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authorTristan Ye <tristan.ye@oracle.com>2010-10-11 16:46:39 +0800
committerJoel Becker <joel.becker@oracle.com>2010-10-11 14:14:55 -0700
commit7bdb0d18bfd381cc5491eb95973ec5604b356c7e (patch)
tree1abe07df935a336eeac5c7705dc9b59341b47b0a /fs/ocfs2/super.c
parent75d9bbc73804285020aa4d99bd2a9600edea8945 (diff)
ocfs2: Add a mount option "coherency=*" to handle cluster coherency for O_DIRECT writes.
Currently, the default behavior of O_DIRECT writes was allowing concurrent writing among nodes to the same file, with no cluster coherency guaranteed (no EX lock held). This can leave stale data in the cache for buffered reads on other nodes. The new mount option introduce a chance to choose two different behaviors for O_DIRECT writes: * coherency=full, as the default value, will disallow concurrent O_DIRECT writes by taking EX locks. * coherency=buffered, allow concurrent O_DIRECT writes without EX lock among nodes, which gains high performance at risk of getting stale data on other nodes. Signed-off-by: Tristan Ye <tristan.ye@oracle.com> Signed-off-by: Joel Becker <joel.becker@oracle.com>
Diffstat (limited to 'fs/ocfs2/super.c')
-rw-r--r--fs/ocfs2/super.c15
1 files changed, 15 insertions, 0 deletions
diff --git a/fs/ocfs2/super.c b/fs/ocfs2/super.c
index b578644b663..9122d59f812 100644
--- a/fs/ocfs2/super.c
+++ b/fs/ocfs2/super.c
@@ -177,6 +177,8 @@ enum {
Opt_noacl,
Opt_usrquota,
Opt_grpquota,
+ Opt_coherency_buffered,
+ Opt_coherency_full,
Opt_resv_level,
Opt_dir_resv_level,
Opt_err,
@@ -205,6 +207,8 @@ static const match_table_t tokens = {
{Opt_noacl, "noacl"},
{Opt_usrquota, "usrquota"},
{Opt_grpquota, "grpquota"},
+ {Opt_coherency_buffered, "coherency=buffered"},
+ {Opt_coherency_full, "coherency=full"},
{Opt_resv_level, "resv_level=%u"},
{Opt_dir_resv_level, "dir_resv_level=%u"},
{Opt_err, NULL}
@@ -1452,6 +1456,12 @@ static int ocfs2_parse_options(struct super_block *sb,
case Opt_grpquota:
mopt->mount_opt |= OCFS2_MOUNT_GRPQUOTA;
break;
+ case Opt_coherency_buffered:
+ mopt->mount_opt |= OCFS2_MOUNT_COHERENCY_BUFFERED;
+ break;
+ case Opt_coherency_full:
+ mopt->mount_opt &= ~OCFS2_MOUNT_COHERENCY_BUFFERED;
+ break;
case Opt_acl:
mopt->mount_opt |= OCFS2_MOUNT_POSIX_ACL;
mopt->mount_opt &= ~OCFS2_MOUNT_NO_POSIX_ACL;
@@ -1550,6 +1560,11 @@ static int ocfs2_show_options(struct seq_file *s, struct vfsmount *mnt)
if (opts & OCFS2_MOUNT_GRPQUOTA)
seq_printf(s, ",grpquota");
+ if (opts & OCFS2_MOUNT_COHERENCY_BUFFERED)
+ seq_printf(s, ",coherency=buffered");
+ else
+ seq_printf(s, ",coherency=full");
+
if (opts & OCFS2_MOUNT_NOUSERXATTR)
seq_printf(s, ",nouser_xattr");
else