[PATCH 4/4] btrfs: add discard_compat support
From: Dmitry Monakhov
Date: Thu Feb 11 2010 - 06:07:36 EST
If any device in the list has no native discard support we add
discard compat support. Devices with native discard support still
getting real discard requests.
Signed-off-by: Dmitry Monakhov <dmonakhov@xxxxxxxxxx>
---
fs/btrfs/ctree.h | 1 +
fs/btrfs/disk-io.c | 8 ++++++++
fs/btrfs/extent-tree.c | 14 ++++++++------
fs/btrfs/super.c | 8 +++++++-
fs/btrfs/volumes.c | 6 ++++++
fs/btrfs/volumes.h | 6 +++++-
6 files changed, 35 insertions(+), 8 deletions(-)
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 9f806dd..54854d1 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -1161,6 +1161,7 @@ struct btrfs_root {
#define BTRFS_MOUNT_SSD_SPREAD (1 << 8)
#define BTRFS_MOUNT_NOSSD (1 << 9)
#define BTRFS_MOUNT_DISCARD (1 << 10)
+#define BTRFS_MOUNT_DISCARD_COMPAT (1 << 11)
#define btrfs_clear_opt(o, opt) ((o) &= ~BTRFS_MOUNT_##opt)
#define btrfs_set_opt(o, opt) ((o) |= BTRFS_MOUNT_##opt)
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 009e3bd..c7d4812 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -1945,6 +1945,14 @@ struct btrfs_root *open_ctree(struct super_block *sb,
"mode\n");
btrfs_set_opt(fs_info->mount_opt, SSD);
}
+ if (btrfs_test_opt(tree_root, DISCARD) &&
+ fs_info->fs_devices->discard_compat) {
+ printk(KERN_INFO "Btrfs detected devices without native discard"
+ " support, enabling discard_compat mode mode\n");
+ btrfs_clear_opt(fs_info->mount_opt, DISCARD);
+ btrfs_set_opt(fs_info->mount_opt, DISCARD_COMPAT);
+ }
+
if (btrfs_super_log_root(disk_super) != 0) {
u64 bytenr = btrfs_super_log_root(disk_super);
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 432a2da..b4c3124 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -1585,20 +1585,21 @@ static int remove_extent_backref(struct btrfs_trans_handle *trans,
}
static void btrfs_issue_discard(struct block_device *bdev,
- u64 start, u64 len)
+ u64 start, u64 len, int do_compat)
{
blkdev_issue_discard(bdev, start >> 9, len >> 9, GFP_KERNEL,
- DISCARD_FL_BARRIER);
+ DISCARD_FL_BARRIER |
+ (do_compat ? DISCARD_FL_COMPAT : 0));
}
static int btrfs_discard_extent(struct btrfs_root *root, u64 bytenr,
u64 num_bytes)
{
- int ret;
+ int ret, do_compat = btrfs_test_opt(root, DISCARD_COMPAT);
u64 map_length = num_bytes;
struct btrfs_multi_bio *multi = NULL;
- if (!btrfs_test_opt(root, DISCARD))
+ if (!btrfs_test_opt(root, DISCARD) && !do_compat)
return 0;
/* Tell the block device(s) that the sectors can be discarded */
@@ -1614,7 +1615,8 @@ static int btrfs_discard_extent(struct btrfs_root *root, u64 bytenr,
for (i = 0; i < multi->num_stripes; i++, stripe++) {
btrfs_issue_discard(stripe->dev->bdev,
stripe->physical,
- map_length);
+ map_length,
+ do_compat);
}
kfree(multi);
}
@@ -3700,7 +3702,7 @@ static int pin_down_bytes(struct btrfs_trans_handle *trans,
* individual btree blocks isn't a good plan. Just
* pin everything in discard mode.
*/
- if (btrfs_test_opt(root, DISCARD))
+ if (btrfs_test_opt(root, DISCARD) || btrfs_test_opt(root, DISCARD_COMPAT))
goto pinit;
buf = btrfs_find_tree_block(root, bytenr, num_bytes);
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index 3f9b457..fe7ccf4 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -67,7 +67,7 @@ enum {
Opt_max_extent, Opt_max_inline, Opt_alloc_start, Opt_nobarrier,
Opt_ssd, Opt_nossd, Opt_ssd_spread, Opt_thread_pool, Opt_noacl,
Opt_compress, Opt_notreelog, Opt_ratio, Opt_flushoncommit,
- Opt_discard, Opt_err,
+ Opt_discard, Opt_discard_compat, Opt_err,
};
static match_table_t tokens = {
@@ -90,6 +90,7 @@ static match_table_t tokens = {
{Opt_flushoncommit, "flushoncommit"},
{Opt_ratio, "metadata_ratio=%d"},
{Opt_discard, "discard"},
+ {Opt_discard_compat, "discard_compat"},
{Opt_err, NULL},
};
@@ -263,6 +264,9 @@ int btrfs_parse_options(struct btrfs_root *root, char *options)
case Opt_discard:
btrfs_set_opt(info->mount_opt, DISCARD);
break;
+ case Opt_discard_compat:
+ btrfs_set_opt(info->mount_opt, DISCARD_COMPAT);
+ break;
case Opt_err:
printk(KERN_INFO "btrfs: unrecognized mount option "
"'%s'\n", p);
@@ -459,6 +463,8 @@ static int btrfs_show_options(struct seq_file *seq, struct vfsmount *vfs)
seq_puts(seq, ",flushoncommit");
if (btrfs_test_opt(root, DISCARD))
seq_puts(seq, ",discard");
+ if (btrfs_test_opt(root, DISCARD_COMPAT))
+ seq_puts(seq, ",discard_compat");
if (!(root->fs_info->sb->s_flags & MS_POSIXACL))
seq_puts(seq, ",noacl");
return 0;
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 220dad5..02e18c8 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -621,6 +621,9 @@ static int __btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
if (!blk_queue_nonrot(bdev_get_queue(bdev)))
fs_devices->rotating = 1;
+ if (!blk_queue_discard(bdev_get_queue(bdev)))
+ fs_devices->discard_compat = 1;
+
fs_devices->open_devices++;
if (device->writeable) {
fs_devices->rw_devices++;
@@ -1522,6 +1525,9 @@ int btrfs_init_new_device(struct btrfs_root *root, char *device_path)
if (!blk_queue_nonrot(bdev_get_queue(bdev)))
root->fs_info->fs_devices->rotating = 1;
+ if (!blk_queue_discard(bdev_get_queue(bdev)))
+ root->fs_info->fs_devices->discard_compat = 1;
+
total_bytes = btrfs_super_total_bytes(&root->fs_info->super_copy);
btrfs_set_super_total_bytes(&root->fs_info->super_copy,
total_bytes + device->total_bytes);
diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h
index 31b0fab..ceb66f0 100644
--- a/fs/btrfs/volumes.h
+++ b/fs/btrfs/volumes.h
@@ -116,7 +116,11 @@ struct btrfs_fs_devices {
/* set when we find or add a device that doesn't have the
* nonrot flag set
*/
- int rotating;
+ unsigned int rotating:1;
+ /* set then we find or add a device that doesn't have the
+ * DISCARD flags set
+ */
+ unsigned int discard_compat:1;
};
struct btrfs_bio_stripe {
--
1.6.6
--
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