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; >>>>>>>>> } >>>>>>>> >>>>>>>> >>>>>>> >>>>>> >>>>>> >>>>> >>>> >>>> >>> >> >> >
Eric Ren
2017-Jan-09 02:13 UTC
[Ocfs2-devel] [PATCH 2/2] ocfs2: fix deadlocks when taking inode lock at vfs entry points
Hi, On 01/09/2017 09:13 AM, Joseph Qi wrote:> ... >> >>> 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.That's fine!>> >>> 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...Oh, sorry, I meant phase3 can go ahead if this patch set is applied;-)> "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.Sorry, I still cannot see it. Without keeping track of the first cluster lock, how can we know if we are under a context that has already been in the protecting of cluster lock? How can we handle the recursive locking (the second cluster lock) if we don't have this information?>>> 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.I think I got your point here. Do you mean that we should just add the lock holder at the first locking position without checking before that? Unfortunately, it's tricky here to know exactly which ocfs2 routine will be the first vfs entry point, such as ocfs2_get_acl() which can be both the first vfs entry point and the second vfs entry point after ocfs2_permission(), right? It will be a coding bug if the problem you concern about happens. I think we don't need to worry about this much because the code logic here is quite simple;-) Thanks for your patience! Eric>> >> 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; >>>>>>>>>> } >>>>>>>>> >>>>>>>>> >>>>>>>> >>>>>>> >>>>>>> >>>>>> >>>>> >>>>> >>>> >>> >>> >> > >