From: Eric Ren <zren@suse.com> To: ocfs2-devel@oss.oracle.com Cc: akpm@linux-foundation.org, mfasheh@versity.com, jlbec@evilplan.org, ghe@suse.com, junxiao.bi@oracle.com, jiangqi903@gmail.com, zren@suse.com, linux-kernel@vger.kernel.org Subject: [PATCH 2/2] ocfs2: fix deadlocks when taking inode lock at vfs entry points Date: Thu, 5 Jan 2017 23:31:02 +0800 [thread overview] Message-ID: <1483630262-22227-3-git-send-email-zren@suse.com> (raw) In-Reply-To: <1483630262-22227-1-git-send-email-zren@suse.com> 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@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
WARNING: multiple messages have this Message-ID (diff)
From: Eric Ren <zren@suse.com> To: ocfs2-devel@oss.oracle.com Cc: akpm@linux-foundation.org, mfasheh@versity.com, jlbec@evilplan.org, ghe@suse.com, junxiao.bi@oracle.com, jiangqi903@gmail.com, zren@suse.com, linux-kernel@vger.kernel.org Subject: [Ocfs2-devel] [PATCH 2/2] ocfs2: fix deadlocks when taking inode lock at vfs entry points Date: Thu, 5 Jan 2017 23:31:02 +0800 [thread overview] Message-ID: <1483630262-22227-3-git-send-email-zren@suse.com> (raw) In-Reply-To: <1483630262-22227-1-git-send-email-zren@suse.com> 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@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
next prev parent reply other threads:[~2017-01-05 15:54 UTC|newest] Thread overview: 64+ messages / expand[flat|nested] mbox.gz Atom feed top 2017-01-05 15:31 [PATCH 0/2] fix deadlock caused by recursive cluster locking Eric Ren 2017-01-05 15:31 ` [Ocfs2-devel] " Eric Ren 2017-01-05 15:31 ` [PATCH 1/2] ocfs2/dlmglue: prepare tracking logic to avoid recursive cluster lock Eric Ren 2017-01-05 15:31 ` [Ocfs2-devel] " Eric Ren 2017-01-06 6:07 ` Joseph Qi 2017-01-06 6:07 ` [Ocfs2-devel] " Joseph Qi 2017-01-06 7:03 ` Eric Ren 2017-01-06 7:03 ` [Ocfs2-devel] " Eric Ren 2017-01-06 7:24 ` Joseph Qi 2017-01-06 7:24 ` [Ocfs2-devel] " Joseph Qi 2017-01-06 8:04 ` Eric Ren 2017-01-06 8:04 ` [Ocfs2-devel] " Eric Ren 2017-01-13 3:59 ` Junxiao Bi 2017-01-13 3:59 ` [Ocfs2-devel] " Junxiao Bi 2017-01-13 6:12 ` Eric Ren 2017-01-13 6:12 ` [Ocfs2-devel] " Eric Ren 2017-01-16 2:42 ` Junxiao Bi 2017-01-16 2:42 ` [Ocfs2-devel] " Junxiao Bi 2017-01-16 3:31 ` Eric Ren 2017-01-16 3:31 ` [Ocfs2-devel] " Eric Ren 2017-01-05 15:31 ` Eric Ren [this message] 2017-01-05 15:31 ` [Ocfs2-devel] [PATCH 2/2] ocfs2: fix deadlocks when taking inode lock at vfs entry points Eric Ren 2017-01-06 6:09 ` Joseph Qi 2017-01-06 6:09 ` [Ocfs2-devel] " Joseph Qi 2017-01-06 6:56 ` Eric Ren 2017-01-06 6:56 ` [Ocfs2-devel] " Eric Ren 2017-01-06 7:14 ` Joseph Qi 2017-01-06 7:14 ` [Ocfs2-devel] " Joseph Qi 2017-01-06 8:21 ` Eric Ren 2017-01-06 8:21 ` [Ocfs2-devel] " Eric Ren 2017-01-06 9:03 ` Joseph Qi 2017-01-06 9:03 ` [Ocfs2-devel] " Joseph Qi 2017-01-06 9:13 ` Eric Ren 2017-01-06 9:13 ` [Ocfs2-devel] " Eric Ren 2017-01-06 9:55 ` Joseph Qi 2017-01-06 9:55 ` [Ocfs2-devel] " Joseph Qi 2017-01-06 11:56 ` Eric Ren 2017-01-06 11:56 ` [Ocfs2-devel] " Eric Ren 2017-01-09 1:13 ` Joseph Qi 2017-01-09 1:13 ` [Ocfs2-devel] " Joseph Qi 2017-01-09 2:13 ` Eric Ren 2017-01-09 2:13 ` [Ocfs2-devel] " Eric Ren 2017-01-12 11:24 ` Eric Ren 2017-01-12 11:24 ` Eric Ren 2017-01-12 11:36 ` Joseph Qi 2017-01-12 11:36 ` Joseph Qi 2017-01-06 14:52 ` kbuild test robot 2017-01-06 14:52 ` [Ocfs2-devel] " kbuild test robot 2017-01-09 5:24 ` Eric Ren 2017-01-09 5:24 ` [Ocfs2-devel] " Eric Ren 2017-01-06 17:53 ` kbuild test robot 2017-01-06 17:53 ` [Ocfs2-devel] " kbuild test robot 2017-01-13 4:22 ` Junxiao Bi 2017-01-13 4:22 ` [Ocfs2-devel] " Junxiao Bi 2017-01-13 6:19 ` Eric Ren 2017-01-13 6:19 ` [Ocfs2-devel] " Eric Ren 2017-01-16 2:46 ` Junxiao Bi 2017-01-16 2:46 ` [Ocfs2-devel] " Junxiao Bi 2017-01-16 3:06 ` Eric Ren 2017-01-16 3:06 ` [Ocfs2-devel] " Eric Ren 2017-01-16 3:13 ` Junxiao Bi 2017-01-16 3:13 ` [Ocfs2-devel] " Junxiao Bi 2017-01-16 3:17 ` Eric Ren 2017-01-16 3:17 ` [Ocfs2-devel] " Eric Ren
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