Commit Graph

130 Commits

Author SHA1 Message Date
Al Viro 84d08fa888 helper for reading ->d_count
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-07-05 18:59:33 +04:00
Vyacheslav Dubeyko e5f7f84843 ] nilfs2: use atomic64_t type for inodes_count and blocks_count fields in nilfs_root struct
The cp_inodes_count and cp_blocks_count are represented as __le64 type in
on-disk structure (struct nilfs_checkpoint).  But analogous fields in
in-core structure (struct nilfs_root) are represented by atomic_t type.

This patch replaces atomic_t on atomic64_t type in representation of
inodes_count and blocks_count fields in struct nilfs_root.

Signed-off-by: Vyacheslav Dubeyko <slava@dubeyko.com>
Acked-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Acked-by: Joern Engel <joern@logfs.org>
Cc: Clemens Eisserer <linuxhippy@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-03 16:08:01 -07:00
Vyacheslav Dubeyko c7ef972c44 nilfs2: implement calculation of free inodes count
Currently, NILFS2 returns 0 as free inodes count (f_ffree) and current
used inodes count as total file nodes in file system (f_files):

df -i
Filesystem      Inodes  IUsed   IFree IUse% Mounted on
/dev/loop0           2      2       0  100% /mnt/nilfs2

This patch implements real calculation of free inodes count.  First of
all, it is calculated total file nodes in file system as
(desc_blocks_count * groups_per_desc_block * entries_per_group).  Then, it
is calculated free inodes count as difference the total file nodes and
used inodes count.  As a result, we have such output for NILFS2:

df -i
Filesystem       Inodes   IUsed    IFree IUse% Mounted on
/dev/loop0      4194304 2114701  2079603   51% /mnt/nilfs2

Reported-by: Clemens Eisserer <linuxhippy@gmail.com>
Signed-off-by: Vyacheslav Dubeyko <slava@dubeyko.com>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Tested-by: Vyacheslav Dubeyko <slava@dubeyko.com>
Cc: Joern Engel <joern@logfs.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-03 16:08:01 -07:00
Eric W. Biederman 7f78e03513 fs: Limit sys_mount to only request filesystem modules.
Modify the request_module to prefix the file system type with "fs-"
and add aliases to all of the filesystems that can be built as modules
to match.

A common practice is to build all of the kernel code and leave code
that is not commonly needed as modules, with the result that many
users are exposed to any bug anywhere in the kernel.

Looking for filesystems with a fs- prefix limits the pool of possible
modules that can be loaded by mount to just filesystems trivially
making things safer with no real cost.

Using aliases means user space can control the policy of which
filesystem modules are auto-loaded by editing /etc/modprobe.d/*.conf
with blacklist and alias directives.  Allowing simple, safe,
well understood work-arounds to known problematic software.

This also addresses a rare but unfortunate problem where the filesystem
name is not the same as it's module name and module auto-loading
would not work.  While writing this patch I saw a handful of such
cases.  The most significant being autofs that lives in the module
autofs4.

This is relevant to user namespaces because we can reach the request
module in get_fs_type() without having any special permissions, and
people get uncomfortable when a user specified string (in this case
the filesystem type) goes all of the way to request_module.

After having looked at this issue I don't think there is any
particular reason to perform any filtering or permission checks beyond
making it clear in the module request that we want a filesystem
module.  The common pattern in the kernel is to call request_module()
without regards to the users permissions.  In general all a filesystem
module does once loaded is call register_filesystem() and go to sleep.
Which means there is not much attack surface exposed by loading a
filesytem module unless the filesystem is mounted.  In a user
namespace filesystems are not mounted unless .fs_flags = FS_USERNS_MOUNT,
which most filesystems do not set today.

Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Acked-by: Kees Cook <keescook@chromium.org>
Reported-by: Kees Cook <keescook@google.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2013-03-03 19:36:31 -08:00
Kirill A. Shutemov 8c0a853770 fs: push rcu_barrier() from deactivate_locked_super() to filesystems
There's no reason to call rcu_barrier() on every
deactivate_locked_super().  We only need to make sure that all delayed rcu
free inodes are flushed before we destroy related cache.

Removing rcu_barrier() from deactivate_locked_super() affects some fast
paths.  E.g.  on my machine exit_group() of a last process in IPC
namespace takes 0.07538s.  rcu_barrier() takes 0.05188s of that time.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-10-02 21:35:55 -04:00
Artem Bityutskiy 166ac34b74 nilfs2: nuke write_super from comments
The '->write_super' superblock method is gone, and this patch removes all the
references to 'write_super' from ntfs.

Cc: KONISHI Ryusuke <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-08-04 12:15:38 +04:00
Ryusuke Konishi 572d8b3945 nilfs2: fix deadlock issue between chcp and thaw ioctls
An fs-thaw ioctl causes deadlock with a chcp or mkcp -s command:

 chcp            D ffff88013870f3d0     0  1325   1324 0x00000004
 ...
 Call Trace:
   nilfs_transaction_begin+0x11c/0x1a0 [nilfs2]
   wake_up_bit+0x20/0x20
   copy_from_user+0x18/0x30 [nilfs2]
   nilfs_ioctl_change_cpmode+0x7d/0xcf [nilfs2]
   nilfs_ioctl+0x252/0x61a [nilfs2]
   do_page_fault+0x311/0x34c
   get_unmapped_area+0x132/0x14e
   do_vfs_ioctl+0x44b/0x490
   __set_task_blocked+0x5a/0x61
   vm_mmap_pgoff+0x76/0x87
   __set_current_blocked+0x30/0x4a
   sys_ioctl+0x4b/0x6f
   system_call_fastpath+0x16/0x1b
 thaw            D ffff88013870d890     0  1352   1351 0x00000004
 ...
 Call Trace:
   rwsem_down_failed_common+0xdb/0x10f
   call_rwsem_down_write_failed+0x13/0x20
   down_write+0x25/0x27
   thaw_super+0x13/0x9e
   do_vfs_ioctl+0x1f5/0x490
   vm_mmap_pgoff+0x76/0x87
   sys_ioctl+0x4b/0x6f
   filp_close+0x64/0x6c
   system_call_fastpath+0x16/0x1b

where the thaw ioctl deadlocked at thaw_super() when called while chcp was
waiting at nilfs_transaction_begin() called from
nilfs_ioctl_change_cpmode().  This deadlock is 100% reproducible.

This is because nilfs_ioctl_change_cpmode() first locks sb->s_umount in
read mode and then waits for unfreezing in nilfs_transaction_begin(),
whereas thaw_super() locks sb->s_umount in write mode.  The locking of
sb->s_umount here was intended to make snapshot mounts and the downgrade
of snapshots to checkpoints exclusive.

This fixes the deadlock issue by replacing the sb->s_umount usage in
nilfs_ioctl_change_cpmode() with a dedicated mutex which protects snapshot
mounts.

Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Cc: Fernando Luis Vazquez Cao <fernando@oss.ntt.co.jp>
Tested-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-07-30 17:25:19 -07:00
Fernando Luis Vazquez Cao 278038ac53 nilfs2: remove references to long gone super operations
->delete_inode(), ->write_super_lockfs(), ->unlockfs() are gone so remove
references to them in the NTFS code.  Noticed while cleaning up the
fsfreeze mess.

Signed-off-by: Fernando Luis Vazquez Cao <fernando@oss.ntt.co.jp>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-07-30 17:25:19 -07:00
David Howells 9249e17fe0 VFS: Pass mount flags to sget()
Pass mount flags to sget() so that it can use them in initialising a new
superblock before the set function is called.  They could also be passed to the
compare function.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-14 16:38:34 +04:00
Al Viro 48fde701af switch open-coded instances of d_make_root() to new helper
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-03-20 21:29:35 -04:00
Al Viro 8de5277879 vfs: check i_nlink limits in vfs_{mkdir,rename_dir,link}
New field of struct super_block - ->s_max_links.  Maximal allowed
value of ->i_nlink or 0; in the latter case all checks still need
to be done in ->link/->mkdir/->rename instances.  Note that this
limit applies both to directoris and to non-directories.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-03-20 21:29:32 -04:00
Al Viro 34c80b1d93 vfs: switch ->show_options() to struct dentry *
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-01-06 23:19:54 -05:00
Al Viro 6b520e0565 vfs: fix the stupidity with i_dentry in inode destructors
Seeing that just about every destructor got that INIT_LIST_HEAD() copied into
it, there is no point whatsoever keeping this INIT_LIST_HEAD in inode_init_once();
the cost of taking it into inode_init_always() will be negligible for pipes
and sockets and negative for everything else.  Not to mention the removal of
boilerplate code from ->destroy_inode() instances...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-01-03 22:52:40 -05:00
Ryusuke Konishi aa405b1f42 nilfs2: always set back pointer to host inode in mapping->host
In the current nilfs, page cache for btree nodes and meta data files
do not set a valid back pointer to the host inode in mapping->host.

This will change it so that every address space in nilfs uses
mapping->host to hold its host inode.

Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
2011-05-10 22:21:57 +09:00
Ryusuke Konishi 4e33f9eab0 nilfs2: implement resize ioctl
This adds resize ioctl which makes online resize possible.

Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
2011-05-10 22:21:46 +09:00
Ryusuke Konishi cfb0a4bfd8 nilfs2: add routine to move secondary super block
After resizing the filesystem, the secondary super block must be moved
to a new location.  This adds a helper function for this.

Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
2011-05-10 22:21:45 +09:00
Ryusuke Konishi e3154e9748 nilfs2: get rid of nilfs_sb_info structure
This directly uses sb->s_fs_info to keep a nilfs filesystem object and
fully removes the intermediate nilfs_sb_info structure.  With this
change, the hierarchy of on-memory structures of nilfs will be
simplified as follows:

Before:
  super_block
       -> nilfs_sb_info
             -> the_nilfs
                   -> cptree --+-> nilfs_root (current file system)
                               +-> nilfs_root (snapshot A)
                               +-> nilfs_root (snapshot B)
                               :
             -> nilfs_sc_info (log writer structure)
After:
  super_block
       -> the_nilfs
             -> cptree --+-> nilfs_root (current file system)
                         +-> nilfs_root (snapshot A)
                         +-> nilfs_root (snapshot B)
                         :
             -> nilfs_sc_info (log writer structure)

The reason why we didn't design so from the beginning is because the
initial shape also differed from the above.  The early hierachy was
composed of "per-mount-point" super_block -> nilfs_sb_info pairs and a
shared nilfs object.  On the kernel 2.6.37, it was changed to the
current shape in order to unify super block instances into one per
device, and this cleanup became applicable as the result.

Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
2011-03-09 11:54:26 +09:00
Ryusuke Konishi f7545144c2 nilfs2: use sb instance instead of nilfs_sb_info struct
This replaces sbi uses with direct reference to sb instance.

Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
2011-03-09 11:05:08 +09:00
Ryusuke Konishi 9b1fc4e497 nilfs2: move next generation counter into nilfs object
Moves s_next_generation counter and a spinlock protecting it to nilfs
object from nilfs_sb_info structure.

Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
2011-03-09 11:05:08 +09:00
Ryusuke Konishi 693dd32122 nilfs2: move s_inode_lock and s_dirty_files into nilfs object
Moves s_inode_lock spinlock and s_dirty_files list to nilfs object
from nilfs_sb_info structure.

Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
2011-03-09 11:05:07 +09:00
Ryusuke Konishi 574e6c3145 nilfs2: move parameters on nilfs_sb_info into nilfs object
This moves four parameter variables on nilfs_sb_info s_resuid,
s_resgid, s_interval and s_watermark to the nilfs object.

Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
2011-03-09 11:05:07 +09:00
Ryusuke Konishi 3b2ce58b0f nilfs2: move mount options to nilfs object
This moves mount_opt local variable to nilfs object from nilfs_sb_info
struct.

Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
2011-03-09 11:05:07 +09:00
Miklos Szeredi 2aa15890f3 mm: prevent concurrent unmap_mapping_range() on the same inode
Michael Leun reported that running parallel opens on a fuse filesystem
can trigger a "kernel BUG at mm/truncate.c:475"

Gurudas Pai reported the same bug on NFS.

The reason is, unmap_mapping_range() is not prepared for more than
one concurrent invocation per inode.  For example:

  thread1: going through a big range, stops in the middle of a vma and
     stores the restart address in vm_truncate_count.

  thread2: comes in with a small (e.g. single page) unmap request on
     the same vma, somewhere before restart_address, finds that the
     vma was already unmapped up to the restart address and happily
     returns without doing anything.

Another scenario would be two big unmap requests, both having to
restart the unmapping and each one setting vm_truncate_count to its
own value.  This could go on forever without any of them being able to
finish.

Truncate and hole punching already serialize with i_mutex.  Other
callers of unmap_mapping_range() do not, and it's difficult to get
i_mutex protection for all callers.  In particular ->d_revalidate(),
which calls invalidate_inode_pages2_range() in fuse, may be called
with or without i_mutex.

This patch adds a new mutex to 'struct address_space' to prevent
running multiple concurrent unmap_mapping_range() on the same mapping.

[ We'll hopefully get rid of all this with the upcoming mm
  preemptibility series by Peter Zijlstra, the "mm: Remove i_mmap_mutex
  lockbreak" patch in particular.  But that is for 2.6.39 ]

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Reported-by: Michael Leun <lkml20101129@newton.leun.net>
Reported-by: Gurudas Pai <gurudas.pai@oracle.com>
Tested-by: Gurudas Pai <gurudas.pai@oracle.com>
Acked-by: Hugh Dickins <hughd@google.com>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-02-23 19:52:52 -08:00
Ryusuke Konishi 0ca7a5b9ac nilfs2: fix crash after one superblock became unavailable
Fixes the following kernel oops in nilfs_setup_super() which could
arise if one of two super-blocks is unavailable.

> BUG: unable to handle kernel NULL pointer dereference at   (null)
> Pid: 3529, comm: mount.nilfs2 Not tainted 2.6.37 #1 /
> EIP: 0060:[<c03196bc>] EFLAGS: 00010202 CPU: 3
> EIP is at memcpy+0xc/0x1b
> Call Trace:
>  [<f953720e>] ? nilfs_setup_super+0x6c/0xa5 [nilfs2]
>  [<f95369e9>] ? nilfs_get_root_dentry+0x81/0xcb [nilfs2]
>  [<f9537a08>] ? nilfs_mount+0x4f9/0x62c [nilfs2]
>  [<c02745cf>] ? kstrdup+0x36/0x3f
>  [<f953750f>] ? nilfs_mount+0x0/0x62c [nilfs2]
>  [<c0293940>] ? vfs_kern_mount+0x4d/0x12c
>  [<c02a5100>] ? get_fs_type+0x76/0x8f
>  [<c0293a68>] ? do_kern_mount+0x33/0xbf
>  [<c02a784a>] ? do_mount+0x2ed/0x714
>  [<c02a6171>] ? copy_mount_options+0x28/0xfc
>  [<c02a7ce3>] ? sys_mount+0x72/0xaf
>  [<c0473085>] ? syscall_call+0x7/0xb

Reported-by: Wakko Warner <wakko@animx.eu.org>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Tested-by: Wakko Warner <wakko@animx.eu.org>
Cc: stable <stable@kernel.org> [2.6.37, 2.6.36]
LKML-Reference: <20110121024918.GA29598@animx.eu.org>
2011-01-22 15:22:36 +09:00
Linus Torvalds 275220f0fc Merge branch 'for-2.6.38/core' of git://git.kernel.dk/linux-2.6-block
* 'for-2.6.38/core' of git://git.kernel.dk/linux-2.6-block: (43 commits)
  block: ensure that completion error gets properly traced
  blktrace: add missing probe argument to block_bio_complete
  block cfq: don't use atomic_t for cfq_group
  block cfq: don't use atomic_t for cfq_queue
  block: trace event block fix unassigned field
  block: add internal hd part table references
  block: fix accounting bug on cross partition merges
  kref: add kref_test_and_get
  bio-integrity: mark kintegrityd_wq highpri and CPU intensive
  block: make kblockd_workqueue smarter
  Revert "sd: implement sd_check_events()"
  block: Clean up exit_io_context() source code.
  Fix compile warnings due to missing removal of a 'ret' variable
  fs/block: type signature of major_to_index(int) to major_to_index(unsigned)
  block: convert !IS_ERR(p) && p to !IS_ERR_NOR_NULL(p)
  cfq-iosched: don't check cfqg in choose_service_tree()
  fs/splice: Pull buf->ops->confirm() from splice_from_pipe actors
  cdrom: export cdrom_check_events()
  sd: implement sd_check_events()
  sr: implement sr_check_events()
  ...
2011-01-13 10:45:01 -08:00
Alexey Dobriyan 57cc7215b7 headers: kobject.h redux
Remove kobject.h from files which don't need it, notably,
sched.h and fs.h.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-10 08:51:44 -08:00
Ryusuke Konishi 06df0f9992 nilfs2: get rid of nilfs_mount_options structure
Only mount_opt member is used in the nilfs_mount_options structure,
and we can simplify it.

Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
2011-01-10 14:05:46 +09:00
Joe Perches b004a5eb0b fs/nilfs2/super.c: Use printf extension %pV
Using %pV reduces the number of printk calls and
eliminates any possible message interleaving from
other printk calls.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
2011-01-10 14:05:45 +09:00
Nick Piggin fa0d7e3de6 fs: icache RCU free inodes
RCU free the struct inode. This will allow:

- Subsequent store-free path walking patch. The inode must be consulted for
  permissions when walking, so an RCU inode reference is a must.
- sb_inode_list_lock to be moved inside i_lock because sb list walkers who want
  to take i_lock no longer need to take sb_inode_list_lock to walk the list in
  the first place. This will simplify and optimize locking.
- Could remove some nested trylock loops in dcache code
- Could potentially simplify things a bit in VM land. Do not need to take the
  page lock to follow page->mapping.

The downsides of this is the performance cost of using RCU. In a simple
creat/unlink microbenchmark, performance drops by about 10% due to inability to
reuse cache-hot slab objects. As iterations increase and RCU freeing starts
kicking over, this increases to about 20%.

In cases where inode lifetimes are longer (ie. many inodes may be allocated
during the average life span of a single inode), a lot of this cache reuse is
not applicable, so the regression caused by this patch is smaller.

The cache-hot regression could largely be avoided by using SLAB_DESTROY_BY_RCU,
however this adds some complexity to list walking and store-free path walking,
so I prefer to implement this at a later date, if it is shown to be a win in
real situations. I haven't found a regression in any non-micro benchmark so I
doubt it will be a problem.

Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07 17:50:26 +11:00
Nick Piggin b7ab39f631 fs: dcache scale dentry refcount
Make d_count non-atomic and protect it with d_lock. This allows us to ensure a
0 refcount dentry remains 0 without dcache_lock. It is also fairly natural when
we start protecting many other dentry members with d_lock.

Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07 17:50:21 +11:00
Tejun Heo d4d7762995 block: clean up blkdev_get() wrappers and their users
After recent blkdev_get() modifications, open_by_devnum() and
open_bdev_exclusive() are simple wrappers around blkdev_get().
Replace them with blkdev_get_by_dev() and blkdev_get_by_path().

blkdev_get_by_dev() is identical to open_by_devnum().
blkdev_get_by_path() is slightly different in that it doesn't
automatically add %FMODE_EXCL to @mode.

All users are converted.  Most conversions are mechanical and don't
introduce any behavior difference.  There are several exceptions.

* btrfs now sets FMODE_EXCL in btrfs_device->mode, so there's no
  reason to OR it explicitly on blkdev_put().

* gfs2, nilfs2 and the generic mount_bdev() now set FMODE_EXCL in
  sb->s_mode.

* With the above changes, sb->s_mode now always should contain
  FMODE_EXCL.  WARN_ON_ONCE() added to kill_block_super() to detect
  errors.

The new blkdev_get_*() functions are with proper docbook comments.
While at it, add function description to blkdev_get() too.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Philipp Reisner <philipp.reisner@linbit.com>
Cc: Neil Brown <neilb@suse.de>
Cc: Mike Snitzer <snitzer@redhat.com>
Cc: Joern Engel <joern@lazybastard.org>
Cc: Chris Mason <chris.mason@oracle.com>
Cc: Jan Kara <jack@suse.cz>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: KONISHI Ryusuke <konishi.ryusuke@lab.ntt.co.jp>
Cc: reiserfs-devel@vger.kernel.org
Cc: xfs-masters@oss.sgi.com
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
2010-11-13 11:55:18 +01:00
Tejun Heo e525fd89d3 block: make blkdev_get/put() handle exclusive access
Over time, block layer has accumulated a set of APIs dealing with bdev
open, close, claim and release.

* blkdev_get/put() are the primary open and close functions.

* bd_claim/release() deal with exclusive open.

* open/close_bdev_exclusive() are combination of open and claim and
  the other way around, respectively.

* bd_link/unlink_disk_holder() to create and remove holder/slave
  symlinks.

* open_by_devnum() wraps bdget() + blkdev_get().

The interface is a bit confusing and the decoupling of open and claim
makes it impossible to properly guarantee exclusive access as
in-kernel open + claim sequence can disturb the existing exclusive
open even before the block layer knows the current open if for another
exclusive access.  Reorganize the interface such that,

* blkdev_get() is extended to include exclusive access management.
  @holder argument is added and, if is @FMODE_EXCL specified, it will
  gain exclusive access atomically w.r.t. other exclusive accesses.

* blkdev_put() is similarly extended.  It now takes @mode argument and
  if @FMODE_EXCL is set, it releases an exclusive access.  Also, when
  the last exclusive claim is released, the holder/slave symlinks are
  removed automatically.

* bd_claim/release() and close_bdev_exclusive() are no longer
  necessary and either made static or removed.

* bd_link_disk_holder() remains the same but bd_unlink_disk_holder()
  is no longer necessary and removed.

* open_bdev_exclusive() becomes a simple wrapper around lookup_bdev()
  and blkdev_get().  It also has an unexpected extra bdev_read_only()
  test which probably should be moved into blkdev_get().

* open_by_devnum() is modified to take @holder argument and pass it to
  blkdev_get().

Most of bdev open/close operations are unified into blkdev_get/put()
and most exclusive accesses are tested atomically at the open time (as
it should).  This cleans up code and removes some, both valid and
invalid, but unnecessary all the same, corner cases.

open_bdev_exclusive() and open_by_devnum() can use further cleanup -
rename to blkdev_get_by_path() and blkdev_get_by_devt() and drop
special features.  Well, let's leave them for another day.

Most conversions are straight-forward.  drbd conversion is a bit more
involved as there was some reordering, but the logic should stay the
same.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Neil Brown <neilb@suse.de>
Acked-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Acked-by: Mike Snitzer <snitzer@redhat.com>
Acked-by: Philipp Reisner <philipp.reisner@linbit.com>
Cc: Peter Osterlund <petero2@telia.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <joel.becker@oracle.com>
Cc: Alex Elder <aelder@sgi.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: dm-devel@redhat.com
Cc: drbd-dev@lists.linbit.com
Cc: Leo Chen <leochen@broadcom.com>
Cc: Scott Branden <sbranden@broadcom.com>
Cc: Chris Mason <chris.mason@oracle.com>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Dave Kleikamp <shaggy@linux.vnet.ibm.com>
Cc: Joern Engel <joern@logfs.org>
Cc: reiserfs-devel@vger.kernel.org
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
2010-11-13 11:55:17 +01:00
Al Viro e4c59d61e8 convert nilfs
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-10-29 04:16:53 -04:00
Linus Torvalds ab34c02afe Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ryusuke/nilfs2
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ryusuke/nilfs2: (36 commits)
  nilfs2: eliminate sparse warning - "context imbalance"
  nilfs2: eliminate sparse warnings - "symbol not declared"
  nilfs2: get rid of bdi from nilfs object
  nilfs2: change license of exported header file
  nilfs2: add bdev freeze/thaw support
  nilfs2: accept 64-bit checkpoint numbers in cp mount option
  nilfs2: remove own inode allocator and destructor for metadata files
  nilfs2: get rid of back pointer to writable sb instance
  nilfs2: get rid of mi_nilfs back pointer to nilfs object
  nilfs2: see state of root dentry for mount check of snapshots
  nilfs2: use iget for all metadata files
  nilfs2: get rid of GCDAT inode
  nilfs2: add routines to redirect access to buffers of DAT file
  nilfs2: add routines to roll back state of DAT file
  nilfs2: add routines to save and restore bmap state
  nilfs2: do not allocate nilfs_mdt_info structure to gc-inodes
  nilfs2: allow nilfs_clear_inode to clear metadata file inodes
  nilfs2: get rid of snapshot mount flag
  nilfs2: simplify life cycle management of nilfs object
  nilfs2: do not allocate multiple super block instances for a device
  ...
2010-10-23 01:26:47 -07:00
Jiro SEKIBA abc0b50b6b nilfs2: eliminate sparse warnings - "symbol not declared"
change nilfs_dat_commit_free and nilfs_inode_cachep static
to fix following warnings

fs/nilfs2/super.c:72:19: warning: symbol 'nilfs_inode_cachep' was not declared. Should it be static?
fs/nilfs2/dat.c:106:6: warning: symbol 'nilfs_dat_commit_free' was not declared. Should it be static?

Signed-off-by: Jiro SEKIBA <jir@unicus.jp>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
2010-10-23 09:24:40 +09:00
Ryusuke Konishi 026a7d63d5 nilfs2: get rid of bdi from nilfs object
Nilfs now can use sb->s_bdi to get backing_dev_info, so we use it
instead of ns_bdi on the nilfs object and remove ns_bdi.

Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
2010-10-23 09:24:39 +09:00
Ryusuke Konishi 5beb6e0b20 nilfs2: add bdev freeze/thaw support
Nilfs hasn't supported the freeze/thaw feature because it didn't work
due to the peculiar design that multiple super block instances could
be allocated for a device.  This limitation was removed by the patch
"nilfs2: do not allocate multiple super block instances for a device".

So now this adds the freeze/thaw support to nilfs.

Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
2010-10-23 09:24:39 +09:00
Ryusuke Konishi c05dbfc260 nilfs2: accept 64-bit checkpoint numbers in cp mount option
The current implementation doesn't mount snapshots with checkpoint
numbers larger than INT_MAX since it uses match_int() for parsing
"cp=" mount option.

This uses simple_strtoull() for the conversion to resolve the issue.

Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
2010-10-23 09:24:39 +09:00
Ryusuke Konishi 2879ed66e4 nilfs2: remove own inode allocator and destructor for metadata files
This finally removes own inode allocator and destructor functions for
metadata files.  Several routines, nilfs_mdt_new(),
nilfs_mdt_new_common(), nilfs_mdt_clear(), nilfs_mdt_destroy(), and
nilfs_alloc_inode_common() will be gone.

Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
2010-10-23 09:24:39 +09:00
Ryusuke Konishi 032dbb3b50 nilfs2: see state of root dentry for mount check of snapshots
After applied the patch that unified sb instances, root dentry of
snapshots can be left in dcache even after their trees are unmounted.

The orphan root dentry/inode keeps a root object, and this causes
false positive of nilfs_checkpoint_is_mounted function.

This resolves the issue by having nilfs_checkpoint_is_mounted test
whether the root dentry is busy or not.

Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
2010-10-23 09:24:38 +09:00
Ryusuke Konishi f1e89c86fd nilfs2: use iget for all metadata files
This makes use of iget5_locked to allocate or get inode for metadata
files to stop using own inode allocator.

Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
2010-10-23 09:24:38 +09:00
Ryusuke Konishi 348fe8da13 nilfs2: simplify life cycle management of nilfs object
This stops pre-allocating nilfs object in nilfs_get_sb routine, and
stops managing its life cycle by reference counting.

nilfs_find_or_create_nilfs() function, nilfs->ns_mount_mutex,
nilfs_objects list, and the reference counter will be removed through
the simplification.

Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
2010-10-23 09:24:36 +09:00
Ryusuke Konishi f11459ad7d nilfs2: do not allocate multiple super block instances for a device
This stops allocating multiple super block instances for a device.

All snapshots and a current mode mount (i.e. latest tree) will be
controlled with nilfs_root objects that are kept within an sb
instance.

nilfs_get_sb() is rewritten so that it always has a root object for
the latest tree and snapshots make additional root objects.

The root dentry of the latest tree is binded to sb->s_root even if it
isn't attached on a directory.  Root dentries of snapshots or the
latest tree are binded to mnt->mnt_root on which they are mounted.

With this patch, nilfs_find_sbinfo() function, nilfs->ns_supers list,
and nilfs->ns_current back pointer, are deleted.  In addition,
init_nilfs() and load_nilfs() are simplified since they will be called
once for a device, not repeatedly called for mount points.

Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
2010-10-23 09:24:36 +09:00
Ryusuke Konishi ab4d8f7ebf nilfs2: split out nilfs_attach_snapshot
This splits the code to attach snapshots into a separate routine for
convenience sake.

Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
2010-10-23 09:24:36 +09:00
Ryusuke Konishi 367ea33486 nilfs2: split out nilfs_get_root_dentry
This splits the code to allocate root dentry into a separate routine
for convenience in successive changes.

Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
2010-10-23 09:24:35 +09:00
Ryusuke Konishi b7c0634204 nilfs2: move inode count and block count into root object
This moves sbi->s_inodes_count and sbi->s_blocks_count into nilfs_root
object.

Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
2010-10-23 09:24:35 +09:00
Ryusuke Konishi e912a5b668 nilfs2: use root object to get ifile
This rewrites functions using ifile so that they get ifile from
nilfs_root object, and will remove sbi->s_ifile.  Some functions that
don't know the root object are extended to receive it from caller.

Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
2010-10-23 09:24:35 +09:00
Ryusuke Konishi 8e656fd518 nilfs2: make snapshots in checkpoint tree exportable
The previous export operations cannot handle multiple versions of
a filesystem if they belong to the same sb instance.

This adds a new type of file handle and extends export operations so
that they can get the inode specified by a checkpoint number as well
as an inode number and a generation number.

Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
2010-10-23 09:24:34 +09:00
Ryusuke Konishi 4d8d9293dc nilfs2: set pointer to root object in inodes
This puts a pointer to nilfs_root object in the private part of
on-memory inode, and makes nilfs_iget function pick up the inode with
the same root object.

Non-root inodes inherit its nilfs_root object from parent inode.  That
of the root inode is allocated through nilfs_attach_checkpoint()
function.

Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
2010-10-23 09:24:34 +09:00
Ryusuke Konishi 0e14a3595b nilfs2: use iget5_locked to get inode
This uses iget5_locked instead of iget_locked so that gc cache can
look up inodes with an inode number and an optional checkpoint number.

Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
2010-10-23 09:24:33 +09:00