Messages in this thread | | | From | Changwei Ge <> | Subject | Re: [Ocfs2-devel] [PATCH 1/3] ocfs2: add ocfs2_try_rw_lock and ocfs2_try_inode_lock | Date | Tue, 28 Nov 2017 01:52:13 +0000 |
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Hi Gang,
On 2017/11/27 17:48, Gang He wrote: > Add ocfs2_try_rw_lock and ocfs2_try_inode_lock functions, which > will be used in non-block IO scenarios. > > Signed-off-by: Gang He <ghe@suse.com> > --- > fs/ocfs2/dlmglue.c | 22 ++++++++++++++++++++++ > fs/ocfs2/dlmglue.h | 4 ++++ > 2 files changed, 26 insertions(+) > > diff --git a/fs/ocfs2/dlmglue.c b/fs/ocfs2/dlmglue.c > index 4689940..5cfbd04 100644 > --- a/fs/ocfs2/dlmglue.c > +++ b/fs/ocfs2/dlmglue.c > @@ -1742,6 +1742,28 @@ int ocfs2_rw_lock(struct inode *inode, int write) > return status; > } > > +int ocfs2_try_rw_lock(struct inode *inode, int write) > +{ > + int status, level; > + struct ocfs2_lock_res *lockres; > + struct ocfs2_super *osb = OCFS2_SB(inode->i_sb); > + > + mlog(0, "inode %llu try to take %s RW lock\n", > + (unsigned long long)OCFS2_I(inode)->ip_blkno, > + write ? "EXMODE" : "PRMODE"); > + > + if (ocfs2_mount_local(osb)) > + return 0; > + > + lockres = &OCFS2_I(inode)->ip_rw_lockres; > + > + level = write ? DLM_LOCK_EX : DLM_LOCK_PR; > + > + status = ocfs2_cluster_lock(OCFS2_SB(inode->i_sb), lockres, level, > + DLM_LKF_NOQUEUE, 0); > + return status; > +}
The newly added function ocfs2_try_rw_lock almost has the same logic with ocfs2_rw_lock.Is it possible to combine them into an unique one? That will be more elegant.
Moreover, can you elaborate further why we need a *NOQUEUE* lock for supporting non-block aio?
Why can't we wait for a while to grant a lock request? Is this necessary?
Thanks, Changwei
> + > void ocfs2_rw_unlock(struct inode *inode, int write) > { > int level = write ? DLM_LOCK_EX : DLM_LOCK_PR; > diff --git a/fs/ocfs2/dlmglue.h b/fs/ocfs2/dlmglue.h > index a7fc18b..05910fc 100644 > --- a/fs/ocfs2/dlmglue.h > +++ b/fs/ocfs2/dlmglue.h > @@ -116,6 +116,7 @@ void ocfs2_refcount_lock_res_init(struct ocfs2_lock_res *lockres, > int ocfs2_create_new_inode_locks(struct inode *inode); > int ocfs2_drop_inode_locks(struct inode *inode); > int ocfs2_rw_lock(struct inode *inode, int write); > +int ocfs2_try_rw_lock(struct inode *inode, int write); > void ocfs2_rw_unlock(struct inode *inode, int write); > int ocfs2_open_lock(struct inode *inode); > int ocfs2_try_open_lock(struct inode *inode, int write); > @@ -140,6 +141,9 @@ int ocfs2_inode_lock_with_page(struct inode *inode, > /* 99% of the time we don't want to supply any additional flags -- > * those are for very specific cases only. */ > #define ocfs2_inode_lock(i, b, e) ocfs2_inode_lock_full_nested(i, b, e, 0, OI_LS_NORMAL) > +#define ocfs2_try_inode_lock(i, b, e)\ > + ocfs2_inode_lock_full_nested(i, b, e, OCFS2_META_LOCK_NOQUEUE,\ > + OI_LS_NORMAL) > void ocfs2_inode_unlock(struct inode *inode, > int ex); > int ocfs2_super_lock(struct ocfs2_super *osb, >
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