Merge git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable
* git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable:
Btrfs: prevent RAID level downgrades when space is low
Btrfs: account for missing devices in RAID allocation profiles
Btrfs: EIO when we fail to read tree roots
Btrfs: fix compiler warnings
Btrfs: Make async snapshot ioctl more generic
Btrfs: pwrite blocked when writing from the mmaped buffer of the same page
Btrfs: Fix a crash when mounting a subvolume
Btrfs: fix sync subvol/snapshot creation
Btrfs: Fix page leak in compressed writeback path
Btrfs: do not BUG if we fail to remove the orphan item for dead snapshots
Btrfs: fixup return code for btrfs_del_orphan_item
Btrfs: do not do fast caching if we are allocating blocks for tree_root
Btrfs: deal with space cache errors better
Btrfs: fix use after free in O_DIRECT
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index c547cca..51d2e4d 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -696,6 +696,7 @@
__btree_submit_bio_done);
}
+#ifdef CONFIG_MIGRATION
static int btree_migratepage(struct address_space *mapping,
struct page *newpage, struct page *page)
{
@@ -712,12 +713,9 @@
if (page_has_private(page) &&
!try_to_release_page(page, GFP_KERNEL))
return -EAGAIN;
-#ifdef CONFIG_MIGRATION
return migrate_page(mapping, newpage, page);
-#else
- return -ENOSYS;
-#endif
}
+#endif
static int btree_writepage(struct page *page, struct writeback_control *wbc)
{
@@ -1009,7 +1007,10 @@
blocksize = btrfs_level_size(root, btrfs_root_level(&root->root_item));
root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
blocksize, generation);
- BUG_ON(!root->node);
+ if (!root->node || !btrfs_buffer_uptodate(root->node, generation)) {
+ free_extent_buffer(root->node);
+ return -EIO;
+ }
root->commit_root = btrfs_root_node(root);
return 0;
}
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index bcd59c7..227e581 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -429,6 +429,7 @@
static int cache_block_group(struct btrfs_block_group_cache *cache,
struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
int load_cache_only)
{
struct btrfs_fs_info *fs_info = cache->fs_info;
@@ -442,9 +443,12 @@
/*
* We can't do the read from on-disk cache during a commit since we need
- * to have the normal tree locking.
+ * to have the normal tree locking. Also if we are currently trying to
+ * 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->transaction->in_commit &&
+ (root && root != root->fs_info->tree_root)) {
spin_lock(&cache->lock);
if (cache->cached != BTRFS_CACHE_NO) {
spin_unlock(&cache->lock);
@@ -2741,6 +2745,7 @@
struct btrfs_root *root = block_group->fs_info->tree_root;
struct inode *inode = NULL;
u64 alloc_hint = 0;
+ int dcs = BTRFS_DC_ERROR;
int num_pages = 0;
int retries = 0;
int ret = 0;
@@ -2795,6 +2800,8 @@
spin_lock(&block_group->lock);
if (block_group->cached != BTRFS_CACHE_FINISHED) {
+ /* We're not cached, don't bother trying to write stuff out */
+ dcs = BTRFS_DC_WRITTEN;
spin_unlock(&block_group->lock);
goto out_put;
}
@@ -2821,6 +2828,8 @@
ret = btrfs_prealloc_file_range_trans(inode, trans, 0, 0, num_pages,
num_pages, num_pages,
&alloc_hint);
+ if (!ret)
+ dcs = BTRFS_DC_SETUP;
btrfs_free_reserved_data_space(inode, num_pages);
out_put:
iput(inode);
@@ -2828,10 +2837,7 @@
btrfs_release_path(root, path);
out:
spin_lock(&block_group->lock);
- if (ret)
- block_group->disk_cache_state = BTRFS_DC_ERROR;
- else
- block_group->disk_cache_state = BTRFS_DC_SETUP;
+ block_group->disk_cache_state = dcs;
spin_unlock(&block_group->lock);
return ret;
@@ -3037,7 +3043,13 @@
u64 btrfs_reduce_alloc_profile(struct btrfs_root *root, u64 flags)
{
- u64 num_devices = root->fs_info->fs_devices->rw_devices;
+ /*
+ * we add in the count of missing devices because we want
+ * to make sure that any RAID levels on a degraded FS
+ * continue to be honored.
+ */
+ u64 num_devices = root->fs_info->fs_devices->rw_devices +
+ root->fs_info->fs_devices->missing_devices;
if (num_devices == 1)
flags &= ~(BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID0);
@@ -4080,7 +4092,7 @@
* space back to the block group, otherwise we will leak space.
*/
if (!alloc && cache->cached == BTRFS_CACHE_NO)
- cache_block_group(cache, trans, 1);
+ cache_block_group(cache, trans, NULL, 1);
byte_in_group = bytenr - cache->key.objectid;
WARN_ON(byte_in_group > cache->key.offset);
@@ -4930,11 +4942,31 @@
btrfs_get_block_group(block_group);
search_start = block_group->key.objectid;
+ /*
+ * this can happen if we end up cycling through all the
+ * raid types, but we want to make sure we only allocate
+ * for the proper type.
+ */
+ if (!block_group_bits(block_group, data)) {
+ u64 extra = BTRFS_BLOCK_GROUP_DUP |
+ BTRFS_BLOCK_GROUP_RAID1 |
+ BTRFS_BLOCK_GROUP_RAID10;
+
+ /*
+ * if they asked for extra copies and this block group
+ * doesn't provide them, bail. This does allow us to
+ * fill raid0 from raid1.
+ */
+ if ((data & extra) && !(block_group->flags & extra))
+ goto loop;
+ }
+
have_block_group:
if (unlikely(block_group->cached == BTRFS_CACHE_NO)) {
u64 free_percent;
- ret = cache_block_group(block_group, trans, 1);
+ ret = cache_block_group(block_group, trans,
+ orig_root, 1);
if (block_group->cached == BTRFS_CACHE_FINISHED)
goto have_block_group;
@@ -4958,7 +4990,8 @@
if (loop > LOOP_CACHING_NOWAIT ||
(loop > LOOP_FIND_IDEAL &&
atomic_read(&space_info->caching_threads) < 2)) {
- ret = cache_block_group(block_group, trans, 0);
+ ret = cache_block_group(block_group, trans,
+ orig_root, 0);
BUG_ON(ret);
}
found_uncached_bg = true;
@@ -5515,7 +5548,7 @@
u64 num_bytes = ins->offset;
block_group = btrfs_lookup_block_group(root->fs_info, ins->objectid);
- cache_block_group(block_group, trans, 0);
+ cache_block_group(block_group, trans, NULL, 0);
caching_ctl = get_caching_control(block_group);
if (!caching_ctl) {
@@ -6300,9 +6333,13 @@
NULL, NULL);
BUG_ON(ret < 0);
if (ret > 0) {
- ret = btrfs_del_orphan_item(trans, tree_root,
- root->root_key.objectid);
- BUG_ON(ret);
+ /* if we fail to delete the orphan item this time
+ * around, it'll get picked up the next time.
+ *
+ * The most common failure here is just -ENOENT.
+ */
+ btrfs_del_orphan_item(trans, tree_root,
+ root->root_key.objectid);
}
}
@@ -7878,7 +7915,14 @@
u64 stripped = BTRFS_BLOCK_GROUP_RAID0 |
BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID10;
- num_devices = root->fs_info->fs_devices->rw_devices;
+ /*
+ * we add in the count of missing devices because we want
+ * to make sure that any RAID levels on a degraded FS
+ * continue to be honored.
+ */
+ num_devices = root->fs_info->fs_devices->rw_devices +
+ root->fs_info->fs_devices->missing_devices;
+
if (num_devices == 1) {
stripped |= BTRFS_BLOCK_GROUP_DUP;
stripped = flags & ~stripped;
@@ -8247,7 +8291,6 @@
break;
if (ret != 0)
goto error;
-
leaf = path->nodes[0];
btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
cache = kzalloc(sizeof(*cache), GFP_NOFS);
diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index c1faded..66836d8 100644
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -48,30 +48,34 @@
struct page **prepared_pages,
struct iov_iter *i)
{
- size_t copied;
+ size_t copied = 0;
int pg = 0;
int offset = pos & (PAGE_CACHE_SIZE - 1);
+ int total_copied = 0;
while (write_bytes > 0) {
size_t count = min_t(size_t,
PAGE_CACHE_SIZE - offset, write_bytes);
struct page *page = prepared_pages[pg];
-again:
- if (unlikely(iov_iter_fault_in_readable(i, count)))
- return -EFAULT;
-
- /* Copy data from userspace to the current page */
- copied = iov_iter_copy_from_user(page, i, offset, count);
+ /*
+ * Copy data from userspace to the current page
+ *
+ * Disable pagefault to avoid recursive lock since
+ * the pages are already locked
+ */
+ pagefault_disable();
+ copied = iov_iter_copy_from_user_atomic(page, i, offset, count);
+ pagefault_enable();
/* Flush processor's dcache for this page */
flush_dcache_page(page);
iov_iter_advance(i, copied);
write_bytes -= copied;
+ total_copied += copied;
+ /* Return to btrfs_file_aio_write to fault page */
if (unlikely(copied == 0)) {
- count = min_t(size_t, PAGE_CACHE_SIZE - offset,
- iov_iter_single_seg_count(i));
- goto again;
+ break;
}
if (unlikely(copied < PAGE_CACHE_SIZE - offset)) {
@@ -81,7 +85,7 @@
offset = 0;
}
}
- return 0;
+ return total_copied;
}
/*
@@ -854,6 +858,8 @@
unsigned long last_index;
int will_write;
int buffered = 0;
+ int copied = 0;
+ int dirty_pages = 0;
will_write = ((file->f_flags & O_DSYNC) || IS_SYNC(inode) ||
(file->f_flags & O_DIRECT));
@@ -970,7 +976,17 @@
WARN_ON(num_pages > nrptrs);
memset(pages, 0, sizeof(struct page *) * nrptrs);
- ret = btrfs_delalloc_reserve_space(inode, write_bytes);
+ /*
+ * Fault pages before locking them in prepare_pages
+ * to avoid recursive lock
+ */
+ if (unlikely(iov_iter_fault_in_readable(&i, write_bytes))) {
+ ret = -EFAULT;
+ goto out;
+ }
+
+ ret = btrfs_delalloc_reserve_space(inode,
+ num_pages << PAGE_CACHE_SHIFT);
if (ret)
goto out;
@@ -978,37 +994,49 @@
pos, first_index, last_index,
write_bytes);
if (ret) {
- btrfs_delalloc_release_space(inode, write_bytes);
+ btrfs_delalloc_release_space(inode,
+ num_pages << PAGE_CACHE_SHIFT);
goto out;
}
- ret = btrfs_copy_from_user(pos, num_pages,
+ copied = btrfs_copy_from_user(pos, num_pages,
write_bytes, pages, &i);
- if (ret == 0) {
+ dirty_pages = (copied + PAGE_CACHE_SIZE - 1) >>
+ PAGE_CACHE_SHIFT;
+
+ if (num_pages > dirty_pages) {
+ if (copied > 0)
+ atomic_inc(
+ &BTRFS_I(inode)->outstanding_extents);
+ btrfs_delalloc_release_space(inode,
+ (num_pages - dirty_pages) <<
+ PAGE_CACHE_SHIFT);
+ }
+
+ if (copied > 0) {
dirty_and_release_pages(NULL, root, file, pages,
- num_pages, pos, write_bytes);
+ dirty_pages, pos, copied);
}
btrfs_drop_pages(pages, num_pages);
- if (ret) {
- btrfs_delalloc_release_space(inode, write_bytes);
- goto out;
+
+ if (copied > 0) {
+ if (will_write) {
+ filemap_fdatawrite_range(inode->i_mapping, pos,
+ pos + copied - 1);
+ } else {
+ balance_dirty_pages_ratelimited_nr(
+ inode->i_mapping,
+ dirty_pages);
+ if (dirty_pages <
+ (root->leafsize >> PAGE_CACHE_SHIFT) + 1)
+ btrfs_btree_balance_dirty(root, 1);
+ btrfs_throttle(root);
+ }
}
- if (will_write) {
- filemap_fdatawrite_range(inode->i_mapping, pos,
- pos + write_bytes - 1);
- } else {
- balance_dirty_pages_ratelimited_nr(inode->i_mapping,
- num_pages);
- if (num_pages <
- (root->leafsize >> PAGE_CACHE_SHIFT) + 1)
- btrfs_btree_balance_dirty(root, 1);
- btrfs_throttle(root);
- }
-
- pos += write_bytes;
- num_written += write_bytes;
+ pos += copied;
+ num_written += copied;
cond_resched();
}
diff --git a/fs/btrfs/free-space-cache.c b/fs/btrfs/free-space-cache.c
index 22ee0dc..60d6842 100644
--- a/fs/btrfs/free-space-cache.c
+++ b/fs/btrfs/free-space-cache.c
@@ -290,7 +290,7 @@
(unsigned long long)BTRFS_I(inode)->generation,
(unsigned long long)generation,
(unsigned long long)block_group->key.objectid);
- goto out;
+ goto free_cache;
}
if (!num_entries)
@@ -524,6 +524,12 @@
return 0;
}
+ node = rb_first(&block_group->free_space_offset);
+ if (!node) {
+ iput(inode);
+ return 0;
+ }
+
last_index = (i_size_read(inode) - 1) >> PAGE_CACHE_SHIFT;
filemap_write_and_wait(inode->i_mapping);
btrfs_wait_ordered_range(inode, inode->i_size &
@@ -543,10 +549,6 @@
*/
first_page_offset = (sizeof(u32) * num_checksums) + sizeof(u64);
- node = rb_first(&block_group->free_space_offset);
- if (!node)
- goto out_free;
-
/*
* Lock all pages first so we can lock the extent safely.
*
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 8039390..72f31ec 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -495,7 +495,7 @@
add_async_extent(async_cow, start, num_bytes,
total_compressed, pages, nr_pages_ret);
- if (start + num_bytes < end && start + num_bytes < actual_end) {
+ if (start + num_bytes < end) {
start += num_bytes;
pages = NULL;
cond_resched();
@@ -5712,9 +5712,9 @@
if (err) {
printk(KERN_ERR "btrfs direct IO failed ino %lu rw %lu "
- "disk_bytenr %lu len %u err no %d\n",
- dip->inode->i_ino, bio->bi_rw, bio->bi_sector,
- bio->bi_size, err);
+ "sector %#Lx len %u err no %d\n",
+ dip->inode->i_ino, bio->bi_rw,
+ (unsigned long long)bio->bi_sector, bio->bi_size, err);
dip->errors = 1;
/*
@@ -5934,8 +5934,7 @@
*/
if (write) {
struct btrfs_ordered_extent *ordered;
- ordered = btrfs_lookup_ordered_extent(inode,
- dip->logical_offset);
+ ordered = btrfs_lookup_ordered_extent(inode, file_offset);
if (!test_bit(BTRFS_ORDERED_PREALLOC, &ordered->flags) &&
!test_bit(BTRFS_ORDERED_NOCOW, &ordered->flags))
btrfs_free_reserved_extent(root, ordered->start,
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index f1c9bb4..f87552a 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -947,23 +947,42 @@
static noinline int btrfs_ioctl_snap_create(struct file *file,
void __user *arg, int subvol,
- int async)
+ int v2)
{
struct btrfs_ioctl_vol_args *vol_args = NULL;
- struct btrfs_ioctl_async_vol_args *async_vol_args = NULL;
+ struct btrfs_ioctl_vol_args_v2 *vol_args_v2 = NULL;
char *name;
u64 fd;
- u64 transid = 0;
int ret;
- if (async) {
- async_vol_args = memdup_user(arg, sizeof(*async_vol_args));
- if (IS_ERR(async_vol_args))
- return PTR_ERR(async_vol_args);
+ if (v2) {
+ u64 transid = 0;
+ u64 *ptr = NULL;
- name = async_vol_args->name;
- fd = async_vol_args->fd;
- async_vol_args->name[BTRFS_SNAPSHOT_NAME_MAX] = '\0';
+ vol_args_v2 = memdup_user(arg, sizeof(*vol_args_v2));
+ if (IS_ERR(vol_args_v2))
+ return PTR_ERR(vol_args_v2);
+
+ if (vol_args_v2->flags & ~BTRFS_SUBVOL_CREATE_ASYNC) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+ name = vol_args_v2->name;
+ fd = vol_args_v2->fd;
+ vol_args_v2->name[BTRFS_SUBVOL_NAME_MAX] = '\0';
+
+ if (vol_args_v2->flags & BTRFS_SUBVOL_CREATE_ASYNC)
+ ptr = &transid;
+
+ ret = btrfs_ioctl_snap_create_transid(file, name, fd,
+ subvol, ptr);
+
+ if (ret == 0 && ptr &&
+ copy_to_user(arg +
+ offsetof(struct btrfs_ioctl_vol_args_v2,
+ transid), ptr, sizeof(*ptr)))
+ ret = -EFAULT;
} else {
vol_args = memdup_user(arg, sizeof(*vol_args));
if (IS_ERR(vol_args))
@@ -971,20 +990,13 @@
name = vol_args->name;
fd = vol_args->fd;
vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
+
+ ret = btrfs_ioctl_snap_create_transid(file, name, fd,
+ subvol, NULL);
}
-
- ret = btrfs_ioctl_snap_create_transid(file, name, fd,
- subvol, &transid);
-
- if (!ret && async) {
- if (copy_to_user(arg +
- offsetof(struct btrfs_ioctl_async_vol_args,
- transid), &transid, sizeof(transid)))
- return -EFAULT;
- }
-
+out:
kfree(vol_args);
- kfree(async_vol_args);
+ kfree(vol_args_v2);
return ret;
}
@@ -2246,7 +2258,7 @@
return btrfs_ioctl_getversion(file, argp);
case BTRFS_IOC_SNAP_CREATE:
return btrfs_ioctl_snap_create(file, argp, 0, 0);
- case BTRFS_IOC_SNAP_CREATE_ASYNC:
+ case BTRFS_IOC_SNAP_CREATE_V2:
return btrfs_ioctl_snap_create(file, argp, 0, 1);
case BTRFS_IOC_SUBVOL_CREATE:
return btrfs_ioctl_snap_create(file, argp, 1, 0);
diff --git a/fs/btrfs/ioctl.h b/fs/btrfs/ioctl.h
index 17c99eb..c344d12 100644
--- a/fs/btrfs/ioctl.h
+++ b/fs/btrfs/ioctl.h
@@ -30,11 +30,15 @@
char name[BTRFS_PATH_NAME_MAX + 1];
};
-#define BTRFS_SNAPSHOT_NAME_MAX 4079
-struct btrfs_ioctl_async_vol_args {
+#define BTRFS_SUBVOL_CREATE_ASYNC (1ULL << 0)
+
+#define BTRFS_SUBVOL_NAME_MAX 4039
+struct btrfs_ioctl_vol_args_v2 {
__s64 fd;
__u64 transid;
- char name[BTRFS_SNAPSHOT_NAME_MAX + 1];
+ __u64 flags;
+ __u64 unused[4];
+ char name[BTRFS_SUBVOL_NAME_MAX + 1];
};
#define BTRFS_INO_LOOKUP_PATH_MAX 4080
@@ -187,6 +191,6 @@
struct btrfs_ioctl_space_args)
#define BTRFS_IOC_START_SYNC _IOR(BTRFS_IOCTL_MAGIC, 24, __u64)
#define BTRFS_IOC_WAIT_SYNC _IOW(BTRFS_IOCTL_MAGIC, 22, __u64)
-#define BTRFS_IOC_SNAP_CREATE_ASYNC _IOW(BTRFS_IOCTL_MAGIC, 23, \
- struct btrfs_ioctl_async_vol_args)
+#define BTRFS_IOC_SNAP_CREATE_V2 _IOW(BTRFS_IOCTL_MAGIC, 23, \
+ struct btrfs_ioctl_vol_args_v2)
#endif
diff --git a/fs/btrfs/orphan.c b/fs/btrfs/orphan.c
index 79cba5f..f8be250 100644
--- a/fs/btrfs/orphan.c
+++ b/fs/btrfs/orphan.c
@@ -56,8 +56,12 @@
return -ENOMEM;
ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
- if (ret)
+ if (ret < 0)
goto out;
+ if (ret) {
+ ret = -ENOENT;
+ goto out;
+ }
ret = btrfs_del_item(trans, root, path);
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index dbb51ea..883c6fa 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -685,9 +685,9 @@
mutex_unlock(&root->d_inode->i_mutex);
if (IS_ERR(new_root)) {
+ dput(root);
deactivate_locked_super(s);
error = PTR_ERR(new_root);
- dput(root);
goto error_free_subvol_name;
}
if (!new_root->d_inode) {
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index cc04dc1..6b98845 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -412,12 +412,16 @@
device->fs_devices = fs_devices;
fs_devices->num_devices++;
- } else if (strcmp(device->name, path)) {
+ } else if (!device->name || strcmp(device->name, path)) {
name = kstrdup(path, GFP_NOFS);
if (!name)
return -ENOMEM;
kfree(device->name);
device->name = name;
+ if (device->missing) {
+ fs_devices->missing_devices--;
+ device->missing = 0;
+ }
}
if (found_transid > fs_devices->latest_trans) {
@@ -1236,6 +1240,9 @@
device->fs_devices->num_devices--;
+ if (device->missing)
+ root->fs_info->fs_devices->missing_devices--;
+
next_device = list_entry(root->fs_info->fs_devices->devices.next,
struct btrfs_device, dev_list);
if (device->bdev == root->fs_info->sb->s_bdev)
@@ -3080,7 +3087,9 @@
device->devid = devid;
device->work.func = pending_bios_fn;
device->fs_devices = fs_devices;
+ device->missing = 1;
fs_devices->num_devices++;
+ fs_devices->missing_devices++;
spin_lock_init(&device->io_lock);
INIT_LIST_HEAD(&device->dev_alloc_list);
memcpy(device->uuid, dev_uuid, BTRFS_UUID_SIZE);
@@ -3278,6 +3287,15 @@
device = add_missing_dev(root, devid, dev_uuid);
if (!device)
return -ENOMEM;
+ } else if (!device->missing) {
+ /*
+ * this happens when a device that was properly setup
+ * in the device info lists suddenly goes bad.
+ * device->bdev is NULL, and so we have to set
+ * device->missing to one here
+ */
+ root->fs_info->fs_devices->missing_devices++;
+ device->missing = 1;
}
}
diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h
index 2b638b6..2740db4 100644
--- a/fs/btrfs/volumes.h
+++ b/fs/btrfs/volumes.h
@@ -44,6 +44,7 @@
int writeable;
int in_fs_metadata;
+ int missing;
spinlock_t io_lock;
@@ -93,6 +94,7 @@
u64 num_devices;
u64 open_devices;
u64 rw_devices;
+ u64 missing_devices;
u64 total_rw_bytes;
struct block_device *latest_bdev;