Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

When path_init is called with a valid dfd, that code checks permissions
on the open directory fd and returns an error if the check fails. This
permission check is redundant, however.

Both callers of path_init immediately call link_path_walk afterward. The
first thing that link_path_walk does for pathnames that do not consist
only of slashes is to check for exec permissions at the starting point of
the path walk.  And this check in path_init() is on the path taken only
when *name != '/' && *name != '\0'.

In most cases, these checks are very quick, but when the dfd is for a
file on a NFS mount with the actimeo=0, each permission check goes
out onto the wire. The result is 2 identical ACCESS calls.

Given that these codepaths are fairly "hot", I think it makes sense to
eliminate the permission check in path_init and simply assume that the
caller will eventually check the permissions before proceeding.
Reported-by: NDave Wysochanski <dwysocha@redhat.com>
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

The compiler may optimize the while loop and make the check just be done once,
so we should use ACCESS_ONCE() to guard access to ->mnt_flags
Signed-off-by: NMiao Xie <miaox@cn.fujitsu.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

dput() was not called in the error path.
Signed-off-by: NCyril Roelandt <tipecaml@gmail.com>
Cc: Sage Weil <sage@inktank.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The kernel keeps FAN_MARK_IGNORED_SURV_MODIFY bit separately from
fsnotify_mark::mask|ignored_mask thus put it in @mflags (mark flags)
field so the user-space reader will be able to detect if such bit were
used on mark creation procedure.

 | pos:	0
 | flags:	04002
 | 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
Signed-off-by: NCyrill Gorcunov <gorcunov@openvz.org>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Andrey Vagin <avagin@openvz.org>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: James Bottomley <jbottomley@parallels.com>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Cc: Matthew Helsley <matt.helsley@gmail.com>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Tvrtko Ursulin <tvrtko.ursulin@onelan.co.uk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This allow us to print out fsnotify details such as watchee inode, device,
mask and optionally a file handle.

For inotify objects if kernel compiled with exportfs support the output
will be

 | 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
 | inotify wd:2 ino:a111 sdev:800013 mask:800afce ignored_mask:0 fhandle-bytes:8 fhandle-type:1 f_handle:11a1000020542153
 | inotify wd:1 ino:6b149 sdev:800013 mask:800afce ignored_mask:0 fhandle-bytes:8 fhandle-type:1 f_handle:49b1060023552153

If kernel compiled without exportfs support, the file handle
won't be provided but inode and device only.

 | pos:	0
 | flags:	02000000
 | inotify wd:3 ino:9e7e sdev:800013 mask:800afce ignored_mask:0
 | inotify wd:2 ino:a111 sdev:800013 mask:800afce ignored_mask:0
 | inotify wd:1 ino:6b149 sdev:800013 mask:800afce ignored_mask:0

For fanotify the output is like

 | pos:	0
 | flags:	04002
 | fanotify flags:10 event-flags:0
 | fanotify mnt_id:12 mask:3b ignored_mask:0
 | fanotify ino:50205 sdev:800013 mask:3b ignored_mask:40000000 fhandle-bytes:8 fhandle-type:1 f_handle:05020500fb1d47e7

To minimize impact on general fsnotify code the new functionality
is gathered in fs/notify/fdinfo.c file.
Signed-off-by: NCyrill Gorcunov <gorcunov@openvz.org>
Acked-by: NPavel Emelyanov <xemul@parallels.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Andrey Vagin <avagin@openvz.org>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: James Bottomley <jbottomley@parallels.com>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Matthew Helsley <matt.helsley@gmail.com>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@onelan.co.uk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

We will need this helper in the next patch to provide a file handle for
inotify marks in /proc/pid/fdinfo output.

The patch is rather providing the way to use inodes directly when dentry
is not available (like in case of inotify system).
Signed-off-by: NCyrill Gorcunov <gorcunov@openvz.org>
Acked-by: NPavel Emelyanov <xemul@parallels.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Andrey Vagin <avagin@openvz.org>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: James Bottomley <jbottomley@parallels.com>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Matthew Helsley <matt.helsley@gmail.com>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@onelan.co.uk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This routine will be used to generate a file handle in fdinfo output for
inotify subsystem, where if no s_export_op present the general
export_encode_fh should be used.  Thus add a test if s_export_op present
inside exportfs_encode_fh itself.
Signed-off-by: NCyrill Gorcunov <gorcunov@openvz.org>
Acked-by: NPavel Emelyanov <xemul@parallels.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Andrey Vagin <avagin@openvz.org>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: James Bottomley <jbottomley@parallels.com>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Matthew Helsley <matt.helsley@gmail.com>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@onelan.co.uk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This allows us to print out eventpoll target file descriptor, events and
data, the /proc/pid/fdinfo/fd consists of

 | pos:	0
 | flags:	02
 | tfd:        5 events:       1d data: ffffffffffffffff enabled: 1

[avagin@: fix for unitialized ret variable]
Signed-off-by: NCyrill Gorcunov <gorcunov@openvz.org>
Acked-by: NPavel Emelyanov <xemul@parallels.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Andrey Vagin <avagin@openvz.org>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: James Bottomley <jbottomley@parallels.com>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Matthew Helsley <matt.helsley@gmail.com>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@onelan.co.uk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This allows us to print out raw counter value.  The /proc/pid/fdinfo/fd
output is

 | pos:	0
 | flags:	04002
 | eventfd-count:               5a
Signed-off-by: NCyrill Gorcunov <gorcunov@openvz.org>
Acked-by: NPavel Emelyanov <xemul@parallels.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Andrey Vagin <avagin@openvz.org>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: James Bottomley <jbottomley@parallels.com>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Matthew Helsley <matt.helsley@gmail.com>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@onelan.co.uk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This patch brings ability to print out auxiliary data associated with
file in procfs interface /proc/pid/fdinfo/fd.

In particular further patches make eventfd, evenpoll, signalfd and
fsnotify to print additional information complete enough to restore
these objects after checkpoint.

To simplify the code we add show_fdinfo callback inside struct
file_operations (as Al and Pavel are proposing).
Signed-off-by: NCyrill Gorcunov <gorcunov@openvz.org>
Acked-by: NPavel Emelyanov <xemul@parallels.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Andrey Vagin <avagin@openvz.org>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: James Bottomley <jbottomley@parallels.com>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Matthew Helsley <matt.helsley@gmail.com>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@onelan.co.uk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This also converts filling memory loop to use memset.
Signed-off-by: NAkinobu Mita <akinobu.mita@gmail.com>
Cc: Artem Bityutskiy <dedekind1@gmail.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: David Laight <david.laight@aculab.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Eilon Greenstein <eilong@broadcom.com>
Cc: Michel Lespinasse <walken@google.com>
Cc: Robert Love <robert.w.love@intel.com>
Cc: Valdis Kletnieks <valdis.kletnieks@vt.edu>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

To avoid an explosion of request_module calls on a chain of abusive
scripts, fail maximum recursion with -ELOOP instead of -ENOEXEC. As soon
as maximum recursion depth is hit, the error will fail all the way back
up the chain, aborting immediately.

This also has the side-effect of stopping the user's shell from attempting
to reexecute the top-level file as a shell script. As seen in the
dash source:

        if (cmd != path_bshell && errno == ENOEXEC) {
                *argv-- = cmd;
                *argv = cmd = path_bshell;
                goto repeat;
        }

The above logic was designed for running scripts automatically that lacked
the "#!" header, not to re-try failed recursion. On a legitimate -ENOEXEC,
things continue to behave as the shell expects.

Additionally, when tracking recursion, the binfmt handlers should not be
involved. The recursion being tracked is the depth of calls through
search_binary_handler(), so that function should be exclusively responsible
for tracking the depth.
Signed-off-by: NKees Cook <keescook@chromium.org>
Cc: halfdog <me@halfdog.net>
Cc: P J P <ppandit@redhat.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

We display a list of supplementary group for each process in
/proc/<pid>/status.  However, we show only the first 32 groups, not all of
them.

Although this is rare, but sometimes processes do have more than 32
supplementary groups, and this kernel limitation breaks user-space apps
that rely on the group list in /proc/<pid>/status.

Number 32 comes from the internal NGROUPS_SMALL macro which defines the
length for the internal kernel "small" groups buffer.  There is no
apparent reason to limit to this value.

This patch removes the 32 groups printing limit.

The Linux kernel limits the amount of supplementary groups by NGROUPS_MAX,
which is currently set to 65536.  And this is the maximum count of groups
we may possibly print.
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Acked-by: NSerge E. Hallyn <serge.hallyn@ubuntu.com>
Acked-by: NKees Cook <keescook@chromium.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

It is currently impossible to examine the state of seccomp for a given
process.  While attaching with gdb and attempting "call
prctl(PR_GET_SECCOMP,...)" will work with some situations, it is not
reliable.  If the process is in seccomp mode 1, this query will kill the
process (prctl not allowed), if the process is in mode 2 with prctl not
allowed, it will similarly be killed, and in weird cases, if prctl is
filtered to return errno 0, it can look like seccomp is disabled.

When reviewing the state of running processes, there should be a way to
externally examine the seccomp mode.  ("Did this build of Chrome end up
using seccomp?" "Did my distro ship ssh with seccomp enabled?")

This adds the "Seccomp" line to /proc/$pid/status.
Signed-off-by: NKees Cook <keescook@chromium.org>
Reviewed-by: NCyrill Gorcunov <gorcunov@openvz.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: James Morris <jmorris@namei.org>
Acked-by: NSerge E. Hallyn <serge.hallyn@ubuntu.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

During c/r sessions we've found that there is no way at the moment to
fetch some VMA associated flags, such as mlock() and madvise().

This leads us to a problem -- we don't know if we should call for mlock()
and/or madvise() after restore on the vma area we're bringing back to
life.

This patch intorduces a new field into "smaps" output called VmFlags,
where all set flags associated with the particular VMA is shown as two
letter mnemonics.

[ Strictly speaking for c/r we only need mlock/madvise bits but it has been
  said that providing just a few flags looks somehow inconsistent.  So all
  flags are here now. ]

This feature is made available on CONFIG_CHECKPOINT_RESTORE=n kernels, as
other applications may start to use these fields.

The data is encoded in a somewhat awkward two letters mnemonic form, to
encourage userspace to be prepared for fields being added or removed in
the future.

[a.p.zijlstra@chello.nl: props to use for_each_set_bit]
[sfr@canb.auug.org.au: props to use array instead of struct]
[akpm@linux-foundation.org: overall redesign and simplification]
[akpm@linux-foundation.org: remove unneeded braces per sfr, avoid using bloaty for_each_set_bit()]
Signed-off-by: NCyrill Gorcunov <gorcunov@openvz.org>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Without this patch it is really hard to interpret a bounding set, if
CAP_LAST_CAP is unknown for a current kernel.

Non-existant capabilities can not be deleted from a bounding set with help
of prctl.

E.g.: Here are two examples without/with this patch.

  CapBnd:	ffffffe0fdecffff
  CapBnd:	00000000fdecffff

I suggest to hide non-existent capabilities. Here is two reasons.
* It's logically and easier for using.
* It helps to checkpoint-restore capabilities of tasks, because tasks
can be restored on another kernel, where CAP_LAST_CAP is bigger.
Signed-off-by: NAndrew Vagin <avagin@openvz.org>
Cc: Andrew G. Morgan <morgan@kernel.org>
Reviewed-by: NSerge E. Hallyn <serge.hallyn@canonical.com>
Cc: Pavel Emelyanov <xemul@parallels.com>
Reviewed-by: NKees Cook <keescook@chromium.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: James Morris <jmorris@namei.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Option parsing code expects an unsigned integer for the codepage option,
but prefixes and stores this option with "cp" before passing to
load_nls().  This makes the displayed option in /proc an invalid one.
Strip the prefix when printing so that the displayed option is valid for
reuse.
Signed-off-by: NDave Reisner <dreisner@archlinux.org>
Acked-by: NOGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

parse_options() is supposed to return value < 0 on error however we
returned 0 (success) in a lot of cases.  This actually was not a problem
in practice because match_token() used by parse_options() is clever and
catches most of the problems for us.
Signed-off-by: NJan Kara <jack@suse.cz>
Cc: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

So far FAT either offsets time stamps by sys_tz.minuteswest or leaves them
as they are (when tz=UTC mount option is used).  However in some cases it
is useful if one can specify time stamp offset on his own (e.g.  when time
zone of the camera connected is different from time zone of the computer,
or when HW clock is in UTC and thus sys_tz.minuteswest == 0).

So provide a mount option time_offset= which allows user to specify offset
in minutes that should be applied to time stamps on the filesystem.

akpm: this code would work incorrectly when used via `mount -o remount',
because cached inodes would not be updated.  But fatfs's fat_remount() is
basically a no-op anyway.
Signed-off-by: NJan Kara <jack@suse.cz>
Acked-by: NOGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Change fatfs so that a warning is emitted when an attempt is made to mount
a filesystem with the unsupported `discard' option.

ext4 aready does this: http://patchwork.ozlabs.org/patch/192668/Signed-off-by: NNamjae Jeon <linkinjeon@gmail.com>
Signed-off-by: NAmit Sahrawat <amit.sahrawat83@gmail.com>
Acked-by: NOGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

If elf_core_dump() is called and fill_note_info() fails in the kmalloc()
then it returns 0 but has not yet initialised all the needed fields.  As a
result we do a kfree(randomness) after correctly skipping the thread data.

[akpm@linux-foundation.org: checkpatch fixes]
Signed-off-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

[yongjun_wei@trendmicro.com.cn: remove duplicated include]
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: NWei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Fixes following sparse warning:

  fs/notify/inode_mark.c:127:22: warning: symbol 'fsnotify_find_inode_mark_locked' was not declared. Should it be static?
Signed-off-by: NTushar Behera <tushar.behera@linaro.org>
Cc: Eric Paris <eparis@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

But the kernel decided to call it "origin" instead.  Fix most of the
sites.
Acked-by: NHugh Dickins <hughd@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Users report a bug, the reproducer is:
$ mkfs.btrfs /dev/loop0
$ mount /dev/loop0 /mnt/btrfs/
$ mkdir /mnt/btrfs/dir
$ chattr +C /mnt/btrfs/dir/
$ dd if=/dev/zero of=/mnt/btrfs/dir/foo bs=4K count=10;
$ lsattr /mnt/btrfs/dir/foo
---------------C- /mnt/btrfs/dir/foo
$ filefrag /mnt/btrfs/dir/foo
/mnt/btrfs/dir/foo: 1 extent found    ---> an extent
$ dd if=/dev/zero of=/mnt/btrfs/dir/foo bs=4K count=1 seek=5 conv=notrunc,nocreat; sync
$ filefrag /mnt/btrfs/dir/foo
/mnt/btrfs/dir/foo: 3 extents found   ---> with nocow, btrfs breaks the extent into three parts

The new created file should not only inherit the NODATACOW flag, but also
honor NODATASUM flag, because we must do COW on a file extent with checksum.
Signed-off-by: NLiu Bo <bo.li.liu@oracle.com>
Signed-off-by: NChris Mason <chris.mason@fusionio.com>

The handling for directory crc hash overflows was fairly obscure,
split_leaf returns EOVERFLOW when we try to extend the item and that is
supposed to bubble up to userland.  For a while it did so, but along the
way we added better handling of errors and forced the FS readonly if we
hit IO errors during the directory insertion.

Along the way, we started testing only for EEXIST and the EOVERFLOW case
was dropped.  The end result is that we may force the FS readonly if we
catch a directory hash bucket overflow.

This fixes a few problem spots.  First I add tests for EOVERFLOW in the
places where we can safely just return the error up the chain.

btrfs_rename is harder though, because it tries to insert the new
directory item only after it has already unlinked anything the rename
was going to overwrite.  Rather than adding very complex logic, I added
a helper to test for the hash overflow case early while it is still safe
to bail out.

Snapshot and subvolume creation had a similar problem, so they are using
the new helper now too.
Signed-off-by: NChris Mason <chris.mason@fusionio.com>
Reported-by: NPascal Junod <pascal@junod.info>

This confuses and angers lockdep even though it's ok.  We don't really need
the lock for free space inodes since only the transaction committer will be
reserving space.  Thanks,
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>
Signed-off-by: NChris Mason <chris.mason@fusionio.com>

This happens because writeback_inodes_sb_nr_if_idle does down_read.  This
doesn't work for us and it has not been fixed upstream yet, so do it
ourselves and use that instead so we can stop having this stupid long
standing lockup.  Thanks,
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>
Signed-off-by: NChris Mason <chris.mason@fusionio.com>

When a new file is created with btrfs_create(), the inode will initially be
created with permissions 0666 and later on in btrfs_init_acl() it will be
adapted to mask out the umask bits. The problem is that this change won't make
it into the btrfs_inode unless there's another change to the inode (e.g. writing
content changing the size or touching the file changing the mtime.)

This fix adds a call to btrfs_update_inode() to btrfs_create() to make sure that
the change will not get lost if the in-memory inode is flushed before other
changes are made to the file.
Signed-off-by: NFilipe Brandenburger <filbranden@google.com>
Reviewed-by: NLiu Bo <bo.li.liu@oracle.com>
Signed-off-by: NChris Mason <chris.mason@fusionio.com>

Raid properties can be shared among raid calculation code, we can put
them into a global table to keep it simple.
Signed-off-by: NLiu Bo <bo.li.liu@oracle.com>
Signed-off-by: NChris Mason <chris.mason@fusionio.com>

This fixes a very special case that can be reproduced by just
disconnecting a disk at runtime, and without unmounting the
filesystem first, start scrub on the filesystem with the
disconnected disk. All read and write EIOs are handled
correctly, only the first superblock is an exception and gives
a BUG() in a subfunction. The BUG() is correct, it would crash
later otherwise. The subfunction must not be called for
superblocks and this is what the fix changes.
Reported-by: NJoeri Vanthienen <mail@joerivanthienen.be>
Signed-off-by: NStefan Behrens <sbehrens@giantdisaster.de>
Signed-off-by: NChris Mason <chris.mason@fusionio.com>

This starts a transaction and dirties the inode everytime we call it, which
is super expensive if you have a write heavy workload.  We will be updating
the inode when the IO completes and we reserve the space for the inode
update when we reserve space for the write, so there is no chance of loss of
information or enospc issues.  Thanks,
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>
Signed-off-by: NChris Mason <chris.mason@fusionio.com>

I noticed while doing fsync tests that we were always dropping the path and
re-searching when we first cow the log root even though we've already gotten
the write lock on the root.  That's because we don't take into account that
there might not be a parent node, so fix the check to make sure there is
actually a parent node before we undo all of this work for nothing.  Thanks,
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>
Signed-off-by: NChris Mason <chris.mason@fusionio.com>

If we are syncing over and over the overhead of doing all those maps in
fill_inode_item and log_changed_extents really starts to hurt, so use map
tokens so we can avoid all the extra mapping.  Since the token maps from our
offset to the end of the page make sure to set the first thing in the item
first so we really only do one map.  Thanks,
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>
Signed-off-by: NChris Mason <chris.mason@fusionio.com>

This gets called at least 4 times for every level while adding an object,
and it involves 3 kmapping calls, which on my box take about 5us a piece.
So instead use a token, which brings us down to 1 kmap call and makes this
function take 1/3 of the time per call.  Thanks,
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>
Signed-off-by: NChris Mason <chris.mason@fusionio.com>

Our token logic depends on token->kaddr being set, and if it is not it sets
everything properly as needed.  So instead of memsetting just set
token->kaddr to NULL.  Thanks,
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>
Signed-off-by: NChris Mason <chris.mason@fusionio.com>

No reason to set the path blocking or loop through all of the pages if the
extent buffer isn't actually marked dirty.  Thanks,
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>
Signed-off-by: NChris Mason <chris.mason@fusionio.com>

This is a high traffic function, let's try and do as little as possible
during normal operations shall we?
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>
Signed-off-by: NChris Mason <chris.mason@fusionio.com>

We don't really need to copy extents from the source tree since we have all
of the information already available to us in the extent_map tree.  So
instead just write the extents straight to the log tree and don't bother to
copy the extent items from the source tree.
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>
Signed-off-by: NChris Mason <chris.mason@fusionio.com>