* [PATCH V3] Btrfs: Batched discard support for btrfs
@ 2011-03-03 13:41 Li Dongyang
0 siblings, 0 replies; only message in thread
From: Li Dongyang @ 2011-03-03 13:41 UTC (permalink / raw)
To: linux-btrfs; +Cc: Lukas Czerner, David Sterba, Kurt Garloff
Here is V3, sorry for sending the patch out without checking the style.
Tested with xfstests 251, we are still only trimming the first stripe of
a free extent from RAID0/1/10/DUP, but I think we are done with FITRIM,
the problem could be addressed by loop inside btrfs_discard_extent() and
trim the extent stripe by stripe, or make the free extent be mapped as a whole,
and that could been done in another patch, Thanks.
Signed-off-by: Li Dongyang <lidongyang@novell.com>
Reviewed-by: David Sterba <dsterba@suse.cz>
Reviewed-by: Kurt Garloff <garloff@suse.de>
---
Changelog V3:
*fix style problems.
*rebase to 2.6.38-rc7.
Changelog V2:
*Check if we have devices support trim before trying to trim the fs, also adjust
minlen according to the discard_granularity.
*Update reserved extent calculations in btrfs_trim_block_group().
*Call cond_resched() without checking need_resched()
*Use bitmap_clear_bits() and unlink_free_space() instead of btrfs_remove_free_space(),
so we won't search the same extent for twice.
*Try harder in btrfs_discard_extent(), now we won't report errors
if it's not a EOPNOTSUPP.
*make sure the block group is cached before trimming it,or we'll see an empty caching
tree if the block group is not cached.
*Minor return value fix in btrfs_discard_block_group().
---
fs/btrfs/ctree.h | 5 ++-
fs/btrfs/disk-io.c | 5 ++-
fs/btrfs/extent-tree.c | 103 +++++++++++++++++++++++++++++++++----------
fs/btrfs/free-space-cache.c | 92 ++++++++++++++++++++++++++++++++++++++
fs/btrfs/free-space-cache.h | 2 +
fs/btrfs/ioctl.c | 46 +++++++++++++++++++
6 files changed, 227 insertions(+), 26 deletions(-)
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 6f820fa..9511af9 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -2148,6 +2148,8 @@ int btrfs_free_extent(struct btrfs_trans_handle *trans,
u64 root_objectid, u64 owner, u64 offset);
int btrfs_free_reserved_extent(struct btrfs_root *root, u64 start, u64 len);
+int btrfs_update_reserved_bytes(struct btrfs_block_group_cache *cache,
+ u64 num_bytes, int reserve, int sinfo);
int btrfs_prepare_extent_commit(struct btrfs_trans_handle *trans,
struct btrfs_root *root);
int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans,
@@ -2218,9 +2220,10 @@ u64 btrfs_account_ro_block_groups_free_space(struct btrfs_space_info *sinfo);
int btrfs_error_unpin_extent_range(struct btrfs_root *root,
u64 start, u64 end);
int btrfs_error_discard_extent(struct btrfs_root *root, u64 bytenr,
- u64 num_bytes);
+ u64 num_bytes, u64 *actual_bytes);
int btrfs_force_chunk_alloc(struct btrfs_trans_handle *trans,
struct btrfs_root *root, u64 type);
+int btrfs_trim_fs(struct btrfs_root *root, struct fstrim_range *range);
/* ctree.c */
int btrfs_bin_search(struct extent_buffer *eb, struct btrfs_key *key,
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index e1aa8d6..bcb9451 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -2947,7 +2947,10 @@ static int btrfs_destroy_pinned_extent(struct btrfs_root *root,
break;
/* opt_discard */
- ret = btrfs_error_discard_extent(root, start, end + 1 - start);
+ if (btrfs_test_opt(root, DISCARD))
+ ret = btrfs_error_discard_extent(root, start,
+ end + 1 - start,
+ NULL);
clear_extent_dirty(unpin, start, end, GFP_NOFS);
btrfs_error_unpin_extent_range(root, start, end);
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 588ff98..fbd7bd6 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -36,8 +36,6 @@
static int update_block_group(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
u64 bytenr, u64 num_bytes, int alloc);
-static int update_reserved_bytes(struct btrfs_block_group_cache *cache,
- u64 num_bytes, int reserve, int sinfo);
static int __btrfs_free_extent(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
u64 bytenr, u64 num_bytes, u64 parent,
@@ -442,7 +440,7 @@ static int cache_block_group(struct btrfs_block_group_cache *cache,
* allocate blocks for the tree root we can't do the fast caching since
* we likely hold important locks.
*/
- if (!trans->transaction->in_commit &&
+ if (trans && (!trans->transaction->in_commit) &&
(root && root != root->fs_info->tree_root)) {
spin_lock(&cache->lock);
if (cache->cached != BTRFS_CACHE_NO) {
@@ -1740,24 +1738,22 @@ static int remove_extent_backref(struct btrfs_trans_handle *trans,
return ret;
}
-static void btrfs_issue_discard(struct block_device *bdev,
+static int btrfs_issue_discard(struct block_device *bdev,
u64 start, u64 len)
{
- blkdev_issue_discard(bdev, start >> 9, len >> 9, GFP_KERNEL, 0);
+ return blkdev_issue_discard(bdev, start >> 9, len >> 9, GFP_KERNEL, 0);
}
static int btrfs_discard_extent(struct btrfs_root *root, u64 bytenr,
- u64 num_bytes)
+ u64 num_bytes, u64 *actual_bytes)
{
int ret;
u64 map_length = num_bytes;
+ u64 discarded_bytes = 0;
struct btrfs_multi_bio *multi = NULL;
- if (!btrfs_test_opt(root, DISCARD))
- return 0;
-
/* Tell the block device(s) that the sectors can be discarded */
- ret = btrfs_map_block(&root->fs_info->mapping_tree, READ,
+ ret = btrfs_map_block(&root->fs_info->mapping_tree, WRITE,
bytenr, &map_length, &multi, 0);
if (!ret) {
struct btrfs_bio_stripe *stripe = multi->stripes;
@@ -1767,13 +1763,21 @@ static int btrfs_discard_extent(struct btrfs_root *root, u64 bytenr,
map_length = num_bytes;
for (i = 0; i < multi->num_stripes; i++, stripe++) {
- btrfs_issue_discard(stripe->dev->bdev,
- stripe->physical,
- map_length);
+ ret = btrfs_issue_discard(stripe->dev->bdev,
+ stripe->physical,
+ map_length);
+ if (!ret)
+ discarded_bytes += map_length;
}
kfree(multi);
}
+ if (discarded_bytes || ret == -EOPNOTSUPP)
+ ret = 0;
+
+ if (actual_bytes)
+ *actual_bytes = discarded_bytes;
+
return ret;
}
@@ -4214,8 +4218,8 @@ int btrfs_pin_extent(struct btrfs_root *root,
* update size of reserved extents. this function may return -EAGAIN
* if 'reserve' is true or 'sinfo' is false.
*/
-static int update_reserved_bytes(struct btrfs_block_group_cache *cache,
- u64 num_bytes, int reserve, int sinfo)
+int btrfs_update_reserved_bytes(struct btrfs_block_group_cache *cache,
+ u64 num_bytes, int reserve, int sinfo)
{
int ret = 0;
if (sinfo) {
@@ -4353,7 +4357,9 @@ int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans,
if (ret)
break;
- ret = btrfs_discard_extent(root, start, end + 1 - start);
+ if (btrfs_test_opt(root, DISCARD))
+ ret = btrfs_discard_extent(root, start,
+ end + 1 - start, NULL);
clear_extent_dirty(unpin, start, end, GFP_NOFS);
unpin_extent_range(root, start, end);
@@ -4694,10 +4700,10 @@ void btrfs_free_tree_block(struct btrfs_trans_handle *trans,
WARN_ON(test_bit(EXTENT_BUFFER_DIRTY, &buf->bflags));
btrfs_add_free_space(cache, buf->start, buf->len);
- ret = update_reserved_bytes(cache, buf->len, 0, 0);
+ ret = btrfs_update_reserved_bytes(cache, buf->len, 0, 0);
if (ret == -EAGAIN) {
/* block group became read-only */
- update_reserved_bytes(cache, buf->len, 0, 1);
+ btrfs_update_reserved_bytes(cache, buf->len, 0, 1);
goto out;
}
@@ -5180,7 +5186,7 @@ checks:
search_start - offset);
BUG_ON(offset > search_start);
- ret = update_reserved_bytes(block_group, num_bytes, 1,
+ ret = btrfs_update_reserved_bytes(block_group, num_bytes, 1,
(data & BTRFS_BLOCK_GROUP_DATA));
if (ret == -EAGAIN) {
btrfs_add_free_space(block_group, offset, num_bytes);
@@ -5401,10 +5407,11 @@ int btrfs_free_reserved_extent(struct btrfs_root *root, u64 start, u64 len)
return -ENOSPC;
}
- ret = btrfs_discard_extent(root, start, len);
+ if (btrfs_test_opt(root, DISCARD))
+ ret = btrfs_discard_extent(root, start, len, NULL);
btrfs_add_free_space(cache, start, len);
- update_reserved_bytes(cache, len, 0, 1);
+ btrfs_update_reserved_bytes(cache, len, 0, 1);
btrfs_put_block_group(cache);
return ret;
@@ -5603,7 +5610,7 @@ int btrfs_alloc_logged_file_extent(struct btrfs_trans_handle *trans,
put_caching_control(caching_ctl);
}
- ret = update_reserved_bytes(block_group, ins->offset, 1, 1);
+ ret = btrfs_update_reserved_bytes(block_group, ins->offset, 1, 1);
BUG_ON(ret);
btrfs_put_block_group(block_group);
ret = alloc_reserved_file_extent(trans, root, 0, root_objectid,
@@ -8719,7 +8726,55 @@ int btrfs_error_unpin_extent_range(struct btrfs_root *root, u64 start, u64 end)
}
int btrfs_error_discard_extent(struct btrfs_root *root, u64 bytenr,
- u64 num_bytes)
+ u64 num_bytes, u64 *actual_bytes)
{
- return btrfs_discard_extent(root, bytenr, num_bytes);
+ return btrfs_discard_extent(root, bytenr, num_bytes, actual_bytes);
+}
+
+int btrfs_trim_fs(struct btrfs_root *root, struct fstrim_range *range)
+{
+ struct btrfs_fs_info *fs_info = root->fs_info;
+ struct btrfs_block_group_cache *cache = NULL;
+ u64 group_trimmed;
+ u64 start;
+ u64 end;
+ u64 trimmed = 0;
+ int ret = 0;
+
+ cache = btrfs_lookup_block_group(fs_info, range->start);
+
+ while (cache) {
+ if (cache->key.objectid >= (range->start + range->len)) {
+ btrfs_put_block_group(cache);
+ break;
+ }
+
+ start = max(range->start, cache->key.objectid);
+ end = min(range->start + range->len,
+ cache->key.objectid + cache->key.offset);
+
+ if (end - start >= range->minlen) {
+ if (!block_group_cache_done(cache)) {
+ ret = cache_block_group(cache, NULL, root, 0);
+ if (!ret)
+ wait_block_group_cache_done(cache);
+ }
+ ret = btrfs_trim_block_group(cache,
+ &group_trimmed,
+ start,
+ end,
+ range->minlen);
+
+ trimmed += group_trimmed;
+ if (ret < 0) {
+ btrfs_put_block_group(cache);
+ break;
+ }
+ }
+
+ cache = next_block_group(fs_info->tree_root, cache);
+ }
+
+ range->len = trimmed;
+ return ret;
}
diff --git a/fs/btrfs/free-space-cache.c b/fs/btrfs/free-space-cache.c
index a039065..d0dc812 100644
--- a/fs/btrfs/free-space-cache.c
+++ b/fs/btrfs/free-space-cache.c
@@ -2154,3 +2154,95 @@ void btrfs_init_free_cluster(struct btrfs_free_cluster *cluster)
cluster->block_group = NULL;
}
+int btrfs_trim_block_group(struct btrfs_block_group_cache *block_group,
+ u64 *trimmed, u64 start, u64 end, u64 minlen)
+{
+ struct btrfs_free_space *entry = NULL;
+ struct btrfs_fs_info *fs_info = block_group->fs_info;
+ u64 bytes = 0;
+ u64 actually_trimmed;
+ int ret = 0;
+
+ *trimmed = 0;
+
+ while (start < end) {
+ spin_lock(&block_group->tree_lock);
+
+ if (block_group->free_space < minlen) {
+ spin_unlock(&block_group->tree_lock);
+ break;
+ }
+
+ entry = tree_search_offset(block_group, start, 0, 1);
+ if (!entry)
+ entry = tree_search_offset(block_group,
+ offset_to_bitmap(block_group,
+ start),
+ 1, 1);
+
+ if (!entry || entry->offset >= end) {
+ spin_unlock(&block_group->tree_lock);
+ break;
+ }
+
+ if (entry->bitmap) {
+ ret = search_bitmap(block_group, entry, &start, &bytes);
+ if (!ret) {
+ if (start >= end) {
+ spin_unlock(&block_group->tree_lock);
+ break;
+ }
+ bytes = min(bytes, end - start);
+ bitmap_clear_bits(block_group, entry,
+ start, bytes);
+ if (entry->bytes == 0)
+ free_bitmap(block_group, entry);
+ } else {
+ start = entry->offset + BITS_PER_BITMAP *
+ block_group->sectorsize;
+ spin_unlock(&block_group->tree_lock);
+ ret = 0;
+ continue;
+ }
+ } else {
+ start = entry->offset;
+ bytes = min(entry->bytes, end - start);
+ unlink_free_space(block_group, entry);
+ kfree(entry);
+ }
+
+ spin_unlock(&block_group->tree_lock);
+
+ if (bytes >= minlen) {
+ int update_ret;
+ update_ret = btrfs_update_reserved_bytes(block_group,
+ bytes, 1, 1);
+
+ ret = btrfs_error_discard_extent(fs_info->extent_root,
+ start,
+ bytes,
+ &actually_trimmed);
+
+ btrfs_add_free_space(block_group,
+ start, bytes);
+ if (!update_ret)
+ btrfs_update_reserved_bytes(block_group,
+ bytes, 0, 1);
+
+ if (ret)
+ break;
+ *trimmed += actually_trimmed;
+ }
+ start += bytes;
+ bytes = 0;
+
+ if (fatal_signal_pending(current)) {
+ ret = -ERESTARTSYS;
+ break;
+ }
+
+ cond_resched();
+ }
+
+ return ret;
+}
diff --git a/fs/btrfs/free-space-cache.h b/fs/btrfs/free-space-cache.h
index e49ca5c..65c3b93 100644
--- a/fs/btrfs/free-space-cache.h
+++ b/fs/btrfs/free-space-cache.h
@@ -68,4 +68,6 @@ u64 btrfs_alloc_from_cluster(struct btrfs_block_group_cache *block_group,
int btrfs_return_cluster_to_free_space(
struct btrfs_block_group_cache *block_group,
struct btrfs_free_cluster *cluster);
+int btrfs_trim_block_group(struct btrfs_block_group_cache *block_group,
+ u64 *trimmed, u64 start, u64 end, u64 minlen);
#endif
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 5fdb2ab..eff9228 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -40,6 +40,7 @@
#include <linux/xattr.h>
#include <linux/vmalloc.h>
#include <linux/slab.h>
+#include <linux/blkdev.h>
#include "compat.h"
#include "ctree.h"
#include "disk-io.h"
@@ -225,6 +226,49 @@ static int btrfs_ioctl_getversion(struct file *file, int __user *arg)
return put_user(inode->i_generation, arg);
}
+static noinline int btrfs_ioctl_fitrim(struct file *file, void __user *arg)
+{
+ struct btrfs_root *root = fdentry(file)->d_sb->s_fs_info;
+ struct btrfs_fs_info *fs_info = root->fs_info;
+ struct btrfs_device *device;
+ struct request_queue *q;
+ struct fstrim_range range;
+ u64 minlen = ULLONG_MAX;
+ u64 num_devices = 0;
+ int ret;
+
+ if (!capable(CAP_SYS_ADMIN))
+ return -EPERM;
+
+ mutex_lock(&fs_info->fs_devices->device_list_mutex);
+ list_for_each_entry(device, &fs_info->fs_devices->devices, dev_list) {
+ if (!device->bdev)
+ continue;
+ q = bdev_get_queue(device->bdev);
+ if (blk_queue_discard(q)) {
+ num_devices++;
+ minlen = min((u64)q->limits.discard_granularity,
+ minlen);
+ }
+ }
+ mutex_unlock(&fs_info->fs_devices->device_list_mutex);
+ if (!num_devices)
+ return -EOPNOTSUPP;
+
+ if (copy_from_user(&range, arg, sizeof(range)))
+ return -EFAULT;
+
+ range.minlen = max(range.minlen, minlen);
+ ret = btrfs_trim_fs(root, &range);
+ if (ret < 0)
+ return ret;
+
+ if (copy_to_user(arg, &range, sizeof(range)))
+ return -EFAULT;
+
+ return 0;
+}
+
static noinline int create_subvol(struct btrfs_root *root,
struct dentry *dentry,
char *name, int namelen,
@@ -2388,6 +2432,8 @@ long btrfs_ioctl(struct file *file, unsigned int
return btrfs_ioctl_setflags(file, argp);
case FS_IOC_GETVERSION:
return btrfs_ioctl_getversion(file, argp);
+ case FITRIM:
+ return btrfs_ioctl_fitrim(file, argp);
case BTRFS_IOC_SNAP_CREATE:
return btrfs_ioctl_snap_create(file, argp, 0);
case BTRFS_IOC_SNAP_CREATE_V2:
--
1.7.1
^ permalink raw reply related [flat|nested] only message in thread
only message in thread, other threads:[~2011-03-03 13:41 UTC | newest]
Thread overview: (only message) (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2011-03-03 13:41 [PATCH V3] Btrfs: Batched discard support for btrfs Li Dongyang
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).