btrfs: add mount option to set commit interval
I'ts hardcoded to 30 seconds which is fine for most users. Higher values
defer data being synced to permanent storage with obvious consequences
when the system crashes. The upper bound is not forced, but a warning is
printed if it's more than 300 seconds (5 minutes).
Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index c17acbc..0632832 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -1351,6 +1351,7 @@
u64 last_trans_log_full_commit;
unsigned long mount_opt;
unsigned long compress_type:4;
+ int commit_interval;
/*
* It is a suggestive number, the read side is safe even it gets a
* wrong number because we will write out the data into a regular
@@ -1969,6 +1970,8 @@
#define BTRFS_MOUNT_CHECK_INTEGRITY_INCLUDING_EXTENT_DATA (1 << 21)
#define BTRFS_MOUNT_PANIC_ON_FATAL_ERROR (1 << 22)
+#define BTRFS_DEFAULT_COMMIT_INTERVAL (30)
+
#define btrfs_clear_opt(o, opt) ((o) &= ~BTRFS_MOUNT_##opt)
#define btrfs_set_opt(o, opt) ((o) |= BTRFS_MOUNT_##opt)
#define btrfs_raw_test_opt(o, opt) ((o) & BTRFS_MOUNT_##opt)
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 2a378ab..572e21e 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -1742,7 +1742,7 @@
do {
cannot_commit = false;
- delay = HZ * 30;
+ delay = HZ * root->fs_info->commit_interval;
mutex_lock(&root->fs_info->transaction_kthread_mutex);
spin_lock(&root->fs_info->trans_lock);
@@ -1754,7 +1754,8 @@
now = get_seconds();
if (cur->state < TRANS_STATE_BLOCKED &&
- (now < cur->start_time || now - cur->start_time < 30)) {
+ (now < cur->start_time ||
+ now - cur->start_time < root->fs_info->commit_interval)) {
spin_unlock(&root->fs_info->trans_lock);
delay = HZ * 5;
goto sleep;
@@ -2194,6 +2195,7 @@
fs_info->defrag_inodes = RB_ROOT;
fs_info->free_chunk_space = 0;
fs_info->tree_mod_log = RB_ROOT;
+ fs_info->commit_interval = BTRFS_DEFAULT_COMMIT_INTERVAL;
/* readahead state */
INIT_RADIX_TREE(&fs_info->reada_tree, GFP_NOFS & ~__GFP_WAIT);
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index 2cc5b80..1967903 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -321,6 +321,7 @@
Opt_no_space_cache, Opt_recovery, Opt_skip_balance,
Opt_check_integrity, Opt_check_integrity_including_extent_data,
Opt_check_integrity_print_mask, Opt_fatal_errors,
+ Opt_commit_interval,
Opt_err,
};
@@ -361,6 +362,7 @@
{Opt_check_integrity_including_extent_data, "check_int_data"},
{Opt_check_integrity_print_mask, "check_int_print_mask=%d"},
{Opt_fatal_errors, "fatal_errors=%s"},
+ {Opt_commit_interval, "commit=%d"},
{Opt_err, NULL},
};
@@ -645,6 +647,29 @@
goto out;
}
break;
+ case Opt_commit_interval:
+ intarg = 0;
+ ret = match_int(&args[0], &intarg);
+ if (ret < 0) {
+ printk(KERN_ERR
+ "btrfs: invalid commit interval\n");
+ ret = -EINVAL;
+ goto out;
+ }
+ if (intarg > 0) {
+ if (intarg > 300) {
+ printk(KERN_WARNING
+ "btrfs: excessive commit interval %d\n",
+ intarg);
+ }
+ info->commit_interval = intarg;
+ } else {
+ printk(KERN_INFO
+ "btrfs: using default commit interval %ds\n",
+ BTRFS_DEFAULT_COMMIT_INTERVAL);
+ info->commit_interval = BTRFS_DEFAULT_COMMIT_INTERVAL;
+ }
+ break;
case Opt_err:
printk(KERN_INFO "btrfs: unrecognized mount option "
"'%s'\n", p);
@@ -981,6 +1006,8 @@
info->metadata_ratio);
if (btrfs_test_opt(root, PANIC_ON_FATAL_ERROR))
seq_puts(seq, ",fatal_errors=panic");
+ if (info->commit_interval != BTRFS_DEFAULT_COMMIT_INTERVAL)
+ seq_printf(seq, ",commit=%d", info->commit_interval);
return 0;
}