The dir_nlink feature has been enabled by default for new ext4
filesystems since e2fsprogs-1.41 in 2008, and was automatically
enabled by the kernel for older ext4 filesystems since the
dir_nlink feature was added with ext4 in kernel 2.6.28+ when
the subdirectory count exceeded EXT4_LINK_MAX-1.

Automatically adding the file system features such as dir_nlink is
generally frowned upon, since it could cause the file system to not be
mountable on older kernel, thus preventing the administrator from
rolling back to an older kernel if necessary.

In this case, the administrator might also want to disable the feature
because glibc's fts_read() function does not correctly optimize
directory traversal for directories that use st_nlinks field of 1 to
indicate that the number of links in the directory are not tracked by
the file system, and could fail to traverse the full directory
hierarchy.  Fortunately, in the past ten years very few users have
complained about incomplete file system traversal by glibc's
fts_read().

This commit also changes ext4_inc_count() to allow i_nlinks to reach
the full EXT4_LINK_MAX links on the parent directory (including "."
and "..") before changing i_links_count to be 1.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=196405Signed-off-by: NAndreas Dilger <adilger@dilger.ca>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>

I get a static checker warning:

    fs/ext4/ext4.h:3091 ext4_set_de_type()
    error: buffer overflow 'ext4_type_by_mode' 15 <= 15

It seems unlikely that we would hit this read overflow in real life, but
it's also simple enough to make the array 16 bytes instead of 15.
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>

Two variables in ext4_inode_info, i_reserved_meta_blocks and
i_allocated_meta_blocks, are unused.  Removing them saves a little
memory per in-memory inode and cleans up clutter in several tracepoints.
Adjust tracepoint output from ext4_alloc_da_blocks() for consistency
and fix a typo and whitespace near these changes.
Signed-off-by: NEric Whitney <enwlinux@gmail.com>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>
Reviewed-by: NJan Kara <jack@suse.cz>

Now, when we mount ext4 filesystem with '-o discard' option, we have to
issue all the discard commands for the blocks to be deallocated and
wait for the completion of the commands on the commit complete phase.
Because this procedure might involve a lot of sequential combinations of
issuing discard commands and waiting for that, the delay of this
procedure might be too much long, even to 17.0s in our test,
and it results in long commit delay and fsync() performance degradation.

To reduce this kind of delay, instead of adding callback for each
extent and handling all of them in a sequential manner on commit phase,
we instead add a separate list of extents to free to the superblock and
then process this list at once after transaction commits so that
we can issue all the discard commands in a parallel manner like XFS
filesystem.

Finally, we could enhance the discard command handling performance.
The result was such that 17.0s delay of a single commit in the worst
case has been enhanced to 4.8s.
Signed-off-by: NDaeho Jeong <daeho.jeong@samsung.com>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>
Tested-by: NHobin Woo <hobin.woo@samsung.com>
Tested-by: NKitae Lee <kitae87.lee@samsung.com>
Reviewed-by: NJan Kara <jack@suse.cz>

The main purpose of mb cache is to achieve deduplication in
extended attributes. In use cases where opportunity for deduplication
is unlikely, it only adds overhead.

Add a mount option to explicitly turn off mb cache.
Suggested-by: NAndreas Dilger <adilger@dilger.ca>
Signed-off-by: NTahsin Erdogan <tahsin@google.com>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>

Ext4 now supports xattr values that are up to 64k in size (vfs limit).
Large xattr values are stored in external inodes each one holding a
single value. Once written the data blocks of these inodes are immutable.

The real world use cases are expected to have a lot of value duplication
such as inherited acls etc. To reduce data duplication on disk, this patch
implements a deduplicator that allows sharing of xattr inodes.

The deduplication is based on an in-memory hash lookup that is a best
effort sharing scheme. When a xattr inode is read from disk (i.e.
getxattr() call), its crc32c hash is added to a hash table. Before
creating a new xattr inode for a value being set, the hash table is
checked to see if an existing inode holds an identical value. If such an
inode is found, the ref count on that inode is incremented. On value
removal the ref count is decremented and if it reaches zero the inode is
deleted.

The quota charging for such inodes is manually managed. Every reference
holder is charged the full size as if there was no sharing happening.
This is consistent with how xattr blocks are also charged.

[ Fixed up journal credits calculation to handle inline data and the
  rare case where an shared xattr block can get freed when two thread
  race on breaking the xattr block sharing. --tytso ]
Signed-off-by: NTahsin Erdogan <tahsin@google.com>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>

IS_NOQUOTA() indicates whether quota is disabled for an inode. Ext4
also uses it to check whether an inode is for a quota file. The
distinction currently doesn't matter because quota is disabled only
for the quota files. When we start disabling quota for other inodes
in the future, we will want to make the distinction clear.

Replace IS_NOQUOTA() call with ext4_is_quota_file() at places where
we are checking for quota files.
Signed-off-by: NTahsin Erdogan <tahsin@google.com>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>

There will be a second mb_cache instance that tracks ea_inodes. Make
existing names more explicit so that it is clear that they refer to
xattr block cache.
Signed-off-by: NTahsin Erdogan <tahsin@google.com>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>

Since this is a xattr specific data structure it is cleaner to keep it in
xattr header file.
Signed-off-by: NTahsin Erdogan <tahsin@google.com>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>

Tracking struct inode * rather than the inode number eliminates the
repeated ext4_xattr_inode_iget() call later. The second call cannot
fail in practice but still requires explanation when it wants to ignore
the return value. Avoid the trouble and make things simple.
Signed-off-by: NTahsin Erdogan <tahsin@google.com>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>

EXT4_XATTR_MAX_LARGE_EA_SIZE definition in ext4 is currently unused.
Besides, vfs enforces its own 64k limit which makes the 1MB limit in
ext4 redundant. Remove it.
Signed-off-by: NTahsin Erdogan <tahsin@google.com>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>

We don't need acls on xattr inodes because they are not directly
accessible from user mode.

Besides lockdep complains about recursive locking of xattr_sem as seen
below.

  =============================================
  [ INFO: possible recursive locking detected ]
  4.11.0-rc8+ #402 Not tainted
  ---------------------------------------------
  python/1894 is trying to acquire lock:
   (&ei->xattr_sem){++++..}, at: [<ffffffff804878a6>] ext4_xattr_get+0x66/0x270

  but task is already holding lock:
   (&ei->xattr_sem){++++..}, at: [<ffffffff80489500>] ext4_xattr_set_handle+0xa0/0x5d0

  other info that might help us debug this:
   Possible unsafe locking scenario:

         CPU0
         ----
    lock(&ei->xattr_sem);
    lock(&ei->xattr_sem);

   *** DEADLOCK ***

   May be due to missing lock nesting notation

  3 locks held by python/1894:
   #0:  (sb_writers#10){.+.+.+}, at: [<ffffffff803d829f>] mnt_want_write+0x1f/0x50
   #1:  (&sb->s_type->i_mutex_key#15){+.+...}, at: [<ffffffff803dda27>] vfs_setxattr+0x57/0xb0
   #2:  (&ei->xattr_sem){++++..}, at: [<ffffffff80489500>] ext4_xattr_set_handle+0xa0/0x5d0

  stack backtrace:
  CPU: 0 PID: 1894 Comm: python Not tainted 4.11.0-rc8+ #402
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
  Call Trace:
   dump_stack+0x67/0x99
   __lock_acquire+0x5f3/0x1830
   lock_acquire+0xb5/0x1d0
   down_read+0x2f/0x60
   ext4_xattr_get+0x66/0x270
   ext4_get_acl+0x43/0x1e0
   get_acl+0x72/0xf0
   posix_acl_create+0x5e/0x170
   ext4_init_acl+0x21/0xc0
   __ext4_new_inode+0xffd/0x16b0
   ext4_xattr_set_entry+0x5ea/0xb70
   ext4_xattr_block_set+0x1b5/0x970
   ext4_xattr_set_handle+0x351/0x5d0
   ext4_xattr_set+0x124/0x180
   ext4_xattr_user_set+0x34/0x40
   __vfs_setxattr+0x66/0x80
   __vfs_setxattr_noperm+0x69/0x1c0
   vfs_setxattr+0xa2/0xb0
   setxattr+0x129/0x160
   path_setxattr+0x87/0xb0
   SyS_setxattr+0xf/0x20
   entry_SYSCALL_64_fastpath+0x18/0xad
Signed-off-by: NTahsin Erdogan <tahsin@google.com>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>

Large xattr support is implemented for EXT4_FEATURE_INCOMPAT_EA_INODE.

If the size of an xattr value is larger than will fit in a single
external block, then the xattr value will be saved into the body
of an external xattr inode.

The also helps support a larger number of xattr, since only the headers
will be stored in the in-inode space or the single external block.

The inode is referenced from the xattr header via "e_value_inum",
which was formerly "e_value_block", but that field was never used.
The e_value_size still contains the xattr size so that listing
xattrs does not need to look up the inode if the data is not accessed.

struct ext4_xattr_entry {
        __u8    e_name_len;     /* length of name */
        __u8    e_name_index;   /* attribute name index */
        __le16  e_value_offs;   /* offset in disk block of value */
        __le32  e_value_inum;   /* inode in which value is stored */
        __le32  e_value_size;   /* size of attribute value */
        __le32  e_hash;         /* hash value of name and value */
        char    e_name[0];      /* attribute name */
};

The xattr inode is marked with the EXT4_EA_INODE_FL flag and also
holds a back-reference to the owning inode in its i_mtime field,
allowing the ext4/e2fsck to verify the correct inode is accessed.

[ Applied fix by Dan Carpenter to avoid freeing an ERR_PTR. ]

Lustre-Jira: https://jira.hpdd.intel.com/browse/LU-80
Lustre-bugzilla: https://bugzilla.lustre.org/show_bug.cgi?id=4424Signed-off-by: NKalpak Shah <kalpak.shah@sun.com>
Signed-off-by: NJames Simmons <uja.ornl@gmail.com>
Signed-off-by: NAndreas Dilger <andreas.dilger@intel.com>
Signed-off-by: NTahsin Erdogan <tahsin@google.com>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>

This INCOMPAT_LARGEDIR feature allows larger directories to be created
in ldiskfs, both with directory sizes over 2GB and and a maximum htree
depth of 3 instead of the current limit of 2. These features are needed
in order to exceed the current limit of approximately 10M entries in a
single directory.

This patch was originally written by Yang Sheng to support the Lustre server.

[ Bumped the credits needed to update an indexed directory -- tytso ]
Signed-off-by: NLiang Zhen <liang.zhen@intel.com>
Signed-off-by: NYang Sheng <yang.sheng@intel.com>
Signed-off-by: NArtem Blagodarenko <artem.blagodarenko@seagate.com>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>
Reviewed-by: NAndreas Dilger <andreas.dilger@intel.com>

Now that we are passing a struct ext4_filename, we do not need to pass
around the original struct qstr too.
Signed-off-by: NEric Biggers <ebiggers@google.com>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>
Reviewed-by: NJan Kara <jack@suse.cz>

Constify static data in ext4 that is never (intentionally) modified so
that it is placed in .rodata and benefits from memory protection.
Signed-off-by: NEric Biggers <ebiggers@google.com>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>

In the initial implementation of ext4 encryption, the filename was
encrypted in ext4_insert_dentry(), which could fail and also required
access to the 'dir' inode.  Since then ext4 filename encryption has been
changed to encrypt the filename earlier, so we can revert the additions
to ext4_insert_dentry().
Signed-off-by: NEric Biggers <ebiggers@google.com>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>

Now that all places setting inode->i_flags that should be reflected in
on-disk flags are gone, we can remove ext4_get_inode_flags() call.
Reviewed-by: NAndreas Dilger <adilger@dilger.ca>
Signed-off-by: NJan Kara <jack@suse.cz>

Return enhanced file attributes from the Ext4 filesystem.  This includes
the following:

 (1) The inode creation time (i_crtime) as stx_btime, setting STATX_BTIME.

 (2) Certain FS_xxx_FL flags are mapped to stx_attribute flags.

This requires that all ext4 inodes have a getattr call, not just some of
them, so to this end, split the ext4_getattr() function and only call part
of it where appropriate.

Example output:

	[root@andromeda ~]# touch foo
	[root@andromeda ~]# chattr +ai foo
	[root@andromeda ~]# /tmp/test-statx foo
	statx(foo) = 0
	results=fff
	  Size: 0               Blocks: 0          IO Block: 4096    regular file
	Device: 08:12           Inode: 2101950     Links: 1
	Access: (0644/-rw-r--r--)  Uid:     0   Gid:     0
	Access: 2016-02-11 17:08:29.031795451+0000
	Modify: 2016-02-11 17:08:29.031795451+0000
	Change: 2016-02-11 17:11:11.987790114+0000
	 Birth: 2016-02-11 17:08:29.031795451+0000
	Attributes: 0000000000000030 (-------- -------- -------- -------- -------- -------- -------- --ai----)
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Add a system call to make extended file information available, including
file creation and some attribute flags where available through the
underlying filesystem.

The getattr inode operation is altered to take two additional arguments: a
u32 request_mask and an unsigned int flags that indicate the
synchronisation mode.  This change is propagated to the vfs_getattr*()
function.

Functions like vfs_stat() are now inline wrappers around new functions
vfs_statx() and vfs_statx_fd() to reduce stack usage.

========
OVERVIEW
========

The idea was initially proposed as a set of xattrs that could be retrieved
with getxattr(), but the general preference proved to be for a new syscall
with an extended stat structure.

A number of requests were gathered for features to be included.  The
following have been included:

 (1) Make the fields a consistent size on all arches and make them large.

 (2) Spare space, request flags and information flags are provided for
     future expansion.

 (3) Better support for the y2038 problem [Arnd Bergmann] (tv_sec is an
     __s64).

 (4) Creation time: The SMB protocol carries the creation time, which could
     be exported by Samba, which will in turn help CIFS make use of
     FS-Cache as that can be used for coherency data (stx_btime).

     This is also specified in NFSv4 as a recommended attribute and could
     be exported by NFSD [Steve French].

 (5) Lightweight stat: Ask for just those details of interest, and allow a
     netfs (such as NFS) to approximate anything not of interest, possibly
     without going to the server [Trond Myklebust, Ulrich Drepper, Andreas
     Dilger] (AT_STATX_DONT_SYNC).

 (6) Heavyweight stat: Force a netfs to go to the server, even if it thinks
     its cached attributes are up to date [Trond Myklebust]
     (AT_STATX_FORCE_SYNC).

And the following have been left out for future extension:

 (7) Data version number: Could be used by userspace NFS servers [Aneesh
     Kumar].

     Can also be used to modify fill_post_wcc() in NFSD which retrieves
     i_version directly, but has just called vfs_getattr().  It could get
     it from the kstat struct if it used vfs_xgetattr() instead.

     (There's disagreement on the exact semantics of a single field, since
     not all filesystems do this the same way).

 (8) BSD stat compatibility: Including more fields from the BSD stat such
     as creation time (st_btime) and inode generation number (st_gen)
     [Jeremy Allison, Bernd Schubert].

 (9) Inode generation number: Useful for FUSE and userspace NFS servers
     [Bernd Schubert].

     (This was asked for but later deemed unnecessary with the
     open-by-handle capability available and caused disagreement as to
     whether it's a security hole or not).

(10) Extra coherency data may be useful in making backups [Andreas Dilger].

     (No particular data were offered, but things like last backup
     timestamp, the data version number and the DOS archive bit would come
     into this category).

(11) Allow the filesystem to indicate what it can/cannot provide: A
     filesystem can now say it doesn't support a standard stat feature if
     that isn't available, so if, for instance, inode numbers or UIDs don't
     exist or are fabricated locally...

     (This requires a separate system call - I have an fsinfo() call idea
     for this).

(12) Store a 16-byte volume ID in the superblock that can be returned in
     struct xstat [Steve French].

     (Deferred to fsinfo).

(13) Include granularity fields in the time data to indicate the
     granularity of each of the times (NFSv4 time_delta) [Steve French].

     (Deferred to fsinfo).

(14) FS_IOC_GETFLAGS value.  These could be translated to BSD's st_flags.
     Note that the Linux IOC flags are a mess and filesystems such as Ext4
     define flags that aren't in linux/fs.h, so translation in the kernel
     may be a necessity (or, possibly, we provide the filesystem type too).

     (Some attributes are made available in stx_attributes, but the general
     feeling was that the IOC flags were to ext[234]-specific and shouldn't
     be exposed through statx this way).

(15) Mask of features available on file (eg: ACLs, seclabel) [Brad Boyer,
     Michael Kerrisk].

     (Deferred, probably to fsinfo.  Finding out if there's an ACL or
     seclabal might require extra filesystem operations).

(16) Femtosecond-resolution timestamps [Dave Chinner].

     (A __reserved field has been left in the statx_timestamp struct for
     this - if there proves to be a need).

(17) A set multiple attributes syscall to go with this.

===============
NEW SYSTEM CALL
===============

The new system call is:

	int ret = statx(int dfd,
			const char *filename,
			unsigned int flags,
			unsigned int mask,
			struct statx *buffer);

The dfd, filename and flags parameters indicate the file to query, in a
similar way to fstatat().  There is no equivalent of lstat() as that can be
emulated with statx() by passing AT_SYMLINK_NOFOLLOW in flags.  There is
also no equivalent of fstat() as that can be emulated by passing a NULL
filename to statx() with the fd of interest in dfd.

Whether or not statx() synchronises the attributes with the backing store
can be controlled by OR'ing a value into the flags argument (this typically
only affects network filesystems):

 (1) AT_STATX_SYNC_AS_STAT tells statx() to behave as stat() does in this
     respect.

 (2) AT_STATX_FORCE_SYNC will require a network filesystem to synchronise
     its attributes with the server - which might require data writeback to
     occur to get the timestamps correct.

 (3) AT_STATX_DONT_SYNC will suppress synchronisation with the server in a
     network filesystem.  The resulting values should be considered
     approximate.

mask is a bitmask indicating the fields in struct statx that are of
interest to the caller.  The user should set this to STATX_BASIC_STATS to
get the basic set returned by stat().  It should be noted that asking for
more information may entail extra I/O operations.

buffer points to the destination for the data.  This must be 256 bytes in
size.

======================
MAIN ATTRIBUTES RECORD
======================

The following structures are defined in which to return the main attribute
set:

	struct statx_timestamp {
		__s64	tv_sec;
		__s32	tv_nsec;
		__s32	__reserved;
	};

	struct statx {
		__u32	stx_mask;
		__u32	stx_blksize;
		__u64	stx_attributes;
		__u32	stx_nlink;
		__u32	stx_uid;
		__u32	stx_gid;
		__u16	stx_mode;
		__u16	__spare0[1];
		__u64	stx_ino;
		__u64	stx_size;
		__u64	stx_blocks;
		__u64	__spare1[1];
		struct statx_timestamp	stx_atime;
		struct statx_timestamp	stx_btime;
		struct statx_timestamp	stx_ctime;
		struct statx_timestamp	stx_mtime;
		__u32	stx_rdev_major;
		__u32	stx_rdev_minor;
		__u32	stx_dev_major;
		__u32	stx_dev_minor;
		__u64	__spare2[14];
	};

The defined bits in request_mask and stx_mask are:

	STATX_TYPE		Want/got stx_mode & S_IFMT
	STATX_MODE		Want/got stx_mode & ~S_IFMT
	STATX_NLINK		Want/got stx_nlink
	STATX_UID		Want/got stx_uid
	STATX_GID		Want/got stx_gid
	STATX_ATIME		Want/got stx_atime{,_ns}
	STATX_MTIME		Want/got stx_mtime{,_ns}
	STATX_CTIME		Want/got stx_ctime{,_ns}
	STATX_INO		Want/got stx_ino
	STATX_SIZE		Want/got stx_size
	STATX_BLOCKS		Want/got stx_blocks
	STATX_BASIC_STATS	[The stuff in the normal stat struct]
	STATX_BTIME		Want/got stx_btime{,_ns}
	STATX_ALL		[All currently available stuff]

stx_btime is the file creation time, stx_mask is a bitmask indicating the
data provided and __spares*[] are where as-yet undefined fields can be
placed.

Time fields are structures with separate seconds and nanoseconds fields
plus a reserved field in case we want to add even finer resolution.  Note
that times will be negative if before 1970; in such a case, the nanosecond
fields will also be negative if not zero.

The bits defined in the stx_attributes field convey information about a
file, how it is accessed, where it is and what it does.  The following
attributes map to FS_*_FL flags and are the same numerical value:

	STATX_ATTR_COMPRESSED		File is compressed by the fs
	STATX_ATTR_IMMUTABLE		File is marked immutable
	STATX_ATTR_APPEND		File is append-only
	STATX_ATTR_NODUMP		File is not to be dumped
	STATX_ATTR_ENCRYPTED		File requires key to decrypt in fs

Within the kernel, the supported flags are listed by:

	KSTAT_ATTR_FS_IOC_FLAGS

[Are any other IOC flags of sufficient general interest to be exposed
through this interface?]

New flags include:

	STATX_ATTR_AUTOMOUNT		Object is an automount trigger

These are for the use of GUI tools that might want to mark files specially,
depending on what they are.

Fields in struct statx come in a number of classes:

 (0) stx_dev_*, stx_blksize.

     These are local system information and are always available.

 (1) stx_mode, stx_nlinks, stx_uid, stx_gid, stx_[amc]time, stx_ino,
     stx_size, stx_blocks.

     These will be returned whether the caller asks for them or not.  The
     corresponding bits in stx_mask will be set to indicate whether they
     actually have valid values.

     If the caller didn't ask for them, then they may be approximated.  For
     example, NFS won't waste any time updating them from the server,
     unless as a byproduct of updating something requested.

     If the values don't actually exist for the underlying object (such as
     UID or GID on a DOS file), then the bit won't be set in the stx_mask,
     even if the caller asked for the value.  In such a case, the returned
     value will be a fabrication.

     Note that there are instances where the type might not be valid, for
     instance Windows reparse points.

 (2) stx_rdev_*.

     This will be set only if stx_mode indicates we're looking at a
     blockdev or a chardev, otherwise will be 0.

 (3) stx_btime.

     Similar to (1), except this will be set to 0 if it doesn't exist.

=======
TESTING
=======

The following test program can be used to test the statx system call:

	samples/statx/test-statx.c

Just compile and run, passing it paths to the files you want to examine.
The file is built automatically if CONFIG_SAMPLES is enabled.

Here's some example output.  Firstly, an NFS directory that crosses to
another FSID.  Note that the AUTOMOUNT attribute is set because transiting
this directory will cause d_automount to be invoked by the VFS.

	[root@andromeda ~]# /tmp/test-statx -A /warthog/data
	statx(/warthog/data) = 0
	results=7ff
	  Size: 4096            Blocks: 8          IO Block: 1048576  directory
	Device: 00:26           Inode: 1703937     Links: 125
	Access: (3777/drwxrwxrwx)  Uid:     0   Gid:  4041
	Access: 2016-11-24 09:02:12.219699527+0000
	Modify: 2016-11-17 10:44:36.225653653+0000
	Change: 2016-11-17 10:44:36.225653653+0000
	Attributes: 0000000000001000 (-------- -------- -------- -------- -------- -------- ---m---- --------)

Secondly, the result of automounting on that directory.

	[root@andromeda ~]# /tmp/test-statx /warthog/data
	statx(/warthog/data) = 0
	results=7ff
	  Size: 4096            Blocks: 8          IO Block: 1048576  directory
	Device: 00:27           Inode: 2           Links: 125
	Access: (3777/drwxrwxrwx)  Uid:     0   Gid:  4041
	Access: 2016-11-24 09:02:12.219699527+0000
	Modify: 2016-11-17 10:44:36.225653653+0000
	Change: 2016-11-17 10:44:36.225653653+0000
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

sched/headers: Prepare to move signal wakeup & sigpending methods from <linux/sched.h> into <linux/sched/signal.h>

Fix up affected files that include this signal functionality via sched.h.
Acked-by: NLinus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: NIngo Molnar <mingo@kernel.org>

->fault(), ->page_mkwrite(), and ->pfn_mkwrite() calls do not need to
take a vma and vmf parameter when the vma already resides in vmf.

Remove the vma parameter to simplify things.

[arnd@arndb.de: fix ARM build]
  Link: http://lkml.kernel.org/r/20170125223558.1451224-1-arnd@arndb.de
Link: http://lkml.kernel.org/r/148521301778.19116.10840599906674778980.stgit@djiang5-desk3.ch.intel.comSigned-off-by: NDave Jiang <dave.jiang@intel.com>
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Reviewed-by: NRoss Zwisler <ross.zwisler@linux.intel.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Darrick J. Wong <darrick.wong@oracle.com>
Cc: Matthew Wilcox <mawilcox@microsoft.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Jan Kara <jack@suse.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

It's very likely the file system independent ioctl name will be
FS_IOC_SHUTDOWN, so let's use the same name for the ext4 ioctl name.
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>

Previously, each filesystem configured without encryption support would
define all the public fscrypt functions to their notsupp_* stubs.  This
list of #defines had to be updated in every filesystem whenever a change
was made to the public fscrypt functions.  To make things more
maintainable now that we have three filesystems using fscrypt, split the
old header fscrypto.h into several new headers.  fscrypt_supp.h contains
the real declarations and is included by filesystems when configured
with encryption support, whereas fscrypt_notsupp.h contains the inline
stubs and is included by filesystems when configured without encryption
support.  fscrypt_common.h contains common declarations needed by both.
Signed-off-by: NEric Biggers <ebiggers@google.com>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>

This ioctl is modeled after the xfs's XFS_IOC_GOINGDOWN ioctl.  (In
fact, it uses the same code points.)
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>

Add a shutdown bit that will cause ext4 processing to fail immediately
with EIO.
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>

We are currently using one bit in s_resize_flags; rename it in order
to allow more of the bits in that unsigned long for other purposes.
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>

Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>

Signed-off-by: NTheodore Ts'o <tytso@mit.edu>

There was an unnecessary amount of complexity around requesting the
filesystem-specific key prefix.  It was unclear why; perhaps it was
envisioned that different instances of the same filesystem type could
use different key prefixes, or that key prefixes could be binary.
However, neither of those things were implemented or really make sense
at all.  So simplify the code by making key_prefix a const char *.
Signed-off-by: NEric Biggers <ebiggers@google.com>
Reviewed-by: NRichard Weinberger <richard@nod.at>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>

Multiple bugs were recently fixed in the "set encryption policy" ioctl.
To make it clear that fscrypt_process_policy() and fscrypt_get_policy()
implement ioctls and therefore their implementations must take standard
security and correctness precautions, rename them to
fscrypt_ioctl_set_policy() and fscrypt_ioctl_get_policy().  Make the
latter take in a struct file * to make it consistent with the former.
Signed-off-by: NEric Biggers <ebiggers@google.com>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>

ext4_sb_has_crypto() just called through to ext4_has_feature_encrypt(),
and all callers except one were already using the latter.  So remove it
and switch its one caller to ext4_has_feature_encrypt().
Signed-off-by: NEric Biggers <ebiggers@google.com>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>

Currently we just silently ignore flags that we don't understand (or
that cannot be manipulated) through EXT4_IOC_SETFLAGS and
EXT4_IOC_FSSETXATTR ioctls. This makes it problematic for the unused
flags to be used in future (some app may be inadvertedly setting them
and we won't notice until the flag gets used). Also this is inconsistent
with other filesystems like XFS or BTRFS which return EOPNOTSUPP when
they see a flag they cannot set.

ext4 has the additional problem that there are flags which are returned
by EXT4_IOC_GETFLAGS ioctl but which cannot be modified via
EXT4_IOC_SETFLAGS. So we have to be careful to ignore value of these
flags and not fail the ioctl when they are set (as e.g. chattr(1) passes
flags returned from EXT4_IOC_GETFLAGS to EXT4_IOC_SETFLAGS without any
masking and thus we'd break this utility).
Signed-off-by: NJan Kara <jack@suse.cz>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>

Add EXT4_JOURNAL_DATA_FL and EXT4_EXTENTS_FL to EXT4_FL_USER_MODIFIABLE
to recognize that they are modifiable by userspace. So far we got away
without having them there because ext4_ioctl_setflags() treats them in a
special way. But it was really confusing like that.
Signed-off-by: NJan Kara <jack@suse.cz>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>

The last user of ext4_aligned_io() was the DAX path in
ext4_direct_IO_write().  This usage was removed by Jan Kara's patch
entitled "ext4: Rip out DAX handling from direct IO path".
Signed-off-by: NRoss Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>

Reads and writes for DAX inodes should no longer end up in direct IO
code. Rip out the support and add a warning.
Reviewed-by: NRoss Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: NJan Kara <jack@suse.cz>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>

Implement basic iomap_begin function that handles reading and use it for
DAX reads.
Reviewed-by: NRoss Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: NJan Kara <jack@suse.cz>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>

If the block size or cluster size is insane, reject the mount.  This
is important for security reasons (although we shouldn't be just
depending on this check).

Ref: http://www.securityfocus.com/archive/1/539661
Ref: https://bugzilla.redhat.com/show_bug.cgi?id=1332506Reported-by: NBorislav Petkov <bp@alien8.de>
Reported-by: NNikolay Borisov <kernel@kyup.com>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>
Cc: stable@vger.kernel.org

If the block size or cluster size is insane, reject the mount.  This
is important for security reasons (although we shouldn't be just
depending on this check).

Ref: http://www.securityfocus.com/archive/1/539661
Ref: https://bugzilla.redhat.com/show_bug.cgi?id=1332506Reported-by: NBorislav Petkov <bp@alien8.de>
Reported-by: NNikolay Borisov <kernel@kyup.com>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>
Cc: stable@vger.kernel.org

CURRENT_TIME_SEC and CURRENT_TIME are not y2038 safe.
current_time() will be transitioned to be y2038 safe
along with vfs.

current_time() returns timestamps according to the
granularities set in the super_block.
The granularity check in ext4_current_time() to call
current_time() or CURRENT_TIME_SEC is not required.
Use current_time() directly to obtain timestamps
unconditionally, and remove ext4_current_time().

Quota files are assumed to be on the same filesystem.
Hence, use current_time() for these files as well.
Signed-off-by: NDeepa Dinamani <deepa.kernel@gmail.com>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>
Reviewed-by: NArnd Bergmann <arnd@arndb.de>