Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
Btrfs: remove free-space-cache.c WARN during log replay
Btrfs: sectorsize align offsets in fiemap
Btrfs: clear pages dirty for io and set them extent mapped
Btrfs: wait on caching if we're loading the free space cache
Btrfs: prefix resize related printks with btrfs:
btrfs: fix stat blocks accounting
Btrfs: avoid unnecessary bitmap search for cluster setup
Btrfs: fix to search one more bitmap for cluster setup
btrfs: mirror_num should be int, not u64
btrfs: Fix up 32/64-bit compatibility for new ioctls
Btrfs: fix barrier flushes
Btrfs: fix tree corruption after multi-thread snapshots and inode_cache flush
diff --git a/fs/btrfs/backref.c b/fs/btrfs/backref.c
index 8855aad..22c64ff 100644
--- a/fs/btrfs/backref.c
+++ b/fs/btrfs/backref.c
@@ -683,7 +683,7 @@
return PTR_ERR(fspath);
if (fspath > fspath_min) {
- ipath->fspath->val[i] = (u64)fspath;
+ ipath->fspath->val[i] = (u64)(unsigned long)fspath;
++ipath->fspath->elem_cnt;
ipath->fspath->bytes_left = fspath - fspath_min;
} else {
diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index 0fe615e..dede441 100644
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -514,10 +514,25 @@
struct btrfs_root *root,
struct extent_buffer *buf)
{
+ /* ensure we can see the force_cow */
+ smp_rmb();
+
+ /*
+ * We do not need to cow a block if
+ * 1) this block is not created or changed in this transaction;
+ * 2) this block does not belong to TREE_RELOC tree;
+ * 3) the root is not forced COW.
+ *
+ * What is forced COW:
+ * when we create snapshot during commiting the transaction,
+ * after we've finished coping src root, we must COW the shared
+ * block to ensure the metadata consistency.
+ */
if (btrfs_header_generation(buf) == trans->transid &&
!btrfs_header_flag(buf, BTRFS_HEADER_FLAG_WRITTEN) &&
!(root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID &&
- btrfs_header_flag(buf, BTRFS_HEADER_FLAG_RELOC)))
+ btrfs_header_flag(buf, BTRFS_HEADER_FLAG_RELOC)) &&
+ !root->force_cow)
return 0;
return 1;
}
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index b9ba59f..04a5dfc 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -848,7 +848,8 @@
enum btrfs_caching_type {
BTRFS_CACHE_NO = 0,
BTRFS_CACHE_STARTED = 1,
- BTRFS_CACHE_FINISHED = 2,
+ BTRFS_CACHE_FAST = 2,
+ BTRFS_CACHE_FINISHED = 3,
};
enum btrfs_disk_cache_state {
@@ -1271,6 +1272,8 @@
* for stat. It may be used for more later
*/
dev_t anon_dev;
+
+ int force_cow;
};
struct btrfs_ioctl_defrag_range_args {
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 62afe5c..632f8f3 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -620,7 +620,7 @@
static int btree_io_failed_hook(struct bio *failed_bio,
struct page *page, u64 start, u64 end,
- u64 mirror_num, struct extent_state *state)
+ int mirror_num, struct extent_state *state)
{
struct extent_io_tree *tree;
unsigned long len;
@@ -2573,22 +2573,10 @@
int errors = 0;
u32 crc;
u64 bytenr;
- int last_barrier = 0;
if (max_mirrors == 0)
max_mirrors = BTRFS_SUPER_MIRROR_MAX;
- /* make sure only the last submit_bh does a barrier */
- if (do_barriers) {
- for (i = 0; i < max_mirrors; i++) {
- bytenr = btrfs_sb_offset(i);
- if (bytenr + BTRFS_SUPER_INFO_SIZE >=
- device->total_bytes)
- break;
- last_barrier = i;
- }
- }
-
for (i = 0; i < max_mirrors; i++) {
bytenr = btrfs_sb_offset(i);
if (bytenr + BTRFS_SUPER_INFO_SIZE >= device->total_bytes)
@@ -2634,17 +2622,136 @@
bh->b_end_io = btrfs_end_buffer_write_sync;
}
- if (i == last_barrier && do_barriers)
- ret = submit_bh(WRITE_FLUSH_FUA, bh);
- else
- ret = submit_bh(WRITE_SYNC, bh);
-
+ /*
+ * we fua the first super. The others we allow
+ * to go down lazy.
+ */
+ ret = submit_bh(WRITE_FUA, bh);
if (ret)
errors++;
}
return errors < i ? 0 : -1;
}
+/*
+ * endio for the write_dev_flush, this will wake anyone waiting
+ * for the barrier when it is done
+ */
+static void btrfs_end_empty_barrier(struct bio *bio, int err)
+{
+ if (err) {
+ if (err == -EOPNOTSUPP)
+ set_bit(BIO_EOPNOTSUPP, &bio->bi_flags);
+ clear_bit(BIO_UPTODATE, &bio->bi_flags);
+ }
+ if (bio->bi_private)
+ complete(bio->bi_private);
+ bio_put(bio);
+}
+
+/*
+ * trigger flushes for one the devices. If you pass wait == 0, the flushes are
+ * sent down. With wait == 1, it waits for the previous flush.
+ *
+ * any device where the flush fails with eopnotsupp are flagged as not-barrier
+ * capable
+ */
+static int write_dev_flush(struct btrfs_device *device, int wait)
+{
+ struct bio *bio;
+ int ret = 0;
+
+ if (device->nobarriers)
+ return 0;
+
+ if (wait) {
+ bio = device->flush_bio;
+ if (!bio)
+ return 0;
+
+ wait_for_completion(&device->flush_wait);
+
+ if (bio_flagged(bio, BIO_EOPNOTSUPP)) {
+ printk("btrfs: disabling barriers on dev %s\n",
+ device->name);
+ device->nobarriers = 1;
+ }
+ if (!bio_flagged(bio, BIO_UPTODATE)) {
+ ret = -EIO;
+ }
+
+ /* drop the reference from the wait == 0 run */
+ bio_put(bio);
+ device->flush_bio = NULL;
+
+ return ret;
+ }
+
+ /*
+ * one reference for us, and we leave it for the
+ * caller
+ */
+ device->flush_bio = NULL;;
+ bio = bio_alloc(GFP_NOFS, 0);
+ if (!bio)
+ return -ENOMEM;
+
+ bio->bi_end_io = btrfs_end_empty_barrier;
+ bio->bi_bdev = device->bdev;
+ init_completion(&device->flush_wait);
+ bio->bi_private = &device->flush_wait;
+ device->flush_bio = bio;
+
+ bio_get(bio);
+ submit_bio(WRITE_FLUSH, bio);
+
+ return 0;
+}
+
+/*
+ * send an empty flush down to each device in parallel,
+ * then wait for them
+ */
+static int barrier_all_devices(struct btrfs_fs_info *info)
+{
+ struct list_head *head;
+ struct btrfs_device *dev;
+ int errors = 0;
+ int ret;
+
+ /* send down all the barriers */
+ head = &info->fs_devices->devices;
+ list_for_each_entry_rcu(dev, head, dev_list) {
+ if (!dev->bdev) {
+ errors++;
+ continue;
+ }
+ if (!dev->in_fs_metadata || !dev->writeable)
+ continue;
+
+ ret = write_dev_flush(dev, 0);
+ if (ret)
+ errors++;
+ }
+
+ /* wait for all the barriers */
+ list_for_each_entry_rcu(dev, head, dev_list) {
+ if (!dev->bdev) {
+ errors++;
+ continue;
+ }
+ if (!dev->in_fs_metadata || !dev->writeable)
+ continue;
+
+ ret = write_dev_flush(dev, 1);
+ if (ret)
+ errors++;
+ }
+ if (errors)
+ return -EIO;
+ return 0;
+}
+
int write_all_supers(struct btrfs_root *root, int max_mirrors)
{
struct list_head *head;
@@ -2666,6 +2773,10 @@
mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
head = &root->fs_info->fs_devices->devices;
+
+ if (do_barriers)
+ barrier_all_devices(root->fs_info);
+
list_for_each_entry_rcu(dev, head, dev_list) {
if (!dev->bdev) {
total_errors++;
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index b232150..930ae89 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -467,13 +467,59 @@
struct btrfs_root *root,
int load_cache_only)
{
+ DEFINE_WAIT(wait);
struct btrfs_fs_info *fs_info = cache->fs_info;
struct btrfs_caching_control *caching_ctl;
int ret = 0;
- smp_mb();
- if (cache->cached != BTRFS_CACHE_NO)
+ caching_ctl = kzalloc(sizeof(*caching_ctl), GFP_NOFS);
+ BUG_ON(!caching_ctl);
+
+ INIT_LIST_HEAD(&caching_ctl->list);
+ mutex_init(&caching_ctl->mutex);
+ init_waitqueue_head(&caching_ctl->wait);
+ caching_ctl->block_group = cache;
+ caching_ctl->progress = cache->key.objectid;
+ atomic_set(&caching_ctl->count, 1);
+ caching_ctl->work.func = caching_thread;
+
+ spin_lock(&cache->lock);
+ /*
+ * This should be a rare occasion, but this could happen I think in the
+ * case where one thread starts to load the space cache info, and then
+ * some other thread starts a transaction commit which tries to do an
+ * allocation while the other thread is still loading the space cache
+ * info. The previous loop should have kept us from choosing this block
+ * group, but if we've moved to the state where we will wait on caching
+ * block groups we need to first check if we're doing a fast load here,
+ * so we can wait for it to finish, otherwise we could end up allocating
+ * from a block group who's cache gets evicted for one reason or
+ * another.
+ */
+ while (cache->cached == BTRFS_CACHE_FAST) {
+ struct btrfs_caching_control *ctl;
+
+ ctl = cache->caching_ctl;
+ atomic_inc(&ctl->count);
+ prepare_to_wait(&ctl->wait, &wait, TASK_UNINTERRUPTIBLE);
+ spin_unlock(&cache->lock);
+
+ schedule();
+
+ finish_wait(&ctl->wait, &wait);
+ put_caching_control(ctl);
+ spin_lock(&cache->lock);
+ }
+
+ if (cache->cached != BTRFS_CACHE_NO) {
+ spin_unlock(&cache->lock);
+ kfree(caching_ctl);
return 0;
+ }
+ WARN_ON(cache->caching_ctl);
+ cache->caching_ctl = caching_ctl;
+ cache->cached = BTRFS_CACHE_FAST;
+ spin_unlock(&cache->lock);
/*
* We can't do the read from on-disk cache during a commit since we need
@@ -484,56 +530,51 @@
if (trans && (!trans->transaction->in_commit) &&
(root && root != root->fs_info->tree_root) &&
btrfs_test_opt(root, SPACE_CACHE)) {
- spin_lock(&cache->lock);
- if (cache->cached != BTRFS_CACHE_NO) {
- spin_unlock(&cache->lock);
- return 0;
- }
- cache->cached = BTRFS_CACHE_STARTED;
- spin_unlock(&cache->lock);
-
ret = load_free_space_cache(fs_info, cache);
spin_lock(&cache->lock);
if (ret == 1) {
+ cache->caching_ctl = NULL;
cache->cached = BTRFS_CACHE_FINISHED;
cache->last_byte_to_unpin = (u64)-1;
} else {
- cache->cached = BTRFS_CACHE_NO;
+ if (load_cache_only) {
+ cache->caching_ctl = NULL;
+ cache->cached = BTRFS_CACHE_NO;
+ } else {
+ cache->cached = BTRFS_CACHE_STARTED;
+ }
}
spin_unlock(&cache->lock);
+ wake_up(&caching_ctl->wait);
if (ret == 1) {
+ put_caching_control(caching_ctl);
free_excluded_extents(fs_info->extent_root, cache);
return 0;
}
- }
-
- if (load_cache_only)
- return 0;
-
- caching_ctl = kzalloc(sizeof(*caching_ctl), GFP_NOFS);
- BUG_ON(!caching_ctl);
-
- INIT_LIST_HEAD(&caching_ctl->list);
- mutex_init(&caching_ctl->mutex);
- init_waitqueue_head(&caching_ctl->wait);
- caching_ctl->block_group = cache;
- caching_ctl->progress = cache->key.objectid;
- /* one for caching kthread, one for caching block group list */
- atomic_set(&caching_ctl->count, 2);
- caching_ctl->work.func = caching_thread;
-
- spin_lock(&cache->lock);
- if (cache->cached != BTRFS_CACHE_NO) {
+ } else {
+ /*
+ * We are not going to do the fast caching, set cached to the
+ * appropriate value and wakeup any waiters.
+ */
+ spin_lock(&cache->lock);
+ if (load_cache_only) {
+ cache->caching_ctl = NULL;
+ cache->cached = BTRFS_CACHE_NO;
+ } else {
+ cache->cached = BTRFS_CACHE_STARTED;
+ }
spin_unlock(&cache->lock);
- kfree(caching_ctl);
+ wake_up(&caching_ctl->wait);
+ }
+
+ if (load_cache_only) {
+ put_caching_control(caching_ctl);
return 0;
}
- cache->caching_ctl = caching_ctl;
- cache->cached = BTRFS_CACHE_STARTED;
- spin_unlock(&cache->lock);
down_write(&fs_info->extent_commit_sem);
+ atomic_inc(&caching_ctl->count);
list_add_tail(&caching_ctl->list, &fs_info->caching_block_groups);
up_write(&fs_info->extent_commit_sem);
@@ -5178,13 +5219,15 @@
}
have_block_group:
- if (unlikely(block_group->cached == BTRFS_CACHE_NO)) {
+ cached = block_group_cache_done(block_group);
+ if (unlikely(!cached)) {
u64 free_percent;
+ found_uncached_bg = true;
ret = cache_block_group(block_group, trans,
orig_root, 1);
if (block_group->cached == BTRFS_CACHE_FINISHED)
- goto have_block_group;
+ goto alloc;
free_percent = btrfs_block_group_used(&block_group->item);
free_percent *= 100;
@@ -5206,7 +5249,6 @@
orig_root, 0);
BUG_ON(ret);
}
- found_uncached_bg = true;
/*
* If loop is set for cached only, try the next block
@@ -5216,10 +5258,7 @@
goto loop;
}
- cached = block_group_cache_done(block_group);
- if (unlikely(!cached))
- found_uncached_bg = true;
-
+alloc:
if (unlikely(block_group->ro))
goto loop;
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 1f87c4d..9472d3d 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -2285,8 +2285,8 @@
clean_io_failure(start, page);
}
if (!uptodate) {
- u64 failed_mirror;
- failed_mirror = (u64)bio->bi_bdev;
+ int failed_mirror;
+ failed_mirror = (int)(unsigned long)bio->bi_bdev;
if (tree->ops && tree->ops->readpage_io_failed_hook)
ret = tree->ops->readpage_io_failed_hook(
bio, page, start, end,
@@ -3366,6 +3366,9 @@
return -ENOMEM;
path->leave_spinning = 1;
+ start = ALIGN(start, BTRFS_I(inode)->root->sectorsize);
+ len = ALIGN(len, BTRFS_I(inode)->root->sectorsize);
+
/*
* lookup the last file extent. We're not using i_size here
* because there might be preallocation past i_size
@@ -3413,7 +3416,7 @@
lock_extent_bits(&BTRFS_I(inode)->io_tree, start, start + len, 0,
&cached_state, GFP_NOFS);
- em = get_extent_skip_holes(inode, off, last_for_get_extent,
+ em = get_extent_skip_holes(inode, start, last_for_get_extent,
get_extent);
if (!em)
goto out;
diff --git a/fs/btrfs/extent_io.h b/fs/btrfs/extent_io.h
index feb9be0..7604c30 100644
--- a/fs/btrfs/extent_io.h
+++ b/fs/btrfs/extent_io.h
@@ -70,7 +70,7 @@
unsigned long bio_flags);
int (*readpage_io_hook)(struct page *page, u64 start, u64 end);
int (*readpage_io_failed_hook)(struct bio *bio, struct page *page,
- u64 start, u64 end, u64 failed_mirror,
+ u64 start, u64 end, int failed_mirror,
struct extent_state *state);
int (*writepage_io_failed_hook)(struct bio *bio, struct page *page,
u64 start, u64 end,
diff --git a/fs/btrfs/free-space-cache.c b/fs/btrfs/free-space-cache.c
index 181760f..6e5b7e4 100644
--- a/fs/btrfs/free-space-cache.c
+++ b/fs/btrfs/free-space-cache.c
@@ -351,6 +351,11 @@
}
}
+ for (i = 0; i < io_ctl->num_pages; i++) {
+ clear_page_dirty_for_io(io_ctl->pages[i]);
+ set_page_extent_mapped(io_ctl->pages[i]);
+ }
+
return 0;
}
@@ -1844,7 +1849,13 @@
info = tree_search_offset(ctl, offset_to_bitmap(ctl, offset),
1, 0);
if (!info) {
- WARN_ON(1);
+ /* the tree logging code might be calling us before we
+ * have fully loaded the free space rbtree for this
+ * block group. So it is possible the entry won't
+ * be in the rbtree yet at all. The caching code
+ * will make sure not to put it in the rbtree if
+ * the logging code has pinned it.
+ */
goto out_lock;
}
}
@@ -2451,16 +2462,23 @@
{
struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
struct btrfs_free_space *entry;
- struct rb_node *node;
int ret = -ENOSPC;
+ u64 bitmap_offset = offset_to_bitmap(ctl, offset);
if (ctl->total_bitmaps == 0)
return -ENOSPC;
/*
- * First check our cached list of bitmaps and see if there is an entry
- * here that will work.
+ * The bitmap that covers offset won't be in the list unless offset
+ * is just its start offset.
*/
+ entry = list_first_entry(bitmaps, struct btrfs_free_space, list);
+ if (entry->offset != bitmap_offset) {
+ entry = tree_search_offset(ctl, bitmap_offset, 1, 0);
+ if (entry && list_empty(&entry->list))
+ list_add(&entry->list, bitmaps);
+ }
+
list_for_each_entry(entry, bitmaps, list) {
if (entry->bytes < min_bytes)
continue;
@@ -2471,38 +2489,10 @@
}
/*
- * If we do have entries on our list and we are here then we didn't find
- * anything, so go ahead and get the next entry after the last entry in
- * this list and start the search from there.
+ * The bitmaps list has all the bitmaps that record free space
+ * starting after offset, so no more search is required.
*/
- if (!list_empty(bitmaps)) {
- entry = list_entry(bitmaps->prev, struct btrfs_free_space,
- list);
- node = rb_next(&entry->offset_index);
- if (!node)
- return -ENOSPC;
- entry = rb_entry(node, struct btrfs_free_space, offset_index);
- goto search;
- }
-
- entry = tree_search_offset(ctl, offset_to_bitmap(ctl, offset), 0, 1);
- if (!entry)
- return -ENOSPC;
-
-search:
- node = &entry->offset_index;
- do {
- entry = rb_entry(node, struct btrfs_free_space, offset_index);
- node = rb_next(&entry->offset_index);
- if (!entry->bitmap)
- continue;
- if (entry->bytes < min_bytes)
- continue;
- ret = btrfs_bitmap_cluster(block_group, entry, cluster, offset,
- bytes, min_bytes);
- } while (ret && node);
-
- return ret;
+ return -ENOSPC;
}
/*
@@ -2520,8 +2510,8 @@
u64 offset, u64 bytes, u64 empty_size)
{
struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
- struct list_head bitmaps;
struct btrfs_free_space *entry, *tmp;
+ LIST_HEAD(bitmaps);
u64 min_bytes;
int ret;
@@ -2560,7 +2550,6 @@
goto out;
}
- INIT_LIST_HEAD(&bitmaps);
ret = setup_cluster_no_bitmap(block_group, cluster, &bitmaps, offset,
bytes, min_bytes);
if (ret)
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 116ab67..526dd51 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -6794,11 +6794,13 @@
struct dentry *dentry, struct kstat *stat)
{
struct inode *inode = dentry->d_inode;
+ u32 blocksize = inode->i_sb->s_blocksize;
+
generic_fillattr(inode, stat);
stat->dev = BTRFS_I(inode)->root->anon_dev;
stat->blksize = PAGE_CACHE_SIZE;
- stat->blocks = (inode_get_bytes(inode) +
- BTRFS_I(inode)->delalloc_bytes) >> 9;
+ stat->blocks = (ALIGN(inode_get_bytes(inode), blocksize) +
+ ALIGN(BTRFS_I(inode)->delalloc_bytes, blocksize)) >> 9;
return 0;
}
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 4a34c47..a90e749 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -1216,12 +1216,12 @@
*devstr = '\0';
devstr = vol_args->name;
devid = simple_strtoull(devstr, &end, 10);
- printk(KERN_INFO "resizing devid %llu\n",
+ printk(KERN_INFO "btrfs: resizing devid %llu\n",
(unsigned long long)devid);
}
device = btrfs_find_device(root, devid, NULL, NULL);
if (!device) {
- printk(KERN_INFO "resizer unable to find device %llu\n",
+ printk(KERN_INFO "btrfs: resizer unable to find device %llu\n",
(unsigned long long)devid);
ret = -EINVAL;
goto out_unlock;
@@ -1267,7 +1267,7 @@
do_div(new_size, root->sectorsize);
new_size *= root->sectorsize;
- printk(KERN_INFO "new size for %s is %llu\n",
+ printk(KERN_INFO "btrfs: new size for %s is %llu\n",
device->name, (unsigned long long)new_size);
if (new_size > old_size) {
@@ -2930,11 +2930,13 @@
goto out;
for (i = 0; i < ipath->fspath->elem_cnt; ++i) {
- rel_ptr = ipath->fspath->val[i] - (u64)ipath->fspath->val;
+ rel_ptr = ipath->fspath->val[i] -
+ (u64)(unsigned long)ipath->fspath->val;
ipath->fspath->val[i] = rel_ptr;
}
- ret = copy_to_user((void *)ipa->fspath, (void *)ipath->fspath, size);
+ ret = copy_to_user((void *)(unsigned long)ipa->fspath,
+ (void *)(unsigned long)ipath->fspath, size);
if (ret) {
ret = -EFAULT;
goto out;
@@ -3017,7 +3019,8 @@
if (ret < 0)
goto out;
- ret = copy_to_user((void *)loi->inodes, (void *)inodes, size);
+ ret = copy_to_user((void *)(unsigned long)loi->inodes,
+ (void *)(unsigned long)inodes, size);
if (ret)
ret = -EFAULT;
diff --git a/fs/btrfs/scrub.c b/fs/btrfs/scrub.c
index f4190f2..fab420d 100644
--- a/fs/btrfs/scrub.c
+++ b/fs/btrfs/scrub.c
@@ -272,7 +272,7 @@
swarn->logical, swarn->dev->name,
(unsigned long long)swarn->sector, root, inum, offset,
min(isize - offset, (u64)PAGE_SIZE), nlink,
- (char *)ipath->fspath->val[i]);
+ (char *)(unsigned long)ipath->fspath->val[i]);
free_ipath(ipath);
return 0;
diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index 6a0574e..81376d9 100644
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -785,6 +785,10 @@
btrfs_save_ino_cache(root, trans);
+ /* see comments in should_cow_block() */
+ root->force_cow = 0;
+ smp_wmb();
+
if (root->commit_root != root->node) {
mutex_lock(&root->fs_commit_mutex);
switch_commit_root(root);
@@ -947,6 +951,10 @@
btrfs_tree_unlock(old);
free_extent_buffer(old);
+ /* see comments in should_cow_block() */
+ root->force_cow = 1;
+ smp_wmb();
+
btrfs_set_root_node(new_root_item, tmp);
/* record when the snapshot was created in key.offset */
key.offset = trans->transid;
diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h
index ab5b1c4..78f2d4d 100644
--- a/fs/btrfs/volumes.h
+++ b/fs/btrfs/volumes.h
@@ -100,6 +100,12 @@
struct reada_zone *reada_curr_zone;
struct radix_tree_root reada_zones;
struct radix_tree_root reada_extents;
+
+ /* for sending down flush barriers */
+ struct bio *flush_bio;
+ struct completion flush_wait;
+ int nobarriers;
+
};
struct btrfs_fs_devices {