Merge branch 'for-linus-4.6' of git://git.kernel.org/pub/scm/linux/ke…

…rnel/git/mason/linux-btrfs

Pull btrfs updates from Chris Mason:
 "We have a good sized cleanup of our internal read ahead code, and the
  first series of commits from Chandan to enable PAGE_SIZE > sectorsize

  Otherwise, it's a normal series of cleanups and fixes, with many
  thanks to Dave Sterba for doing most of the patch wrangling this time"

* 'for-linus-4.6' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: (82 commits)
  btrfs: make sure we stay inside the bvec during __btrfs_lookup_bio_sums
  btrfs: Fix misspellings in comments.
  btrfs: Print Warning only if ENOSPC_DEBUG is enabled
  btrfs: scrub: silence an uninitialized variable warning
  btrfs: move btrfs_compression_type to compression.h
  btrfs: rename btrfs_print_info to btrfs_print_mod_info
  Btrfs: Show a warning message if one of objectid reaches its highest value
  Documentation: btrfs: remove usage specific information
  btrfs: use kbasename in btrfsic_mount
  Btrfs: do not collect ordered extents when logging that inode exists
  Btrfs: fix race when checking if we can skip fsync'ing an inode
  Btrfs: fix listxattrs not listing all xattrs packed in the same item
  Btrfs: fix deadlock between direct IO reads and buffered writes
  Btrfs: fix extent_same allowing destination offset beyond i_size
  Btrfs: fix file loss on log replay after renaming a file and fsync
  Btrfs: fix unreplayable log after snapshot delete + parent dir fsync
  Btrfs: fix lockdep deadlock warning due to dev_replace
  btrfs: drop unused argument in btrfs_ioctl_get_supported_features
  btrfs: add GET_SUPPORTED_FEATURES to the control device ioctls
  btrfs: change max_inline default to 2048
  ...

Documentation/filesystems/btrfs.txt

@@ -1,20 +1,10 @@
-
 BTRFS
 =====
 
-Btrfs is a copy on write filesystem for Linux aimed at
-implementing advanced features while focusing on fault tolerance,
-repair and easy administration. Initially developed by Oracle, Btrfs
-is licensed under the GPL and open for contribution from anyone.
-
-Linux has a wealth of filesystems to choose from, but we are facing a
-number of challenges with scaling to the large storage subsystems that
-are becoming common in today's data centers. Filesystems need to scale
-in their ability to address and manage large storage, and also in
-their ability to detect, repair and tolerate errors in the data stored
-on disk.  Btrfs is under heavy development, and is not suitable for
-any uses other than benchmarking and review. The Btrfs disk format is
-not yet finalized.
+Btrfs is a copy on write filesystem for Linux aimed at implementing advanced
+features while focusing on fault tolerance, repair and easy administration.
+Jointly developed by several companies, licensed under the GPL and open for
+contribution from anyone.
 
 The main Btrfs features include:
 
@@ -28,243 +18,14 @@ The main Btrfs features include:
     * Checksums on data and metadata (multiple algorithms available)
     * Compression
     * Integrated multiple device support, with several raid algorithms
-    * Online filesystem check (not yet implemented)
-    * Very fast offline filesystem check
-    * Efficient incremental backup and FS mirroring (not yet implemented)
+    * Offline filesystem check
+    * Efficient incremental backup and FS mirroring
     * Online filesystem defragmentation
 
+For more information please refer to the wiki
 
-Mount Options
-=============
-
-When mounting a btrfs filesystem, the following option are accepted.
-Options with (*) are default options and will not show in the mount options.
-
-  alloc_start=<bytes>
-	Debugging option to force all block allocations above a certain
-	byte threshold on each block device.  The value is specified in
-	bytes, optionally with a K, M, or G suffix, case insensitive.
-	Default is 1MB.
-
-  noautodefrag(*)
-  autodefrag
-	Disable/enable auto defragmentation.
-	Auto defragmentation detects small random writes into files and queue
-	them up for the defrag process.  Works best for small files;
-	Not well suited for large database workloads.
-
-  check_int
-  check_int_data
-  check_int_print_mask=<value>
-	These debugging options control the behavior of the integrity checking
-	module (the BTRFS_FS_CHECK_INTEGRITY config option required).
-
-	check_int enables the integrity checker module, which examines all
-	block write requests to ensure on-disk consistency, at a large
-	memory and CPU cost.
-
-	check_int_data includes extent data in the integrity checks, and
-	implies the check_int option.
-
-	check_int_print_mask takes a bitmask of BTRFSIC_PRINT_MASK_* values
-	as defined in fs/btrfs/check-integrity.c, to control the integrity
-	checker module behavior.
-
-	See comments at the top of fs/btrfs/check-integrity.c for more info.
-
-  commit=<seconds>
-	Set the interval of periodic commit, 30 seconds by default. Higher
-	values defer data being synced to permanent storage with obvious
-	consequences when the system crashes. The upper bound is not forced,
-	but a warning is printed if it's more than 300 seconds (5 minutes).
-
-  compress
-  compress=<type>
-  compress-force
-  compress-force=<type>
-	Control BTRFS file data compression.  Type may be specified as "zlib"
-	"lzo" or "no" (for no compression, used for remounting).  If no type
-	is specified, zlib is used.  If compress-force is specified,
-	all files will be compressed, whether or not they compress well.
-	If compression is enabled, nodatacow and nodatasum are disabled.
-
-  degraded
-	Allow mounts to continue with missing devices.  A read-write mount may
-	fail with too many devices missing, for example if a stripe member
-	is completely missing.
-
-  device=<devicepath>
-	Specify a device during mount so that ioctls on the control device
-	can be avoided.  Especially useful when trying to mount a multi-device
-	setup as root.  May be specified multiple times for multiple devices.
-
-  nodiscard(*)
-  discard
-	Disable/enable discard mount option.
-	Discard issues frequent commands to let the block device reclaim space
-	freed by the filesystem.
-	This is useful for SSD devices, thinly provisioned
-	LUNs and virtual machine images, but may have a significant
-	performance impact.  (The fstrim command is also available to
-	initiate batch trims from userspace).
-
-  noenospc_debug(*)
-  enospc_debug
-	Disable/enable debugging option to be more verbose in some ENOSPC conditions.
-
-  fatal_errors=<action>
-	Action to take when encountering a fatal error:
-	  "bug" - BUG() on a fatal error.  This is the default.
-	  "panic" - panic() on a fatal error.
-
-  noflushoncommit(*)
-  flushoncommit
-	The 'flushoncommit' mount option forces any data dirtied by a write in a
-	prior transaction to commit as part of the current commit.  This makes
-	the committed state a fully consistent view of the file system from the
-	application's perspective (i.e., it includes all completed file system
-	operations).  This was previously the behavior only when a snapshot is
-	created.
-
-  inode_cache
-	Enable free inode number caching.   Defaults to off due to an overflow
-	problem when the free space crcs don't fit inside a single page.
-
-  max_inline=<bytes>
-	Specify the maximum amount of space, in bytes, that can be inlined in
-	a metadata B-tree leaf.  The value is specified in bytes, optionally
-	with a K, M, or G suffix, case insensitive.  In practice, this value
-	is limited by the root sector size, with some space unavailable due
-	to leaf headers.  For a 4k sector size, max inline data is ~3900 bytes.
-
-  metadata_ratio=<value>
-	Specify that 1 metadata chunk should be allocated after every <value>
-	data chunks.  Off by default.
-
-  acl(*)
-  noacl
-	Enable/disable support for Posix Access Control Lists (ACLs).  See the
-	acl(5) manual page for more information about ACLs.
-
-  barrier(*)
-  nobarrier
-        Enable/disable the use of block layer write barriers.  Write barriers
-	ensure that certain IOs make it through the device cache and are on
-	persistent storage. If disabled on a device with a volatile
-	(non-battery-backed) write-back cache, nobarrier option will lead to
-	filesystem corruption on a system crash or power loss.
-
-  datacow(*)
-  nodatacow
-	Enable/disable data copy-on-write for newly created files.
-	Nodatacow implies nodatasum, and disables all compression.
-
-  datasum(*)
-  nodatasum
-	Enable/disable data checksumming for newly created files.
-	Datasum implies datacow.
-
-  treelog(*)
-  notreelog
-	Enable/disable the tree logging used for fsync and O_SYNC writes.
-
-  recovery
-	Enable autorecovery attempts if a bad tree root is found at mount time.
-	Currently this scans a list of several previous tree roots and tries to
-	use the first readable.
-
-  rescan_uuid_tree
-	Force check and rebuild procedure of the UUID tree. This should not
-	normally be needed.
-
-  skip_balance
-	Skip automatic resume of interrupted balance operation after mount.
-	May be resumed with "btrfs balance resume."
-
-  space_cache (*)
-	Enable the on-disk freespace cache.
-  nospace_cache
-	Disable freespace cache loading without clearing the cache.
-  clear_cache
-	Force clearing and rebuilding of the disk space cache if something
-	has gone wrong.
-
-  ssd
-  nossd
-  ssd_spread
-	Options to control ssd allocation schemes.  By default, BTRFS will
-	enable or disable ssd allocation heuristics depending on whether a
-	rotational or non-rotational disk is in use.  The ssd and nossd options
-	can override this autodetection.
-
-	The ssd_spread mount option attempts to allocate into big chunks
-	of unused space, and may perform better on low-end ssds.  ssd_spread
-	implies ssd, enabling all other ssd heuristics as well.
-
-  subvol=<path>
-	Mount subvolume at <path> rather than the root subvolume.  <path> is
-	relative to the top level subvolume.
-
-  subvolid=<ID>
-	Mount subvolume specified by an ID number rather than the root subvolume.
-	This allows mounting of subvolumes which are not in the root of the mounted
-	filesystem.
-	You can use "btrfs subvolume list" to see subvolume ID numbers.
-
-  subvolrootid=<objectid> (deprecated)
-	Mount subvolume specified by <objectid> rather than the root subvolume.
-	This allows mounting of subvolumes which are not in the root of the mounted
-	filesystem.
-	You can use "btrfs subvolume show " to see the object ID for a subvolume.
-
-  thread_pool=<number>
-	The number of worker threads to allocate.  The default number is equal
-	to the number of CPUs + 2, or 8, whichever is smaller.
-
-  user_subvol_rm_allowed
-	Allow subvolumes to be deleted by a non-root user. Use with caution.
-
-MAILING LIST
-============
-
-There is a Btrfs mailing list hosted on vger.kernel.org. You can
-find details on how to subscribe here:
-
-http://vger.kernel.org/vger-lists.html#linux-btrfs
-
-Mailing list archives are available from gmane:
-
-http://dir.gmane.org/gmane.comp.file-systems.btrfs
-
-
-
-IRC
-===
-
-Discussion of Btrfs also occurs on the #btrfs channel of the Freenode
-IRC network.
-
-
-
-	UTILITIES
-	=========
-
-Userspace tools for creating and manipulating Btrfs file systems are
-available from the git repository at the following location:
-
- http://git.kernel.org/?p=linux/kernel/git/mason/btrfs-progs.git
- git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-progs.git
-
-These include the following tools:
-
-* mkfs.btrfs: create a filesystem
-
-* btrfs: a single tool to manage the filesystems, refer to the manpage for more details
-
-* 'btrfsck' or 'btrfs check': do a consistency check of the filesystem
-
-Other tools for specific tasks:
-
-* btrfs-convert: in-place conversion from ext2/3/4 filesystems
+  https://btrfs.wiki.kernel.org
 
-* btrfs-image: dump filesystem metadata for debugging
+that maintains information about administration tasks, frequently asked
+questions, use cases, mount options, comprehensible changelogs, features,
+manual pages, source code repositories, contacts etc.

fs/btrfs/backref.c

@@ -148,8 +148,7 @@ int __init btrfs_prelim_ref_init(void)
 
 void btrfs_prelim_ref_exit(void)
 {
-	if (btrfs_prelim_ref_cache)
-		kmem_cache_destroy(btrfs_prelim_ref_cache);
+	kmem_cache_destroy(btrfs_prelim_ref_cache);
 }
 
 /*
@@ -566,17 +565,14 @@ static void __merge_refs(struct list_head *head, int mode)
 		struct __prelim_ref *pos2 = pos1, *tmp;
 
 		list_for_each_entry_safe_continue(pos2, tmp, head, list) {
-			struct __prelim_ref *xchg, *ref1 = pos1, *ref2 = pos2;
+			struct __prelim_ref *ref1 = pos1, *ref2 = pos2;
 			struct extent_inode_elem *eie;
 
 			if (!ref_for_same_block(ref1, ref2))
 				continue;
 			if (mode == 1) {
-				if (!ref1->parent && ref2->parent) {
-					xchg = ref1;
-					ref1 = ref2;
-					ref2 = xchg;
-				}
+				if (!ref1->parent && ref2->parent)
+					swap(ref1, ref2);
 			} else {
 				if (ref1->parent != ref2->parent)
 					continue;

fs/btrfs/check-integrity.c

@@ -95,6 +95,7 @@
 #include <linux/genhd.h>
 #include <linux/blkdev.h>
 #include <linux/vmalloc.h>
+#include <linux/string.h>
 #include "ctree.h"
 #include "disk-io.h"
 #include "hash.h"
@@ -105,6 +106,7 @@
 #include "locking.h"
 #include "check-integrity.h"
 #include "rcu-string.h"
+#include "compression.h"
 
 #define BTRFSIC_BLOCK_HASHTABLE_SIZE 0x10000
 #define BTRFSIC_BLOCK_LINK_HASHTABLE_SIZE 0x10000
@@ -176,7 +178,7 @@ struct btrfsic_block {
  * Elements of this type are allocated dynamically and required because
  * each block object can refer to and can be ref from multiple blocks.
  * The key to lookup them in the hashtable is the dev_bytenr of
- * the block ref to plus the one from the block refered from.
+ * the block ref to plus the one from the block referred from.
  * The fact that they are searchable via a hashtable and that a
  * ref_cnt is maintained is not required for the btrfs integrity
  * check algorithm itself, it is only used to make the output more
@@ -3076,7 +3078,7 @@ int btrfsic_mount(struct btrfs_root *root,
 
 	list_for_each_entry(device, dev_head, dev_list) {
 		struct btrfsic_dev_state *ds;
-		char *p;
+		const char *p;
 
 		if (!device->bdev || !device->name)
 			continue;
@@ -3092,11 +3094,7 @@ int btrfsic_mount(struct btrfs_root *root,
 		ds->state = state;
 		bdevname(ds->bdev, ds->name);
 		ds->name[BDEVNAME_SIZE - 1] = '\0';
-		for (p = ds->name; *p != '\0'; p++);
-		while (p > ds->name && *p != '/')
-			p--;
-		if (*p == '/')
-			p++;
+		p = kbasename(ds->name);
 		strlcpy(ds->name, p, sizeof(ds->name));
 		btrfsic_dev_state_hashtable_add(ds,
 						&btrfsic_dev_state_hashtable);

fs/btrfs/compression.h

@@ -48,6 +48,15 @@ int btrfs_submit_compressed_read(struct inode *inode, struct bio *bio,
 void btrfs_clear_biovec_end(struct bio_vec *bvec, int vcnt,
 				   unsigned long pg_index,
 				   unsigned long pg_offset);
+
+enum btrfs_compression_type {
+	BTRFS_COMPRESS_NONE  = 0,
+	BTRFS_COMPRESS_ZLIB  = 1,
+	BTRFS_COMPRESS_LZO   = 2,
+	BTRFS_COMPRESS_TYPES = 2,
+	BTRFS_COMPRESS_LAST  = 3,
+};
+
 struct btrfs_compress_op {
 	struct list_head *(*alloc_workspace)(void);