ocfs2: Local alloc window size changeable via mount option
Local alloc is a performance optimization in ocfs2 in which a node
takes a window of bits from the global bitmap and then uses that for
all small local allocations. This window size is fixed to 8MB currently.
This patch allows users to specify the window size in MB including
disabling it by passing in 0. If the number specified is too large,
the fs will use the default value of 8MB.
mount -o localalloc=X /dev/sdX /mntpoint
Signed-off-by: Sunil Mushran <sunil.mushran@oracle.com>
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
diff --git a/fs/ocfs2/super.c b/fs/ocfs2/super.c
index 8044ed9..1104f14 100644
--- a/fs/ocfs2/super.c
+++ b/fs/ocfs2/super.c
@@ -87,6 +87,7 @@
unsigned long mount_opt;
unsigned int atime_quantum;
signed short slot;
+ unsigned int localalloc_opt;
};
static int ocfs2_parse_options(struct super_block *sb, char *options,
@@ -151,6 +152,7 @@
Opt_atime_quantum,
Opt_slot,
Opt_commit,
+ Opt_localalloc,
Opt_err,
};
@@ -167,6 +169,7 @@
{Opt_atime_quantum, "atime_quantum=%u"},
{Opt_slot, "preferred_slot=%u"},
{Opt_commit, "commit=%u"},
+ {Opt_localalloc, "localalloc=%d"},
{Opt_err, NULL}
};
@@ -602,6 +605,7 @@
osb->s_atime_quantum = parsed_options.atime_quantum;
osb->preferred_slot = parsed_options.slot;
osb->osb_commit_interval = parsed_options.commit_interval;
+ osb->local_alloc_size = parsed_options.localalloc_opt;
sb->s_magic = OCFS2_SUPER_MAGIC;
@@ -756,6 +760,7 @@
mopt->mount_opt = 0;
mopt->atime_quantum = OCFS2_DEFAULT_ATIME_QUANTUM;
mopt->slot = OCFS2_INVALID_SLOT;
+ mopt->localalloc_opt = OCFS2_DEFAULT_LOCAL_ALLOC_SIZE;
if (!options) {
status = 1;
@@ -834,6 +839,15 @@
option = JBD_DEFAULT_MAX_COMMIT_AGE;
mopt->commit_interval = HZ * option;
break;
+ case Opt_localalloc:
+ option = 0;
+ if (match_int(&args[0], &option)) {
+ status = 0;
+ goto bail;
+ }
+ if (option >= 0 && (option <= ocfs2_local_alloc_size(sb) * 8))
+ mopt->localalloc_opt = option;
+ break;
default:
mlog(ML_ERROR,
"Unrecognized mount option \"%s\" "
@@ -886,6 +900,9 @@
seq_printf(s, ",commit=%u",
(unsigned) (osb->osb_commit_interval / HZ));
+ if (osb->local_alloc_size != OCFS2_DEFAULT_LOCAL_ALLOC_SIZE)
+ seq_printf(s, ",localalloc=%d", osb->local_alloc_size);
+
return 0;
}