Implement ASCII case-insensitive support. It's primary purpose is for
supporting existing filesystems that already use this case-insensitive
mode migrated from IRIX. But, if you only need ASCII-only case-insensitive
support (ie. English only) and will never use another language, then this
mode is perfectly adequate.

ASCII-CI is implemented by generating hashes based on lower-case letters
and doing lower-case compares. It implements a new xfs_nameops vector for
doing the hashes and comparisons for all filename operations.

To create a filesystem with this CI mode, use: # mkfs.xfs -n version=ci
<device>

SGI-PV: 981516
SGI-Modid: xfs-linux-melb:xfs-kern:31209a
Signed-off-by: NBarry Naujok <bnaujok@sgi.com>
Signed-off-by: NChristoph Hellwig <hch@infradead.org>

This implements the code to store the actual filename found during a
lookup in the dentry cache and to avoid multiple entries in the dcache
pointing to the same inode.

To avoid polluting the dcache, we implement a new directory inode
operations for lookup. xfs_vn_ci_lookup() stores the correct case name in
the dcache.

The "actual name" is only allocated and returned for a case- insensitive
match and not an actual match.

Another unusual interaction with the dcache is not storing negative
dentries like other filesystems doing a d_add(dentry, NULL) when an ENOENT
is returned. During the VFS lookup, if a dentry returned has no inode,
dput is called and ENOENT is returned. By not doing a d_add, this actually
removes it completely from the dcache to be reused. create/rename have to
be modified to support unhashed dentries being passed in.

SGI-PV: 981521
SGI-Modid: xfs-linux-melb:xfs-kern:31208a
Signed-off-by: NBarry Naujok <bnaujok@sgi.com>
Signed-off-by: NChristoph Hellwig <hch@infradead.org>

This add a dcache entry to the dcache for lookup, but changing the name
that is associated with the entry rather than the one passed in to the
lookup routine.

First, it sees if the case-exact match already exists in the dcache and
uses it if one exists. Otherwise, it allocates a new node with the new
name and splices it into the dcache.

Original code from ntfs_lookup in fs/ntfs/namei.c by Anton Altaparmakov.
Signed-off-by: NBarry Naujok <bnaujok@sgi.com>
Signed-off-by: NAnton Altaparmakov <aia21@cantab.net>
Acked-by: NChristoph Hellwig <hch@infradead.org>

The end of the xfs_da_args structure has 4 unsigned char fields for
true/false information on directory and attr operations using the
xfs_da_args structure.

The following converts these 4 into a op_flags field that uses the first 4
bits for these fields and allows expansion for future operation
information (eg. case-insensitive lookup request).

SGI-PV: 981520
SGI-Modid: xfs-linux-melb:xfs-kern:31206a
Signed-off-by: NBarry Naujok <bnaujok@sgi.com>
Signed-off-by: NChristoph Hellwig <hch@infradead.org>

Adds two pieces of functionality for the basis of case-insensitive support
in XFS:

1. A comparison result enumerated type: xfs_dacmp. It represents an

exact match, case-insensitive match or no match at all. This patch

only implements different and exact results.

2. xfs_nameops vector for specifying how to perform the hash generation

of filenames and comparision methods. In this patch the hash vector

points to the existing xfs_da_hashname function and the comparison

method does a length compare, and if the same, does a memcmp and

return the xfs_dacmp result.

All filename functions that use the hash (create, lookup remove, rename,
etc) now use the xfs_nameops.hashname function and all directory lookup
functions also use the xfs_nameops.compname function.

The lookup functions also handle case-insensitive results even though the
default comparison function cannot return that. And important aspect of
the lookup functions is that an exact match always has precedence over a
case-insensitive. So while a case-insensitive match is found, we have to
keep looking just in case there is an exact match. In the meantime, the
info for the first case-insensitive match is retained if no exact match is
found.

SGI-PV: 981519
SGI-Modid: xfs-linux-melb:xfs-kern:31205a
Signed-off-by: NBarry Naujok <bnaujok@sgi.com>
Signed-off-by: NChristoph Hellwig <hch@infradead.org>

de-duplicate calls to xfs_attr_trace_enter

Every call to xfs_attr_trace_enter() shares the exact same 16 args in the
middle... just send in the context pointer and let the next level down
split it into the ktrace.

Compile tested only.

SGI-PV: 976035
SGI-Modid: xfs-linux-melb:xfs-kern:31200a
Signed-off-by: NEric Sandeen <sandeen@sandeen.net>
Signed-off-by: NNiv Sardi <xaiki@sgi.com>
Signed-off-by: NJosef 'Jeff' Sipek <jeffpc@josefsipek.net>
Signed-off-by: NLachlan McIlroy <lachlan@sgi.com>

SGI-PV: 981951
SGI-Modid: xfs-linux-melb:xfs-kern:31199a
Signed-off-by: NChristoph Hellwig <hch@infradead.org>
Signed-off-by: NDavid Chinner <dgc@sgi.com>
Signed-off-by: NLachlan McIlroy <lachlan@sgi.com>

SGI-PV: 981951
SGI-Modid: xfs-linux-melb:xfs-kern:31198a
Signed-off-by: NChristoph Hellwig <hch@infradead.org>
Signed-off-by: NDavid Chinner <dgc@sgi.com>
Signed-off-by: NLachlan McIlroy <lachlan@sgi.com>

xfs_binval aka xfs_flush_buftarg is the first thing done in
xfs_free_buftarg, so there is no need to have duplicated calls just before
xfs_free_buftarg in the mount failure path.

SGI-PV: 981951
SGI-Modid: xfs-linux-melb:xfs-kern:31197a
Signed-off-by: NChristoph Hellwig <hch@infradead.org>
Signed-off-by: NDavid Chinner <dgc@sgi.com>
Signed-off-by: NLachlan McIlroy <lachlan@sgi.com>

xfs_mount_init is inlined into xfs_fs_fill_super and allocation switched
to kzalloc. Plug a leak of the mount structure for most early mount
failures. Move xfs_icsb_init_counters to as late as possible in the mount
path and make sure to undo it so that no stale hotplug cpu notifiers are
left around on mount failures.

SGI-PV: 981951
SGI-Modid: xfs-linux-melb:xfs-kern:31196a
Signed-off-by: NChristoph Hellwig <hch@infradead.org>
Signed-off-by: NDavid Chinner <dgc@sgi.com>
Signed-off-by: NLachlan McIlroy <lachlan@sgi.com>

Switch xfs_args_allocate to kzalloc and handle failures.

SGI-PV: 981951
SGI-Modid: xfs-linux-melb:xfs-kern:31195a
Signed-off-by: NChristoph Hellwig <hch@infradead.org>
Signed-off-by: NDavid Chinner <dgc@sgi.com>
Signed-off-by: NLachlan McIlroy <lachlan@sgi.com>

Split setting the block and sector size out of xfs_fs_fill_super into a
small helper to make xfs_fs_fill_super more readable.

SGI-PV: 981951
SGI-Modid: xfs-linux-melb:xfs-kern:31194a
Signed-off-by: NChristoph Hellwig <hch@infradead.org>
Signed-off-by: NDavid Chinner <dgc@sgi.com>
Signed-off-by: NLachlan McIlroy <lachlan@sgi.com>

Currently closing the rt/log block device is done in the wrong spot, and
far too early. So revampt it:

- xfs_blkdev_put moved out of xfs_free_buftarg into the caller so that

it is done after tearing down the buftarg completely.

- call to xfs_unmountfs_close moved from xfs_mountfs into caller so

that it's done after tearing down the filesystem completely.

- xfs_unmountfs_close is renamed to xfs_close_devices and made static

in xfs_super.c

- opening of the block devices is split into a helper xfs_open_devices

that is symetric in use to xfs_close_devices

- xfs_unmountfs can now lose struct cred

- error handling around device opening sanitized in xfs_fs_fill_super

SGI-PV: 981951
SGI-Modid: xfs-linux-melb:xfs-kern:31193a
Signed-off-by: NChristoph Hellwig <hch@infradead.org>
Signed-off-by: NDavid Chinner <dgc@sgi.com>
Signed-off-by: NLachlan McIlroy <lachlan@sgi.com>

Freeing of the superblock is already handled in the caller, and that is
more symmetric with the mount path, too.

SGI-PV: 981951
SGI-Modid: xfs-linux-melb:xfs-kern:31192a
Signed-off-by: NChristoph Hellwig <hch@infradead.org>
Signed-off-by: NDavid Chinner <dgc@sgi.com>
Signed-off-by: NLachlan McIlroy <lachlan@sgi.com>

xfs_mount is already pretty linux-specific so merge it into
xfs_fs_fill_super to allow for a more structured mount code in the next
patches. xfs_start_flags and xfs_finish_flags also move to xfs_super.c.

SGI-PV: 981951
SGI-Modid: xfs-linux-melb:xfs-kern:31189a
Signed-off-by: NChristoph Hellwig <hch@infradead.org>
Signed-off-by: NDavid Chinner <dgc@sgi.com>
Signed-off-by: NLachlan McIlroy <lachlan@sgi.com>

xfs_unmount is small and already pretty Linux specific, so merge it into
the callers. The real unmount path is simplified a little by doing a
WARN_ON on the xfs_unmount_flush retval directly instead of propagating
the error back to the caller, and the mout failure case in simplified
significantly by removing the forced shutdown case and all the dmapi
events that shouldn't be sent because the dmapi mount event hasn't been
sent by that time either.

SGI-PV: 981951
SGI-Modid: xfs-linux-melb:xfs-kern:31188a
Signed-off-by: NChristoph Hellwig <hch@infradead.org>
Signed-off-by: NDavid Chinner <dgc@sgi.com>
Signed-off-by: NLachlan McIlroy <lachlan@sgi.com>

xfs_igrow_start just expands to xfs_zero_eof with two asserts that are
useless in the context of the only caller and some rather confusing
comments.

xfs_igrow_finish is just a few lines of code decorated again with useless
asserts and confusing comments.

Just kill those two and merge them into xfs_setattr.

SGI-PV: 981498
SGI-Modid: xfs-linux-melb:xfs-kern:31186a
Signed-off-by: NChristoph Hellwig <hch@infradead.org>
Signed-off-by: NDavid Chinner <dgc@sgi.com>
Signed-off-by: NLachlan McIlroy <lachlan@sgi.com>

xfs_mntupdate already is completely Linux specific due to the VFS flags
passed in, so it might aswell be merged into xfs_fs_remount.

SGI-PV: 981498
SGI-Modid: xfs-linux-melb:xfs-kern:31185a
Signed-off-by: NChristoph Hellwig <hch@infradead.org>
Signed-off-by: NDavid Chinner <dgc@sgi.com>
Signed-off-by: NLachlan McIlroy <lachlan@sgi.com>

Quite useless wrapper that doesn't help making the code more readable.

SGI-PV: 981498
SGI-Modid: xfs-linux-melb:xfs-kern:31184a
Signed-off-by: NChristoph Hellwig <hch@infradead.org>
Signed-off-by: NDavid Chinner <dgc@sgi.com>
Signed-off-by: NLachlan McIlroy <lachlan@sgi.com>

Recent changes to update the version number during mount (attr2 stuff)
failed to change the assert that checked for calid flags being changed on
mount. Clearly this path hasn't been exercised by the test code....

SGI-PV: 981950
SGI-Modid: xfs-linux-melb:xfs-kern:31183a
Signed-off-by: NDavid Chinner <dgc@sgi.com>
Signed-off-by: NEric Sandeen <sandeen@sandeen.net>
Signed-off-by: NLachlan McIlroy <lachlan@sgi.com>

No need for addition permission checks in the xattr handler,
fs/xattr.c:xattr_permission() already does them, and in fact slightly more
strict then what was in the attr_capable handlers.

SGI-PV: 981809
SGI-Modid: xfs-linux-melb:xfs-kern:31164a
Signed-off-by: NChristoph Hellwig <hch@infradead.org>
Signed-off-by: NTim Shimmin <tes@sgi.com>
Signed-off-by: NLachlan McIlroy <lachlan@sgi.com>

The l_flushsema doesn't exactly have completion semantics, nor mutex
semantics. It's used as a list of tasks which are waiting to be notified
that a flush has completed. It was also being used in a way that was
potentially racy, depending on the semaphore implementation.

By using a sv_t instead of a semaphore we avoid the need for a separate
counter, since we know we just need to wake everything on the queue.

Original waitqueue implementation from Matthew Wilcox. Cleanup and
conversion to sv_t by Christoph Hellwig.

SGI-PV: 981507
SGI-Modid: xfs-linux-melb:xfs-kern:31059a
Signed-off-by: NMatthew Wilcox <willy@linux.intel.com>
Signed-off-by: NChristoph Hellwig <hch@infradead.org>
Signed-off-by: NDavid Chinner <dgc@sgi.com>
Signed-off-by: NLachlan McIlroy <lachlan@sgi.com>

We found this while experimenting with 2GiB xfs logs. The previous code
never assumed that xfs logs would ever get so large.

SGI-PV: 981502
SGI-Modid: xfs-linux-melb:xfs-kern:31058a
Signed-off-by: NMichael Nishimoto <miken@agami.com>
Signed-off-by: NDavid Chinner <dgc@sgi.com>
Signed-off-by: NLachlan McIlroy <lachlan@sgi.com>

SGI-PV: 981498
SGI-Modid: xfs-linux-melb:xfs-kern:31057a
Signed-off-by: NDenys Vlasenko <vda.linux@googlemail.com>
Signed-off-by: NDavid Chinner <dgc@sgi.com>
Signed-off-by: NLachlan McIlroy <lachlan@sgi.com>

SGI-PV: 981498
SGI-Modid: xfs-linux-melb:xfs-kern:31056a
Signed-off-by: NDenys Vlasenko <vda.linux@googlemail.com>
Signed-off-by: NDavid Chinner <dgc@sgi.com>
Signed-off-by: NLachlan McIlroy <lachlan@sgi.com>

kmem_free() function takes (ptr, size) arguments but doesn't actually use
second one.

This patch removes size argument from all callsites.

SGI-PV: 981498
SGI-Modid: xfs-linux-melb:xfs-kern:31050a
Signed-off-by: NDenys Vlasenko <vda.linux@googlemail.com>
Signed-off-by: NDavid Chinner <dgc@sgi.com>
Signed-off-by: NLachlan McIlroy <lachlan@sgi.com>

features2 fields.

Previously, mounting with noattr2 failed to achieve anything because
although it cleared the attr2 mount flag, it would set it again as soon as
it processed the superblock fields. The fix now has an explicit noattr2
flag and uses it later to fix up the versionnum and features2 fields.

SGI-PV: 980021
SGI-Modid: xfs-linux-melb:xfs-kern:31003a
Signed-off-by: NTim Shimmin <tes@sgi.com>
Signed-off-by: NChristoph Hellwig <hch@infradead.org>
Signed-off-by: NLachlan McIlroy <lachlan@sgi.com>

SGI-PV: 976035
SGI-Modid: xfs-linux-melb:xfs-kern:30834a
Signed-off-by: NBarry Naujok <bnaujok@sgi.com>
Signed-off-by: NChristoph Hellwig <hch@infradead.org>
Signed-off-by: NLachlan McIlroy <lachlan@sgi.com>

Simplify the code of include/linux/task_io_accounting.h.

It is also more reasonable to have all the task i/o-related statistics in a
single struct (task_io_accounting).
Signed-off-by: NAndrea Righi <righi.andrea@gmail.com>
Signed-off-by: NOleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

In order to avoid the "Busy inodes after unmount" error message, we need to
ensure that nfs_async_unlink_release() releases the super block after the
call to nfs_free_unlinkdata().
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Jeff, Trond,

The commit

48b605f8 (NFS: implement option checking
when remounting NFS filesystems (resend))

generate an Oops on my platform when rebooting while its root FS on
an NFS share (NFSv3, TCP) :

Unmounting local filesystems...done.
Unable to handle kernel NULL pointer dereference at virtual address 00000000
pgd = c3d00000
[00000000] *pgd=a3d72031, *pte=00000000, *ppte=00000000
Internal error: Oops: 17 [#1]
Modules linked in: cpufreq_powersave cpufreq_ondemand cpufreq_userspace cpufreq_conservative ext3 jbd sd_mod pata_pcmcia libata scsi_mod pcmcia loop firmware_class pxafb cfbcopyarea cfbimgblt cfbfillrect pxa2xx_cs pxa2xx_core pcmcia_core snd_pxa2xx_ac97 snd_ac97_codec ac97_bus snd_pxa2xx_pcm snd_pcm_oss snd_mixer_oss snd_pcm snd_timer snd isp116x_hcd soundcore rtc_sa1100 snd_page_alloc pxa25x_udc usbcore rtc_ds1307 rtc_core
CPU: 0    Not tainted  (2.6.26-03414-g33af79d1-dirty #15)
PC is at nfs_remount+0x40/0x264
LR is at do_remount_sb+0x158/0x194
pc : [<c00bbf54>]    lr : [<c0076c40>]    psr: 60000013
sp : c2dd1e70  ip : c2dd1e98  fp : c2dd1e94
r10: 00000040  r9 : c3d17000  r8 : c3c3fc40
r7 : 00000000  r6 : 00000000  r5 : c3d2b200  r4 : 00000000
r3 : 00000003  r2 : 00000000  r1 : c2dd1e9c  r0 : c3c3fc00
Flags: nZCv  IRQs on  FIQs on  Mode SVC_32  ISA ARM  Segment user
Control: 0000397f  Table: a3d00000  DAC: 00000015
Process mount (pid: 1462, stack limit = 0xc2dd0270)
Stack: (0xc2dd1e70 to 0xc2dd2000)
1e60:                                     00000000 c3c3fc00 00000000 00000000
1e80: c3c3fc40 c3d17000 c2dd1ebc c2dd1e98 c0076c40 c00bbf20 c01c61e4 00000001
1ea0: c2dd1ebc 00000001 c3c3fc00 c2dd1ef0 c2dd1ee4 c2dd1ec0 c008c6d8 c0076af4
1ec0: 00000021 00000040 c2dd1ef0 c3d77000 c3eaa000 00000000 c2dd1f6c c2dd1ee8
1ee0: c008d1bc c008c5f8 00000000 c2dd0000 c3c0c320 c3805b38 c002064c 0001f820
1f00: 0001f810 00000001 00000001 00000000 c2dd0000 00000000 c2dd1f34 c2dd1f28
1f20: c005ead8 c005e6f8 c2dd1f44 c2dd1f38 c005eaf8 c005ead0 c2dd1f6c c2dd1f48
1f40: c008ae3c 00000000 c3d77000 0001f810 c0ed0021 c0020ca8 c2dd0000 00000000
1f60: c2dd1fa4 c2dd1f70 c008d2d4 c008d0bc 00000000 0001f810 c2dd1f9c c3eaa000
1f80: c3d17000 00000000 00000000 be8b6aa8 be8b6ad0 00000015 00000000 c2dd1fa8
1fa0: c0020b00 c008d254 00000000 be8b6aa8 0001f810 0001f820 0001f830 c0ed0021
1fc0: 00000000 be8b6aa8 be8b6ad0 00000015 00000000 be8b6ad0 0001f810 be8b6aa8
1fe0: 0001f810 be8b6964 0000aab8 40125124 60000010 0001f810 00000000 00000000
Backtrace:
[<c00bbf14>] (nfs_remount+0x0/0x264) from [<c0076c40>] (do_remount_sb+0x158/0x194)
  r9:c3d17000 r8:c3c3fc40 r7:00000000 r6:00000000 r5:c3c3fc00
r4:00000000
[<c0076ae8>] (do_remount_sb+0x0/0x194) from [<c008c6d8>] (do_remount+0xec/0x118)
  r6:c2dd1ef0 r5:c3c3fc00 r4:00000001
[<c008c5ec>] (do_remount+0x0/0x118) from [<c008d1bc>] (do_mount+0x10c/0x198)
[<c008d0b0>] (do_mount+0x0/0x198) from [<c008d2d4>] (sys_mount+0x8c/0xd4)
[<c008d248>] (sys_mount+0x0/0xd4) from [<c0020b00>] (ret_fast_syscall+0x0/0x2c)
  r7:00000015 r6:be8b6ad0 r5:be8b6aa8 r4:00000000
Code: 0a000086 ea000006 e3530003 8a000004 (e5923000)
---[ end trace 55e1b689cf8c8a6a ]---
------------[ cut here ]------------
WARNING: at kernel/exit.c:966 do_exit+0x3c/0x628()
Modules linked in: cpufreq_powersave cpufreq_ondemand cpufreq_userspace cpufreq_conservative ext3 jbd sd_mod pata_pcmcia libata scsi_mod pcmcia loop firmware_class pxafb cfbcopyarea cfbimgblt cfbfillrect pxa2xx_cs pxa2xx_core pcmcia_core snd_pxa2xx_ac97 snd_ac97_codec ac97_bus snd_pxa2xx_pcm snd_pcm_oss snd_mixer_oss snd_pcm snd_timer snd isp116x_hcd soundcore rtc_sa1100 snd_page_alloc pxa25x_udc usbcore rtc_ds1307 rtc_core
[<c0025168>] (dump_stack+0x0/0x14) from [<c0032154>] (warn_on_slowpath+0x4c/0x68)
[<c0032108>] (warn_on_slowpath+0x0/0x68) from [<c003531c>] (do_exit+0x3c/0x628)
  r6:0000000b r5:c3c3dc80 r4:c2dd0000
[<c00352e0>] (do_exit+0x0/0x628) from [<c0025004>] (die+0x2b0/0x30c)
[<c0024d54>] (die+0x0/0x30c) from [<c00270bc>] (__do_kernel_fault+0x6c/0x80)
[<c0027050>] (__do_kernel_fault+0x0/0x80) from [<c00272e0>] (do_page_fault+0x210/0x230)
  r7:c3fa7118 r6:c3c3dc80 r5:c3d166a8 r4:00010000
[<c00270d0>] (do_page_fault+0x0/0x230) from [<c00201ec>] (do_DataAbort+0x3c/0xa0)
[<c00201b0>] (do_DataAbort+0x0/0xa0) from [<c002064c>] (__dabt_svc+0x4c/0x60)
Exception stack(0xc2dd1e28 to 0xc2dd1e70)
1e20:                   c3c3fc00 c2dd1e9c 00000000 00000003 00000000 c3d2b200
1e40: 00000000 00000000 c3c3fc40 c3d17000 00000040 c2dd1e94 c2dd1e98 c2dd1e70
1e60: c0076c40 c00bbf54 60000013 ffffffff
  r8:c3c3fc40 r7:00000000 r6:00000000 r5:c2dd1e5c r4:ffffffff
[<c00bbf14>] (nfs_remount+0x0/0x264) from [<c0076c40>] (do_remount_sb+0x158/0x194)
  r9:c3d17000 r8:c3c3fc40 r7:00000000 r6:00000000 r5:c3c3fc00
r4:00000000
[<c0076ae8>] (do_remount_sb+0x0/0x194) from [<c008c6d8>] (do_remount+0xec/0x118)
  r6:c2dd1ef0 r5:c3c3fc00 r4:00000001
[<c008c5ec>] (do_remount+0x0/0x118) from [<c008d1bc>] (do_mount+0x10c/0x198)
[<c008d0b0>] (do_mount+0x0/0x198) from [<c008d2d4>] (sys_mount+0x8c/0xd4)
[<c008d248>] (sys_mount+0x0/0xd4) from [<c0020b00>] (ret_fast_syscall+0x0/0x2c)
  r7:00000015 r6:be8b6ad0 r5:be8b6aa8 r4:00000000
---[ end trace 55e1b689cf8c8a6a ]---
/etc/rc6.d/S60umountroot: line 17:  1462 Segmentation fault      mount $MOUNT_FORCE_OPT -n -o remount,ro -t dummytype dummydev / 2> /dev/null

The new super.c:nfs_remount function doesn't check the validity of the
options/options4 pointers. Unfortunately, this seems to happend.
The obvious patch seems to check the pointers, and not to do anything if
the happend to be NULL.

Tested on an XScale PXA255 system, latest git.

Regards,

	M.
Signed-off-by: NMarc Zyngier <marc.zyngier@altran.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Put all i/o statistics in struct proc_io_accounting and use inline functions to
initialize and increment statistics, removing a lot of single variable
assignments.

This also reduces the kernel size as following (with CONFIG_TASK_XACCT=y and
CONFIG_TASK_IO_ACCOUNTING=y).

    text    data     bss     dec     hex filename
   11651       0       0   11651    2d83 kernel/exit.o.before
   11619       0       0   11619    2d63 kernel/exit.o.after
   10886     132     136   11154    2b92 kernel/fork.o.before
   10758     132     136   11026    2b12 kernel/fork.o.after

 3082029  807968 4818600 8708597  84e1f5 vmlinux.o.before
 3081869  807968 4818600 8708437  84e155 vmlinux.o.after
Signed-off-by: NAndrea Righi <righi.andrea@gmail.com>
Acked-by: NOleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Oleg Nesterov points out that we should check that the task is still alive
before we iterate over the threads.  This patch includes a fixup for this.

Also simplify do_io_accounting() implementation.
Signed-off-by: NAndrea Righi <righi.andrea@gmail.com>
Signed-off-by: NOleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

* dup2() should return -EBADF on exceeded sysctl_nr_open
* dup() should *not* return -EINVAL even if you have rlimit set to 0;
  it should get -EMFILE instead.

Check for orig_start exceeding rlimit taken to sys_fcntl().
Failing expand_files() in dup{2,3}() now gets -EMFILE remapped to -EBADF.
Consequently, remaining checks for rlimit are taken to expand_files().
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Since Ulrich is OK with getting rid of dup3(fd, fd, flags) completely,
to hell the damn thing goes.  Corner case for dup2() is handled in
sys_dup2() (complete with -EBADF if dup2(fd, fd) is called with fd
that is not open), the rest is done in dup3().
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

fs.h needs path.h, not namei.h; nfs_fs.h doesn't need it at all.
Several places in the tree needed direct include.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

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

make it atomic_long_t; while we are at it, get rid of useless checks in affs,
hfs and hpfs - ->open() always has it equal to 1, ->release() - to 0.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Al Viro notice one cornercase that the new dup3() code.  The dup2()
function, as a special case, handles dup-ing to the same file
descriptor.  In this case the current dup3() code does nothing at
all.  I.e., it ingnores the flags parameter.  This shouldn't happen,
the close-on-exec flag should be set if requested.

In case the O_CLOEXEC bit in the flags parameter is not set the
dup3() function should behave in this respect identical to dup2().
This means dup3(fd, fd, 0) should not actively reset the c-o-e
flag.

The patch below implements this minor change.

[AV: credits to Artur Grabowski for bringing that up as potential subtle point
in dup2() behaviour]
Signed-off-by: NUlrich Drepper <drepper@redhat.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

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