Eric Ren
2017-Jan-06 11:56 UTC
[Ocfs2-devel] [PATCH 2/2] ocfs2: fix deadlocks when taking inode lock at vfs entry points
Hi! On 01/06/2017 05:55 PM, Joseph Qi wrote:> On 17/1/6 17:13, Eric Ren wrote: >> Hi, >> >>>>>>>> >>>>>>>> Fixes them by adding the tracking logic (in the previous patch) for >>>>>>>> these funcs above, ocfs2_permission(), ocfs2_iop_[set|get]_acl(), >>>>>>>> ocfs2_setattr(). >>>>>>> As described cases above, shall we just add the tracking logic only for set/get_acl()? >>>>>> >>>>>> The idea is to detect recursive locking on the running task stack. Take case 1) for >>>>>> example if ocfs2_permisssion() >>>>>> is not changed: >>>>>> >>>>>> ocfs2_permission() <=== take PR, ocfs2_holder is not added >>>>>> ocfs2_iop_get_acl <=== still take PR, because there is no lock holder on the >>>>>> tracking list >>>>> I mean we have no need to check if locked by me, just do inode lock and add holder. >>>>> This will make code more clean, IMO. >>>> Oh, sorry, I get your point this time. I think we need to check it if there are more >>>> than one processes that hold >>>> PR lock on the same resource. If I don't understand you correctly, please tell me why >>>> you think it's not neccessary >>>> to check before getting lock? >>> The code logic can only check if it is locked by myself. In the case >> Why only...? >>> described above, ocfs2_permission is the first entry to take inode lock. >>> And even if check succeeds, it is a bug without unlock, but not the case >>> of recursive lock. >> >> By checking succeeds, you mean it's locked by me, right? If so, this flag >> "arg_flags = OCFS2_META_LOCK_GETBH" >> will be passed down to ocfs2_inode_lock_full(), which gets back buffer head of >> the disk inode for us if necessary, but doesn't take cluster locking again. So, there is >> no need to unlock in such case. > I am trying to state my point more clearly...Thanks a lot!> The issue case you are trying to fix is: > Process A > take inode lock (phase1) > ... > <<< race window (phase2, Process B)The deadlock only happens if process B is on a remote node and request EX lock. Quote the patch[1/2]'s commit message: A deadlock will occur if a remote EX request comes in between two of ocfs2_inode_lock(). Briefly describe how the deadlock is formed: On one hand, OCFS2_LOCK_BLOCKED flag of this lockres is set in BAST(ocfs2_generic_handle_bast) when downconvert is started on behalf of the remote EX lock request. Another hand, the recursive cluster lock (the second one) will be blocked in in __ocfs2_cluster_lock() because of OCFS2_LOCK_BLOCKED. But, the downconvert never complete, why? because there is no chance for the first cluster lock on this node to be unlocked - we block ourselves in the code path. ---> ... > take inode lock again (phase3) > > Deadlock happens because Process B in phase2 and Process A in phase3 > are waiting for each other.It's local lock's (like i_mutex) responsibility to protect critical section from racing among processes on the same node.> So you are trying to fix it by making phase3 finish without really doingPhase3 can go ahead because this node is already under protection of cluster lock.> __ocfs2_cluster_lock, then Process B can continue either. > Let us bear in mind that phase1 and phase3 are in the same context and > executed in order. That's why I think there is no need to check if locked > by myself in phase1. > If phase1 finds it is already locked by myself, that means the holder > is left by last operation without dec holder. That's why I think it is a bug > instead of a recursive lock case.Did I answer your question? Thanks! Eric> > Thanks, > Joseph >> >> Thanks, >> Eric >> >>> >>> Thanks, >>> Joseph >>>> >>>> Thanks, >>>> Eric >>>>> >>>>> Thanks, >>>>> Joseph >>>>>> >>>>>> Thanks for your review;-) >>>>>> Eric >>>>>> >>>>>>> >>>>>>> Thanks, >>>>>>> Joseph >>>>>>>> >>>>>>>> Signed-off-by: Eric Ren <zren at suse.com> >>>>>>>> --- >>>>>>>> fs/ocfs2/acl.c | 39 ++++++++++++++++++++++++++++++++++----- >>>>>>>> fs/ocfs2/file.c | 44 ++++++++++++++++++++++++++++++++++---------- >>>>>>>> 2 files changed, 68 insertions(+), 15 deletions(-) >>>>>>>> >>>>>>>> diff --git a/fs/ocfs2/acl.c b/fs/ocfs2/acl.c >>>>>>>> index bed1fcb..c539890 100644 >>>>>>>> --- a/fs/ocfs2/acl.c >>>>>>>> +++ b/fs/ocfs2/acl.c >>>>>>>> @@ -284,16 +284,31 @@ int ocfs2_iop_set_acl(struct inode *inode, struct posix_acl >>>>>>>> *acl, int type) >>>>>>>> { >>>>>>>> struct buffer_head *bh = NULL; >>>>>>>> int status = 0; >>>>>>>> - >>>>>>>> - status = ocfs2_inode_lock(inode, &bh, 1); >>>>>>>> + int arg_flags = 0, has_locked; >>>>>>>> + struct ocfs2_holder oh; >>>>>>>> + struct ocfs2_lock_res *lockres; >>>>>>>> + >>>>>>>> + lockres = &OCFS2_I(inode)->ip_inode_lockres; >>>>>>>> + has_locked = (ocfs2_is_locked_by_me(lockres) != NULL); >>>>>>>> + if (has_locked) >>>>>>>> + arg_flags = OCFS2_META_LOCK_GETBH; >>>>>>>> + status = ocfs2_inode_lock_full(inode, &bh, 1, arg_flags); >>>>>>>> if (status < 0) { >>>>>>>> if (status != -ENOENT) >>>>>>>> mlog_errno(status); >>>>>>>> return status; >>>>>>>> } >>>>>>>> + if (!has_locked) >>>>>>>> + ocfs2_add_holder(lockres, &oh); >>>>>>>> + >>>>>>>> status = ocfs2_set_acl(NULL, inode, bh, type, acl, NULL, NULL); >>>>>>>> - ocfs2_inode_unlock(inode, 1); >>>>>>>> + >>>>>>>> + if (!has_locked) { >>>>>>>> + ocfs2_remove_holder(lockres, &oh); >>>>>>>> + ocfs2_inode_unlock(inode, 1); >>>>>>>> + } >>>>>>>> brelse(bh); >>>>>>>> + >>>>>>>> return status; >>>>>>>> } >>>>>>>> @@ -303,21 +318,35 @@ struct posix_acl *ocfs2_iop_get_acl(struct inode *inode, >>>>>>>> int type) >>>>>>>> struct buffer_head *di_bh = NULL; >>>>>>>> struct posix_acl *acl; >>>>>>>> int ret; >>>>>>>> + int arg_flags = 0, has_locked; >>>>>>>> + struct ocfs2_holder oh; >>>>>>>> + struct ocfs2_lock_res *lockres; >>>>>>>> osb = OCFS2_SB(inode->i_sb); >>>>>>>> if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL)) >>>>>>>> return NULL; >>>>>>>> - ret = ocfs2_inode_lock(inode, &di_bh, 0); >>>>>>>> + >>>>>>>> + lockres = &OCFS2_I(inode)->ip_inode_lockres; >>>>>>>> + has_locked = (ocfs2_is_locked_by_me(lockres) != NULL); >>>>>>>> + if (has_locked) >>>>>>>> + arg_flags = OCFS2_META_LOCK_GETBH; >>>>>>>> + ret = ocfs2_inode_lock_full(inode, &di_bh, 0, arg_flags); >>>>>>>> if (ret < 0) { >>>>>>>> if (ret != -ENOENT) >>>>>>>> mlog_errno(ret); >>>>>>>> return ERR_PTR(ret); >>>>>>>> } >>>>>>>> + if (!has_locked) >>>>>>>> + ocfs2_add_holder(lockres, &oh); >>>>>>>> acl = ocfs2_get_acl_nolock(inode, type, di_bh); >>>>>>>> - ocfs2_inode_unlock(inode, 0); >>>>>>>> + if (!has_locked) { >>>>>>>> + ocfs2_remove_holder(lockres, &oh); >>>>>>>> + ocfs2_inode_unlock(inode, 0); >>>>>>>> + } >>>>>>>> brelse(di_bh); >>>>>>>> + >>>>>>>> return acl; >>>>>>>> } >>>>>>>> diff --git a/fs/ocfs2/file.c b/fs/ocfs2/file.c >>>>>>>> index c488965..62be75d 100644 >>>>>>>> --- a/fs/ocfs2/file.c >>>>>>>> +++ b/fs/ocfs2/file.c >>>>>>>> @@ -1138,6 +1138,9 @@ int ocfs2_setattr(struct dentry *dentry, struct iattr *attr) >>>>>>>> handle_t *handle = NULL; >>>>>>>> struct dquot *transfer_to[MAXQUOTAS] = { }; >>>>>>>> int qtype; >>>>>>>> + int arg_flags = 0, had_lock; >>>>>>>> + struct ocfs2_holder oh; >>>>>>>> + struct ocfs2_lock_res *lockres; >>>>>>>> trace_ocfs2_setattr(inode, dentry, >>>>>>>> (unsigned long long)OCFS2_I(inode)->ip_blkno, >>>>>>>> @@ -1173,13 +1176,20 @@ int ocfs2_setattr(struct dentry *dentry, struct iattr *attr) >>>>>>>> } >>>>>>>> } >>>>>>>> - status = ocfs2_inode_lock(inode, &bh, 1); >>>>>>>> + lockres = &OCFS2_I(inode)->ip_inode_lockres; >>>>>>>> + had_lock = (ocfs2_is_locked_by_me(lockres) != NULL); >>>>>>>> + if (had_lock) >>>>>>>> + arg_flags = OCFS2_META_LOCK_GETBH; >>>>>>>> + status = ocfs2_inode_lock_full(inode, &bh, 1, arg_flags); >>>>>>>> if (status < 0) { >>>>>>>> if (status != -ENOENT) >>>>>>>> mlog_errno(status); >>>>>>>> goto bail_unlock_rw; >>>>>>>> } >>>>>>>> - inode_locked = 1; >>>>>>>> + if (!had_lock) { >>>>>>>> + ocfs2_add_holder(lockres, &oh); >>>>>>>> + inode_locked = 1; >>>>>>>> + } >>>>>>>> if (size_change) { >>>>>>>> status = inode_newsize_ok(inode, attr->ia_size); >>>>>>>> @@ -1260,7 +1270,8 @@ int ocfs2_setattr(struct dentry *dentry, struct iattr *attr) >>>>>>>> bail_commit: >>>>>>>> ocfs2_commit_trans(osb, handle); >>>>>>>> bail_unlock: >>>>>>>> - if (status) { >>>>>>>> + if (status && inode_locked) { >>>>>>>> + ocfs2_remove_holder(lockres, &oh); >>>>>>>> ocfs2_inode_unlock(inode, 1); >>>>>>>> inode_locked = 0; >>>>>>>> } >>>>>>>> @@ -1278,8 +1289,10 @@ int ocfs2_setattr(struct dentry *dentry, struct iattr *attr) >>>>>>>> if (status < 0) >>>>>>>> mlog_errno(status); >>>>>>>> } >>>>>>>> - if (inode_locked) >>>>>>>> + if (inode_locked) { >>>>>>>> + ocfs2_remove_holder(lockres, &oh); >>>>>>>> ocfs2_inode_unlock(inode, 1); >>>>>>>> + } >>>>>>>> brelse(bh); >>>>>>>> return status; >>>>>>>> @@ -1321,20 +1334,31 @@ int ocfs2_getattr(struct vfsmount *mnt, >>>>>>>> int ocfs2_permission(struct inode *inode, int mask) >>>>>>>> { >>>>>>>> int ret; >>>>>>>> + int has_locked; >>>>>>>> + struct ocfs2_holder oh; >>>>>>>> + struct ocfs2_lock_res *lockres; >>>>>>>> if (mask & MAY_NOT_BLOCK) >>>>>>>> return -ECHILD; >>>>>>>> - ret = ocfs2_inode_lock(inode, NULL, 0); >>>>>>>> - if (ret) { >>>>>>>> - if (ret != -ENOENT) >>>>>>>> - mlog_errno(ret); >>>>>>>> - goto out; >>>>>>>> + lockres = &OCFS2_I(inode)->ip_inode_lockres; >>>>>>>> + has_locked = (ocfs2_is_locked_by_me(lockres) != NULL); >>>>>>>> + if (!has_locked) { >>>>>>>> + ret = ocfs2_inode_lock(inode, NULL, 0); >>>>>>>> + if (ret) { >>>>>>>> + if (ret != -ENOENT) >>>>>>>> + mlog_errno(ret); >>>>>>>> + goto out; >>>>>>>> + } >>>>>>>> + ocfs2_add_holder(lockres, &oh); >>>>>>>> } >>>>>>>> ret = generic_permission(inode, mask); >>>>>>>> - ocfs2_inode_unlock(inode, 0); >>>>>>>> + if (!has_locked) { >>>>>>>> + ocfs2_remove_holder(lockres, &oh); >>>>>>>> + ocfs2_inode_unlock(inode, 0); >>>>>>>> + } >>>>>>>> out: >>>>>>>> return ret; >>>>>>>> } >>>>>>> >>>>>>> >>>>>> >>>>> >>>>> >>>> >>> >>> >> > >
Joseph Qi
2017-Jan-09 01:13 UTC
[Ocfs2-devel] [PATCH 2/2] ocfs2: fix deadlocks when taking inode lock at vfs entry points
On 17/1/6 19:56, Eric Ren wrote:> Hi! > > On 01/06/2017 05:55 PM, Joseph Qi wrote: >> On 17/1/6 17:13, Eric Ren wrote: >>> Hi, >>> >>>>>>>>> >>>>>>>>> Fixes them by adding the tracking logic (in the previous >>>>>>>>> patch) for >>>>>>>>> these funcs above, ocfs2_permission(), ocfs2_iop_[set|get]_acl(), >>>>>>>>> ocfs2_setattr(). >>>>>>>> As described cases above, shall we just add the tracking logic >>>>>>>> only for set/get_acl()? >>>>>>> >>>>>>> The idea is to detect recursive locking on the running task >>>>>>> stack. Take case 1) for example if ocfs2_permisssion() >>>>>>> is not changed: >>>>>>> >>>>>>> ocfs2_permission() <=== take PR, ocfs2_holder is not added >>>>>>> ocfs2_iop_get_acl <=== still take PR, because there is no >>>>>>> lock holder on the tracking list >>>>>> I mean we have no need to check if locked by me, just do inode >>>>>> lock and add holder. >>>>>> This will make code more clean, IMO. >>>>> Oh, sorry, I get your point this time. I think we need to check it >>>>> if there are more than one processes that hold >>>>> PR lock on the same resource. If I don't understand you >>>>> correctly, please tell me why you think it's not neccessary >>>>> to check before getting lock? >>>> The code logic can only check if it is locked by myself. In the case >>> Why only...? >>>> described above, ocfs2_permission is the first entry to take inode >>>> lock. >>>> And even if check succeeds, it is a bug without unlock, but not the >>>> case >>>> of recursive lock. >>> >>> By checking succeeds, you mean it's locked by me, right? If so, this >>> flag >>> "arg_flags = OCFS2_META_LOCK_GETBH" >>> will be passed down to ocfs2_inode_lock_full(), which gets back >>> buffer head of >>> the disk inode for us if necessary, but doesn't take cluster locking >>> again. So, there is >>> no need to unlock in such case. >> I am trying to state my point more clearly... > > Thanks a lot! > >> The issue case you are trying to fix is: >> Process A >> take inode lock (phase1) >> ... >> <<< race window (phase2, Process B) > > The deadlock only happens if process B is on a remote node and request > EX lock. > > Quote the patch[1/2]'s commit message: > > A deadlock will occur if a remote EX request comes in between two of > ocfs2_inode_lock(). Briefly describe how the deadlock is formed: > > On one hand, OCFS2_LOCK_BLOCKED flag of this lockres is set in > BAST(ocfs2_generic_handle_bast) when downconvert is started on behalf of > the remote EX lock request. Another hand, the recursive cluster lock > (the > second one) will be blocked in in __ocfs2_cluster_lock() because of > OCFS2_LOCK_BLOCKED. But, the downconvert never complete, why? because > there is no chance for the first cluster lock on this node to be unlocked > - we block ourselves in the code path. > --- > >> ... >> take inode lock again (phase3) >> >> Deadlock happens because Process B in phase2 and Process A in phase3 >> are waiting for each other. > It's local lock's (like i_mutex) responsibility to protect critical > section from racing > among processes on the same node.I know we are talking a cluster lock issue. And the Process B I described is downconvert thread.> >> So you are trying to fix it by making phase3 finish without really doing > > Phase3 can go ahead because this node is already under protection of > cluster lock.You said it was blocked... "Another hand, the recursive cluster lock (the second one) will be blocked in __ocfs2_cluster_lock() because of OCFS2_LOCK_BLOCKED."> >> __ocfs2_cluster_lock, then Process B can continue either. >> Let us bear in mind that phase1 and phase3 are in the same context and >> executed in order. That's why I think there is no need to check if >> locked >> by myself in phase1. >> If phase1 finds it is already locked by myself, that means the holder >> is left by last operation without dec holder. That's why I think it >> is a bug >> instead of a recursive lock case. > > Did I answer your question? > > Thanks! > Eric > >> >> Thanks, >> Joseph >>> >>> Thanks, >>> Eric >>> >>>> >>>> Thanks, >>>> Joseph >>>>> >>>>> Thanks, >>>>> Eric >>>>>> >>>>>> Thanks, >>>>>> Joseph >>>>>>> >>>>>>> Thanks for your review;-) >>>>>>> Eric >>>>>>> >>>>>>>> >>>>>>>> Thanks, >>>>>>>> Joseph >>>>>>>>> >>>>>>>>> Signed-off-by: Eric Ren <zren at suse.com> >>>>>>>>> --- >>>>>>>>> fs/ocfs2/acl.c | 39 ++++++++++++++++++++++++++++++++++----- >>>>>>>>> fs/ocfs2/file.c | 44 >>>>>>>>> ++++++++++++++++++++++++++++++++++---------- >>>>>>>>> 2 files changed, 68 insertions(+), 15 deletions(-) >>>>>>>>> >>>>>>>>> diff --git a/fs/ocfs2/acl.c b/fs/ocfs2/acl.c >>>>>>>>> index bed1fcb..c539890 100644 >>>>>>>>> --- a/fs/ocfs2/acl.c >>>>>>>>> +++ b/fs/ocfs2/acl.c >>>>>>>>> @@ -284,16 +284,31 @@ int ocfs2_iop_set_acl(struct inode >>>>>>>>> *inode, struct posix_acl *acl, int type) >>>>>>>>> { >>>>>>>>> struct buffer_head *bh = NULL; >>>>>>>>> int status = 0; >>>>>>>>> - >>>>>>>>> - status = ocfs2_inode_lock(inode, &bh, 1); >>>>>>>>> + int arg_flags = 0, has_locked; >>>>>>>>> + struct ocfs2_holder oh; >>>>>>>>> + struct ocfs2_lock_res *lockres; >>>>>>>>> + >>>>>>>>> + lockres = &OCFS2_I(inode)->ip_inode_lockres; >>>>>>>>> + has_locked = (ocfs2_is_locked_by_me(lockres) != NULL); >>>>>>>>> + if (has_locked) >>>>>>>>> + arg_flags = OCFS2_META_LOCK_GETBH; >>>>>>>>> + status = ocfs2_inode_lock_full(inode, &bh, 1, arg_flags); >>>>>>>>> if (status < 0) { >>>>>>>>> if (status != -ENOENT) >>>>>>>>> mlog_errno(status); >>>>>>>>> return status; >>>>>>>>> } >>>>>>>>> + if (!has_locked) >>>>>>>>> + ocfs2_add_holder(lockres, &oh); >>>>>>>>> + >>>>>>>>> status = ocfs2_set_acl(NULL, inode, bh, type, acl, NULL, >>>>>>>>> NULL); >>>>>>>>> - ocfs2_inode_unlock(inode, 1); >>>>>>>>> + >>>>>>>>> + if (!has_locked) { >>>>>>>>> + ocfs2_remove_holder(lockres, &oh); >>>>>>>>> + ocfs2_inode_unlock(inode, 1); >>>>>>>>> + } >>>>>>>>> brelse(bh); >>>>>>>>> + >>>>>>>>> return status; >>>>>>>>> } >>>>>>>>> @@ -303,21 +318,35 @@ struct posix_acl >>>>>>>>> *ocfs2_iop_get_acl(struct inode *inode, int type) >>>>>>>>> struct buffer_head *di_bh = NULL; >>>>>>>>> struct posix_acl *acl; >>>>>>>>> int ret; >>>>>>>>> + int arg_flags = 0, has_locked; >>>>>>>>> + struct ocfs2_holder oh; >>>>>>>>> + struct ocfs2_lock_res *lockres; >>>>>>>>> osb = OCFS2_SB(inode->i_sb); >>>>>>>>> if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL)) >>>>>>>>> return NULL; >>>>>>>>> - ret = ocfs2_inode_lock(inode, &di_bh, 0); >>>>>>>>> + >>>>>>>>> + lockres = &OCFS2_I(inode)->ip_inode_lockres; >>>>>>>>> + has_locked = (ocfs2_is_locked_by_me(lockres) != NULL); >>>>>>>>> + if (has_locked) >>>>>>>>> + arg_flags = OCFS2_META_LOCK_GETBH; >>>>>>>>> + ret = ocfs2_inode_lock_full(inode, &di_bh, 0, arg_flags); >>>>>>>>> if (ret < 0) { >>>>>>>>> if (ret != -ENOENT) >>>>>>>>> mlog_errno(ret); >>>>>>>>> return ERR_PTR(ret); >>>>>>>>> } >>>>>>>>> + if (!has_locked) >>>>>>>>> + ocfs2_add_holder(lockres, &oh); >>>>>>>>> acl = ocfs2_get_acl_nolock(inode, type, di_bh); >>>>>>>>> - ocfs2_inode_unlock(inode, 0); >>>>>>>>> + if (!has_locked) { >>>>>>>>> + ocfs2_remove_holder(lockres, &oh); >>>>>>>>> + ocfs2_inode_unlock(inode, 0); >>>>>>>>> + } >>>>>>>>> brelse(di_bh); >>>>>>>>> + >>>>>>>>> return acl; >>>>>>>>> } >>>>>>>>> diff --git a/fs/ocfs2/file.c b/fs/ocfs2/file.c >>>>>>>>> index c488965..62be75d 100644 >>>>>>>>> --- a/fs/ocfs2/file.c >>>>>>>>> +++ b/fs/ocfs2/file.c >>>>>>>>> @@ -1138,6 +1138,9 @@ int ocfs2_setattr(struct dentry *dentry, >>>>>>>>> struct iattr *attr) >>>>>>>>> handle_t *handle = NULL; >>>>>>>>> struct dquot *transfer_to[MAXQUOTAS] = { }; >>>>>>>>> int qtype; >>>>>>>>> + int arg_flags = 0, had_lock; >>>>>>>>> + struct ocfs2_holder oh; >>>>>>>>> + struct ocfs2_lock_res *lockres; >>>>>>>>> trace_ocfs2_setattr(inode, dentry, >>>>>>>>> (unsigned long long)OCFS2_I(inode)->ip_blkno, >>>>>>>>> @@ -1173,13 +1176,20 @@ int ocfs2_setattr(struct dentry >>>>>>>>> *dentry, struct iattr *attr) >>>>>>>>> } >>>>>>>>> } >>>>>>>>> - status = ocfs2_inode_lock(inode, &bh, 1); >>>>>>>>> + lockres = &OCFS2_I(inode)->ip_inode_lockres; >>>>>>>>> + had_lock = (ocfs2_is_locked_by_me(lockres) != NULL); >>>>>>>>> + if (had_lock) >>>>>>>>> + arg_flags = OCFS2_META_LOCK_GETBH; >>>>>>>>> + status = ocfs2_inode_lock_full(inode, &bh, 1, arg_flags); >>>>>>>>> if (status < 0) { >>>>>>>>> if (status != -ENOENT) >>>>>>>>> mlog_errno(status); >>>>>>>>> goto bail_unlock_rw; >>>>>>>>> } >>>>>>>>> - inode_locked = 1; >>>>>>>>> + if (!had_lock) { >>>>>>>>> + ocfs2_add_holder(lockres, &oh); >>>>>>>>> + inode_locked = 1; >>>>>>>>> + } >>>>>>>>> if (size_change) { >>>>>>>>> status = inode_newsize_ok(inode, attr->ia_size); >>>>>>>>> @@ -1260,7 +1270,8 @@ int ocfs2_setattr(struct dentry *dentry, >>>>>>>>> struct iattr *attr) >>>>>>>>> bail_commit: >>>>>>>>> ocfs2_commit_trans(osb, handle); >>>>>>>>> bail_unlock: >>>>>>>>> - if (status) { >>>>>>>>> + if (status && inode_locked) { >>>>>>>>> + ocfs2_remove_holder(lockres, &oh); >>>>>>>>> ocfs2_inode_unlock(inode, 1); >>>>>>>>> inode_locked = 0; >>>>>>>>> } >>>>>>>>> @@ -1278,8 +1289,10 @@ int ocfs2_setattr(struct dentry >>>>>>>>> *dentry, struct iattr *attr) >>>>>>>>> if (status < 0) >>>>>>>>> mlog_errno(status); >>>>>>>>> } >>>>>>>>> - if (inode_locked) >>>>>>>>> + if (inode_locked) { >>>>>>>>> + ocfs2_remove_holder(lockres, &oh); >>>>>>>>> ocfs2_inode_unlock(inode, 1); >>>>>>>>> + } >>>>>>>>> brelse(bh); >>>>>>>>> return status; >>>>>>>>> @@ -1321,20 +1334,31 @@ int ocfs2_getattr(struct vfsmount *mnt, >>>>>>>>> int ocfs2_permission(struct inode *inode, int mask) >>>>>>>>> { >>>>>>>>> int ret; >>>>>>>>> + int has_locked; >>>>>>>>> + struct ocfs2_holder oh; >>>>>>>>> + struct ocfs2_lock_res *lockres; >>>>>>>>> if (mask & MAY_NOT_BLOCK) >>>>>>>>> return -ECHILD; >>>>>>>>> - ret = ocfs2_inode_lock(inode, NULL, 0); >>>>>>>>> - if (ret) { >>>>>>>>> - if (ret != -ENOENT) >>>>>>>>> - mlog_errno(ret); >>>>>>>>> - goto out; >>>>>>>>> + lockres = &OCFS2_I(inode)->ip_inode_lockres; >>>>>>>>> + has_locked = (ocfs2_is_locked_by_me(lockres) != NULL); >>>>>>>>> + if (!has_locked) { >>>>>>>>> + ret = ocfs2_inode_lock(inode, NULL, 0); >>>>>>>>> + if (ret) { >>>>>>>>> + if (ret != -ENOENT) >>>>>>>>> + mlog_errno(ret); >>>>>>>>> + goto out; >>>>>>>>> + } >>>>>>>>> + ocfs2_add_holder(lockres, &oh); >>>>>>>>> } >>>>>>>>> ret = generic_permission(inode, mask); >>>>>>>>> - ocfs2_inode_unlock(inode, 0); >>>>>>>>> + if (!has_locked) { >>>>>>>>> + ocfs2_remove_holder(lockres, &oh); >>>>>>>>> + ocfs2_inode_unlock(inode, 0); >>>>>>>>> + } >>>>>>>>> out: >>>>>>>>> return ret; >>>>>>>>> } >>>>>>>> >>>>>>>> >>>>>>> >>>>>> >>>>>> >>>>> >>>> >>>> >>> >> >> >