Hi Tariq,
On 01/06/2016 10:27 AM, Tariq Saeed wrote:
> Orabug: 21793017
>
> commit 743b5f1434f5 ("ocfs2: take inode lock in ocfs2_iop_set/get_acl()")
> introduced this issue. ocfs2_setattr called by chmod command
> holds cluster wide inode lock (Orabug 21685187) when calling
> posix_acl_chmod. This latter function in turn calls ocfs2_iop_get_acl
> and ocfs2_iop_set_acl. These two are also called directly from vfs
> layer for getfacl/setfacl commands and therefore acquire the cluster wide
> inode lock. If a remote conversion request comes after the first inode
> lock in ocfs2_setattr, OCFS2_LOCK_BLOCKED will be set in l_flags. This
> will cause the second call to inode lock from the ocfs2_iop_get_acl()
> to block indefinetly.
This fixed part of the deadlock. There is another part.
ocfs2_mknod()->posix_acl_create()->ocfs2_iop_get_acl()
Thanks,
Junxiao.
>
> To solve this, we need to use nolock version of getacl. Since
> nolock version of posix_acl_chmod does not exist, we restore a slightly
> modified version of ocfs2_acl_chmod, which was removed in
> commit 702e5bc68ad2 ("ocfs2: use generic posix ACL infrastructure")
> that uses nolock version of getacl.
>
> Signed-off-by: Tariq Saeed <tariq.x.sa...@oracle.com>
> ---
> fs/ocfs2/acl.c | 25 +++++++++++++++++++++++++
> fs/ocfs2/acl.h | 1 +
> fs/ocfs2/file.c | 4 ++--
> 3 files changed, 28 insertions(+), 2 deletions(-)
>
> diff --git a/fs/ocfs2/acl.c b/fs/ocfs2/acl.c
> index 0cdf497..0fbd18c 100644
> --- a/fs/ocfs2/acl.c
> +++ b/fs/ocfs2/acl.c
> @@ -322,3 +322,28 @@ struct posix_acl *ocfs2_iop_get_acl(struct inode *inode,
> int type)
> brelse(di_bh);
> return acl;
> }
> +
> +int ocfs2_acl_chmod(struct inode *inode, struct buffer_head *bh)
> +{
> + struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
> + struct posix_acl *acl;
> + int ret;
> +
> + if (S_ISLNK(inode->i_mode))
> + return -EOPNOTSUPP;
> +
> + if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL))
> + return 0;
> +
> + acl = ocfs2_get_acl_nolock(inode, ACL_TYPE_ACCESS, bh);
> + if (IS_ERR(acl) || !acl)
> + return PTR_ERR(acl);
> + ret = __posix_acl_chmod(&acl, GFP_KERNEL, inode->i_mode);
> + if (ret)
> + return ret;
> + ret = ocfs2_set_acl(NULL, inode, NULL, ACL_TYPE_ACCESS,
> + acl, NULL, NULL);
> + posix_acl_release(acl);
> + return ret;
> +}
> +
> diff --git a/fs/ocfs2/acl.h b/fs/ocfs2/acl.h
> index 3fce68d..035e587 100644
> --- a/fs/ocfs2/acl.h
> +++ b/fs/ocfs2/acl.h
> @@ -35,5 +35,6 @@ int ocfs2_set_acl(handle_t *handle,
> struct posix_acl *acl,
> struct ocfs2_alloc_context *meta_ac,
> struct ocfs2_alloc_context *data_ac);
> +extern int ocfs2_acl_chmod(struct inode *, struct buffer_head *);
>
> #endif /* OCFS2_ACL_H */
> diff --git a/fs/ocfs2/file.c b/fs/ocfs2/file.c
> index 0e5b451..77d30cb 100644
> --- a/fs/ocfs2/file.c
> +++ b/fs/ocfs2/file.c
> @@ -1268,20 +1268,20 @@ bail_unlock_rw:
> if (size_change)
> ocfs2_rw_unlock(inode, 1);
> bail:
> - brelse(bh);
>
> /* Release quota pointers in case we acquired them */
> for (qtype = 0; qtype < OCFS2_MAXQUOTAS; qtype++)
> dqput(transfer_to[qtype]);
>
> if (!status && attr->ia_valid & ATTR_MODE) {
> - status = posix_acl_chmod(inode, inode->i_mode);
> + status = ocfs2_acl_chmod(inode, bh);
> if (status < 0)
> mlog_errno(status);
> }
> if (inode_locked)
> ocfs2_inode_unlock(inode, 1);
>
> + brelse(bh);
> return status;
> }
>
>
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