Merge branch 'next' into for-linus

Prepare first set of updates for 3.10 merge window.

15 files changed, 727 insertions, 69 deletions

diff --git a/Documentation/filesystems/00-INDEX b/Documentation/filesystems/00-INDEX
index 8c624a18f67d..8042050eb265 100644
--- a/Documentation/filesystems/00-INDEX
+++ b/Documentation/filesystems/00-INDEX
@@ -38,6 +38,8 @@ dnotify_test.c
         - example program for dnotify
 ecryptfs.txt
         - docs on eCryptfs: stacked cryptographic filesystem for Linux.
+efivarfs.txt
+        - info for the efivarfs filesystem.
 exofs.txt
         - info, usage, mount options, design about EXOFS.
 ext2.txt
@@ -48,6 +50,8 @@ ext4.txt
         - info, mount options and specifications for the Ext4 filesystem.
 files.txt
         - info on file management in the Linux kernel.
+f2fs.txt
+        - info and mount options for the F2FS filesystem.
 fuse.txt
         - info on the Filesystem in User SpacE including mount options.
 gfs2.txt
diff --git a/Documentation/filesystems/Locking b/Documentation/filesystems/Locking
index e540a24e5d06..0706d32a61e6 100644
--- a/Documentation/filesystems/Locking
+++ b/Documentation/filesystems/Locking
@@ -10,6 +10,7 @@ be able to use diff(1).
 --------------------------- dentry_operations --------------------------
 prototypes:
         int (*d_revalidate)(struct dentry *, unsigned int);
+        int (*d_weak_revalidate)(struct dentry *, unsigned int);
         int (*d_hash)(const struct dentry *, const struct inode *,
                         struct qstr *);
         int (*d_compare)(const struct dentry *, const struct inode *,
@@ -25,6 +26,7 @@ prototypes:
 locking rules:
                 rename_lock     ->d_lock        may block       rcu-walk
 d_revalidate:   no              no              yes (ref-walk)  maybe
+d_weak_revalidate:no            no              yes             no
 d_hash          no              no              no              maybe
 d_compare:      yes             no              no              maybe
 d_delete:       no              yes             no              no
@@ -80,7 +82,6 @@ rename:		yes (all)	(see below)
 readlink:       no
 follow_link:    no
 put_link:       no
-truncate:       yes             (see below)
 setattr:        yes
 permission:     no (may not block if called in rcu-walk mode)
 get_acl:        no
@@ -96,11 +97,6 @@ atomic_open:	yes
         Additionally, ->rmdir(), ->unlink() and ->rename() have ->i_mutex on
 victim.
         cross-directory ->rename() has (per-superblock) ->s_vfs_rename_sem.
-        ->truncate() is never called directly - it's a callback, not a
-method. It's called by vmtruncate() - deprecated library function used by
-->setattr(). Locking information above applies to that call (i.e. is
-inherited from ->setattr() - vmtruncate() is used when ATTR_SIZE had been
-passed).
 
 See Documentation/filesystems/directory-locking for more detailed discussion
 of the locking scheme for directory operations.
diff --git a/Documentation/filesystems/caching/backend-api.txt b/Documentation/filesystems/caching/backend-api.txt
index 382d52cdaf2d..d78bab9622c6 100644
--- a/Documentation/filesystems/caching/backend-api.txt
+++ b/Documentation/filesystems/caching/backend-api.txt
@@ -308,6 +308,18 @@ performed on the denizens of the cache.  These are held in a structure of type:
      obtained by calling object->cookie->def->get_aux()/get_attr().
 
 
+ (*) Invalidate data object [mandatory]:
+
+        int (*invalidate_object)(struct fscache_operation *op)
+
+     This is called to invalidate a data object (as pointed to by op->object).
+     All the data stored for this object should be discarded and an
+     attr_changed operation should be performed.  The caller will follow up
+     with an object update operation.
+
+     fscache_op_complete() must be called on op before returning.
+
+
  (*) Discard object [mandatory]:
 
         void (*drop_object)(struct fscache_object *object)
@@ -419,7 +431,10 @@ performed on the denizens of the cache.  These are held in a structure of type:
 
      If an I/O error occurs, fscache_io_error() should be called and -ENOBUFS
      returned if possible or fscache_end_io() called with a suitable error
-     code..
+     code.
+
+     fscache_put_retrieval() should be called after a page or pages are dealt
+     with.  This will complete the operation when all pages are dealt with.
 
 
  (*) Request pages be read from cache [mandatory]:
@@ -526,6 +541,27 @@ FS-Cache provides some utilities that a cache backend may make use of:
      error value should be 0 if successful and an error otherwise.
 
 
+ (*) Record that one or more pages being retrieved or allocated have been dealt
+     with:
+
+        void fscache_retrieval_complete(struct fscache_retrieval *op,
+                                        int n_pages);
+
+     This is called to record the fact that one or more pages have been dealt
+     with and are no longer the concern of this operation.  When the number of
+     pages remaining in the operation reaches 0, the operation will be
+     completed.
+
+
+ (*) Record operation completion:
+
+        void fscache_op_complete(struct fscache_operation *op);
+
+     This is called to record the completion of an operation.  This deducts
+     this operation from the parent object's run state, potentially permitting
+     one or more pending operations to start running.
+
+
  (*) Set highest store limit:
 
         void fscache_set_store_limit(struct fscache_object *object,
diff --git a/Documentation/filesystems/caching/netfs-api.txt b/Documentation/filesystems/caching/netfs-api.txt
index 7cc6bf2871eb..97e6c0ecc5ef 100644
--- a/Documentation/filesystems/caching/netfs-api.txt
+++ b/Documentation/filesystems/caching/netfs-api.txt
@@ -35,8 +35,9 @@ This document contains the following sections:
         (12) Index and data file update
         (13) Miscellaneous cookie operations
         (14) Cookie unregistration
-        (15) Index and data file invalidation
-        (16) FS-Cache specific page flags.
+        (15) Index invalidation
+        (16) Data file invalidation
+        (17) FS-Cache specific page flags.
 
 
 =============================
@@ -767,13 +768,42 @@ the cookies for "child" indices, objects and pages have been relinquished
 first.
 
 
-================================
-INDEX AND DATA FILE INVALIDATION
-================================
+==================
+INDEX INVALIDATION
+==================
+
+There is no direct way to invalidate an index subtree.  To do this, the caller
+should relinquish and retire the cookie they have, and then acquire a new one.
+
+
+======================
+DATA FILE INVALIDATION
+======================
+
+Sometimes it will be necessary to invalidate an object that contains data.
+Typically this will be necessary when the server tells the netfs of a foreign
+change - at which point the netfs has to throw away all the state it had for an
+inode and reload from the server.
+
+To indicate that a cache object should be invalidated, the following function
+can be called:
+
+        void fscache_invalidate(struct fscache_cookie *cookie);
+
+This can be called with spinlocks held as it defers the work to a thread pool.
+All extant storage, retrieval and attribute change ops at this point are
+cancelled and discarded.  Some future operations will be rejected until the
+cache has had a chance to insert a barrier in the operations queue.  After
+that, operations will be queued again behind the invalidation operation.
+
+The invalidation operation will perform an attribute change operation and an
+auxiliary data update operation as it is very likely these will have changed.
+
+Using the following function, the netfs can wait for the invalidation operation
+to have reached a point at which it can start submitting ordinary operations
+once again:
 
-There is no direct way to invalidate an index subtree or a data file.  To do
-this, the caller should relinquish and retire the cookie they have, and then
-acquire a new one.
+        void fscache_wait_on_invalidate(struct fscache_cookie *cookie);
 
 
 ===========================
diff --git a/Documentation/filesystems/caching/object.txt b/Documentation/filesystems/caching/object.txt
index 58313348da87..100ff41127e4 100644
--- a/Documentation/filesystems/caching/object.txt
+++ b/Documentation/filesystems/caching/object.txt
@@ -216,7 +216,14 @@ servicing netfs requests:
      The normal running state.  In this state, requests the netfs makes will be
      passed on to the cache.
 
- (6) State FSCACHE_OBJECT_UPDATING.
+ (6) State FSCACHE_OBJECT_INVALIDATING.
+
+     The object is undergoing invalidation.  When the state comes here, it
+     discards all pending read, write and attribute change operations as it is
+     going to clear out the cache entirely and reinitialise it.  It will then
+     continue to the FSCACHE_OBJECT_UPDATING state.
+
+ (7) State FSCACHE_OBJECT_UPDATING.
 
      The state machine comes here to update the object in the cache from the
      netfs's records.  This involves updating the auxiliary data that is used
@@ -225,13 +232,13 @@ servicing netfs requests:
 And there are terminal states in which an object cleans itself up, deallocates
 memory and potentially deletes stuff from disk:
 
- (7) State FSCACHE_OBJECT_LC_DYING.
+ (8) State FSCACHE_OBJECT_LC_DYING.
 
      The object comes here if it is dying because of a lookup or creation
      error.  This would be due to a disk error or system error of some sort.
      Temporary data is cleaned up, and the parent is released.
 
- (8) State FSCACHE_OBJECT_DYING.
+ (9) State FSCACHE_OBJECT_DYING.
 
      The object comes here if it is dying due to an error, because its parent
      cookie has been relinquished by the netfs or because the cache is being
@@ -241,27 +248,27 @@ memory and potentially deletes stuff from disk:
      can destroy themselves.  This object waits for all its children to go away
      before advancing to the next state.
 
- (9) State FSCACHE_OBJECT_ABORT_INIT.
+(10) State FSCACHE_OBJECT_ABORT_INIT.
 
      The object comes to this state if it was waiting on its parent in
      FSCACHE_OBJECT_INIT, but its parent died.  The object will destroy itself
      so that the parent may proceed from the FSCACHE_OBJECT_DYING state.
 
-(10) State FSCACHE_OBJECT_RELEASING.
-(11) State FSCACHE_OBJECT_RECYCLING.
+(11) State FSCACHE_OBJECT_RELEASING.
+(12) State FSCACHE_OBJECT_RECYCLING.
 
      The object comes to one of these two states when dying once it is rid of
      all its children, if it is dying because the netfs relinquished its
      cookie.  In the first state, the cached data is expected to persist, and
      in the second it will be deleted.
 
-(12) State FSCACHE_OBJECT_WITHDRAWING.
+(13) State FSCACHE_OBJECT_WITHDRAWING.
 
      The object transits to this state if the cache decides it wants to
      withdraw the object from service, perhaps to make space, but also due to
      error or just because the whole cache is being withdrawn.
 
-(13) State FSCACHE_OBJECT_DEAD.
+(14) State FSCACHE_OBJECT_DEAD.
 
      The object transits to this state when the in-memory object record is
      ready to be deleted.  The object processor shouldn't ever see an object in
diff --git a/Documentation/filesystems/caching/operations.txt b/Documentation/filesystems/caching/operations.txt
index b6b070c57cbf..bee2a5f93d60 100644
--- a/Documentation/filesystems/caching/operations.txt
+++ b/Documentation/filesystems/caching/operations.txt
@@ -174,7 +174,7 @@ Operations are used through the following procedure:
      necessary (the object might have died whilst the thread was waiting).
 
      When it has finished doing its processing, it should call
-     fscache_put_operation() on it.
+     fscache_op_complete() and fscache_put_operation() on it.
 
  (4) The operation holds an effective lock upon the object, preventing other
      exclusive ops conflicting until it is released.  The operation can be
diff --git a/Documentation/filesystems/efivarfs.txt b/Documentation/filesystems/efivarfs.txt
new file mode 100644
index 000000000000..c477af086e65
--- /dev/null
+++ b/Documentation/filesystems/efivarfs.txt
@@ -0,0 +1,16 @@
+
+efivarfs - a (U)EFI variable filesystem
+
+The efivarfs filesystem was created to address the shortcomings of
+using entries in sysfs to maintain EFI variables. The old sysfs EFI
+variables code only supported variables of up to 1024 bytes. This
+limitation existed in version 0.99 of the EFI specification, but was
+removed before any full releases. Since variables can now be larger
+than a single page, sysfs isn't the best interface for this.
+
+Variables can be created, deleted and modified with the efivarfs
+filesystem.
+
+efivarfs is typically mounted like this,
+
+        mount -t efivarfs none /sys/firmware/efi/efivars
diff --git a/Documentation/filesystems/ext4.txt b/Documentation/filesystems/ext4.txt
index 104322bf378c..34ea4f1fa6ea 100644
--- a/Documentation/filesystems/ext4.txt
+++ b/Documentation/filesystems/ext4.txt
@@ -200,12 +200,9 @@ inode_readahead_blks=n	This tuning parameter controls the maximum
                         table readahead algorithm will pre-read into
                         the buffer cache.  The default value is 32 blocks.
 
-nouser_xattr            Disables Extended User Attributes. If you have extended
-                        attribute support enabled in the kernel configuration
-                        (CONFIG_EXT4_FS_XATTR), extended attribute support
-                        is enabled by default on mount. See the attr(5) manual
-                        page and http://acl.bestbits.at/ for more information
-                        about extended attributes.
+nouser_xattr            Disables Extended User Attributes.  See the
+                        attr(5) manual page and http://acl.bestbits.at/
+                        for more information about extended attributes.
 
 noacl                   This option disables POSIX Access Control List
                         support. If ACL support is enabled in the kernel
diff --git a/Documentation/filesystems/f2fs.txt b/Documentation/filesystems/f2fs.txt
new file mode 100644
index 000000000000..dcf338e62b71
--- /dev/null
+++ b/Documentation/filesystems/f2fs.txt
@@ -0,0 +1,421 @@
+================================================================================
+WHAT IS Flash-Friendly File System (F2FS)?
+================================================================================
+
+NAND flash memory-based storage devices, such as SSD, eMMC, and SD cards, have
+been equipped on a variety systems ranging from mobile to server systems. Since
+they are known to have different characteristics from the conventional rotating
+disks, a file system, an upper layer to the storage device, should adapt to the
+changes from the sketch in the design level.
+
+F2FS is a file system exploiting NAND flash memory-based storage devices, which
+is based on Log-structured File System (LFS). The design has been focused on
+addressing the fundamental issues in LFS, which are snowball effect of wandering
+tree and high cleaning overhead.
+
+Since a NAND flash memory-based storage device shows different characteristic
+according to its internal geometry or flash memory management scheme, namely FTL,
+F2FS and its tools support various parameters not only for configuring on-disk
+layout, but also for selecting allocation and cleaning algorithms.
+
+The file system formatting tool, "mkfs.f2fs", is available from the following
+git tree:
+>> git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs-tools.git
+
+For reporting bugs and sending patches, please use the following mailing list:
+>> linux-f2fs-devel@lists.sourceforge.net
+
+================================================================================
+BACKGROUND AND DESIGN ISSUES
+================================================================================
+
+Log-structured File System (LFS)
+--------------------------------
+"A log-structured file system writes all modifications to disk sequentially in
+a log-like structure, thereby speeding up  both file writing and crash recovery.
+The log is the only structure on disk; it contains indexing information so that
+files can be read back from the log efficiently. In order to maintain large free
+areas on disk for fast writing, we divide  the log into segments and use a
+segment cleaner to compress the live information from heavily fragmented
+segments." from Rosenblum, M. and Ousterhout, J. K., 1992, "The design and
+implementation of a log-structured file system", ACM Trans. Computer Systems
+10, 1, 26–52.
+
+Wandering Tree Problem
+----------------------
+In LFS, when a file data is updated and written to the end of log, its direct
+pointer block is updated due to the changed location. Then the indirect pointer
+block is also updated due to the direct pointer block update. In this manner,
+the upper index structures such as inode, inode map, and checkpoint block are
+also updated recursively. This problem is called as wandering tree problem [1],
+and in order to enhance the performance, it should eliminate or relax the update
+propagation as much as possible.
+
+[1] Bityutskiy, A. 2005. JFFS3 design issues. http://www.linux-mtd.infradead.org/
+
+Cleaning Overhead
+-----------------
+Since LFS is based on out-of-place writes, it produces so many obsolete blocks
+scattered across the whole storage. In order to serve new empty log space, it
+needs to reclaim these obsolete blocks seamlessly to users. This job is called
+as a cleaning process.
+
+The process consists of three operations as follows.
+1. A victim segment is selected through referencing segment usage table.
+2. It loads parent index structures of all the data in the victim identified by
+   segment summary blocks.
+3. It checks the cross-reference between the data and its parent index structure.
+4. It moves valid data selectively.
+
+This cleaning job may cause unexpected long delays, so the most important goal
+is to hide the latencies to users. And also definitely, it should reduce the
+amount of valid data to be moved, and move them quickly as well.
+
+================================================================================
+KEY FEATURES
+================================================================================
+
+Flash Awareness
+---------------
+- Enlarge the random write area for better performance, but provide the high
+  spatial locality
+- Align FS data structures to the operational units in FTL as best efforts
+
+Wandering Tree Problem
+----------------------
+- Use a term, “node”, that represents inodes as well as various pointer blocks
+- Introduce Node Address Table (NAT) containing the locations of all the “node”
+  blocks; this will cut off the update propagation.
+
+Cleaning Overhead
+-----------------
+- Support a background cleaning process
+- Support greedy and cost-benefit algorithms for victim selection policies
+- Support multi-head logs for static/dynamic hot and cold data separation
+- Introduce adaptive logging for efficient block allocation
+
+================================================================================
+MOUNT OPTIONS
+================================================================================
+
+background_gc_off      Turn off cleaning operations, namely garbage collection,
+                       triggered in background when I/O subsystem is idle.
+disable_roll_forward   Disable the roll-forward recovery routine
+discard                Issue discard/TRIM commands when a segment is cleaned.
+no_heap                Disable heap-style segment allocation which finds free
+                       segments for data from the beginning of main area, while
+                       for node from the end of main area.
+nouser_xattr           Disable Extended User Attributes. Note: xattr is enabled
+                       by default if CONFIG_F2FS_FS_XATTR is selected.
+noacl                  Disable POSIX Access Control List. Note: acl is enabled
+                       by default if CONFIG_F2FS_FS_POSIX_ACL is selected.
+active_logs=%u         Support configuring the number of active logs. In the
+                       current design, f2fs supports only 2, 4, and 6 logs.
+                       Default number is 6.
+disable_ext_identify   Disable the extension list configured by mkfs, so f2fs
+                       does not aware of cold files such as media files.
+
+================================================================================
+DEBUGFS ENTRIES
+================================================================================
+
+/sys/kernel/debug/f2fs/ contains information about all the partitions mounted as
+f2fs. Each file shows the whole f2fs information.
+
+/sys/kernel/debug/f2fs/status includes:
+ - major file system information managed by f2fs currently
+ - average SIT information about whole segments
+ - current memory footprint consumed by f2fs.
+
+================================================================================
+USAGE
+================================================================================
+
+1. Download userland tools and compile them.
+
+2. Skip, if f2fs was compiled statically inside kernel.
+   Otherwise, insert the f2fs.ko module.
+ # insmod f2fs.ko
+
+3. Create a directory trying to mount
+ # mkdir /mnt/f2fs
+
+4. Format the block device, and then mount as f2fs
+ # mkfs.f2fs -l label /dev/block_device
+ # mount -t f2fs /dev/block_device /mnt/f2fs
+
+Format options
+--------------
+-l [label]   : Give a volume label, up to 256 unicode name.
+-a [0 or 1]  : Split start location of each area for heap-based allocation.
+               1 is set by default, which performs this.
+-o [int]     : Set overprovision ratio in percent over volume size.
+               5 is set by default.
+-s [int]     : Set the number of segments per section.
+               1 is set by default.
+-z [int]     : Set the number of sections per zone.
+               1 is set by default.
+-e [str]     : Set basic extension list. e.g. "mp3,gif,mov"
+
+================================================================================
+DESIGN
+================================================================================
+
+On-disk Layout
+--------------
+
+F2FS divides the whole volume into a number of segments, each of which is fixed
+to 2MB in size. A section is composed of consecutive segments, and a zone
+consists of a set of sections. By default, section and zone sizes are set to one
+segment size identically, but users can easily modify the sizes by mkfs.
+
+F2FS splits the entire volume into six areas, and all the areas except superblock
+consists of multiple segments as described below.
+
+                                            align with the zone size <-|
+                 |-> align with the segment size
+     _________________________________________________________________________
+    |            |            |   Segment   |    Node     |   Segment  |      |
+    | Superblock | Checkpoint |    Info.    |   Address   |   Summary  | Main |
+    |    (SB)    |   (CP)     | Table (SIT) | Table (NAT) | Area (SSA) |      |
+    |____________|_____2______|______N______|______N______|______N_____|__N___|
+                                                                       .      .
+                                                             .                .
+                                                 .                            .
+                                    ._________________________________________.
+                                    |_Segment_|_..._|_Segment_|_..._|_Segment_|
+                                    .           .
+                                    ._________._________
+                                    |_section_|__...__|_
+                                    .            .
+                                    .________.
+                                    |__zone__|
+
+- Superblock (SB)
+ : It is located at the beginning of the partition, and there exist two copies
+   to avoid file system crash. It contains basic partition information and some
+   default parameters of f2fs.
+
+- Checkpoint (CP)
+ : It contains file system information, bitmaps for valid NAT/SIT sets, orphan
+   inode lists, and summary entries of current active segments.
+
+- Segment Information Table (SIT)
+ : It contains segment information such as valid block count and bitmap for the
+   validity of all the blocks.
+
+- Node Address Table (NAT)
+ : It is composed of a block address table for all the node blocks stored in
+   Main area.
+
+- Segment Summary Area (SSA)
+ : It contains summary entries which contains the owner information of all the
+   data and node blocks stored in Main area.
+
+- Main Area
+ : It contains file and directory data including their indices.
+
+In order to avoid misalignment between file system and flash-based storage, F2FS
+aligns the start block address of CP with the segment size. Also, it aligns the
+start block address of Main area with the zone size by reserving some segments
+in SSA area.
+
+Reference the following survey for additional technical details.
+https://wiki.linaro.org/WorkingGroups/Kernel/Projects/FlashCardSurvey
+
+File System Metadata Structure
+------------------------------
+
+F2FS adopts the checkpointing scheme to maintain file system consistency. At
+mount time, F2FS first tries to find the last valid checkpoint data by scanning
+CP area. In order to reduce the scanning time, F2FS uses only two copies of CP.
+One of them always indicates the last valid data, which is called as shadow copy
+mechanism. In addition to CP, NAT and SIT also adopt the shadow copy mechanism.
+
+For file system consistency, each CP points to which NAT and SIT copies are
+valid, as shown as below.
+
+  +--------+----------+---------+
+  |   CP   |    SIT   |   NAT   |
+  +--------+----------+---------+
+  .         .          .          .
+  .            .              .              .
+  .               .                 .                 .
+  +-------+-------+--------+--------+--------+--------+
+  | CP #0 | CP #1 | SIT #0 | SIT #1 | NAT #0 | NAT #1 |
+  +-------+-------+--------+--------+--------+--------+
+     |             ^                          ^
+     |             |                          |
+     `----------------------------------------'
+
+Index Structure
+---------------
+
+The key data structure to manage the data locations is a "node". Similar to
+traditional file structures, F2FS has three types of node: inode, direct node,
+indirect node. F2FS assigns 4KB to an inode block which contains 923 data block
+indices, two direct node pointers, two indirect node pointers, and one double
+indirect node pointer as described below. One direct node block contains 1018
+data blocks, and one indirect node block contains also 1018 node blocks. Thus,
+one inode block (i.e., a file) covers:
+
+  4KB * (923 + 2 * 1018 + 2 * 1018 * 1018 + 1018 * 1018 * 1018) := 3.94TB.
+
+   Inode block (4KB)
+     |- data (923)
+     |- direct node (2)
+     |          `- data (1018)
+     |- indirect node (2)
+     |            `- direct node (1018)
+     |                       `- data (1018)
+     `- double indirect node (1)
+                         `- indirect node (1018)
+                                      `- direct node (1018)
+                                                 `- data (1018)
+
+Note that, all the node blocks are mapped by NAT which means the location of
+each node is translated by the NAT table. In the consideration of the wandering
+tree problem, F2FS is able to cut off the propagation of node updates caused by
+leaf data writes.
+
+Directory Structure
+-------------------
+
+A directory entry occupies 11 bytes, which consists of the following attributes.
+
+- hash          hash value of the file name
+- ino           inode number
+- len           the length of file name
+- type          file type such as directory, symlink, etc
+
+A dentry block consists of 214 dentry slots and file names. Therein a bitmap is
+used to represent whether each dentry is valid or not. A dentry block occupies
+4KB with the following composition.
+
+  Dentry Block(4 K) = bitmap (27 bytes) + reserved (3 bytes) +
+                      dentries(11 * 214 bytes) + file name (8 * 214 bytes)
+
+                         [Bucket]
+             +--------------------------------+
+             |dentry block 1 | dentry block 2 |
+             +--------------------------------+
+             .               .
+       .                             .
+  .       [Dentry Block Structure: 4KB]       .
+  +--------+----------+----------+------------+
+  | bitmap | reserved | dentries | file names |
+  +--------+----------+----------+------------+
+  [Dentry Block: 4KB] .   .
+                 .               .
+            .                          .
+            +------+------+-----+------+
+            | hash | ino  | len | type |
+            +------+------+-----+------+
+            [Dentry Structure: 11 bytes]
+
+F2FS implements multi-level hash tables for directory structure. Each level has
+a hash table with dedicated number of hash buckets as shown below. Note that
+"A(2B)" means a bucket includes 2 data blocks.
+
+----------------------
+A : bucket
+B : block
+N : MAX_DIR_HASH_DEPTH
+----------------------
+
+level #0   | A(2B)
+           |
+level #1   | A(2B) - A(2B)
+           |
+level #2   | A(2B) - A(2B) - A(2B) - A(2B)
+     .     |   .       .       .       .
+level #N/2 | A(2B) - A(2B) - A(2B) - A(2B) - A(2B) - ... - A(2B)
+     .     |   .       .       .       .
+level #N   | A(4B) - A(4B) - A(4B) - A(4B) - A(4B) - ... - A(4B)
+
+The number of blocks and buckets are determined by,
+
+                            ,- 2, if n < MAX_DIR_HASH_DEPTH / 2,
+  # of blocks in level #n = |
+                            `- 4, Otherwise
+
+                             ,- 2^n, if n < MAX_DIR_HASH_DEPTH / 2,
+  # of buckets in level #n = |
+                             `- 2^((MAX_DIR_HASH_DEPTH / 2) - 1), Otherwise
+
+When F2FS finds a file name in a directory, at first a hash value of the file
+name is calculated. Then, F2FS scans the hash table in level #0 to find the
+dentry consisting of the file name and its inode number. If not found, F2FS
+scans the next hash table in level #1. In this way, F2FS scans hash tables in
+each levels incrementally from 1 to N. In each levels F2FS needs to scan only
+one bucket determined by the following equation, which shows O(log(# of files))
+complexity.
+
+  bucket number to scan in level #n = (hash value) % (# of buckets in level #n)
+
+In the case of file creation, F2FS finds empty consecutive slots that cover the
+file name. F2FS searches the empty slots in the hash tables of whole levels from
+1 to N in the same way as the lookup operation.
+
+The following figure shows an example of two cases holding children.
+       --------------> Dir <--------------
+       |                                 |
+    child                             child
+
+    child - child                     [hole] - child
+
+    child - child - child             [hole] - [hole] - child
+
+   Case 1:                           Case 2:
+   Number of children = 6,           Number of children = 3,
+   File size = 7                     File size = 7
+
+Default Block Allocation
+------------------------
+
+At runtime, F2FS manages six active logs inside "Main" area: Hot/Warm/Cold node
+and Hot/Warm/Cold data.
+
+- Hot node      contains direct node blocks of directories.
+- Warm node     contains direct node blocks except hot node blocks.
+- Cold node     contains indirect node blocks
+- Hot data      contains dentry blocks
+- Warm data     contains data blocks except hot and cold data blocks
+- Cold data     contains multimedia data or migrated data blocks
+
+LFS has two schemes for free space management: threaded log and copy-and-compac-
+tion. The copy-and-compaction scheme which is known as cleaning, is well-suited
+for devices showing very good sequential write performance, since free segments
+are served all the time for writing new data. However, it suffers from cleaning
+overhead under high utilization. Contrarily, the threaded log scheme suffers
+from random writes, but no cleaning process is needed. F2FS adopts a hybrid
+scheme where the copy-and-compaction scheme is adopted by default, but the
+policy is dynamically changed to the threaded log scheme according to the file
+system status.
+
+In order to align F2FS with underlying flash-based storage, F2FS allocates a
+segment in a unit of section. F2FS expects that the section size would be the
+same as the unit size of garbage collection in FTL. Furthermore, with respect
+to the mapping granularity in FTL, F2FS allocates each section of the active
+logs from different zones as much as possible, since FTL can write the data in
+the active logs into one allocation unit according to its mapping granularity.
+
+Cleaning process
+----------------
+
+F2FS does cleaning both on demand and in the background. On-demand cleaning is
+triggered when there are not enough free segments to serve VFS calls. Background
+cleaner is operated by a kernel thread, and triggers the cleaning job when the
+system is idle.
+
+F2FS supports two victim selection policies: greedy and cost-benefit algorithms.
+In the greedy algorithm, F2FS selects a victim segment having the smallest number
+of valid blocks. In the cost-benefit algorithm, F2FS selects a victim segment
+according to the segment age and the number of valid blocks in order to address
+log block thrashing problem in the greedy algorithm. F2FS adopts the greedy
+algorithm for on-demand cleaner, while background cleaner adopts cost-benefit
+algorithm.
+
+In order to identify whether the data in the victim segment are valid or not,
+F2FS manages a bitmap. Each bit represents the validity of a block, and the
+bitmap is composed of a bit stream covering whole blocks in main area.
diff --git a/Documentation/filesystems/nfs/nfs41-server.txt b/Documentation/filesystems/nfs/nfs41-server.txt
index 092fad92a3f0..01c2db769791 100644
--- a/Documentation/filesystems/nfs/nfs41-server.txt
+++ b/Documentation/filesystems/nfs/nfs41-server.txt
@@ -39,21 +39,10 @@ interoperability problems with future clients.  Known issues:
           from a linux client are possible, but we aren't really
           conformant with the spec (for example, we don't use kerberos
           on the backchannel correctly).
-        - Incomplete backchannel support: incomplete backchannel gss
-          support and no support for BACKCHANNEL_CTL mean that
-          callbacks (hence delegations and layouts) may not be
-          available and clients confused by the incomplete
-          implementation may fail.
         - We do not support SSV, which provides security for shared
           client-server state (thus preventing unauthorized tampering
           with locks and opens, for example).  It is mandatory for
           servers to support this, though no clients use it yet.
-        - Mandatory operations which we do not support, such as
-          DESTROY_CLIENTID, are not currently used by clients, but will be
-          (and the spec recommends their uses in common cases), and
-          clients should not be expected to know how to recover from the
-          case where they are not supported.  This will eventually cause
-          interoperability failures.
 
 In addition, some limitations are inherited from the current NFSv4
 implementation:
@@ -89,7 +78,7 @@ Operations
    |                      | MNI        | or OPT)      |                |
    +----------------------+------------+--------------+----------------+
    | ACCESS               | REQ        |              | Section 18.1   |
-NS | BACKCHANNEL_CTL      | REQ        |              | Section 18.33  |
+I  | BACKCHANNEL_CTL      | REQ        |              | Section 18.33  |
 I  | BIND_CONN_TO_SESSION | REQ        |              | Section 18.34  |
    | CLOSE                | REQ        |              | Section 18.2   |
    | COMMIT               | REQ        |              | Section 18.3   |
@@ -99,7 +88,7 @@ NS*| DELEGPURGE           | OPT        | FDELG (REQ)  | Section 18.5   |
    | DELEGRETURN          | OPT        | FDELG,       | Section 18.6   |
    |                      |            | DDELG, pNFS  |                |
    |                      |            | (REQ)        |                |
-NS | DESTROY_CLIENTID     | REQ        |              | Section 18.50  |
+I  | DESTROY_CLIENTID     | REQ        |              | Section 18.50  |
 I  | DESTROY_SESSION      | REQ        |              | Section 18.37  |
 I  | EXCHANGE_ID          | REQ        |              | Section 18.35  |
 I  | FREE_STATEID         | REQ        |              | Section 18.38  |
@@ -192,7 +181,6 @@ EXCHANGE_ID:
 
 CREATE_SESSION:
 * backchannel attributes are ignored
-* backchannel security parameters are ignored
 
 SEQUENCE:
 * no support for dynamic slot table renegotiation (optional)
@@ -202,7 +190,7 @@ Nonstandard compound limitations:
   ca_maxrequestsize request and a ca_maxresponsesize reply, so we may
   fail to live up to the promise we made in CREATE_SESSION fore channel
   negotiation.
-* No more than one IO operation (read, write, readdir) allowed per
-  compound.
+* No more than one read-like operation allowed per compound; encoding
+  replies that cross page boundaries (except for read data) not handled.
 
 See also http://wiki.linux-nfs.org/wiki/index.php/Server_4.0_and_4.1_issues.
diff --git a/Documentation/filesystems/porting b/Documentation/filesystems/porting
index 0742feebc6e2..4db22f6491e0 100644
--- a/Documentation/filesystems/porting
+++ b/Documentation/filesystems/porting
@@ -281,7 +281,7 @@ ext2_write_failed and callers for an example.
 
 [mandatory]
 
-        ->truncate is going away.  The whole truncate sequence needs to be
+        ->truncate is gone.  The whole truncate sequence needs to be
 implemented in ->setattr, which is now mandatory for filesystems
 implementing on-disk size changes.  Start with a copy of the old inode_setattr
 and vmtruncate, and the reorder the vmtruncate + foofs_vmtruncate sequence to
@@ -441,3 +441,7 @@ d_make_root() drops the reference to inode if dentry allocation fails.
 two, it gets "is it an O_EXCL or equivalent?" boolean argument.  Note that
 local filesystems can ignore tha argument - they are guaranteed that the
 object doesn't exist.  It's remote/distributed ones that might care...
+--
+[mandatory]
+        FS_REVAL_DOT is gone; if you used to have it, add ->d_weak_revalidate()
+in your dentry operations instead.
diff --git a/Documentation/filesystems/proc.txt b/Documentation/filesystems/proc.txt
index a1793d670cd0..fd8d0d594fc7 100644
--- a/Documentation/filesystems/proc.txt
+++ b/Documentation/filesystems/proc.txt
@@ -33,7 +33,7 @@ Table of Contents
   2     Modifying System Parameters
 
   3     Per-Process Parameters
-  3.1   /proc/<pid>/oom_score_adj - Adjust the oom-killer
+  3.1   /proc/<pid>/oom_adj & /proc/<pid>/oom_score_adj - Adjust the oom-killer
                                                                 score
   3.2   /proc/<pid>/oom_score - Display current oom-killer score
   3.3   /proc/<pid>/io - Display the IO accounting fields
@@ -41,6 +41,7 @@ Table of Contents
   3.5   /proc/<pid>/mountinfo - Information about mounts
   3.6   /proc/<pid>/comm  & /proc/<pid>/task/<tid>/comm
   3.7   /proc/<pid>/task/<tid>/children - Information about task children
+  3.8   /proc/<pid>/fdinfo/<fd> - Information about opened file
 
   4     Configuring procfs
   4.1   Mount options
@@ -142,7 +143,7 @@ Table 1-1: Process specific entries in /proc
  pagemap        Page table
  stack          Report full stack trace, enable via CONFIG_STACKTRACE
  smaps          a extension based on maps, showing the memory consumption of
-                each mapping
+                each mapping and flags associated with it
 ..............................................................................
 
 For example, to get the status information of a process, all you have to do is
@@ -181,6 +182,7 @@ read the file /proc/PID/status:
   CapPrm: 0000000000000000
   CapEff: 0000000000000000
   CapBnd: ffffffffffffffff
+  Seccomp:        0
   voluntary_ctxt_switches:        0
   nonvoluntary_ctxt_switches:     1
 
@@ -237,6 +239,7 @@ Table 1-2: Contents of the status files (as of 2.6.30-rc7)
  CapPrm                      bitmap of permitted capabilities
  CapEff                      bitmap of effective capabilities
  CapBnd                      bitmap of capabilities bounding set
+ Seccomp                     seccomp mode, like prctl(PR_GET_SECCOMP, ...)
  Cpus_allowed                mask of CPUs on which this process may run
  Cpus_allowed_list           Same as previous, but in "list format"
  Mems_allowed                mask of memory nodes allowed to this process
@@ -415,8 +418,9 @@ Swap:                  0 kB
 KernelPageSize:        4 kB
 MMUPageSize:           4 kB
 Locked:              374 kB
+VmFlags: rd ex mr mw me de
 
-The first of these lines shows the same information as is displayed for the
+the first of these lines shows the same information as is displayed for the
 mapping in /proc/PID/maps.  The remaining lines show the size of the mapping
 (size), the amount of the mapping that is currently resident in RAM (RSS), the
 process' proportional share of this mapping (PSS), the number of clean and
@@ -430,6 +434,41 @@ and a page is modified, the file page is replaced by a private anonymous copy.
 "Swap" shows how much would-be-anonymous memory is also used, but out on
 swap.
 
+"VmFlags" field deserves a separate description. This member represents the kernel
+flags associated with the particular virtual memory area in two letter encoded
+manner. The codes are the following:
+    rd  - readable
+    wr  - writeable
+    ex  - executable
+    sh  - shared
+    mr  - may read
+    mw  - may write
+    me  - may execute
+    ms  - may share
+    gd  - stack segment growns down
+    pf  - pure PFN range
+    dw  - disabled write to the mapped file
+    lo  - pages are locked in memory
+    io  - memory mapped I/O area
+    sr  - sequential read advise provided
+    rr  - random read advise provided
+    dc  - do not copy area on fork
+    de  - do not expand area on remapping
+    ac  - area is accountable
+    nr  - swap space is not reserved for the area
+    ht  - area uses huge tlb pages
+    nl  - non-linear mapping
+    ar  - architecture specific flag
+    dd  - do not include area into core dump
+    mm  - mixed map area
+    hg  - huge page advise flag
+    nh  - no-huge page advise flag
+    mg  - mergable advise flag
+
+Note that there is no guarantee that every flag and associated mnemonic will
+be present in all further kernel releases. Things get changed, the flags may
+be vanished or the reverse -- new added.
+
 This file is only present if the CONFIG_MMU kernel configuration option is
 enabled.
 
@@ -1320,10 +1359,10 @@ of the kernel.
 CHAPTER 3: PER-PROCESS PARAMETERS
 ------------------------------------------------------------------------------
 
-3.1 /proc/<pid>/oom_score_adj- Adjust the oom-killer score
+3.1 /proc/<pid>/oom_adj & /proc/<pid>/oom_score_adj- Adjust the oom-killer score
 --------------------------------------------------------------------------------
 
-This file can be used to adjust the badness heuristic used to select which
+These file can be used to adjust the badness heuristic used to select which
 process gets killed in out of memory conditions.
 
 The badness heuristic assigns a value to each candidate task ranging from 0
@@ -1361,6 +1400,12 @@ same system, cpuset, mempolicy, or memory controller resources to use at least
 equivalent to discounting 50% of the task's allowed memory from being considered
 as scoring against the task.
 
+For backwards compatibility with previous kernels, /proc/<pid>/oom_adj may also
+be used to tune the badness score.  Its acceptable values range from -16
+(OOM_ADJUST_MIN) to +15 (OOM_ADJUST_MAX) and a special value of -17
+(OOM_DISABLE) to disable oom killing entirely for that task.  Its value is
+scaled linearly with /proc/<pid>/oom_score_adj.
+
 The value of /proc/<pid>/oom_score_adj may be reduced no lower than the last
 value set by a CAP_SYS_RESOURCE process. To reduce the value any lower
 requires CAP_SYS_RESOURCE.
@@ -1375,7 +1420,9 @@ minimal amount of work.
 -------------------------------------------------------------
 
 This file can be used to check the current score used by the oom-killer is for
-any given <pid>.
+any given <pid>. Use it together with /proc/<pid>/oom_score_adj to tune which
+process should be killed in an out-of-memory situation.
+
 
 3.3  /proc/<pid>/io - Display the IO accounting fields
 -------------------------------------------------------
@@ -1587,6 +1634,93 @@ pids, so one need to either stop or freeze processes being inspected
 if precise results are needed.
 
 
+3.7     /proc/<pid>/fdinfo/<fd> - Information about opened file
+---------------------------------------------------------------
+This file provides information associated with an opened file. The regular
+files have at least two fields -- 'pos' and 'flags'. The 'pos' represents
+the current offset of the opened file in decimal form [see lseek(2) for
+details] and 'flags' denotes the octal O_xxx mask the file has been
+created with [see open(2) for details].
+
+A typical output is
+
+        pos:    0
+        flags:  0100002
+
+The files such as eventfd, fsnotify, signalfd, epoll among the regular pos/flags
+pair provide additional information particular to the objects they represent.
+
+        Eventfd files
+        ~~~~~~~~~~~~~
+        pos:    0
+        flags:  04002
+        eventfd-count:  5a
+
+        where 'eventfd-count' is hex value of a counter.
+
+        Signalfd files
+        ~~~~~~~~~~~~~~
+        pos:    0
+        flags:  04002
+        sigmask:        0000000000000200
+
+        where 'sigmask' is hex value of the signal mask associated
+        with a file.
+
+        Epoll files
+        ~~~~~~~~~~~
+        pos:    0
+        flags:  02
+        tfd:        5 events:       1d data: ffffffffffffffff
+
+        where 'tfd' is a target file descriptor number in decimal form,
+        'events' is events mask being watched and the 'data' is data
+        associated with a target [see epoll(7) for more details].
+
+        Fsnotify files
+        ~~~~~~~~~~~~~~
+        For inotify files the format is the following
+
+        pos:    0
+        flags:  02000000
+        inotify wd:3 ino:9e7e sdev:800013 mask:800afce ignored_mask:0 fhandle-bytes:8 fhandle-type:1 f_handle:7e9e0000640d1b6d
+
+        where 'wd' is a watch descriptor in decimal form, ie a target file
+        descriptor number, 'ino' and 'sdev' are inode and device where the
+        target file resides and the 'mask' is the mask of events, all in hex
+        form [see inotify(7) for more details].
+
+        If the kernel was built with exportfs support, the path to the target
+        file is encoded as a file handle.  The file handle is provided by three
+        fields 'fhandle-bytes', 'fhandle-type' and 'f_handle', all in hex
+        format.
+
+        If the kernel is built without exportfs support the file handle won't be
+        printed out.
+
+        If there is no inotify mark attached yet the 'inotify' line will be omitted.
+
+        For fanotify files the format is
+
+        pos:    0
+        flags:  02
+        fanotify flags:10 event-flags:0
+        fanotify mnt_id:12 mflags:40 mask:38 ignored_mask:40000003
+        fanotify ino:4f969 sdev:800013 mflags:0 mask:3b ignored_mask:40000000 fhandle-bytes:8 fhandle-type:1 f_handle:69f90400c275b5b4
+
+        where fanotify 'flags' and 'event-flags' are values used in fanotify_init
+        call, 'mnt_id' is the mount point identifier, 'mflags' is the value of
+        flags associated with mark which are tracked separately from events
+        mask. 'ino', 'sdev' are target inode and device, 'mask' is the events
+        mask and 'ignored_mask' is the mask of events which are to be ignored.
+        All in hex format. Incorporation of 'mflags', 'mask' and 'ignored_mask'
+        does provide information about flags and mask used in fanotify_mark
+        call [see fsnotify manpage for details].
+
+        While the first three lines are mandatory and always printed, the rest is
+        optional and may be omitted if no marks created yet.
+
+
 ------------------------------------------------------------------------------
 Configuring procfs
 ------------------------------------------------------------------------------
diff --git a/Documentation/filesystems/vfat.txt b/Documentation/filesystems/vfat.txt
index de1e6c4dccff..d230dd9c99b0 100644
--- a/Documentation/filesystems/vfat.txt
+++ b/Documentation/filesystems/vfat.txt
@@ -111,6 +111,15 @@ tz=UTC        -- Interpret timestamps as UTC rather than local time.
                  useful when mounting devices (like digital cameras)
                  that are set to UTC in order to avoid the pitfalls of
                  local time.
+time_offset=minutes
+              -- Set offset for conversion of timestamps from local time
+                 used by FAT to UTC. I.e. <minutes> minutes will be subtracted
+                 from each timestamp to convert it to UTC used internally by
+                 Linux. This is useful when time zone set in sys_tz is
+                 not the time zone used by the filesystem. Note that this
+                 option still does not provide correct time stamps in all
+                 cases in presence of DST - time stamps in a different DST
+                 setting will be off by one hour.
 
 showexec      -- If set, the execute permission bits of the file will be
                  allowed only if the extension part of the name is .EXE,
diff --git a/Documentation/filesystems/vfs.txt b/Documentation/filesystems/vfs.txt
index 2ee133e030c3..bc4b06b3160a 100644
--- a/Documentation/filesystems/vfs.txt
+++ b/Documentation/filesystems/vfs.txt
@@ -350,7 +350,6 @@ struct inode_operations {
         int (*readlink) (struct dentry *, char __user *,int);
         void * (*follow_link) (struct dentry *, struct nameidata *);
         void (*put_link) (struct dentry *, struct nameidata *, void *);
-        void (*truncate) (struct inode *);
         int (*permission) (struct inode *, int);
         int (*get_acl)(struct inode *, int);
         int (*setattr) (struct dentry *, struct iattr *);
@@ -431,16 +430,6 @@ otherwise noted.
         started might not be in the page cache at the end of the
         walk).
 
-  truncate: Deprecated. This will not be called if ->setsize is defined.
-        Called by the VFS to change the size of a file.  The
-        i_size field of the inode is set to the desired size by the
-        VFS before this method is called.  This method is called by
-        the truncate(2) system call and related functionality.
-
-        Note: ->truncate and vmtruncate are deprecated. Do not add new
-        instances/calls of these. Filesystems should be converted to do their
-        truncate sequence via ->setattr().
-
   permission: called by the VFS to check for access rights on a POSIX-like
         filesystem.
 
@@ -911,6 +900,7 @@ defined:
 
 struct dentry_operations {
         int (*d_revalidate)(struct dentry *, unsigned int);
+        int (*d_weak_revalidate)(struct dentry *, unsigned int);
         int (*d_hash)(const struct dentry *, const struct inode *,
                         struct qstr *);
         int (*d_compare)(const struct dentry *, const struct inode *,
@@ -926,8 +916,13 @@ struct dentry_operations {
 
   d_revalidate: called when the VFS needs to revalidate a dentry. This
         is called whenever a name look-up finds a dentry in the
-        dcache. Most filesystems leave this as NULL, because all their
-        dentries in the dcache are valid
+        dcache. Most local filesystems leave this as NULL, because all their
+        dentries in the dcache are valid. Network filesystems are different
+        since things can change on the server without the client necessarily
+        being aware of it.
+
+        This function should return a positive value if the dentry is still
+        valid, and zero or a negative error code if it isn't.
 
         d_revalidate may be called in rcu-walk mode (flags & LOOKUP_RCU).
         If in rcu-walk mode, the filesystem must revalidate the dentry without
@@ -938,6 +933,20 @@ struct dentry_operations {
         If a situation is encountered that rcu-walk cannot handle, return
         -ECHILD and it will be called again in ref-walk mode.
 
+ d_weak_revalidate: called when the VFS needs to revalidate a "jumped" dentry.
+        This is called when a path-walk ends at dentry that was not acquired by
+        doing a lookup in the parent directory. This includes "/", "." and "..",
+        as well as procfs-style symlinks and mountpoint traversal.
+
+        In this case, we are less concerned with whether the dentry is still
+        fully correct, but rather that the inode is still valid. As with
+        d_revalidate, most local filesystems will set this to NULL since their
+        dcache entries are always valid.
+
+        This function has the same return code semantics as d_revalidate.
+
+        d_weak_revalidate is only called after leaving rcu-walk mode.
+
   d_hash: called when the VFS adds a dentry to the hash table. The first
         dentry passed to d_hash is the parent directory that the name is
         to be hashed into. The inode is the dentry's inode.
diff --git a/Documentation/filesystems/xfs.txt b/Documentation/filesystems/xfs.txt
index 3fc0c31a6f5d..3e4b3dd1e046 100644
--- a/Documentation/filesystems/xfs.txt
+++ b/Documentation/filesystems/xfs.txt
@@ -43,7 +43,7 @@ When mounting an XFS filesystem, the following options are accepted.
         Issue command 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 performance
-        impact.  This option is incompatible with the nodelaylog option.
+        impact.
 
   dmapi
         Enable the DMAPI (Data Management API) event callouts.
@@ -72,8 +72,15 @@ When mounting an XFS filesystem, the following options are accepted.
         Indicates that XFS is allowed to create inodes at any location
         in the filesystem, including those which will result in inode
         numbers occupying more than 32 bits of significance.  This is
-        provided for backwards compatibility, but causes problems for
-        backup applications that cannot handle large inode numbers.
+        the default allocation option. Applications which do not handle
+        inode numbers bigger than 32 bits, should use inode32 option.
+
+  inode32
+        Indicates that XFS is limited to create inodes at locations which
+        will not result in inode numbers with more than 32 bits of
+        significance. This is provided for backwards compatibility, since
+        64 bits inode numbers might cause problems for some applications
+        that cannot handle large inode numbers.
 
   largeio/nolargeio
         If "nolargeio" is specified, the optimal I/O reported in