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authorLinus Torvalds <torvalds@linux-foundation.org>2020-03-31 23:00:16 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2020-03-31 23:00:16 +0300
commit15c981d16d70e8a5be297fa4af07a64ab7e080ed (patch)
tree9487ba1525d75501cd1a3896dac4e6321efd3a55 /lib
parent1455c69900c8c6442b182a74087931f4ffb1cac4 (diff)
parent6ff06729c22ec0b7498d900d79cc88cfb8aceaeb (diff)
downloadlinux-15c981d16d70e8a5be297fa4af07a64ab7e080ed.tar.xz
Merge tag 'for-5.7-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux
Pull btrfs updates from David Sterba: "A number of core changes that make things work better in general, code is simpler and cleaner. Core changes: - per-inode file extent tree, for in memory tracking of contiguous extent ranges to make sure i_size adjustments are accurate - tree root structures are protected by reference counts, replacing SRCU that did not cover some cases - leak detector for tree root structures - per-transaction pinned extent tracking - buffer heads are replaced by bios for super block access - speedup of extent back reference resolution, on an example test scenario the runtime of send went down from a hour to minutes - factor out locking scheme used for subvolume writer and NOCOW exclusion, abstracted as DREW lock, double reader-writer exclusion (allow either readers or writers) - cleanup and abstract extent allocation policies, preparation for zoned device support - make reflink/clone_range work on inline extents - add more cancellation point for relocation, improves long response from 'balance cancel' - add page migration callback for data pages - switch to guid for uuids, with additional cleanups of the interface - make ranged full fsyncs more efficient - removal of obsolete ioctl flag BTRFS_SUBVOL_CREATE_ASYNC - remove b-tree readahead from delayed refs paths, avoiding seek and read unnecessary blocks Features: - v2 of ioctl to delete subvolumes, allowing to delete by id and more future extensions Fixes: - fix qgroup rescan worker that could block umount - fix crash during unmount due to race with delayed inode workers - fix dellaloc flushing logic that could create unnecessary chunks under heavy load - fix missing file extent item for hole after ranged fsync - several fixes in relocation error handling Other: - more documentation of relocation, device replace, space reservations - many random cleanups" * tag 'for-5.7-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: (210 commits) btrfs: fix missing semaphore unlock in btrfs_sync_file btrfs: use nofs allocations for running delayed items btrfs: sysfs: Use scnprintf() instead of snprintf() btrfs: do not resolve backrefs for roots that are being deleted btrfs: track reloc roots based on their commit root bytenr btrfs: restart relocate_tree_blocks properly btrfs: reloc: reorder reservation before root selection btrfs: do not readahead in build_backref_tree btrfs: do not use readahead for running delayed refs btrfs: Remove async_transid from btrfs_mksubvol/create_subvol/create_snapshot btrfs: Remove transid argument from btrfs_ioctl_snap_create_transid btrfs: Remove BTRFS_SUBVOL_CREATE_ASYNC support btrfs: kill the subvol_srcu btrfs: make btrfs_cleanup_fs_roots use the radix tree lock btrfs: don't take an extra root ref at allocation time btrfs: hold a ref on the root on the dead roots list btrfs: make inodes hold a ref on their roots btrfs: move the root freeing stuff into btrfs_put_root btrfs: move ino_cache_inode dropping out of btrfs_free_fs_root btrfs: make the extent buffer leak check per fs info ...
Diffstat (limited to 'lib')
-rw-r--r--lib/uuid.c10
1 files changed, 10 insertions, 0 deletions
diff --git a/lib/uuid.c b/lib/uuid.c
index b6a1edb61d87..562d53977cab 100644
--- a/lib/uuid.c
+++ b/lib/uuid.c
@@ -40,6 +40,16 @@ void generate_random_uuid(unsigned char uuid[16])
}
EXPORT_SYMBOL(generate_random_uuid);
+void generate_random_guid(unsigned char guid[16])
+{
+ get_random_bytes(guid, 16);
+ /* Set GUID version to 4 --- truly random generation */
+ guid[7] = (guid[7] & 0x0F) | 0x40;
+ /* Set the GUID variant to DCE */
+ guid[8] = (guid[8] & 0x3F) | 0x80;
+}
+EXPORT_SYMBOL(generate_random_guid);
+
static void __uuid_gen_common(__u8 b[16])
{
prandom_bytes(b, 16);