This function write out filesystem state to super blocks in order to
share the same cleanup work. This is a preparation for making super
block writeback alternately.
Cc: Jiro SEKIBA <jir@unicus.jp>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Previously, default_backing_dev_info was used for the mapping of btree
node caches. This uses device dependent backing_dev_info to allow
detailed control of the device for the btree node pages.
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
This is a companion patch to ("nilfs2: fix possible circular locking
for get information ioctls").
This corrects lock order reversal between mm->mmap_sem and
nilfs->ns_segctor_sem in nilfs_clean_segments() which was detected by
lockdep check:
=======================================================
[ INFO: possible circular locking dependency detected ]
2.6.30-rc3-nilfs-00003-g360bdc1 #7
-------------------------------------------------------
mmap/5294 is trying to acquire lock:
(&nilfs->ns_segctor_sem){++++.+}, at: [<d0d0e846>] nilfs_transaction_begin+0xb6/0x10c [nilfs2]
but task is already holding lock:
(&mm->mmap_sem){++++++}, at: [<c043700a>] do_page_fault+0x1d8/0x30a
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #1 (&mm->mmap_sem){++++++}:
[<c01470a5>] __lock_acquire+0x1066/0x13b0
[<c01474a9>] lock_acquire+0xba/0xdd
[<c01836bc>] might_fault+0x68/0x88
[<c023c61d>] copy_from_user+0x2a/0x111
[<d0d120d0>] nilfs_ioctl_prepare_clean_segments+0x1d/0xf1 [nilfs2]
[<d0d0e2aa>] nilfs_clean_segments+0x6d/0x1b9 [nilfs2]
[<d0d11f68>] nilfs_ioctl+0x2ad/0x318 [nilfs2]
[<c01a3be7>] vfs_ioctl+0x22/0x69
[<c01a408e>] do_vfs_ioctl+0x460/0x499
[<c01a4107>] sys_ioctl+0x40/0x5a
[<c01031a4>] sysenter_do_call+0x12/0x38
[<ffffffff>] 0xffffffff
-> #0 (&nilfs->ns_segctor_sem){++++.+}:
[<c0146e0b>] __lock_acquire+0xdcc/0x13b0
[<c01474a9>] lock_acquire+0xba/0xdd
[<c0433f1d>] down_read+0x2a/0x3e
[<d0d0e846>] nilfs_transaction_begin+0xb6/0x10c [nilfs2]
[<d0cfe0e5>] nilfs_page_mkwrite+0xe7/0x154 [nilfs2]
[<c0183b0b>] __do_fault+0x165/0x376
[<c01855cd>] handle_mm_fault+0x287/0x5d1
[<c043712d>] do_page_fault+0x2fb/0x30a
[<c0435462>] error_code+0x72/0x78
[<ffffffff>] 0xffffffff
where nilfs_clean_segments() holds:
nilfs->ns_segctor_sem -> copy_from_user()
--> page fault -> mm->mmap_sem
And, page fault path may hold:
page fault -> mm->mmap_sem
--> nilfs_page_mkwrite() -> nilfs->ns_segctor_sem
Even though nilfs_clean_segments() does not perform write access on
given user pages, it may cause deadlock because nilfs->ns_segctor_sem
is shared per device and mm->mmap_sem can be shared with other tasks.
To avoid this problem, this patch moves all calls of copy_from_user()
outside the nilfs->ns_segctor_sem lock in the ioctl.
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
A MODULE_VERSION() macro has been used in out-of-tree nilfs modules,
but it's needless and not updated in tree. So, this removes it along
with the version declaration.
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
After a review of user's feedback for finding out other compatibility
issues, I found nilfs improperly initializes timestamps in inode;
CURRENT_TIME was used there instead of CURRENT_TIME_SEC even though nilfs
didn't have nanosecond timestamps on disk. A few users gave us the report
that the tar program sometimes failed to expand symbolic links on nilfs,
and it turned out to be the cause.
Instead of applying the above displacement, I've decided to support
nanosecond timestamps on this occation. Fortunetaly, a needless 64-bit
field was in the nilfs_inode struct, and I found it's available for this
purpose without impact for the users.
So, this will do the enhancement and resolve the tar problem.
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>
The former versions didn't have extra super blocks. This improves the
weak point by introducing another super block at unused region in tail of
the partition.
This doesn't break disk format compatibility; older versions just ingore
the secondary super block, and new versions just recover it if it doesn't
exist. The partition created by an old mkfs may not have unused region,
but in that case, the secondary super block will not be added.
This doesn't make more redundant copies of the super block; it is a future
work.
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>
Pekka Enberg advised me:
> It would be nice if BUG(), BUG_ON(), and panic() calls would be
> converted to proper error handling using WARN_ON() calls. The BUG()
> call in nilfs_cpfile_delete_checkpoints(), for example, looks to be
> triggerable from user-space via the ioctl() system call.
This will follow the comment and keep them to a minimum.
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
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>
Pekka Enberg suggested converting ->ioctl operations to use
->unlocked_ioctl to avoid BKL.
The conversion was verified to be safe, so I will take it on this
occasion.
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
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>
This removes compat code from the nilfs ioctls and applies the same
function for both .ioctl and .compat_ioctl file operations.
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>
Pekka Enberg pointed out that double error handlings found after
nilfs_transaction_end() can be avoided by separating abort operation:
OK, I don't understand this. The only way nilfs_transaction_end() can
fail is if we have NILFS_TI_SYNC set and we fail to construct the
segment. But why do we want to construct a segment if we don't commit?
I guess what I'm asking is why don't we have a separate
nilfs_transaction_abort() function that can't fail for the erroneous
case to avoid this double error value tracking thing?
This does the separation and renames nilfs_transaction_end() to
nilfs_transaction_commit() for clarification.
Since, some calls of these functions were used just for exclusion control
against the segment constructor, they are replaced with semaphore
operations.
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
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>
This adds the following common structures of the NILFS2 file system.
* nilfs_inode_info structure:
gives on-memory inode.
* nilfs_sb_info structure:
keeps per-mount state and a special inode for the ifile.
This structure is attached to the super_block structure.
* the_nilfs structure:
keeps shared state and locks among a read/write mount and snapshot
mounts. This keeps special inodes for the sufile, cpfile, dat, and
another dat inode used during GC (gcdat). This also has a hash table
of dummy inodes to cache disk blocks during GC (gcinodes).
* nilfs_transaction_info structure:
keeps per task state while nilfs is writing logs or doing indivisible
inode or namespace operations. This structure is used to identify
context during log making and store nest level of the lock which
ensures atomicity of file system operations.
Signed-off-by: Koji Sato <sato.koji@lab.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>
Ryusuke Konishi