aboutsummaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
-rw-r--r--Documentation/filesystems/ocfs2.txt7
-rw-r--r--fs/ocfs2/file.c29
-rw-r--r--fs/ocfs2/ocfs2.h3
-rw-r--r--fs/ocfs2/super.c15
4 files changed, 52 insertions, 2 deletions
diff --git a/Documentation/filesystems/ocfs2.txt b/Documentation/filesystems/ocfs2.txt
index 1f7ae14..5393e66 100644
--- a/Documentation/filesystems/ocfs2.txt
+++ b/Documentation/filesystems/ocfs2.txt
@@ -87,3 +87,10 @@ dir_resv_level= (*) By default, directory reservations will scale with file
reservations - users should rarely need to change this
value. If allocation reservations are turned off, this
option will have no effect.
+coherency=full (*) Disallow concurrent O_DIRECT writes, cluster inode
+ lock will be taken to force other nodes drop cache,
+ therefore full cluster coherency is guaranteed even
+ for O_DIRECT writes.
+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.
diff --git a/fs/ocfs2/file.c b/fs/ocfs2/file.c
index 13af993..9e8cc43 100644
--- a/fs/ocfs2/file.c
+++ b/fs/ocfs2/file.c
@@ -2225,6 +2225,8 @@ static ssize_t ocfs2_file_aio_write(struct kiocb *iocb,
struct file *file = iocb->ki_filp;
struct inode *inode = file->f_path.dentry->d_inode;
struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
+ int full_coherency = !(osb->s_mount_opt &
+ OCFS2_MOUNT_COHERENCY_BUFFERED);
mlog_entry("(0x%p, %u, '%.*s')\n", file,
(unsigned int)nr_segs,
@@ -2248,14 +2250,37 @@ relock:
have_alloc_sem = 1;
}
- /* concurrent O_DIRECT writes are allowed */
- rw_level = !direct_io;
+ /*
+ * Concurrent O_DIRECT writes are allowed with
+ * mount_option "coherency=buffered".
+ */
+ rw_level = (!direct_io || full_coherency);
+
ret = ocfs2_rw_lock(inode, rw_level);
if (ret < 0) {
mlog_errno(ret);
goto out_sems;
}
+ /*
+ * O_DIRECT writes with "coherency=full" need to take EX cluster
+ * inode_lock to guarantee coherency.
+ */
+ if (direct_io && full_coherency) {
+ /*
+ * We need to take and drop the inode lock to force
+ * other nodes to drop their caches. Buffered I/O
+ * already does this in write_begin().
+ */
+ ret = ocfs2_inode_lock(inode, NULL, 1);
+ if (ret < 0) {
+ mlog_errno(ret);
+ goto out_sems;
+ }
+
+ ocfs2_inode_unlock(inode, 1);
+ }
+
can_do_direct = direct_io;
ret = ocfs2_prepare_inode_for_write(file, ppos,
iocb->ki_left, appending,
diff --git a/fs/ocfs2/ocfs2.h b/fs/ocfs2/ocfs2.h
index 687e291d..3064fee 100644
--- a/fs/ocfs2/ocfs2.h
+++ b/fs/ocfs2/ocfs2.h
@@ -263,6 +263,9 @@ enum ocfs2_mount_options
control lists */
OCFS2_MOUNT_USRQUOTA = 1 << 10, /* We support user quotas */
OCFS2_MOUNT_GRPQUOTA = 1 << 11, /* We support group quotas */
+
+ OCFS2_MOUNT_COHERENCY_BUFFERED = 1 << 12 /* Allow concurrent O_DIRECT
+ writes */
};
#define OCFS2_OSB_SOFT_RO 0x0001
diff --git a/fs/ocfs2/super.c b/fs/ocfs2/super.c
index b578644..9122d59 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