With the use of RCU in files structure, the look-up of files using fds can now
be lock-free. The lookup is protected by rcu_read_lock()/rcu_read_unlock().
This patch changes the readers to use lock-free lookup.
Signed-off-by: Maneesh Soni <maneesh@in.ibm.com>
Signed-off-by: Ravikiran Thirumalai <kiran_th@gmail.com>
Signed-off-by: Dipankar Sarma <dipankar@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Patch to eliminate struct files_struct.file_lock spinlock on the reader side
and use rcu refcounting rcuref_xxx api for the f_count refcounter. The
updates to the fdtable are done by allocating a new fdtable structure and
setting files->fdt to point to the new structure. The fdtable structure is
protected by RCU thereby allowing lock-free lookup. For fd arrays/sets that
are vmalloced, we use keventd to free them since RCU callbacks can't sleep. A
global list of fdtable to be freed is not scalable, so we use a per-cpu list.
If keventd is already handling the current cpu's work, we use a timer to defer
queueing of that work.
Since the last publication, this patch has been re-written to avoid using
explicit memory barriers and use rcu_assign_pointer(), rcu_dereference()
premitives instead. This required that the fd information is kept in a
separate structure (fdtable) and updated atomically.
Signed-off-by: Dipankar Sarma <dipankar@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
In order for the RCU to work, the file table array, sets and their sizes must
be updated atomically. Instead of ensuring this through too many memory
barriers, we put the arrays and their sizes in a separate structure. This
patch takes the first step of putting the file table elements in a separate
structure fdtable that is embedded withing files_struct. It also changes all
the users to refer to the file table using files_fdtable() macro. Subsequent
applciation of RCU becomes easier after this.
Signed-off-by: Dipankar Sarma <dipankar@in.ibm.com>
Signed-Off-By: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Implement a per-kiocb lock to serialise retry operations and cancel. This
is done using wait_on_bit_lock() on the KIF_LOCKED bit of kiocb->ki_flags.
Also, make the cancellation path lock the kiocb and subsequently release
all references to it if the cancel was successful. This version includes a
fix for the deadlock with __aio_run_iocbs.
Signed-off-by: Benjamin LaHaise <bcrl@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Note that other than few exceptions, most of the current filesystem and/or
drivers do not have aio cancel specifically defined (kiob->ki_cancel field
is mostly NULL). However, sys_io_cancel system call universally sets
return code to -EAGAIN. This gives applications a wrong impression that
this call is implemented but just never works. We have customer inquires
about this issue.
Changed by Benjamin LaHaise to EINVAL instead of ENOSYS
Signed-off-by: S. Wendy Cheng <wcheng@redhat.com>
Acked-by: Benjamin LaHaise <bcrl@kvack.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch for old autofs (version 3) cleans dentries which are not putted
after killing the automount daemon (it's analogue of recent patch for
autofs4).
Signed-off-by: Alexander Krizhanovsky <klx@yandex.ru>
Cc: Ian Kent <raven@themaw.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch removes the inode_post_link and inode_post_rename LSM hooks as
they are unused (and likely useless).
Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch removes the inode_post_create/mkdir/mknod/symlink LSM hooks as
they are obsoleted by the new inode_init_security hook that enables atomic
inode security labeling.
If anyone sees any reason to retain these hooks, please speak now. Also,
is anyone using the post_rename/link hooks; if not, those could also be
removed.
Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch modifies ext3 to call the inode_init_security LSM hook to obtain
the security attribute for a newly created inode and to set the resulting
attribute on the new inode as part of the same transaction. This parallels
the existing processing for setting ACLs on newly created inodes.
Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch modifies ext2 to call the inode_init_security LSM hook to obtain
the security attribute for a newly created inode and to set the resulting
attribute on the new inode. This parallels the existing processing for
setting ACLs on newly created inodes.
Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Update the file systems in fs/ implementing a delete_inode() callback to
call truncate_inode_pages(). One implementation note: In developing this
patch I put the calls to truncate_inode_pages() at the very top of those
filesystems delete_inode() callbacks in order to retain the previous
behavior. I'm guessing that some of those could probably be optimized.
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
Acked-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Allow file systems supporting ->delete_inode() to call
truncate_inode_pages() on their own. OCFS2 wants this so it can query the
cluster before making a final decision on whether to wipe an inode from
disk or not. In some corner cases an inode marked on the local node via
voting may not actually get orphaned. A good example is node death before
the transaction moving the inode to the orphan dir commits to the journal.
Without this patch, the truncate_inode_pages() call in
generic_delete_inode() would discard valid data for such inodes.
During earlier discussion in the 2.6.13 merge plan thread, Christoph
Hellwig indicated that other file systems might also find this useful.
IMHO, the best solution would be to just allow ->drop_inode() to do the
cluster query but it seems that would require a substantial reworking of
that section of the code. Assuming it is safe to call write_inode_now() in
ocfs2_delete_inode() for those inodes which won't actually get wiped, this
solution should get us by for now.
Trivial testing of this patch (and a related OCFS2 update) has shown this
to avoid the corruption I'm seeing.
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
Acked-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
<qualifier> void * is not the same as void <qualifier> *...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
fs/ntfs/aops.c::ntfs_end_buffer_async_read() to a bit spin lock
in the first buffer head of a page.
Signed-off-by: Anton Altaparmakov <aia21@cantab.net>
lock protection over the buffer submission for i/o which allows the
removal of the get_bh()/put_bh() pairs for each buffer.
Signed-off-by: Anton Altaparmakov <aia21@cantab.net>
Also, add BUG() checks to ntfs_attr_make_non_resident() and
ntfs_attr_set() to ensure that these functions are never called
for compressed or encrypted attributes.
Signed-off-by: Anton Altaparmakov <aia21@cantab.net>
- Fix a bug in ntfs_map_runlist_nolock() where we forgot to protect
access to the allocated size in the ntfs inode with the size lock.
- Fix ntfs_attr_vcn_to_lcn_nolock() and ntfs_attr_find_vcn_nolock() to
return LCN_ENOENT when there is no runlist and the allocated size is
zero.
- Fix load_attribute_list() to handle the case of a NULL runlist.
Signed-off-by: Anton Altaparmakov <aia21@cantab.net>
index entry is in the index root, we forgot to set the @ir pointer in
the index context. Thanks for Yura Pakhuchiy for finding this bug.
Signed-off-by: Anton Altaparmakov <aia21@cantab.net>
in the two critical regions. This means we no longer need to
panic() when the allocation fails as it now cannot fail.
Signed-off-by: Anton Altaparmakov <aia21@cantab.net>
- Modify fs/ntfs/malloc.h::ntfs_malloc_nofs() to do the kmalloc() based
allocations with __GFP_HIGHMEM, analogous to how the vmalloc() based
allocations are done.
- Add fs/ntfs/malloc.h::ntfs_malloc_nofs_nofail() which is analogous to
ntfs_malloc_nofs() but it performs allocations with __GFP_NOFAIL and
hence cannot fail.
Signed-off-by: Anton Altaparmakov <aia21@cantab.net>
- Support journals ($LogFile) which have been modified by chkdsk. This
means users can boot into Windows after we marked the volume dirty.
The Windows boot will run chkdsk and then reboot. The user can then
immediately boot into Linux rather than having to do a full Windows
boot first before rebooting into Linux and we will recognize such a
journal and empty it as it is clean by definition.
- Support journals ($LogFile) with only one restart page as well as
journals with two different restart pages. We sanity check both and
either use the only sane one or the more recent one of the two in the
case that both are valid.
Signed-off-by: Anton Altaparmakov <aia21@cantab.net>
Fix http://bugzilla.kernel.org/show_bug.cgi?id=4857
When pivot_root is called from an init script in an initramfs environment,
it causes a circular reference in the mount tree.
The cause of this is that pivot_root() is not prepared to handle pivoting
an unattached mount. In an initramfs environment, rootfs is the root of
the namespace, and so it is not attached.
This patch fixes this and related problems, by returning -EINVAL if either
the current root or the new root is detached.
Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Acked-by: Al Viro <viro@parcelfarce.linux.theplanet.co.uk>
Cc: <bigfish@asmallpond.org>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
attached patch should fix the following race:
Proc 1 Proc 2
__flush_batch()
ll_rw_block()
do_get_write_access()
lock_buffer
jh is only waiting for checkpoint
-> b_transaction == NULL ->
do nothing
unlock_buffer
test_set_buffer_locked()
test_clear_buffer_dirty()
__journal_file_buffer()
change the data
submit_bh()
and we have sent wrong data to disk... We now clean the dirty buffer flag
under buffer lock in all cases and hence we know that whenever a buffer is
starting to be journaled we either finish the pending write-out before
attaching a buffer to a transaction or we won't write the buffer until the
transaction is going to be committed.
The test in jbd_unexpected_dirty_buffer() is redundant - remove it.
Furthermore we have to clear the buffer dirty bit under the buffer lock to
prevent races with buffer write-out (and hence prevent returning a buffer with
IO happening).
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Use block layer predefined function.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Dipankar Sarma