diff --git a/fs/btrfs/block-group.c b/fs/btrfs/block-group.c
index 176e8a292fd10d867ee2da4a37933d4b12a836a3..c037ef514b64a015859475f56ee861bedbf14b47 100644
--- a/fs/btrfs/block-group.c
+++ b/fs/btrfs/block-group.c
@@ -940,7 +940,7 @@ int btrfs_remove_block_group(struct btrfs_trans_handle *trans,
path = btrfs_alloc_path();
if (!path) {
ret = -ENOMEM;
- goto out_put_group;
+ goto out;
}
/*
@@ -978,7 +978,7 @@ int btrfs_remove_block_group(struct btrfs_trans_handle *trans,
ret = btrfs_orphan_add(trans, BTRFS_I(inode));
if (ret) {
btrfs_add_delayed_iput(inode);
- goto out_put_group;
+ goto out;
}
clear_nlink(inode);
/* One for the block groups ref */
@@ -1001,13 +1001,13 @@ int btrfs_remove_block_group(struct btrfs_trans_handle *trans,
ret = btrfs_search_slot(trans, tree_root, &key, path, -1, 1);
if (ret < 0)
- goto out_put_group;
+ goto out;
if (ret > 0)
btrfs_release_path(path);
if (ret == 0) {
ret = btrfs_del_item(trans, tree_root, path);
if (ret)
- goto out_put_group;
+ goto out;
btrfs_release_path(path);
}
@@ -1016,6 +1016,9 @@ int btrfs_remove_block_group(struct btrfs_trans_handle *trans,
&fs_info->block_group_cache_tree);
RB_CLEAR_NODE(&block_group->cache_node);
+ /* Once for the block groups rbtree */
+ btrfs_put_block_group(block_group);
+
if (fs_info->first_logical_byte == block_group->start)
fs_info->first_logical_byte = (u64)-1;
spin_unlock(&fs_info->block_group_cache_lock);
@@ -1089,6 +1092,25 @@ int btrfs_remove_block_group(struct btrfs_trans_handle *trans,
spin_unlock(&block_group->space_info->lock);
+ /*
+ * Remove the free space for the block group from the free space tree
+ * and the block group's item from the extent tree before marking the
+ * block group as removed. This is to prevent races with tasks that
+ * freeze and unfreeze a block group, this task and another task
+ * allocating a new block group - the unfreeze task ends up removing
+ * the block group's extent map before the task calling this function
+ * deletes the block group item from the extent tree, allowing for
+ * another task to attempt to create another block group with the same
+ * item key (and failing with -EEXIST and a transaction abort).
+ */
+ ret = remove_block_group_free_space(trans, block_group);
+ if (ret)
+ goto out;
+
+ ret = remove_block_group_item(trans, path, block_group);
+ if (ret < 0)
+ goto out;
+
mutex_lock(&fs_info->chunk_mutex);
spin_lock(&block_group->lock);
block_group->removed = 1;
@@ -1123,17 +1145,6 @@ int btrfs_remove_block_group(struct btrfs_trans_handle *trans,
mutex_unlock(&fs_info->chunk_mutex);
- ret = remove_block_group_free_space(trans, block_group);
- if (ret)
- goto out_put_group;
-
- /* Once for the block groups rbtree */
- btrfs_put_block_group(block_group);
-
- ret = remove_block_group_item(trans, path, block_group);
- if (ret < 0)
- goto out;
-
if (remove_em) {
struct extent_map_tree *em_tree;
@@ -1145,10 +1156,9 @@ int btrfs_remove_block_group(struct btrfs_trans_handle *trans,
free_extent_map(em);
}
-out_put_group:
+out:
/* Once for the lookup reference */
btrfs_put_block_group(block_group);
-out:
if (remove_rsv)
btrfs_delayed_refs_rsv_release(fs_info, 1);
btrfs_free_path(path);
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 30ce7039bc273d4faadf7e29e7f46dba1b28c4d6..d404cce8ae406aacc46a8459304c95a3e809beb3 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -1009,6 +1009,8 @@ enum {
BTRFS_ROOT_DEAD_RELOC_TREE,
/* Mark dead root stored on device whose cleanup needs to be resumed */
BTRFS_ROOT_DEAD_TREE,
+ /* The root has a log tree. Used only for subvolume roots. */
+ BTRFS_ROOT_HAS_LOG_TREE,
};
/*
diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index 2c14312b05e8ee282d7638cd277286dc42835894..2520605afc256ebe2d0e415051370100928f7b34 100644
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -1533,7 +1533,7 @@ lock_and_cleanup_extent_if_need(struct btrfs_inode *inode, struct page **pages,
}
static noinline int check_can_nocow(struct btrfs_inode *inode, loff_t pos,
- size_t *write_bytes)
+ size_t *write_bytes, bool nowait)
{
struct btrfs_fs_info *fs_info = inode->root->fs_info;
struct btrfs_root *root = inode->root;
@@ -1541,27 +1541,43 @@ static noinline int check_can_nocow(struct btrfs_inode *inode, loff_t pos,
u64 num_bytes;
int ret;
- if (!btrfs_drew_try_write_lock(&root->snapshot_lock))
+ if (!nowait && !btrfs_drew_try_write_lock(&root->snapshot_lock))
return -EAGAIN;
lockstart = round_down(pos, fs_info->sectorsize);
lockend = round_up(pos + *write_bytes,
fs_info->sectorsize) - 1;
+ num_bytes = lockend - lockstart + 1;
- btrfs_lock_and_flush_ordered_range(inode, lockstart,
- lockend, NULL);
+ if (nowait) {
+ struct btrfs_ordered_extent *ordered;
+
+ if (!try_lock_extent(&inode->io_tree, lockstart, lockend))
+ return -EAGAIN;
+
+ ordered = btrfs_lookup_ordered_range(inode, lockstart,
+ num_bytes);
+ if (ordered) {
+ btrfs_put_ordered_extent(ordered);
+ ret = -EAGAIN;
+ goto out_unlock;
+ }
+ } else {
+ btrfs_lock_and_flush_ordered_range(inode, lockstart,
+ lockend, NULL);
+ }
- num_bytes = lockend - lockstart + 1;
ret = can_nocow_extent(&inode->vfs_inode, lockstart, &num_bytes,
NULL, NULL, NULL);
if (ret <= 0) {
ret = 0;
- btrfs_drew_write_unlock(&root->snapshot_lock);
+ if (!nowait)
+ btrfs_drew_write_unlock(&root->snapshot_lock);
} else {
*write_bytes = min_t(size_t, *write_bytes ,
num_bytes - pos + lockstart);
}
-
+out_unlock:
unlock_extent(&inode->io_tree, lockstart, lockend);
return ret;
@@ -1633,7 +1649,7 @@ static noinline ssize_t btrfs_buffered_write(struct kiocb *iocb,
if ((BTRFS_I(inode)->flags & (BTRFS_INODE_NODATACOW |
BTRFS_INODE_PREALLOC)) &&
check_can_nocow(BTRFS_I(inode), pos,
- &write_bytes) > 0) {
+ &write_bytes, false) > 0) {
/*
* For nodata cow case, no need to reserve
* data space.
@@ -1904,13 +1920,25 @@ static ssize_t btrfs_file_write_iter(struct kiocb *iocb,
pos = iocb->ki_pos;
count = iov_iter_count(from);
if (iocb->ki_flags & IOCB_NOWAIT) {
+ size_t nocow_bytes = count;
+
/*
* We will allocate space in case nodatacow is not set,
* so bail
*/
if (!(BTRFS_I(inode)->flags & (BTRFS_INODE_NODATACOW |
BTRFS_INODE_PREALLOC)) ||
- check_can_nocow(BTRFS_I(inode), pos, &count) <= 0) {
+ check_can_nocow(BTRFS_I(inode), pos, &nocow_bytes,
+ true) <= 0) {
+ inode_unlock(inode);
+ return -EAGAIN;
+ }
+ /*
+ * There are holes in the range or parts of the range that must
+ * be COWed (shared extents, RO block groups, etc), so just bail
+ * out.
+ */
+ if (nocow_bytes < count) {
inode_unlock(inode);
return -EAGAIN;
}
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index d04c82c8841817e203312889edf66110360539e3..18d384f4af54e1d9c606bfeec8fff79688669a7d 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -985,6 +985,7 @@ static noinline int cow_file_range(struct inode *inode,
u64 num_bytes;
unsigned long ram_size;
u64 cur_alloc_size = 0;
+ u64 min_alloc_size;
u64 blocksize = fs_info->sectorsize;
struct btrfs_key ins;
struct extent_map *em;
@@ -1035,10 +1036,26 @@ static noinline int cow_file_range(struct inode *inode,
btrfs_drop_extent_cache(BTRFS_I(inode), start,
start + num_bytes - 1, 0);
+ /*
+ * Relocation relies on the relocated extents to have exactly the same
+ * size as the original extents. Normally writeback for relocation data
+ * extents follows a NOCOW path because relocation preallocates the
+ * extents. However, due to an operation such as scrub turning a block
+ * group to RO mode, it may fallback to COW mode, so we must make sure
+ * an extent allocated during COW has exactly the requested size and can
+ * not be split into smaller extents, otherwise relocation breaks and
+ * fails during the stage where it updates the bytenr of file extent
+ * items.
+ */
+ if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID)
+ min_alloc_size = num_bytes;
+ else
+ min_alloc_size = fs_info->sectorsize;
+
while (num_bytes > 0) {
cur_alloc_size = num_bytes;
ret = btrfs_reserve_extent(root, cur_alloc_size, cur_alloc_size,
- fs_info->sectorsize, 0, alloc_hint,
+ min_alloc_size, 0, alloc_hint,
&ins, 1, 1);
if (ret < 0)
goto out_unlock;
@@ -1361,6 +1378,8 @@ static int fallback_to_cow(struct inode *inode, struct page *locked_page,
int *page_started, unsigned long *nr_written)
{
const bool is_space_ino = btrfs_is_free_space_inode(BTRFS_I(inode));
+ const bool is_reloc_ino = (BTRFS_I(inode)->root->root_key.objectid ==
+ BTRFS_DATA_RELOC_TREE_OBJECTID);
const u64 range_bytes = end + 1 - start;
struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
u64 range_start = start;
@@ -1391,18 +1410,23 @@ static int fallback_to_cow(struct inode *inode, struct page *locked_page,
* data space info, which we incremented in the step above.
*
* If we need to fallback to cow and the inode corresponds to a free
- * space cache inode, we must also increment bytes_may_use of the data
- * space_info for the same reason. Space caches always get a prealloc
+ * space cache inode or an inode of the data relocation tree, we must
+ * also increment bytes_may_use of the data space_info for the same
+ * reason. Space caches and relocated data extents always get a prealloc
* extent for them, however scrub or balance may have set the block
- * group that contains that extent to RO mode.
+ * group that contains that extent to RO mode and therefore force COW
+ * when starting writeback.
*/
count = count_range_bits(io_tree, &range_start, end, range_bytes,
EXTENT_NORESERVE, 0);
- if (count > 0 || is_space_ino) {
- const u64 bytes = is_space_ino ? range_bytes : count;
+ if (count > 0 || is_space_ino || is_reloc_ino) {
+ u64 bytes = count;
struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
struct btrfs_space_info *sinfo = fs_info->data_sinfo;
+ if (is_space_ino || is_reloc_ino)
+ bytes = range_bytes;
+
spin_lock(&sinfo->lock);
btrfs_space_info_update_bytes_may_use(fs_info, sinfo, bytes);
spin_unlock(&sinfo->lock);
@@ -7865,9 +7889,6 @@ static ssize_t btrfs_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
dio_data.overwrite = 1;
inode_unlock(inode);
relock = true;
- } else if (iocb->ki_flags & IOCB_NOWAIT) {
- ret = -EAGAIN;
- goto out;
}
ret = btrfs_delalloc_reserve_space(inode, &data_reserved,
offset, count);
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 168deb8ef68aa36cc8fe886ffbc2daa0bf9df46a..e8f7c5f008944035b746af003b61e4ed543374df 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -2692,7 +2692,7 @@ static int btrfs_ioctl_get_subvol_info(struct file *file, void __user *argp)
btrfs_put_root(root);
out_free:
btrfs_free_path(path);
- kzfree(subvol_info);
+ kfree(subvol_info);
return ret;
}
diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c
index 920cee312f4efea8b55404c8e34def0f1cf5d6ad..cd5348f352ddc083b49903386a60bdc3f47ada04 100644
--- a/fs/btrfs/tree-log.c
+++ b/fs/btrfs/tree-log.c
@@ -169,6 +169,7 @@ static int start_log_trans(struct btrfs_trans_handle *trans,
if (ret)
goto out;
+ set_bit(BTRFS_ROOT_HAS_LOG_TREE, &root->state);
clear_bit(BTRFS_ROOT_MULTI_LOG_TASKS, &root->state);
root->log_start_pid = current->pid;
}
@@ -195,6 +196,9 @@ static int join_running_log_trans(struct btrfs_root *root)
{
int ret = -ENOENT;
+ if (!test_bit(BTRFS_ROOT_HAS_LOG_TREE, &root->state))
+ return ret;
+
mutex_lock(&root->log_mutex);
if (root->log_root) {
ret = 0;
@@ -3303,6 +3307,7 @@ int btrfs_free_log(struct btrfs_trans_handle *trans, struct btrfs_root *root)
if (root->log_root) {
free_log_tree(trans, root->log_root);
root->log_root = NULL;
+ clear_bit(BTRFS_ROOT_HAS_LOG_TREE, &root->state);
}
return 0;
}