fuse: use release_pages()

Replace iterated page_cache_release() with release_pages(), which is
faster and shorter.

Needs release_pages() to be exported to modules.

Suggested-by: Andrew Morton <akp

fuse: use release_pages()

Replace iterated page_cache_release() with release_pages(), which is
faster and shorter.

Needs release_pages() to be exported to modules.

Suggested-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

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fuse: use clear_highpage() and KM_USER0 instead of KM_USER1

Commit 7909b1c640 ("fuse: don't use atomic kmap") removed KM_USER0 usage
from fuse/dev.c. Switch KM_USER1 uses to KM_USER0 for clarity.

fuse: use clear_highpage() and KM_USER0 instead of KM_USER1

Commit 7909b1c640 ("fuse: don't use atomic kmap") removed KM_USER0 usage
from fuse/dev.c. Switch KM_USER1 uses to KM_USER0 for clarity. Also
replace open coded clear_highpage().

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Cc: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

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use clear_page()/copy_page() in favor of memset()/memcpy() on whole pages

After all that's what they are intended for.

Signed-off-by: Jan Beulich <jbeulich@novell.com>
Cc: Miklos Szeredi <miklos@sz

use clear_page()/copy_page() in favor of memset()/memcpy() on whole pages

After all that's what they are intended for.

Signed-off-by: Jan Beulich <jbeulich@novell.com>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

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fuse: Initialize total_len in fuse_retrieve()

fs/fuse/dev.c:1357: warning: ‘total_len’ may be used uninitialized in this
function

Initialize total_len to zero, else its value will be undefined.

Si

fuse: Initialize total_len in fuse_retrieve()

fs/fuse/dev.c:1357: warning: ‘total_len’ may be used uninitialized in this
function

Initialize total_len to zero, else its value will be undefined.

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>

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fuse: fix lock annotations

Sparse doesn't understand lock annotations of the form
__releases(&foo->lock). Change them to __releases(foo->lock). Same
for __acquires().

Signed-off-by: Miklos Szered

fuse: fix lock annotations

Sparse doesn't understand lock annotations of the form
__releases(&foo->lock). Change them to __releases(foo->lock). Same
for __acquires().

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>

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fuse: flush background queue on connection close

David Bartly reported that fuse can hang in fuse_get_req_nofail() when
the connection to the filesystem server is no longer active.

If bg_queue is n

fuse: flush background queue on connection close

David Bartly reported that fuse can hang in fuse_get_req_nofail() when
the connection to the filesystem server is no longer active.

If bg_queue is not empty then flush_bg_queue() called from
request_end() can put more requests on to the pending queue. If this
happens while ending requests on the processing queue then those
background requests will be queued to the pending list and never
ended.

Another problem is that fuse_dev_release() didn't wake up processes
sleeping on blocked_waitq.

Solve this by:

a) flushing the background queue before calling end_requests() on the
pending and processing queues

b) setting blocked = 0 and waking up processes waiting on
blocked_waitq()

Thanks to David for an excellent bug report.

Reported-by: David Bartley <andareed@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
CC: stable@kernel.org

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fuse: add retrieve request

Userspace filesystem can request data to be retrieved from the inode's
mapping. This request is synchronous and the retrieved data is queued
as a new request. If the wri

fuse: add retrieve request

Userspace filesystem can request data to be retrieved from the inode's
mapping. This request is synchronous and the retrieved data is queued
as a new request. If the write to the fuse device returns an error
then the retrieve request was not completed and a reply will not be
sent.

Only present pages are returned in the retrieve reply. Retrieving
stops when it finds a non-present page and only data prior to that is
returned.

This request doesn't change the dirty state of pages.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>

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fuse: add store request

Userspace filesystem can request data to be stored in the inode's
mapping. This request is synchronous and has no reply. If the write
to the fuse device returns an error th

fuse: add store request

Userspace filesystem can request data to be stored in the inode's
mapping. This request is synchronous and has no reply. If the write
to the fuse device returns an error then the store request was not
fully completed (but may have updated some pages).

If the stored data overflows the current file size, then the size is
extended, similarly to a write(2) on the filesystem.

Pages which have been completely stored are marked uptodate.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>

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fuse: don't use atomic kmap

Don't use atomic kmap for mapping userspace buffers in device
read/write/splice.

This is necessary because the next patch (adding store notify)
requires that caller of f

fuse: don't use atomic kmap

Don't use atomic kmap for mapping userspace buffers in device
read/write/splice.

This is necessary because the next patch (adding store notify)
requires that caller of fuse_copy_page() may sleep between
invocations. The simplest way to ensure this is to change the atomic
kmaps to non-atomic ones.

Thankfully architectures where kmap() is not a no-op are going out of
fashion, so we can ignore the (probably negligible) performance impact
of this change.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>

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driver core: add devname module aliases to allow module on-demand auto-loading

This adds:
alias: devname:<name>
to some common kernel modules, which will allow the on-demand loading
of the kernel

driver core: add devname module aliases to allow module on-demand auto-loading

This adds:
alias: devname:<name>
to some common kernel modules, which will allow the on-demand loading
of the kernel module when the device node is accessed.

Ideally all these modules would be compiled-in, but distros seems too
much in love with their modularization that we need to cover the common
cases with this new facility. It will allow us to remove a bunch of pretty
useless init scripts and modprobes from init scripts.

The static device node aliases will be carried in the module itself. The
program depmod will extract this information to a file in the module directory:
$ cat /lib/modules/2.6.34-00650-g537b60d-dirty/modules.devname
# Device nodes to trigger on-demand module loading.
microcode cpu/microcode c10:184
fuse fuse c10:229
ppp_generic ppp c108:0
tun net/tun c10:200
dm_mod mapper/control c10:235

Udev will pick up the depmod created file on startup and create all the
static device nodes which the kernel modules specify, so that these modules
get automatically loaded when the device node is accessed:
$ /sbin/udevd --debug
...
static_dev_create_from_modules: mknod '/dev/cpu/microcode' c10:184
static_dev_create_from_modules: mknod '/dev/fuse' c10:229
static_dev_create_from_modules: mknod '/dev/ppp' c108:0
static_dev_create_from_modules: mknod '/dev/net/tun' c10:200
static_dev_create_from_modules: mknod '/dev/mapper/control' c10:235
udev_rules_apply_static_dev_perms: chmod '/dev/net/tun' 0666
udev_rules_apply_static_dev_perms: chmod '/dev/fuse' 0666

A few device nodes are switched to statically allocated numbers, to allow
the static nodes to work. This might also useful for systems which still run
a plain static /dev, which is completely unsafe to use with any dynamic minor
numbers.

Note:
The devname aliases must be limited to the *common* and *single*instance*
device nodes, like the misc devices, and never be used for conceptually limited
systems like the loop devices, which should rather get fixed properly and get a
control node for losetup to talk to, instead of creating a random number of
device nodes in advance, regardless if they are ever used.

This facility is to hide the mess distros are creating with too modualized
kernels, and just to hide that these modules are not compiled-in, and not to
paper-over broken concepts. Thanks! :)

Cc: Greg Kroah-Hartman <gregkh@suse.de>
Cc: David S. Miller <davem@davemloft.net>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Cc: Chris Mason <chris.mason@oracle.com>
Cc: Alasdair G Kergon <agk@redhat.com>
Cc: Tigran Aivazian <tigran@aivazian.fsnet.co.uk>
Cc: Ian Kent <raven@themaw.net>
Signed-Off-By: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

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fuse: support splice() reading from fuse device

Allow userspace filesystem implementation to use splice() to read from
the fuse device.

The userspace filesystem can now transfer data coming from a

fuse: support splice() reading from fuse device

Allow userspace filesystem implementation to use splice() to read from
the fuse device.

The userspace filesystem can now transfer data coming from a WRITE
request to an arbitrary file descriptor (regular file, block device or
socket) without having to go through a userspace buffer.

The semantics of using splice() to read messages are:

1) with a single splice() call move the whole message from the fuse
device to a temporary pipe
2) read the header from the pipe and determine the message type
3a) if message is a WRITE then splice data from pipe to destination
3b) else read rest of message to userspace buffer

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>

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fuse: allow splice to move pages

When splicing buffers to the fuse device with SPLICE_F_MOVE, try to
move pages from the pipe buffer into the page cache. This allows
populating the fuse filesystem'

fuse: allow splice to move pages

When splicing buffers to the fuse device with SPLICE_F_MOVE, try to
move pages from the pipe buffer into the page cache. This allows
populating the fuse filesystem's cache without ever touching the page
contents, i.e. zero copy read capability.

The following steps are performed when trying to move a page into the
page cache:

- buf->ops->confirm() to make sure the new page is uptodate
- buf->ops->steal() to try to remove the new page from it's previous place
- remove_from_page_cache() on the old page
- add_to_page_cache_locked() on the new page

If any of the above steps fail (non fatally) then the code falls back
to copying the page. In particular ->steal() will fail if there are
external references (other than the page cache and the pipe buffer) to
the page.

Also since the remove_from_page_cache() + add_to_page_cache_locked()
are non-atomic it is possible that the page cache is repopulated in
between the two and add_to_page_cache_locked() will fail. This could
be fixed by creating a new atomic replace_page_cache_page() function.

fuse_readpages_end() needed to be reworked so it works even if
page->mapping is NULL for some or all pages which can happen if the
add_to_page_cache_locked() failed.

A number of sanity checks were added to make sure the stolen pages
don't have weird flags set, etc... These could be moved into generic
splice/steal code.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>

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fuse: support splice() writing to fuse device

Allow userspace filesystem implementation to use splice() to write to
the fuse device. The semantics of using splice() are:

1) buffer the message hea

fuse: support splice() writing to fuse device

Allow userspace filesystem implementation to use splice() to write to
the fuse device. The semantics of using splice() are:

1) buffer the message header and data in a temporary pipe
2) with a *single* splice() call move the message from the temporary pipe
to the fuse device

The READ reply message has the most interesting use for this, since
now the data from an arbitrary file descriptor (which could be a
regular file, a block device or a socket) can be tranferred into the
fuse device without having to go through a userspace buffer. It will
also allow zero copy moving of pages.

One caveat is that the protocol on the fuse device requires the length
of the whole message to be written into the header. But the length of
the data transferred into the temporary pipe may not be known in
advance. The current library implementation works around this by
using vmplice to write the header and modifying the header after
splicing the data into the pipe (error handling omitted):

struct fuse_out_header out;

iov.iov_base = &out;
iov.iov_len = sizeof(struct fuse_out_header);
vmsplice(pip[1], &iov, 1, 0);
len = splice(input_fd, input_offset, pip[1], NULL, len, 0);
/* retrospectively modify the header: */
out.len = len + sizeof(struct fuse_out_header);
splice(pip[0], NULL, fuse_chan_fd(req->ch), NULL, out.len, flags);

This works since vmsplice only saves a pointer to the data, it does
not copy the data itself.

Since pipes are currently limited to 16 pages and messages need to be
spliced atomically, the length of the data is limited to 15 pages (or
60kB for 4k pages).

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>

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fuse: use get_user_pages_fast()

Replace uses of get_user_pages() with get_user_pages_fast(). It looks
nicer and should be faster in most cases.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>

fuse: fix large stack use

gcc 4.4 warns about:
fs/fuse/dev.c: In function ‘fuse_notify_inval_entry’:
fs/fuse/dev.c:925: warning: the frame size of 1060 bytes is larger than 1024 bytes

The probl

fuse: fix large stack use

gcc 4.4 warns about:
fs/fuse/dev.c: In function ‘fuse_notify_inval_entry’:
fs/fuse/dev.c:925: warning: the frame size of 1060 bytes is larger than 1024 bytes

The problem is we declare two structures and a large array on the stack,
I move the array alway from the stack and allocate memory for it dynamically.

Signed-off-by: Fang Wenqi <antonf@turbolinux.com.cn>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>

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fuse: cleanup in fuse_notify_inval_...()

Small cleanup in fuse_notify_inval_inode() and
fuse_notify_inval_entry().

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>

Revert "fuse: Fix build error" as unnecessary

This reverts commit 097041e576ee3a50d92dd643ee8ca65bf6a62e21.

Trond had a better fix, which is the parent of this one ("Fix compile
error due to conges

Revert "fuse: Fix build error" as unnecessary

This reverts commit 097041e576ee3a50d92dd643ee8ca65bf6a62e21.

Trond had a better fix, which is the parent of this one ("Fix compile
error due to congestion_wait() changes")

Requested-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Acked-by: Larry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

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fuse: Fix build error

When building v2.6.31-rc2-344-g69ca06c, the following build errors are
found due to missing includes:

CC [M] fs/fuse/dev.o
fs/fuse/dev.c: In function ‘request_end’:
fs/fuse/

fuse: Fix build error

When building v2.6.31-rc2-344-g69ca06c, the following build errors are
found due to missing includes:

CC [M] fs/fuse/dev.o
fs/fuse/dev.c: In function ‘request_end’:
fs/fuse/dev.c:289: error: ‘BLK_RW_SYNC’ undeclared (first use in this function)
...
fs/nfs/write.c: In function ‘nfs_set_page_writeback’:
fs/nfs/write.c:207: error: ‘BLK_RW_ASYNC’ undeclared (first use in this function)

Signed-off-by: Larry Finger@lwfinger.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

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Fix congestion_wait() sync/async vs read/write confusion

Commit 1faa16d22877f4839bd433547d770c676d1d964c accidentally broke
the bdi congestion wait queue logic, causing us to wait on congestion
for

Fix congestion_wait() sync/async vs read/write confusion

Commit 1faa16d22877f4839bd433547d770c676d1d964c accidentally broke
the bdi congestion wait queue logic, causing us to wait on congestion
for WRITE (== 1) when we really wanted BLK_RW_ASYNC (== 0) instead.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

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fuse: make the number of max background requests and congestion threshold tunable

The practical values for these limits depend on the design of the
filesystem server so let userspace set them at ini

fuse: make the number of max background requests and congestion threshold tunable

The practical values for these limits depend on the design of the
filesystem server so let userspace set them at initialization time.

Signed-off-by: Csaba Henk <csaba@gluster.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>

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fuse: invalidation reverse calls

Add notification messages that allow the filesystem to invalidate VFS
caches.

Two notifications are added:

1) inode invalidation

- invalidate cached attribute

fuse: invalidation reverse calls

Add notification messages that allow the filesystem to invalidate VFS
caches.

Two notifications are added:

1) inode invalidation

- invalidate cached attributes
- invalidate a range of pages in the page cache (this is optional)

2) dentry invalidation

- try to invalidate a subtree in the dentry cache

Care must be taken while accessing the 'struct super_block' for the
mount, as it can go away while an invalidation is in progress. To
prevent this, introduce a rw-semaphore, that is taken for read during
the invalidation and taken for write in the ->kill_sb callback.

Cc: Csaba Henk <csaba@gluster.com>
Cc: Anand Avati <avati@zresearch.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>

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fuse: fix return value of fuse_dev_write()

On 64 bit systems -- where sizeof(ssize_t) > sizeof(int) -- the following test
exposes a bug due to a non-careful return of an int or unsigned value:

impl

fuse: fix return value of fuse_dev_write()

On 64 bit systems -- where sizeof(ssize_t) > sizeof(int) -- the following test
exposes a bug due to a non-careful return of an int or unsigned value:

implement a FUSE filesystem which sends an unsolicited notification to
the kernel with invalid opcode. The respective write to /dev/fuse
will return (1 << 32) - EINVAL with errno == 0 instead of -1 with
errno == EINVAL.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
CC: stable@kernel.org

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fuse: export symbols to be used by CUSE

Export the following symbols for CUSE.

fuse_conn_put()
fuse_conn_get()
fuse_conn_kill()
fuse_send_init()
fuse_do_open()
fuse_sync_release()
fuse_direct_io()

fuse: export symbols to be used by CUSE

Export the following symbols for CUSE.

fuse_conn_put()
fuse_conn_get()
fuse_conn_kill()
fuse_send_init()
fuse_do_open()
fuse_sync_release()
fuse_direct_io()
fuse_do_ioctl()
fuse_file_poll()
fuse_request_alloc()
fuse_get_req()
fuse_put_request()
fuse_request_send()
fuse_abort_conn()
fuse_dev_release()
fuse_dev_operations

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>

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fuse: update fuse_conn_init() and separate out fuse_conn_kill()

Update fuse_conn_init() such that it doesn't take @sb and move bdi
registration into a separate function. Also separate out
fuse_conn

fuse: update fuse_conn_init() and separate out fuse_conn_kill()

Update fuse_conn_init() such that it doesn't take @sb and move bdi
registration into a separate function. Also separate out
fuse_conn_kill() from fuse_put_super().

These will be used to implement cuse.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>

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fuse: fix poll notify

Move fuse_copy_finish() to before calling fuse_notify_poll_wakeup().
This is not a big issue because fuse_notify_poll_wakeup() should be
atomic, but it's cleaner this way, and

fuse: fix poll notify

Move fuse_copy_finish() to before calling fuse_notify_poll_wakeup().
This is not a big issue because fuse_notify_poll_wakeup() should be
atomic, but it's cleaner this way, and later uses of notification will
need to be able to finish the copying before performing some actions.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>

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