If a commit is triggered by fsync(), set a flag indicating the journal
blocks associated with the transaction should be flushed out using
WRITE_SYNC.
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

Add a mount option which allows the user to disable automatic
allocation of blocks whose allocation by delayed allocation when the
file was originally truncated or when the file is renamed over an
existing file.  This feature is intended to save users from the
effects of naive application writers, but it reduces the effectiveness
of the delayed allocation code.  This mount option disables this
safety feature, which may be desirable for prodcutions systems where
the risk of unclean shutdowns or unexpected system crashes is low.
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

Instead of looping over all of the block groups in a flex group
summing their summary statistics, start tracking used_dirs in struct
flex_groups, and use struct flex_groups instead.  This should save a
bit of CPU for mkdir-heavy workloads.
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

Reduce pressure on the sb_bgl_lock family of locks by using atomic_t's
to track the number of free blocks and inodes in each flex_group.
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

Remove tuning knobs in /proc/fs/ext4/<dev/* since they have been
replaced by knobs in sysfs at /sys/fs/ext4/<dev>/*.
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

Add basic sysfs support so that information about the mounted
filesystem and various tuning parameters can be accessed via
/sys/fs/ext4/<dev>/*.
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

Add a new superblock value which tracks the lifetime amount of writes
to the filesystem.  This is useful in estimating the amount of wear on
solid state drives (SSD's) caused by writes to the filesystem.
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

With delayed allocation we should not/cannot discard inode prealloc
space during file close. We would still have dirty pages for which we
haven't allocated blocks yet. With this fix after each get_blocks
request we check whether we have zero reserved blocks and if yes and
we don't have any writers on the file we discard inode prealloc space.
Signed-off-by: NAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

When renaming a file such that a link to another inode is overwritten,
force any delay allocated blocks that to be allocated so that if the
filesystem is mounted with data=ordered, the data blocks will be
pushed out to disk along with the journal commit.  Many application
programs expect this, so we do this to avoid zero length files if the
system crashes unexpectedly.
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

When closing a file that had been previously truncated, force any
delay allocated blocks that to be allocated so that if the filesystem
is mounted with data=ordered, the data blocks will be pushed out to
disk along with the journal commit.  Many application programs expect
this, so we do this to avoid zero length files if the system crashes
unexpectedly.
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

Add an ioctl which forces all of the delay allocated blocks to be
allocated.  This also provides a function ext4_alloc_da_blocks() which
will be used by the following commits to force files to be fully
allocated to preserve application-expected ext3 behaviour.
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

The mpage_da_writepages() function is only used in one place, so
inline it to simplify the call stack and make the code easier to
understand.
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

Struct mpage_da_data and mpage_add_bh_to_extent() use a fake struct
buffer_head which is 104 bytes on an x86_64 system, but only use 24
bytes of the structure.  On systems that use a spinlock for atomic_t,
the stack savings will be even greater.

It turns out that using a fake struct buffer_head doesn't even save
that much code, and it makes the code more confusing since it's not
used as a "real" buffer head.  So just store pass b_size and b_state
in mpage_add_bh_to_extent(), and store b_size, b_state, and b_block_nr
in the mpage_da_data structure.
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

This parameter was always set to ext4_da_get_block_write().
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

Some poeple are reading the ext4 feature list too literally and create
dubious test cases involving very long filenames and 1k blocksize and
then complain when they run into an htree-imposed limit.  So add fine
print to the "fix 32000 subdirectory limit" ext4 feature.
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

Make sure we validate extent details only when read from the disk.
Signed-off-by: NAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: NThiemo Nagel <thiemo.nagel@ph.tum.de>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

This patch adds checks to validate the extent entries along with extent
headers, to avoid crashes caused by corrupt filesystems.
Signed-off-by: NAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

ext4_iget() returns -ESTALE if invoked on a deleted inode, in order to
report errors to NFS properly.  However, in ext4_lookup(), this
-ESTALE can be propagated to userspace if the filesystem is corrupted
such that a directory entry references a deleted inode.  This leads to
a misleading error message - "Stale NFS file handle" - and confusion
on the part of the admin.

The bug can be easily reproduced by creating a new filesystem, making
a link to an unused inode using debugfs, then mounting and attempting
to ls -l said link.

This patch thus changes ext4_lookup to return -EIO if it receives
-ESTALE from ext4_iget(), as ext4 does for other filesystem metadata
corruption; and also invokes the appropriate ext*_error functions when
this case is detected.
Signed-off-by: NBryan Donlan <bdonlan@gmail.com>
Cc: <linux-ext4@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

The find_group_flex() inode allocator is now only used if the
filesystem is mounted using the "oldalloc" mount option.  It is
replaced with the original Orlov allocator that has been updated for
flex_bg filesystems (it should behave the same way if flex_bg is
disabled).  The inode allocator now functions by taking into account
each flex_bg group, instead of each block group, when deciding whether
or not it's time to allocate a new directory into a fresh flex_bg.

The block allocator has also been changed so that the first block
group in each flex_bg is preferred for use for storing directory
blocks.  This keeps directory blocks close together, which is good for
speeding up e2fsck since large directories are more likely to look
like this:

debugfs:  stat /home/tytso/Maildir/cur
Inode: 1844562   Type: directory    Mode:  0700   Flags: 0x81000
Generation: 1132745781    Version: 0x00000000:0000ad71
User: 15806   Group: 15806   Size: 1060864
File ACL: 0    Directory ACL: 0
Links: 2   Blockcount: 2072
Fragment:  Address: 0    Number: 0    Size: 0
 ctime: 0x499c0ff4:164961f4 -- Wed Feb 18 08:41:08 2009
 atime: 0x499c0ff4:00000000 -- Wed Feb 18 08:41:08 2009
 mtime: 0x49957f51:00000000 -- Fri Feb 13 09:10:25 2009
crtime: 0x499c0f57:00d51440 -- Wed Feb 18 08:38:31 2009
Size of extra inode fields: 28
BLOCKS:
(0):7348651, (1-258):7348654-7348911
TOTAL: 259
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

At the moment there are few restrictions on which flags may be set on
which inodes.  Specifically DIRSYNC may only be set on directories and
IMMUTABLE and APPEND may not be set on links.  Tighten that to disallow
TOPDIR being set on non-directories and only NODUMP and NOATIME to be set
on non-regular file, non-directories.

Introduces a flags masking function which masks flags based on mode and
use it during inode creation and when flags are set via the ioctl to
facilitate future consistency.
Signed-off-by: NDuane Griffin <duaneg@dghda.com>
Acked-by: NAndreas Dilger <adilger@sun.com>
Cc: <linux-ext4@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

At present INDEX and EXTENTS are the only flags that new ext4 inodes do
NOT inherit from their parent.  In addition prevent the flags DIRTY,
ECOMPR, IMAGIC, TOPDIR, HUGE_FILE and EXT_MIGRATE from being inherited. 
List inheritable flags explicitly to prevent future flags from
accidentally being inherited.

This fixes the TOPDIR flag inheritance bug reported at
http://bugzilla.kernel.org/show_bug.cgi?id=9866.
Signed-off-by: NDuane Griffin <duaneg@dghda.com>
Acked-by: NAndreas Dilger <adilger@sun.com>
Cc: <linux-ext4@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

As spotted by kmemtrace, struct ext4_sb_info is 17664 bytes on 64-bit
which makes it a very bad fit for SLAB allocators.  The culprit of the
wasted memory is ->s_blockgroup_lock which can be as big as 16 KB when
NR_CPUS >= 32.

To fix that, allocate ->s_blockgroup_lock, which fits nicely in a order 2
page in the worst case, separately.  This shinks down struct ext4_sb_info
enough to fit a 2 KB slab cache so now we allocate 16 KB + 2 KB instead of
32 KB saving 14 KB of memory.
Acked-by: NAndreas Dilger <adilger@sun.com>
Signed-off-by: NPekka Enberg <penberg@cs.helsinki.fi>
Cc: <linux-ext4@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

The rec_len field in the directory entry is 16 bits, so to encode
blocksizes larger than 64k becomes problematic.  This patch allows us
to supprot block sizes up to 256k, by using the low 2 bits to extend
the range of rec_len to 2**18-1 (since valid rec_len sizes must be a
multiple of 4).  We use the convention that a rec_len of 0 or 65535
means the filesystem block size, for compatibility with older kernels.

It's unlikely we'll see VM pages of up to 256k, but at some point we
might find that the Linux VM has been enhanced to support filesystem
block sizes > than the VM page size, at which point it might be useful
for some applications to allow very large filesystem block sizes.
Signed-off-by: NWei Yongjun <yjwei@cn.fujitsu.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

Signed-off-by: NWei Yongjun <yjwei@cn.fujitsu.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

The static function ext4_group_used_meta_blocks() only has one caller,
who already has access to the block group's group descriptor.  So it's
better to have ext4_init_block_bitmap() pass the group descriptor to
ext4_group_used_meta_blocks(), so it doesn't need to call
ext4_group_desc().  Previously this function did not check if
ext4_group_desc() returned NULL due to an error, potentially causing a
kernel OOPS report.  This avoids the issue entirely.
Signed-off-by: NThadeu Lima de Souza Cascardo <cascardo@holoscopio.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

Remove some leftovers from when the old block allocator was removed
(c2ea3fde).  ext4_sb_info is now a bit lighter.  Also remove a dangling
read_block_bitmap() prototype.
Signed-off-by: NMike Snitzer <snitzer@gmail.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

Merge branch 'bzip2-lzma-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/x86/linux-2.6-tip

* 'bzip2-lzma-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/x86/linux-2.6-tip:
  bzip2/lzma: don't ask for compression mode for the default initramfs
  bzip2/lzma: consistently capitalize LZMA in Kconfig
  bzip2/lzma: clarify the meaning of the CONFIG_RD_ options
  bzip2/lzma: move CONFIG_RD_* options under CONFIG_EMBEDDED

<linux/irq.h> relies on <linux/gfp.h> and <linux/topology.h> having been
included previous.  If not, the errors like below will result.

    CC      arch/mips/mti-malta/malta-int.o
  In file included from arch/mips/mti-malta/malta-int.c:25:
  include/linux/irq.h: In function ‘init_alloc_desc_masks’:
  include/linux/irq.h:444: error: implicit declaration of function ‘cpu_to_node’
  include/linux/irq.h:446: error: ‘GFP_ATOMIC’ undeclared (first use in this function)
  include/linux/irq.h:446: error: (Each undeclared identifier is reported only once
  include/linux/irq.h:446: error: for each function it appears in.)
  make[3]: *** [arch/mips/mti-malta/malta-int.o] Error 1
  make[2]: *** [arch/mips/mti-malta] Error 2
  make[1]: *** [sub-make] Error 2

Fixed by including the two missing headers.
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Fix kernel-doc errors in sched.c:  the structs don't have
kernel-doc notation and the short function description needs to
be one line only.

  Error(kernel/sched.c:3197): cannot understand prototype: 'struct sd_lb_stats '
  Error(kernel/sched.c:3228): cannot understand prototype: 'struct sg_lb_stats '
  Error(kernel/sched.c:3375): duplicate section name 'Description'
Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com>
cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Fix kernel-doc error in maple (it's not kernel-doc):

  Error(drivers/sh/maple/maple.c:782): cannot understand prototype: 'struct bus_type maple_bus_type = '
Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com>
cc: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

* 'futexes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  futex: remove the pointer math from double_unlock_hb, fix
  futex: remove the pointer math from double_unlock_hb
  futex: clean up fault logic
  futex: unlock before returning -EFAULT
  futex: use current->time_slack_ns for rt tasks too
  futex: add double_unlock_hb()
  futex: additional (get|put)_futex_key() fixes
  futex: update futex commentary

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/security-testing-2.6

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/security-testing-2.6:
  smack: Add a new '-CIPSO' option to the network address label configuration
  netlabel: Cleanup the Smack/NetLabel code to fix incoming TCP connections
  lsm: Remove the socket_post_accept() hook
  selinux: Remove the "compat_net" compatibility code
  netlabel: Label incoming TCP connections correctly in SELinux
  lsm: Relocate the IPv4 security_inet_conn_request() hooks
  TOMOYO: Fix a typo.
  smack: convert smack to standard linux lists

Annotate struct fs_struct's usage count to indicate the restrictions upon it.
It may not be incremented, except by clone(CLONE_FS), as this affects the
check in check_unsafe_exec() in fs/exec.c.
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NHugh Dickins <hugh@veritas.com>
Cc: stable@kernel.org
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

check_unsafe_exec() also notes whether the fs_struct is being
shared by more threads than will get killed by the exec, and if so
sets LSM_UNSAFE_SHARE to make bprm_set_creds() careful about euid.
But /proc/<pid>/cwd and /proc/<pid>/root lookups make transient
use of get_fs_struct(), which also raises that sharing count.

This might occasionally cause a setuid program not to change euid,
in the same way as happened with files->count (check_unsafe_exec
also looks at sighand->count, but /proc doesn't raise that one).

We'd prefer exec not to unshare fs_struct: so fix this in procfs,
replacing get_fs_struct() by get_fs_path(), which does path_get
while still holding task_lock, instead of raising fs->count.
Signed-off-by: NHugh Dickins <hugh@veritas.com>
Cc: stable@kernel.org
___

 fs/proc/base.c |   50 +++++++++++++++--------------------------------
 1 file changed, 16 insertions(+), 34 deletions(-)
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Joe Malicki reports that setuid sometimes doesn't: very rarely,
a setuid root program does not get root euid; and, by the way,
they have a health check running lsof every few minutes.

Right, check_unsafe_exec() notes whether the files_struct is being
shared by more threads than will get killed by the exec, and if so
sets LSM_UNSAFE_SHARE to make bprm_set_creds() careful about euid.
But /proc/<pid>/fd and /proc/<pid>/fdinfo lookups make transient
use of get_files_struct(), which also raises that sharing count.

There's a rather simple fix for this: exec's check on files->count
has been redundant ever since 2.6.1 made it unshare_files() (except
while compat_do_execve() omitted to do so) - just remove that check.

[Note to -stable: this patch will not apply before 2.6.29: earlier
releases should just remove the files->count line from unsafe_exec().]
Reported-by: NJoe Malicki <jmalicki@metacarta.com>
Narrowed-down-by: NMichael Itz <mitz@metacarta.com>
Tested-by: NJoe Malicki <jmalicki@metacarta.com>
Signed-off-by: NHugh Dickins <hugh@veritas.com>
Cc: stable@kernel.org
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

2.6.26's commit fd8328be
"sanitize handling of shared descriptor tables in failing execve()"
moved the unshare_files() from flush_old_exec() and several binfmts
to the head of do_execve(); but forgot to make the same change to
compat_do_execve(), leaving a CLONE_FILES files_struct shared across
exec from a 32-bit process on a 64-bit kernel.

It's arguable whether the files_struct really ought to be unshared
across exec; but 2.6.1 made that so to stop the loading binary's fd
leaking into other threads, and a 32-bit process on a 64-bit kernel
ought to behave in the same way as 32 on 32 and 64 on 64.
Signed-off-by: NHugh Dickins <hugh@veritas.com>
Cc: stable@kernel.org
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Impact: Kconfig noise reduction, documentation

The default initramfs is so small that it makes no sense to worry
about the additional memory taken by not double-compressing it.
Therefore, don't bug the user with it.

Also, improve the description of the option, which was downright
incorrect.
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>

Impact: message formatting

Consistently spell LZMA in all capitals, since it (unlike gzip or
bzip2) is an acronym.
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>

Impact: Kconfig clarification

Make it clear that the CONFIG_RD_* options are about what formats are
supported, not about what formats are actually being used.
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>

Impact: reduce Kconfig noise

Move the options that control possible initramfs/initrd compressions
underneath CONFIG_EMBEDDED.  The only impact of leaving these options
set to y is additional code in the init section of the kernel; there
is no reason to burden non-embedded users with these options.
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>