Eric Ren
2017-Jan-05 15:31 UTC
[Ocfs2-devel] [PATCH 2/2] ocfs2: fix deadlocks when taking inode lock at vfs entry points
Commit 743b5f1434f5 ("ocfs2: take inode lock in ocfs2_iop_set/get_acl()") results in a deadlock, as the author "Tariq Saeed" realized shortly after the patch was merged. The discussion happened here (https://oss.oracle.com/pipermail/ocfs2-devel/2015-September/011085.html). The reason why taking cluster inode lock at vfs entry points opens up a self deadlock window, is explained in the previous patch of this series. So far, we have seen two different code paths that have this issue. 1. do_sys_open may_open inode_permission ocfs2_permission ocfs2_inode_lock() <=== take PR generic_permission get_acl ocfs2_iop_get_acl ocfs2_inode_lock() <=== take PR 2. fchmod|fchmodat chmod_common notify_change ocfs2_setattr <=== take EX posix_acl_chmod get_acl ocfs2_iop_get_acl <=== take PR ocfs2_iop_set_acl <=== take EX Fixes them by adding the tracking logic (in the previous patch) for these funcs above, ocfs2_permission(), ocfs2_iop_[set|get]_acl(), ocfs2_setattr(). 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; } -- 2.6.6
Joseph Qi
2017-Jan-06 06:09 UTC
[Ocfs2-devel] [PATCH 2/2] ocfs2: fix deadlocks when taking inode lock at vfs entry points
Hi Eric, On 17/1/5 23:31, Eric Ren wrote:> Commit 743b5f1434f5 ("ocfs2: take inode lock in ocfs2_iop_set/get_acl()") > results in a deadlock, as the author "Tariq Saeed" realized shortly > after the patch was merged. The discussion happened here > (https://oss.oracle.com/pipermail/ocfs2-devel/2015-September/011085.html). > > The reason why taking cluster inode lock at vfs entry points opens up > a self deadlock window, is explained in the previous patch of this > series. > > So far, we have seen two different code paths that have this issue. > 1. do_sys_open > may_open > inode_permission > ocfs2_permission > ocfs2_inode_lock() <=== take PR > generic_permission > get_acl > ocfs2_iop_get_acl > ocfs2_inode_lock() <=== take PR > 2. fchmod|fchmodat > chmod_common > notify_change > ocfs2_setattr <=== take EX > posix_acl_chmod > get_acl > ocfs2_iop_get_acl <=== take PR > ocfs2_iop_set_acl <=== take EX > > 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()? 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; > }
kbuild test robot
2017-Jan-06 14:52 UTC
[Ocfs2-devel] [PATCH 2/2] ocfs2: fix deadlocks when taking inode lock at vfs entry points
Hi Eric, [auto build test ERROR on linus/master] [also build test ERROR on v4.10-rc2 next-20170106] [if your patch is applied to the wrong git tree, please drop us a note to help improve the system] url: https://github.com/0day-ci/linux/commits/Eric-Ren/fix-deadlock-caused-by-recursive-cluster-locking/20170106-200837 config: ia64-allyesconfig (attached as .config) compiler: ia64-linux-gcc (GCC) 6.2.0 reproduce: wget https://git.kernel.org/cgit/linux/kernel/git/wfg/lkp-tests.git/plain/sbin/make.cross -O ~/bin/make.cross chmod +x ~/bin/make.cross # save the attached .config to linux build tree make.cross ARCH=ia64 All errors (new ones prefixed by >>): In file included from fs/ocfs2/acl.c:31:0: fs/ocfs2/acl.c: In function 'ocfs2_iop_set_acl':>> fs/ocfs2/dlmglue.h:189:29: error: inlining failed in call to always_inline 'ocfs2_is_locked_by_me': function body not availableinline struct ocfs2_holder *ocfs2_is_locked_by_me(struct ocfs2_lock_res *lockres); ^~~~~~~~~~~~~~~~~~~~~ fs/ocfs2/acl.c:292:16: note: called from here has_locked = (ocfs2_is_locked_by_me(lockres) != NULL); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ In file included from fs/ocfs2/acl.c:31:0:>> fs/ocfs2/dlmglue.h:189:29: error: inlining failed in call to always_inline 'ocfs2_is_locked_by_me': function body not availableinline struct ocfs2_holder *ocfs2_is_locked_by_me(struct ocfs2_lock_res *lockres); ^~~~~~~~~~~~~~~~~~~~~ fs/ocfs2/acl.c:292:16: note: called from here has_locked = (ocfs2_is_locked_by_me(lockres) != NULL); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ In file included from fs/ocfs2/acl.c:31:0:>> fs/ocfs2/dlmglue.h:185:13: error: inlining failed in call to always_inline 'ocfs2_add_holder': function body not availableinline void ocfs2_add_holder(struct ocfs2_lock_res *lockres, ^~~~~~~~~~~~~~~~ fs/ocfs2/acl.c:302:3: note: called from here ocfs2_add_holder(lockres, &oh); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ In file included from fs/ocfs2/acl.c:31:0:>> fs/ocfs2/dlmglue.h:187:13: error: inlining failed in call to always_inline 'ocfs2_remove_holder': function body not availableinline void ocfs2_remove_holder(struct ocfs2_lock_res *lockres, ^~~~~~~~~~~~~~~~~~~ fs/ocfs2/acl.c:307:3: note: called from here ocfs2_remove_holder(lockres, &oh); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ -- In file included from arch/ia64/include/uapi/asm/intrinsics.h:21:0, from arch/ia64/include/asm/intrinsics.h:10, from arch/ia64/include/asm/bitops.h:18, from include/linux/bitops.h:36, from include/linux/kernel.h:10, from include/linux/list.h:8, from include/linux/wait.h:6, from include/linux/fs.h:5, from fs/ocfs2/file.c:27: fs/ocfs2/file.c: In function 'ocfs2_file_write_iter': arch/ia64/include/uapi/asm/cmpxchg.h:56:2: warning: value computed is not used [-Wunused-value] ((__typeof__(*(ptr))) __xchg((unsigned long) (x), (ptr), sizeof(*(ptr)))) ~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ fs/ocfs2/file.c:2334:3: note: in expansion of macro 'xchg' xchg(&iocb->ki_complete, saved_ki_complete); ^~~~ In file included from fs/ocfs2/file.c:49:0: fs/ocfs2/file.c: In function 'ocfs2_permission':>> fs/ocfs2/dlmglue.h:189:29: error: inlining failed in call to always_inline 'ocfs2_is_locked_by_me': function body not availableinline struct ocfs2_holder *ocfs2_is_locked_by_me(struct ocfs2_lock_res *lockres); ^~~~~~~~~~~~~~~~~~~~~ fs/ocfs2/file.c:1345:16: note: called from here has_locked = (ocfs2_is_locked_by_me(lockres) != NULL); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ In file included from fs/ocfs2/file.c:49:0:>> fs/ocfs2/dlmglue.h:189:29: error: inlining failed in call to always_inline 'ocfs2_is_locked_by_me': function body not availableinline struct ocfs2_holder *ocfs2_is_locked_by_me(struct ocfs2_lock_res *lockres); ^~~~~~~~~~~~~~~~~~~~~ fs/ocfs2/file.c:1345:16: note: called from here has_locked = (ocfs2_is_locked_by_me(lockres) != NULL); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ In file included from fs/ocfs2/file.c:49:0:>> fs/ocfs2/dlmglue.h:185:13: error: inlining failed in call to always_inline 'ocfs2_add_holder': function body not availableinline void ocfs2_add_holder(struct ocfs2_lock_res *lockres, ^~~~~~~~~~~~~~~~ fs/ocfs2/file.c:1353:3: note: called from here ocfs2_add_holder(lockres, &oh); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ In file included from fs/ocfs2/file.c:49:0:>> fs/ocfs2/dlmglue.h:187:13: error: inlining failed in call to always_inline 'ocfs2_remove_holder': function body not availableinline void ocfs2_remove_holder(struct ocfs2_lock_res *lockres, ^~~~~~~~~~~~~~~~~~~ fs/ocfs2/file.c:1359:3: note: called from here ocfs2_remove_holder(lockres, &oh); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ vim +/ocfs2_is_locked_by_me +189 fs/ocfs2/dlmglue.h 63e0c48a Joel Becker 2008-01-30 179 void ocfs2_set_locking_protocol(void); 9fb5ed3a Eric Ren 2017-01-05 180 9fb5ed3a Eric Ren 2017-01-05 181 /* 9fb5ed3a Eric Ren 2017-01-05 182 * Keep a list of processes who have interest in a lockres. 9fb5ed3a Eric Ren 2017-01-05 183 * Note: this is now only uesed for check recursive cluster lock. 9fb5ed3a Eric Ren 2017-01-05 184 */ 9fb5ed3a Eric Ren 2017-01-05 @185 inline void ocfs2_add_holder(struct ocfs2_lock_res *lockres, 9fb5ed3a Eric Ren 2017-01-05 186 struct ocfs2_holder *oh); 9fb5ed3a Eric Ren 2017-01-05 @187 inline void ocfs2_remove_holder(struct ocfs2_lock_res *lockres, 9fb5ed3a Eric Ren 2017-01-05 188 struct ocfs2_holder *oh); 9fb5ed3a Eric Ren 2017-01-05 @189 inline struct ocfs2_holder *ocfs2_is_locked_by_me(struct ocfs2_lock_res *lockres); 9fb5ed3a Eric Ren 2017-01-05 190 ccd979bd Mark Fasheh 2005-12-15 191 #endif /* DLMGLUE_H */ :::::: The code at line 189 was first introduced by commit :::::: 9fb5ed3abab2100ae8d99cee9b25fb92e3154224 ocfs2/dlmglue: prepare tracking logic to avoid recursive cluster lock :::::: TO: Eric Ren <zren at suse.com> :::::: CC: 0day robot <fengguang.wu at intel.com> --- 0-DAY kernel test infrastructure Open Source Technology Center https://lists.01.org/pipermail/kbuild-all Intel Corporation -------------- next part -------------- A non-text attachment was scrubbed... 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kbuild test robot
2017-Jan-06 17:53 UTC
[Ocfs2-devel] [PATCH 2/2] ocfs2: fix deadlocks when taking inode lock at vfs entry points
Hi Eric, [auto build test WARNING on linus/master] [also build test WARNING on v4.10-rc2 next-20170106] [if your patch is applied to the wrong git tree, please drop us a note to help improve the system] url: https://github.com/0day-ci/linux/commits/Eric-Ren/fix-deadlock-caused-by-recursive-cluster-locking/20170106-200837 reproduce: # apt-get install sparse make ARCH=x86_64 allmodconfig make C=1 CF=-D__CHECK_ENDIAN__ sparse warnings: (new ones prefixed by >>) include/linux/compiler.h:253:8: sparse: attribute 'no_sanitize_address': unknown attribute>> fs/ocfs2/dlmglue.h:189:50: sparse: marked inline, but without a definitionfs/ocfs2/dlmglue.h:185:29: sparse: marked inline, but without a definition fs/ocfs2/dlmglue.h:187:32: sparse: marked inline, but without a definition>> fs/ocfs2/dlmglue.h:189:50: sparse: marked inline, but without a definitionfs/ocfs2/dlmglue.h:185:29: sparse: marked inline, but without a definition fs/ocfs2/dlmglue.h:187:32: sparse: marked inline, but without a definition -- include/linux/compiler.h:253:8: sparse: attribute 'no_sanitize_address': unknown attribute>> fs/ocfs2/dlmglue.h:189:50: sparse: marked inline, but without a definitionfs/ocfs2/dlmglue.h:185:29: sparse: marked inline, but without a definition fs/ocfs2/dlmglue.h:187:32: sparse: marked inline, but without a definition fs/ocfs2/dlmglue.h:187:32: sparse: marked inline, but without a definition>> fs/ocfs2/dlmglue.h:189:50: sparse: marked inline, but without a definitionfs/ocfs2/dlmglue.h:185:29: sparse: marked inline, but without a definition fs/ocfs2/dlmglue.h:187:32: sparse: marked inline, but without a definition vim +189 fs/ocfs2/dlmglue.h 34d024f8 Mark Fasheh 2007-09-24 173 void ocfs2_wake_downconvert_thread(struct ocfs2_super *osb); ccd979bd Mark Fasheh 2005-12-15 174 ccd979bd Mark Fasheh 2005-12-15 175 struct ocfs2_dlm_debug *ocfs2_new_dlm_debug(void); ccd979bd Mark Fasheh 2005-12-15 176 void ocfs2_put_dlm_debug(struct ocfs2_dlm_debug *dlm_debug); ccd979bd Mark Fasheh 2005-12-15 177 63e0c48a Joel Becker 2008-01-30 178 /* To set the locking protocol on module initialization */ 63e0c48a Joel Becker 2008-01-30 179 void ocfs2_set_locking_protocol(void); 9fb5ed3a Eric Ren 2017-01-05 180 9fb5ed3a Eric Ren 2017-01-05 181 /* 9fb5ed3a Eric Ren 2017-01-05 182 * Keep a list of processes who have interest in a lockres. 9fb5ed3a Eric Ren 2017-01-05 183 * Note: this is now only uesed for check recursive cluster lock. 9fb5ed3a Eric Ren 2017-01-05 184 */ 9fb5ed3a Eric Ren 2017-01-05 185 inline void ocfs2_add_holder(struct ocfs2_lock_res *lockres, 9fb5ed3a Eric Ren 2017-01-05 186 struct ocfs2_holder *oh); 9fb5ed3a Eric Ren 2017-01-05 187 inline void ocfs2_remove_holder(struct ocfs2_lock_res *lockres, 9fb5ed3a Eric Ren 2017-01-05 188 struct ocfs2_holder *oh); 9fb5ed3a Eric Ren 2017-01-05 @189 inline struct ocfs2_holder *ocfs2_is_locked_by_me(struct ocfs2_lock_res *lockres); 9fb5ed3a Eric Ren 2017-01-05 190 ccd979bd Mark Fasheh 2005-12-15 191 #endif /* DLMGLUE_H */ :::::: The code at line 189 was first introduced by commit :::::: 9fb5ed3abab2100ae8d99cee9b25fb92e3154224 ocfs2/dlmglue: prepare tracking logic to avoid recursive cluster lock :::::: TO: Eric Ren <zren at suse.com> :::::: CC: 0day robot <fengguang.wu at intel.com> --- 0-DAY kernel test infrastructure Open Source Technology Center https://lists.01.org/pipermail/kbuild-all Intel Corporation
Junxiao Bi
2017-Jan-13 04:22 UTC
[Ocfs2-devel] [PATCH 2/2] ocfs2: fix deadlocks when taking inode lock at vfs entry points
On 01/05/2017 11:31 PM, Eric Ren wrote:> Commit 743b5f1434f5 ("ocfs2: take inode lock in ocfs2_iop_set/get_acl()") > results in a deadlock, as the author "Tariq Saeed" realized shortly > after the patch was merged. The discussion happened here > (https://oss.oracle.com/pipermail/ocfs2-devel/2015-September/011085.html). > > The reason why taking cluster inode lock at vfs entry points opens up > a self deadlock window, is explained in the previous patch of this > series. > > So far, we have seen two different code paths that have this issue. > 1. do_sys_open > may_open > inode_permission > ocfs2_permission > ocfs2_inode_lock() <=== take PR > generic_permission > get_acl > ocfs2_iop_get_acl > ocfs2_inode_lock() <=== take PR > 2. fchmod|fchmodat > chmod_common > notify_change > ocfs2_setattr <=== take EX > posix_acl_chmod > get_acl > ocfs2_iop_get_acl <=== take PR > ocfs2_iop_set_acl <=== take EX > > Fixes them by adding the tracking logic (in the previous patch) for > these funcs above, ocfs2_permission(), ocfs2_iop_[set|get]_acl(), > ocfs2_setattr(). > > 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==true, it is a bug? I think we should BUG_ON for it, that can help us catch bug at the first time.> + 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);The same thing as ocfs2_setattr. Thanks, Junxiao.> + 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; > } >