Original problem: in some circumstances seq_file interface can present
infinite proc file to the following script when normally said proc file is
finite:
while read line; do
[do something with $line]
done </proc/$FILE
bash, to implement such loop does essentially
read(0, buf, 128);
[find \n]
lseek(0, -difference, SEEK_CUR);
Consider, proc file prints list of objects each of them consists of many
lines, each line is shorter than 128 bytes.
Two objects in list, with ->index'es being 0 and 1. Current one is 1, as
bash prints second object line by line.
Imagine first object being removed right before lseek().
traverse() will be called, because there is negative offset.
traverse() will reset ->index to 0 (!).
traverse() will call ->next() and get NULL in any usual iterate-over-list
code using list_for_each_entry_continue() and such. There is one object in
list now after all...
traverse() will return 0, lseek() will update file position and pretend
everything is OK.
So, what we have now: ->f_pos points to place where second object will be
printed, but ->index is 0. seq_read() instead of returning EOF, will start
printing first line of first object every time it's called, until enough
objects are added to ->f_pos return in bounds.
Fix is to update ->index only after we're sure we saw enough objects down
the road.
Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Part two in the O_CLOEXEC saga: adding support for file descriptors received
through Unix domain sockets.
The patch is once again pretty minimal, it introduces a new flag for recvmsg
and passes it just like the existing MSG_CMSG_COMPAT flag. I think this bit
is not used otherwise but the networking people will know better.
This new flag is not recognized by recvfrom and recv. These functions cannot
be used for that purpose and the asymmetry this introduces is not worse than
the already existing MSG_CMSG_COMPAT situations.
The patch must be applied on the patch which introduced O_CLOEXEC. It has to
remove static from the new get_unused_fd_flags function but since scm.c cannot
live in a module the function still hasn't to be exported.
Here's a test program to make sure the code works. It's so much longer than
the actual patch...
#include <errno.h>
#include <error.h>
#include <fcntl.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <sys/socket.h>
#include <sys/un.h>
#ifndef O_CLOEXEC
# define O_CLOEXEC 02000000
#endif
#ifndef MSG_CMSG_CLOEXEC
# define MSG_CMSG_CLOEXEC 0x40000000
#endif
int
main (int argc, char *argv[])
{
if (argc > 1)
{
int fd = atol (argv[1]);
printf ("child: fd = %d\n", fd);
if (fcntl (fd, F_GETFD) == 0 || errno != EBADF)
{
puts ("file descriptor valid in child");
return 1;
}
return 0;
}
struct sockaddr_un sun;
strcpy (sun.sun_path, "./testsocket");
sun.sun_family = AF_UNIX;
char databuf[] = "hello";
struct iovec iov[1];
iov[0].iov_base = databuf;
iov[0].iov_len = sizeof (databuf);
union
{
struct cmsghdr hdr;
char bytes[CMSG_SPACE (sizeof (int))];
} buf;
struct msghdr msg = { .msg_iov = iov, .msg_iovlen = 1,
.msg_control = buf.bytes,
.msg_controllen = sizeof (buf) };
struct cmsghdr *cmsg = CMSG_FIRSTHDR (&msg);
cmsg->cmsg_level = SOL_SOCKET;
cmsg->cmsg_type = SCM_RIGHTS;
cmsg->cmsg_len = CMSG_LEN (sizeof (int));
msg.msg_controllen = cmsg->cmsg_len;
pid_t child = fork ();
if (child == -1)
error (1, errno, "fork");
if (child == 0)
{
int sock = socket (PF_UNIX, SOCK_STREAM, 0);
if (sock < 0)
error (1, errno, "socket");
if (bind (sock, (struct sockaddr *) &sun, sizeof (sun)) < 0)
error (1, errno, "bind");
if (listen (sock, SOMAXCONN) < 0)
error (1, errno, "listen");
int conn = accept (sock, NULL, NULL);
if (conn == -1)
error (1, errno, "accept");
*(int *) CMSG_DATA (cmsg) = sock;
if (sendmsg (conn, &msg, MSG_NOSIGNAL) < 0)
error (1, errno, "sendmsg");
return 0;
}
/* For a test suite this should be more robust like a
barrier in shared memory. */
sleep (1);
int sock = socket (PF_UNIX, SOCK_STREAM, 0);
if (sock < 0)
error (1, errno, "socket");
if (connect (sock, (struct sockaddr *) &sun, sizeof (sun)) < 0)
error (1, errno, "connect");
unlink (sun.sun_path);
*(int *) CMSG_DATA (cmsg) = -1;
if (recvmsg (sock, &msg, MSG_CMSG_CLOEXEC) < 0)
error (1, errno, "recvmsg");
int fd = *(int *) CMSG_DATA (cmsg);
if (fd == -1)
error (1, 0, "no descriptor received");
char fdname[20];
snprintf (fdname, sizeof (fdname), "%d", fd);
execl ("/proc/self/exe", argv[0], fdname, NULL);
puts ("execl failed");
return 1;
}
[akpm@linux-foundation.org: Fix fastcall inconsistency noted by Michael Buesch]
[akpm@linux-foundation.org: build fix]
Signed-off-by: Ulrich Drepper <drepper@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Michael Buesch <mb@bu3sch.de>
Cc: Michael Kerrisk <mtk-manpages@gmx.net>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The problem is as follows: in multi-threaded code (or more correctly: all
code using clone() with CLONE_FILES) we have a race when exec'ing.
thread #1 thread #2
fd=open()
fork + exec
fcntl(fd,F_SETFD,FD_CLOEXEC)
In some applications this can happen frequently. Take a web browser. One
thread opens a file and another thread starts, say, an external PDF viewer.
The result can even be a security issue if that open file descriptor
refers to a sensitive file and the external program can somehow be tricked
into using that descriptor.
Just adding O_CLOEXEC support to open() doesn't solve the whole set of
problems. There are other ways to create file descriptors (socket,
epoll_create, Unix domain socket transfer, etc). These can and should be
addressed separately though. open() is such an easy case that it makes not
much sense putting the fix off.
The test program:
#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <unistd.h>
#ifndef O_CLOEXEC
# define O_CLOEXEC 02000000
#endif
int
main (int argc, char *argv[])
{
int fd;
if (argc > 1)
{
fd = atol (argv[1]);
printf ("child: fd = %d\n", fd);
if (fcntl (fd, F_GETFD) == 0 || errno != EBADF)
{
puts ("file descriptor valid in child");
return 1;
}
return 0;
}
fd = open ("/proc/self/exe", O_RDONLY | O_CLOEXEC);
printf ("in parent: new fd = %d\n", fd);
char buf[20];
snprintf (buf, sizeof (buf), "%d", fd);
execl ("/proc/self/exe", argv[0], buf, NULL);
puts ("execl failed");
return 1;
}
[kyle@parisc-linux.org: parisc fix]
Signed-off-by: Ulrich Drepper <drepper@redhat.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Cc: Davide Libenzi <davidel@xmailserver.org>
Cc: Michael Kerrisk <mtk-manpages@gmx.net>
Cc: Chris Zankel <chris@zankel.net>
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
fs/block_dev.c: Use list_for_each_entry() instead of list_for_each()
in nr_blockdev_pages()
Signed-off-by: Matthias Kaehlcke <matthias.kaehlcke@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
All manipulations with struct seq_file::version are done under
struct seq_file::lock except one introduced in commit
d6b7a781c51c91dd054e5c437885205592faac21
aka "[PATCH] Speed up /proc/pid/maps"
Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
It's a bit dopey-looking and can permit a task to cause a pagefault in an mm
which it doesn't have permission to read from.
Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Remove useless tolower in isofs
Signed-off-by: dave young <hidave.darkstar@gmail.com>
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Don't use explicit extern specifier and quieten sparse warning:
fs/afs/vnode.c:564:12: warning: function 'afs_vnode_link' with external linkage has definition
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Acked-By: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Function proc_register() will assign proc_dir_operations and
proc_dir_inode_operations to ent's members proc_fops and proc_iops
correctly if ent is a directory. So the early assignment isn't
necessary.
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Some users have been having problems with utilities like cp or dd dumping
core when they try to copy a file that's too large for the destination
filesystem (typically, > 4gb). Apparently, some defunct standards required
SIGXFSZ to be sent in such circumstances, but SUS only requires/allows it
for when a written file exceeds the process's resource limits. I'd like to
limit SIGXFSZs to the bare minimum required by SUS.
Patch sent per http://lkml.org/lkml/2007/4/10/302
Signed-off-by: Micah Cowan <micahcowan@ubuntu.com>
Acked-by: Alan Cox <alan@redhat.com>
Cc: <reiserfs-dev@namesys.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch is using mmap()'s randomization functionality in such a way that
it maps the main executable of (specially compiled/linked -pie/-fpie)
ET_DYN binaries onto a random address (in cases in which mmap() is allowed
to perform a randomization).
Origin of this patch is in exec-shield
(http://people.redhat.com/mingo/exec-shield/)
[jkosina@suse.cz: pie randomization: fix BAD_ADDR macro]
Signed-off-by: Jan Kratochvil <honza@jikos.cz>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Roland McGrath <roland@redhat.com>
Cc: Jakub Jelinek <jakub@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
fs/isofs/* had a bunch of CodingStyle issues.
* Indentation was a mix of spaces and tabs
* "int * foo" instead of "int *foo"
* "while ( foo )" instead of "while (foo)"
* if (foo) blah; on one line instead of two
* Missing printk KERN_ levels
* lots of trailing whitespace
* lines >80 columns changed to wrap.
* Unnecessary prototype removed by shuffling code order in C file.
Should be no functional changes other than slight size increase due to
printk changes. Further improvement possible, but this is a start..
Signed-off-by: Dave Jones <davej@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
warning: 'adfs_partition' defined but not used
warning: 'riscix_partition' defined but not used
warning: 'linux_partition' defined but not used
Signed-off-by: Denver Gingerich <denver@ossguy.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch fixes the following warnings.
fs/fat/dir.c: In function 'fat_parse_long':
include/linux/msdos_fs.h:294: warning: array subscript is above array bounds
include/linux/msdos_fs.h:295: warning: array subscript is above array bounds
include/linux/msdos_fs.h:295: warning: array subscript is above array bounds
The ->name is defined as "name[8], ext[3]", but fat_checksum() uses
those as name[11]. There is no actual problem, but it's not a good manner.
Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This includes /proc/fs/nfsfs/servers and /proc/fs/nfsfs/volumes entries.
Both need to show the header and use the list_head.
Signed-off-by: Pavel Emelianov <xemul@openvz.org>
Acked-by: Trond Myklebust <trond.myklebust@fys.uio.no>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
One more simple and stupid switching to the new API.
Signed-off-by: Pavel Emelianov <xemul@openvz.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Simple and stupid like some previous ones. Just use new API.
Signed-off-by: Pavel Emelianov <xemul@openvz.org>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
These proc files show some header before dumping the list, so the
seq_list_start_head() is used.
Signed-off-by: Pavel Emelianov <xemul@openvz.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
gcc-4.3:
fs/freevxfs/vxfs_lookup.c: In function 'vxfs_find_entry':
fs/freevxfs/vxfs_lookup.c:139: warning: cast from pointer to integer of different size
fs/freevxfs/vxfs_lookup.c: In function 'vxfs_readdir':
fs/freevxfs/vxfs_lookup.c:294: warning: cast from pointer to integer of different size
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch adds checking for granted memory while filling up inode data to
prevent possible NULL pointer usage. If there is not enough memory to fill
inode data we just mark it as "bad". Also some whitespace cleanup.
Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com>
Cc: Jan Kara <jack@ucw.cz>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add checking for granted memory for inode data at the moment of its
creation.
Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com>
Cc: Jan Kara <jack@ucw.cz>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit 411187fb05 caused uptime not to increase
during suspend. This may cause confusion so I restore the old behaviour by
using the boot based time instead of monotonic for uptime.
Signed-off-by: Tomas Janousek <tjanouse@redhat.com>
Acked-by: John Stultz <johnstul@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit 411187fb05 caused boot time to move and
process start times to become invalid after suspend. Using boot based time
for those restores the old behaviour and fixes the issue.
[akpm@linux-foundation.org: little cleanup]
Signed-off-by: Tomas Janousek <tjanouse@redhat.com>
Cc: Tomas Smetana <tsmetana@redhat.com>
Acked-by: John Stultz <johnstul@us.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix following races:
===========================================
1. Write via ->write_proc sleeps in copy_from_user(). Module disappears
meanwhile. Or, more generically, system call done on /proc file, method
supplied by module is called, module dissapeares meanwhile.
pde = create_proc_entry()
if (!pde)
return -ENOMEM;
pde->write_proc = ...
open
write
copy_from_user
pde = create_proc_entry();
if (!pde) {
remove_proc_entry();
return -ENOMEM;
/* module unloaded */
}
*boom*
==========================================
2. bogo-revoke aka proc_kill_inodes()
remove_proc_entry vfs_read
proc_kill_inodes [check ->f_op validness]
[check ->f_op->read validness]
[verify_area, security permissions checks]
->f_op = NULL;
if (file->f_op->read)
/* ->f_op dereference, boom */
NOTE, NOTE, NOTE: file_operations are proxied for regular files only. Let's
see how this scheme behaves, then extend if needed for directories.
Directories creators in /proc only set ->owner for them, so proxying for
directories may be unneeded.
NOTE, NOTE, NOTE: methods being proxied are ->llseek, ->read, ->write,
->poll, ->unlocked_ioctl, ->ioctl, ->compat_ioctl, ->open, ->release.
If your in-tree module uses something else, yell on me. Full audit pending.
[akpm@linux-foundation.org: build fix]
Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
invalidate_mapping_pages() can sometimes take a long time (millions of pages
to free). Long enough for the softlockup detector to trigger.
We used to have a cond_resched() in there but I took it out because the
drop_caches code calls invalidate_mapping_pages() under inode_lock.
The patch adds a nasty flag and puts the cond_resched() back.
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We have to check that also the second checkpoint list is non-empty before
dropping the transaction.
Signed-off-by: Jan Kara <jack@suse.cz>
Cc: Chuck Ebbert <cebbert@redhat.com>
Cc: Kirill Korotaev <dev@openvz.org>
Cc: <linux-ext4@vger.kernel.org>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We have to check that also the second checkpoint list is non-empty before
dropping the transaction.
Signed-off-by: Jan Kara <jack@suse.cz>
Cc: Chuck Ebbert <cebbert@redhat.com>
Cc: Kirill Korotaev <dev@openvz.org>
Cc: <linux-ext4@vger.kernel.org>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
OGAWA Hirofumi <hirofumi@mail.parknet.co.jp> reported that he's noticed
nfsd read corruption in recent kernels, and did the hard work of
discovering that it's due to splice updating the file position twice.
This means that the next operation would start further ahead than it
should.
nfsd_vfs_read()
splice_direct_to_actor()
while(len) {
do_splice_to() [update sd->pos]
-> generic_file_splice_read() [read from sd->pos]
nfsd_direct_splice_actor()
-> __splice_from_pipe() [update sd->pos]
There's nothing wrong with the core splice code, but the direct
splicing is an addon that calls both input and output paths.
So it has to take care in locally caching offset so it remains correct.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
while changing task_stime() i noticed a whitespace style problem in
array.c - fix it. While at it, fix all the other style problems too,
most of them in the scheduler-stats related portions of array.c.
There is no change in functionality:
text data bss dec hex filename
4356 28 0 4384 1120 array.o-before
4356 28 0 4384 1120 array.o-after
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Alexey Dobriyan noticed that task_stime() contains a piece of dead code.
(which is a remnant of earlier versions of this code) Remove that code.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ericvh/v9fs:
9p: fix a race condition bug in umount which caused a segfault
9p: re-enable mount time debug option
9p: cache meta-data when cache=loose
net/9p: set error to EREMOTEIO if trans->write returns zero
net/9p: change net/9p module name to 9pnet
9p: Reorganization of 9p file system code
* 'for-linus' of git://oss.sgi.com:8090/xfs/xfs-2.6: (37 commits)
[XFS] Fix lockdep annotations for xfs_lock_inodes
[LIB]: export radix_tree_preload()
[XFS] Fix XFS_IOC_FSBULKSTAT{,_SINGLE} & XFS_IOC_FSINUMBERS in compat mode
[XFS] Compat ioctl handler for handle operations
[XFS] Compat ioctl handler for XFS_IOC_FSGEOMETRY_V1.
[XFS] Clean up function name handling in tracing code
[XFS] Quota inode has no parent.
[XFS] Concurrent Multi-File Data Streams
[XFS] Use uninitialized_var macro to stop warning about rtx
[XFS] XFS should not be looking at filp reference counts
[XFS] Use is_power_of_2 instead of open coding checks
[XFS] Reduce shouting by removing unnecessary macros from dir2 code.
[XFS] Simplify XFS min/max macros.
[XFS] Kill off xfs_count_bits
[XFS] Cancel transactions on xfs_itruncate_start error.
[XFS] Use do_div() on 64 bit types.
[XFS] Fix remount,readonly path to flush everything correctly.
[XFS] Cleanup inode extent size hint extraction
[XFS] Prevent ENOSPC from aborting transactions that need to succeed
[XFS] Prevent deadlock when flushing inodes on unmount
...
Shows how many people are testing coda - the bug had been there for 5 years
and results of stepping on it are not subtle.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
During reorganization, the mount time debug option was removed in favor
of module-load-time parameters. However, the mount time option is still
a useful for feature during debug and for user-fault isolation when the
module is compiled into the kernel.
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
This patch expands the impact of the loose cache mode to allow for cached
metadata increasing the performance of directory listings and other metadata
read operations.
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
This patchset moves non-filesystem interfaces of v9fs from fs/9p to net/9p.
It moves the transport, packet marshalling and connection layers to net/9p
leaving only the VFS related files in fs/9p. This work is being done in
preparation for in-kernel 9p servers as well as alternate 9p clients (other
than VFS).
Signed-off-by: Latchesar Ionkov <lucho@ionkov.net>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
* 32bit struct xfs_fsop_bulkreq has different size and layout of
members, no matter the alignment. Move the code out of the #else
branch (why was it there in the first place?). Define _32 variants of
the ioctl constants.
* 32bit struct xfs_bstat is different because of time_t and on
i386 because of different padding. Make xfs_bulkstat_one() accept a
custom "output formatter" in the private_data argument which takes care
of the xfs_bulkstat_one_compat() that takes care of the different
layout in the compat case.
* i386 struct xfs_inogrp has different padding.
Add a similar "output formatter" mecanism to xfs_inumbers().
SGI-PV: 967354
SGI-Modid: xfs-linux-melb:xfs-kern:29102a
Signed-off-by: Michal Marek <mmarek@suse.cz>
Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Tim Shimmin <tes@sgi.com>
32bit struct xfs_fsop_handlereq has different size and offsets (due to
pointers). TODO: case XFS_IOC_{FSSETDM,ATTRLIST,ATTRMULTI}_BY_HANDLE still
not handled.
SGI-PV: 967354
SGI-Modid: xfs-linux-melb:xfs-kern:29101a
Signed-off-by: Michal Marek <mmarek@suse.cz>
Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Tim Shimmin <tes@sgi.com>
i386 struct xfs_fsop_geom_v1 has no padding after the last member, so the
size is different.
SGI-PV: 967354
SGI-Modid: xfs-linux-melb:xfs-kern:29100a
Signed-off-by: Michal Marek <mmarek@suse.cz>
Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Tim Shimmin <tes@sgi.com>
Remove the hardcoded "fnames" for tracing, and just embed them in tracing
macros via __FUNCTION__. Kills a lot of #ifdefs too.
SGI-PV: 967353
SGI-Modid: xfs-linux-melb:xfs-kern:29099a
Signed-off-by: Eric Sandeen <sandeen@sandeen.net>
Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Tim Shimmin <tes@sgi.com>
Avoid using a special "zero inode" as the parent of the quota inode as
this can confuse the filestreams code into thinking the quota inode has a
parent. We do not want the quota inode to follow filestreams allocation
rules, so pass a NULL as the parent inode and detect this condition when
doing stream associations.
SGI-PV: 964469
SGI-Modid: xfs-linux-melb:xfs-kern:29098a
Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Tim Shimmin <tes@sgi.com>
In media spaces, video is often stored in a frame-per-file format. When
dealing with uncompressed realtime HD video streams in this format, it is
crucial that files do not get fragmented and that multiple files a placed
contiguously on disk.
When multiple streams are being ingested and played out at the same time,
it is critical that the filesystem does not cross the streams and
interleave them together as this creates seek and readahead cache miss
latency and prevents both ingest and playout from meeting frame rate
targets.
This patch set creates a "stream of files" concept into the allocator to
place all the data from a single stream contiguously on disk so that RAID
array readahead can be used effectively. Each additional stream gets
placed in different allocation groups within the filesystem, thereby
ensuring that we don't cross any streams. When an AG fills up, we select a
new AG for the stream that is not in use.
The core of the functionality is the stream tracking - each inode that we
create in a directory needs to be associated with the directories' stream.
Hence every time we create a file, we look up the directories' stream
object and associate the new file with that object.
Once we have a stream object for a file, we use the AG that the stream
object point to for allocations. If we can't allocate in that AG (e.g. it
is full) we move the entire stream to another AG. Other inodes in the same
stream are moved to the new AG on their next allocation (i.e. lazy
update).
Stream objects are kept in a cache and hold a reference on the inode.
Hence the inode cannot be reclaimed while there is an outstanding stream
reference. This means that on unlink we need to remove the stream
association and we also need to flush all the associations on certain
events that want to reclaim all unreferenced inodes (e.g. filesystem
freeze).
SGI-PV: 964469
SGI-Modid: xfs-linux-melb:xfs-kern:29096a
Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Barry Naujok <bnaujok@sgi.com>
Signed-off-by: Donald Douwsma <donaldd@sgi.com>
Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Tim Shimmin <tes@sgi.com>
Signed-off-by: Vlad Apostolov <vapo@sgi.com>
Appease gcc in regards to "warning: 'rtx' is used uninitialized in
this function".
SGI-PV: 907752
SGI-Modid: xfs-linux-melb:xfs-kern:29007a
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Tim Shimmin <tes@sgi.com>
A check for file_count is always a bad idea. Linux has the ->release
method to deal with cleanups on last close and ->flush is only for the
very rare case where we want to perform an operation on every drop of a
reference to a file struct.
This patch gets rid of vop_close and surrounding code in favour of simply
doing the page flushing from ->release.
SGI-PV: 966562
SGI-Modid: xfs-linux-melb:xfs-kern:28952a
Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Tim Shimmin <tes@sgi.com>
xfs_count_bits is only called once, and is then compared to 0. IOW, what
it really wants to know is, is the bitmap empty. This can be done more
simply, certainly.
SGI-PV: 966503
SGI-Modid: xfs-linux-melb:xfs-kern:28944a
Signed-off-by: Eric Sandeen <sandeen@sandeen.net>
Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Tim Shimmin <tes@sgi.com>
The remount readonly path can fail to writeback properly because we still
have active transactions after calling xfs_quiesce_fs(). Further
investigation shows that this path is broken in the same ways that the xfs
freeze path was broken so fix it the same way.
SGI-PV: 964464
SGI-Modid: xfs-linux-melb:xfs-kern:28869a
Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Tim Shimmin <tes@sgi.com>
During delayed allocation extent conversion or unwritten extent
conversion, we need to reserve some blocks for transactions reservations.
We need to reserve these blocks in case a btree split occurs and we need
to allocate some blocks.
Unfortunately, we've only ever reserved the number of data blocks we are
allocating, so in both the unwritten and delalloc case we can get ENOSPC
to the transaction reservation. This is bad because in both cases we
cannot report the failure to the writing application.
The fix is two-fold:
1 - leverage the reserved block infrastructure XFS already
has to reserve a small pool of blocks by default to allow
specially marked transactions to dip into when we are at
ENOSPC.
Default setting is min(5%, 1024 blocks).
2 - convert critical transaction reservations to be allowed
to dip into this pool. Spots changed are delalloc
conversion, unwritten extent conversion and growing a
filesystem at ENOSPC.
This also allows growing the filesytsem to succeed at ENOSPC.
SGI-PV: 964468
SGI-Modid: xfs-linux-melb:xfs-kern:28865a
Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Tim Shimmin <tes@sgi.com>
When we are unmounting the filesystem, we flush all the inodes to disk.
Unfortunately, if we have an inode cluster that has just been freed and
marked stale sitting in an incore log buffer (i.e. hasn't been flushed to
disk), it will be holding all the flush locks on the inodes in that
cluster.
xfs_iflush_all() which is called during unmount walks all the inodes
trying to reclaim them, and it doing so calls xfs_finish_reclaim() on each
inode. If the inode is dirty, if grabs the flush lock and flushes it.
Unfortunately, find dirty inodes that already have their flush lock held
and so we sleep.
At this point in the unmount process, we are running single-threaded.
There is nothing more that can push on the log to force the transaction
holding the inode flush locks to disk and hence we deadlock.
The fix is to issue a log force before flushing the inodes on unmount so
that all the flush locks will be released before we start flushing the
inodes.
SGI-PV: 964538
SGI-Modid: xfs-linux-melb:xfs-kern:28862a
Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Tim Shimmin <tes@sgi.com>
If we have multiple unwritten extents within a single page, we fail to
tell the I/o completion construction handlers we need a new handle for the
second and subsequent blocks in the page. While we still issue the I/O
correctly, we do not have the correct ranges recorded in the ioend
structures and hence when we go to convert the unwritten extents we screw
it up.
Make sure we start a new ioend every time the mapping changes so that we
convert the correct ranges on I/O completion.
SGI-PV: 964647
SGI-Modid: xfs-linux-melb:xfs-kern:28797a
Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Tim Shimmin <tes@sgi.com>
With the per-cpu superblock counters, batch updates are no longer atomic
across the entire batch of changes. This is not an issue if each
individual change in the batch is applied atomically. Unfortunately, free
block count changes are not applied atomically, and they are applied in a
manner guaranteed to cause problems.
Essentially, the free block count reservation that the transaction took
initially is returned to the in core counters before a second delta takes
away what is used. because these two operations are not atomic, we can
race with another thread that can use the returned transaction reservation
before the transaction takes the space away again and we can then get
ENOSPC being reported in a spot where we don't have an ENOSPC condition,
nor should we ever see one there.
Fix it up by rolling the two deltas into the one so it can be applied
safely (i.e. atomically) to the incore counters.
SGI-PV: 964465
SGI-Modid: xfs-linux-melb:xfs-kern:28796a
Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Tim Shimmin <tes@sgi.com>
Currently we do not wait on extent conversion to occur, and hence we can
return to userspace from a synchronous direct I/O write without having
completed all the actions in the write. Hence a read after the write may
see zeroes (unwritten extent) rather than the data that was written.
Block the I/O completion by triggering a synchronous workqueue flush to
ensure that the conversion has occurred before we return to userspace.
SGI-PV: 964092
SGI-Modid: xfs-linux-melb:xfs-kern:28775a
Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Tim Shimmin <tes@sgi.com>
When processing multiple extent maps, xfs_bmapi needs to keep track of the
extent behind the one it is currently working on to be able to trim extent
ranges correctly. Failing to update the previous pointer can result in
corrupted extent lists in memory and this will result in panics or assert
failures.
Update the previous pointer correctly when we move to the next extent to
process.
SGI-PV: 965631
SGI-Modid: xfs-linux-melb:xfs-kern:28773a
Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Vlad Apostolov <vapo@sgi.com>
Signed-off-by: Tim Shimmin <tes@sgi.com>
When we have a couple of hundred transactions on the fly at once, they all
typically modify the on disk superblock in some way.
create/unclink/mkdir/rmdir modify inode counts, allocation/freeing modify
free block counts.
When these counts are modified in a transaction, they must eventually lock
the superblock buffer and apply the mods. The buffer then remains locked
until the transaction is committed into the incore log buffer. The result
of this is that with enough transactions on the fly the incore superblock
buffer becomes a bottleneck.
The result of contention on the incore superblock buffer is that
transaction rates fall - the more pressure that is put on the superblock
buffer, the slower things go.
The key to removing the contention is to not require the superblock fields
in question to be locked. We do that by not marking the superblock dirty
in the transaction. IOWs, we modify the incore superblock but do not
modify the cached superblock buffer. In short, we do not log superblock
modifications to critical fields in the superblock on every transaction.
In fact we only do it just before we write the superblock to disk every
sync period or just before unmount.
This creates an interesting problem - if we don't log or write out the
fields in every transaction, then how do the values get recovered after a
crash? the answer is simple - we keep enough duplicate, logged information
in other structures that we can reconstruct the correct count after log
recovery has been performed.
It is the AGF and AGI structures that contain the duplicate information;
after recovery, we walk every AGI and AGF and sum their individual
counters to get the correct value, and we do a transaction into the log to
correct them. An optimisation of this is that if we have a clean unmount
record, we know the value in the superblock is correct, so we can avoid
the summation walk under normal conditions and so mount/recovery times do
not change under normal operation.
One wrinkle that was discovered during development was that the blocks
used in the freespace btrees are never accounted for in the AGF counters.
This was once a valid optimisation to make; when the filesystem is full,
the free space btrees are empty and consume no space. Hence when it
matters, the "accounting" is correct. But that means the when we do the
AGF summations, we would not have a correct count and xfs_check would
complain. Hence a new counter was added to track the number of blocks used
by the free space btrees. This is an *on-disk format change*.
As a result of this, lazy superblock counters are a mkfs option and at the
moment on linux there is no way to convert an old filesystem. This is
possible - xfs_db can be used to twiddle the right bits and then
xfs_repair will do the format conversion for you. Similarly, you can
convert backwards as well. At some point we'll add functionality to
xfs_admin to do the bit twiddling easily....
SGI-PV: 964999
SGI-Modid: xfs-linux-melb:xfs-kern:28652a
Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Tim Shimmin <tes@sgi.com>
If hole punching at EOF is done as two steps (i.e. truncate then extend)
the file is in a transient state between the two steps where an
application can see the incorrect file size. Punching a hole to EOF needs
to be treated in teh same way as all other hole punching cases so that the
file size is never seen to change.
SGI-PV: 962012
SGI-Modid: xfs-linux-melb:xfs-kern:28641a
Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Vlad Apostolov <vapo@sgi.com>
Signed-off-by: Tim Shimmin <tes@sgi.com>
When setting the length of the iclogbuf to write out we should just be
changing the desired byte count rather completely reassociating the buffer
memory with the buffer. Reassociating the buffer memory changes the
apparent length of the buffer and hence when we free the buffer, we don't
free all the vmap()d space we originally allocated.
SGI-PV: 964983
SGI-Modid: xfs-linux-melb:xfs-kern:28640a
Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Tim Shimmin <tes@sgi.com>
Don't reference the log buffer after running the callbacks as the callback
can trigger the log buffers to be freed during unmount.
SGI-PV: 964545
SGI-Modid: xfs-linux-melb:xfs-kern:28567a
Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Tim Shimmin <tes@sgi.com>
Recent fixes to the filesystem freezing code introduced a vn_iowait call
in the middle of the sync code. Unfortunately, at the point where this
call was added we are holding the ilock. The ilock is needed by I/O
completion for unwritten extent conversion and now updating the file size.
Hence I/o cannot complete if we hold the ilock while waiting for I/O
completion.
Fix up the bug and clean the code up around it.
SGI-PV: 963674
SGI-Modid: xfs-linux-melb:xfs-kern:28566a
Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Tim Shimmin <tes@sgi.com>
When growing a filesystem we don't check to see if the new size overflows
the page cache index range, so we can do silly things like grow a
filesystem page 16TB on a 32bit. Check new filesystem sizes against the
limits the kernel can support.
SGI-PV: 957886
SGI-Modid: xfs-linux-melb:xfs-kern:28563a
Signed-Off-By: Nathan Scott <nscott@aconex.com>
Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Tim Shimmin <tes@sgi.com>
Many block drivers (aoe, iscsi) really want refcountable pages in bios,
which is what almost everyone send down. XFS unfortunately has a few
places where it sends down buffers that may come from kmalloc, which
breaks them.
Fix the places that use kmalloc()d buffers.
SGI-PV: 964546
SGI-Modid: xfs-linux-melb:xfs-kern:28562a
Signed-Off-By: Christoph Hellwig <hch@infradead.org>
Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Tim Shimmin <tes@sgi.com>
* git://git.linux-nfs.org/pub/linux/nfs-2.6: (122 commits)
sunrpc: drop BKL around wrap and unwrap
NFSv4: Make sure unlock is really an unlock when cancelling a lock
NLM: fix source address of callback to client
SUNRPC client: add interface for binding to a local address
SUNRPC server: record the destination address of a request
SUNRPC: cleanup transport creation argument passing
NFSv4: Make the NFS state model work with the nosharedcache mount option
NFS: Error when mounting the same filesystem with different options
NFS: Add the mount option "nosharecache"
NFS: Add support for mounting NFSv4 file systems with string options
NFS: Add final pieces to support in-kernel mount option parsing
NFS: Introduce generic mount client API
NFS: Add enums and match tables for mount option parsing
NFS: Improve debugging output in NFS in-kernel mount client
NFS: Clean up in-kernel NFS mount
NFS: Remake nfsroot_mount as a permanent part of NFS client
SUNRPC: Add a convenient default for the hostname when calling rpc_create()
SUNRPC: Rename rpcb_getport to be consistent with new rpcb_getport_sync name
SUNRPC: Rename rpcb_getport_external routine
SUNRPC: Allow rpcbind requests to be interrupted by a signal.
...
When nfsd was transitioned to use splice instead of sendfile() for data
transfers, a line setting the page index was lost. Restore it, so that
nfsd is functional when that path is used.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
If the output actor doesn't transfer the full amount of data, we will
increment ppos too much. Two related bugs in there:
- We need to break out and return actor() retval if it is shorted than
what we spliced into the pipe.
- Adjust ppos only according to actor() return.
Also fix loop problem in generic_file_splice_read(), it should not keep
going when data has already been transferred.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Revalidate read/write permissions for splice(2) and vmslice(2), in case
security policy has changed since the files were opened.
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Well, first of all, I don't want to change so many files either.
What I do:
Adding a new parameter "struct bin_attribute *" in the
.read/.write methods for the sysfs binary attributes.
In fact, only the four lines change in fs/sysfs/bin.c and
include/linux/sysfs.h do the real work.
But I have to update all the files that use binary attributes
to make them compatible with the new .read and .write methods.
I'm not sure if I missed any. :(
Why I do this:
For a sysfs attribute, we can get a pointer pointing to the
struct attribute in the .show/.store method,
while we can't do this for the binary attributes.
I don't know why this is different, but this does make it not
so handy to use the binary attributes as the regular ones.
So I think this patch is reasonable. :)
Who benefits from it:
The patch that exposes ACPI tables in sysfs
requires such an improvement.
All the table binary attributes share the same .read method.
Parameter "struct bin_attribute *" is used to get
the table signature and instance number which are used to
distinguish different ACPI table binary attributes.
Without this parameter, we need to offer different .read methods
for different ACPI table binary attributes.
This is impossible as there are various ACPI tables on different
platforms, and we don't know what they are until they are loaded.
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch makes dentries and inodes for sysfs directories
reclaimable.
* sysfs_notify() is modified to walk sysfs_dirent tree instead of
dentry tree.
* sysfs_update_file() and sysfs_chmod_file() use sysfs_get_dentry() to
grab the victim dentry.
* sysfs_rename_dir() and sysfs_move_dir() grab all dentries using
sysfs_get_dentry() on startup.
* Dentries for all shadowed directories are pinned in memory to serve
as lookup start point.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Some sysfs operations require dentry and inode. sysfs_get_dentry()
looks up and gets dentry for the specified sysfs_dirent. It finds the
first ancestor with dentry attached and starts looking up dentries
from there.
Looking up from the nearest ancestor is necessary to support shadowed
directories because we can't reliably lookup dentry for one of the
shadows. Dentries for each shadow will be pinned in memory such that
they can serve as the starting point for dentry lookup.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
After add/remove path restructuring, the only user of
sysfs_drop_dentry() is sysfs_addrm_finish(). Move sysfs_drop_dentry()
to dir.c and make it static.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The original add/remove code had the following problems.
* parent's timestamps are updated on dentry instantiation. this is
incorrect with reclaimable files.
* updating parent's timestamps isn't synchronized.
* parent nlink update assumes the inode is accessible which won't be
true once directory dentries are made reclaimable.
This patch restructures add/remove paths to resolve the above
problems. Add/removal are done in the following steps.
1. sysfs_addrm_start() : acquire locks including sysfs_mutex and other
resources.
2-a. sysfs_add_one() : add new sd. linking the new sd into the
children list is caller's responsibility.
2-b. sysfs_remove_one() : remove a sd. unlinking the sd from the
children list is caller's responsibility.
3. sysfs_addrm_finish() : release all resources and clean up.
Steps 2-a and/or 2-b can be repeated multiple times.
Parent's inode is looked up during sysfs_addrm_start(). If available
(always at the moment), it's pinned and nlink is updated as sd's are
added and removed. Timestamps are updated during finish if any sd has
been added or removed. If parent's inode is not available during
start, sysfs_mutex ensures that parent inode is not created till
add/remove is complete.
All the complexity is contained inside the helper functions.
Especially, dentry/inode handling is properly hidden from the rest of
sysfs which now mostly operate on sysfs_dirents. As an added bonus,
codes which use these helpers to add and remove sysfs_dirents are now
more structured and simpler.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
As kobj sysfs dentries and inodes are gonna be made reclaimable,
i_mutex can't be used to protect sysfs_dirent tree. Use sysfs_mutex
globally instead. As the whole tree is protected with sysfs_mutex,
there is no reason to keep sysfs_rename_sem. Drop it.
While at it, add docbook comments to functions which require
sysfs_mutex locking.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Replace sysfs_lock and kobj_sysfs_assoc_lock with sysfs_assoc_lock.
sysfs_lock was originally to be used to protect sysfs_dirent tree but
mutex seems better choice, so there is no reason to keep sysfs_lock
separate. Merge the two spinlocks into one.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
As kobj sysfs dentries and inodes are gonna be made reclaimable,
dentry can't be used as naming token for sysfs file/directory, replace
kobj->dentry with kobj->sd. The only external interface change is
shadow directory handling. All other changes are contained in kobj
and sysfs.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Implement sysfs_find_dirent() and sysfs_get_dirent().
sysfs_dirent_exist() is replaced by sysfs_find_dirent(). These will
be used to make directory entries reclamiable.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Implement SYSFS_FLAG_REMOVED flag which currently is used only to
improve sanity check in sysfs_deactivate(). The flag will be used to
make directory entries reclamiable.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Rename sysfs_dirent->s_type to s_flags, pack type into lower eight
bits and reserve the rest for flags. sysfs_type() can used to access
the type. All existing sd->s_type accesses are converted to use
sysfs_type(). While at it, type test is changed to equality test
instead of bit-and test where appropriate.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
sysfs_drop_dentry() used to go through sd->s_dentry and
sd->s_parent->s_dentry to access the inodes. This is incorrect
because inode can be cached without dentry.
This patch makes sysfs_drop_dentry() access inodes using ilookup() on
sd->s_ino. This is both correct and simpler.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Fix oops on x86_64 caused by the dereference of dir in
sysfs_drop_dentry() made before checking if dir is not NULL
(cf. http://marc.info/?l=linux-kernel&m=118151626704924&w=2).
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Make sysfs_dirent use singly linked list for its tree structure.
sysfs_link_sibling() and sysfs_unlink_sibling() functions are added to
handle simpler cases. It adds some complexity and cpu cycle overhead
but reduced memory footprint is worthwhile on big machines.
This change reduces the sizeof sysfs_dirent from 104 to 88 on 64bit
and from 60 to 52 on 32bit.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Make sysfs_dirent->s_active an atomic_t instead of rwsem. This
reduces the size of sysfs_dirent from 136 to 104 on 64bit and from 76
to 60 on 32bit with lock debugging turned off. With lock debugging
turned on the reduction is much larger.
s_active starts at zero and each active reference increments s_active.
Putting a reference decrements s_active. Deactivation subtracts
SD_DEACTIVATED_BIAS which is currently INT_MIN and assumed to be small
enough to make s_active negative. If s_active is negative,
sysfs_get() no longer grants new references. Deactivation succeeds
immediately if there is no active user; otherwise, it waits using a
completion for the last put.
Due to the removal of lockdep tricks, this change makes things less
trickier in release_sysfs_dirent(). As all the complexity is
contained in three s_active functions, I think it's more readable this
way.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
These functions are about to receive more complexity and doesn't
really need to be inlined in the first place. Move them from
fs/sysfs/sysfs.h to fs/sysfs/dir.c.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The root sysfs_dirent didn't point to the root dentry fix it.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
After dentry is reclaimed, sysfs always used to allocate new dentry
and inode if the file is accessed again. This causes problem with
operations which only pin the inode. For example, if inotify watch is
added to a sysfs file and the dentry for the file is reclaimed, the
next update event creates new dentry and new inode making the inotify
watch miss all the events from there on.
This patch fixes it by using iget_locked() instead of new_inode().
sysfs_new_inode() is renamed to sysfs_get_inode() and inode is
initialized iff the inode is newly allocated. sysfs_instantiate() is
responsible for unlocking new inodes.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Reorganize/clean up sysfs_new_inode() and sysfs_create().
* sysfs_init_inode() is separated out from sysfs_new_inode() and is
responsible for basic initialization.
* sysfs_instantiate() replaces the last step of sysfs_create() and is
responsible for dentry instantitaion.
* type-specific initialization is moved out to the callers.
* mode is specified only once when creating a sysfs_dirent.
* spurious list_del_init(&sd->s_sibling) dropped from create_dir()
This change is to
* prepare for inode allocation fix.
* separate alloc and init code for synchronization update.
* make dentry/inode initialization more flexible for later changes.
This patch doesn't introduce visible behavior change.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
sysfs_alloc_ino() isn't used out side of fs/sysfs/dir.c. Make it
static.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
