flags & XFS_IFEXTENTS)) { error = xfs_iread_extents(NULL, quotip, XFS_DATA_FORK); if (error) @@ -673,7 +679,8 @@ xfs_dq_get_next_id( error = -ENOENT; } - xfs_iunlock(quotip, lock_flags); + if (lock_flags) + xfs_iunlock(quotip, lock_flags); return error; } @@ -733,7 +740,8 @@ xfs_qm_dqget( if (XFS_IS_DQUOT_UNINITIALIZED(dqp)) { xfs_dqunlock(dqp); mutex_unlock(&qi->qi_tree_lock); - error = xfs_dq_get_next_id(mp, type, &id); + error = xfs_dq_get_next_id(mp, type, &id, + flags); if (error) return error; goto restart; @@ -768,7 +776,7 @@ xfs_qm_dqget( /* If we are asked to find next active id, keep looking */ if (error == -ENOENT && (flags & XFS_QMOPT_DQNEXT)) { - error = xfs_dq_get_next_id(mp, type, &id); + error = xfs_dq_get_next_id(mp, type, &id, flags); if (!error) goto restart; } @@ -827,7 +835,7 @@ xfs_qm_dqget( if (flags & XFS_QMOPT_DQNEXT) { if (XFS_IS_DQUOT_UNINITIALIZED(dqp)) { xfs_qm_dqput(dqp); - error = xfs_dq_get_next_id(mp, type, &id); + error = xfs_dq_get_next_id(mp, type, &id, flags); if (error) return error; goto restart;