Make them depend on TCGETS2. If that one is implemented the rest should be
there as well.
Acked-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Invalidate attributes on rename, since some filesystems may update
st_ctime. Reported by Szabolcs Szakacsits
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>
I found problems accessing (executing) previously existing files, until
I did chmod on them (or setattr).
If the fi->attr_version is not initialized, then it could be
larger than fc->attr_version until a setattr is executed, and as a
result the inode attributes would never be set.
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>
FUSE_FILE_OPS is meant to signal that the kernel will send the open file to to
the userspace filesystem for operations on open files, so that sillyrenaming
unlinked files becomes unnecessary.
However this needs VFS changes, which won't make it into 2.6.24.
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>
Some open flags (O_APPEND, O_DIRECT) can be changed with fcntl(F_SETFL, ...)
after open, but fuse currently only sends the flags to userspace in open.
To make it possible to correcly handle changing flags, send the
current value to userspace in each read and write.
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>
Currently reading a fuse file will stop at cached i_size and return
EOF, even though the file might have grown since the attributes were
last updated.
So detect if trying to read past EOF, and refresh the attributes
before continuing with the read.
Thanks to mpb for the report.
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>
In commit a686cd898b:
"Val's cross-port of the ext3 reservations code into ext2."
include/linux/ext2_fs.h got a new function whose return value is only
defined if __KERNEL__ is defined. Putting #ifdef __KERNEL__ around the
function seems to help, patch below.
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Oleg noticed that the call of task_pid_nr_ns() in proc_pid_readdir
is racy with respect to tasks exiting.
After a bit of examination it also appears that the call itself
is completely unnecessary.
So to fix the problem this patch modifies next_tgid() to return
both a tgid and the task struct in question.
A structure is introduced to return these values because it is
slightly cleaner and easier to optimize, and the resulting code
is a little shorter.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
proc_kill_inodes() can clear ->i_fop in the middle of vfs_readdir resulting in
NULL dereference during "file->f_op->readdir(file, buf, filler)".
The solution is to remove proc_kill_inodes() completely:
a) we don't have tricky modules implementing their tricky readdir hooks which
could keeping this revoke from hell.
b) In a situation when module is gone but PDE still alive, standard
readdir will return only "." and "..", because pde->next was cleared by
remove_proc_entry().
c) the race proc_kill_inode() destined to prevent is not completely
fixed, just race window made smaller, because vfs_readdir() is run
without sb_lock held and without file_list_lock held. Effectively,
->i_fop is cleared at random moment, which can't fix properly anything.
BUG: unable to handle kernel NULL pointer dereference at virtual address 00000018
printing eip: c1061205 *pdpt = 0000000005b22001 *pde = 0000000000000000
Oops: 0000 [#1] PREEMPT SMP
Modules linked in: foo af_packet ipv6 cpufreq_ondemand loop serio_raw sr_mod k8temp cdrom hwmon amd_rng
Pid: 2033, comm: find Not tainted (2.6.24-rc1-b1d08ac064268d0ae2281e98bf5e82627e0f0c56 #2)
EIP: 0060:[<c1061205>] EFLAGS: 00010246 CPU: 0
EIP is at vfs_readdir+0x47/0x74
EAX: c6b6a780 EBX: 00000000 ECX: c1061040 EDX: c5decf94
ESI: c6b6a780 EDI: fffffffe EBP: c9797c54 ESP: c5decf78
DS: 007b ES: 007b FS: 00d8 GS: 0033 SS: 0068
Process find (pid: 2033, ti=c5dec000 task=c64bba90 task.ti=c5dec000)
Stack: c5decf94 c1061040 fffffff7 0805ffbc 00000000 c6b6a780 c1061295 0805ffbc
00000000 00000400 00000000 00000004 0805ffbc 4588eff4 c5dec000 c10026ba
00000004 0805ffbc 00000400 0805ffbc 4588eff4 bfdc6c70 000000dc 0000007b
Call Trace:
[<c1061040>] filldir64+0x0/0xc5
[<c1061295>] sys_getdents64+0x63/0xa5
[<c10026ba>] sysenter_past_esp+0x5f/0x85
=======================
Code: 49 83 78 18 00 74 43 8d 6b 74 bf fe ff ff ff 89 e8 e8 b8 c0 12 00 f6 83 2c 01 00 00 10 75 22 8b 5e 10 8b 4c 24 04 89 f0 8b 14 24 <ff> 53 18 f6 46 1a 04 89 c7 75 0b 8b 56 0c 8b 46 08 e8 c8 66 00
EIP: [<c1061205>] vfs_readdir+0x47/0x74 SS:ESP 0068:c5decf78
hch: "Nice, getting rid of this is a very good step formwards.
Unfortunately we have another copy of this junk in
security/selinux/selinuxfs.c:sel_remove_entries() which would need the
same treatment."
Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru>
Acked-by: Christoph Hellwig <hch@infradead.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Cc: James Morris <jmorris@namei.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-2.6:
sysfs: fix off-by-one error in fill_read_buffer()
kobject: two typo fixes
UIO: add UIO documentation target to DocBook Makefile
UIO: fix up the UIO documentation
create /sys/.../power when CONFIG_PM is set
allow LEGACY_PTYS to be set to 0
I found that there is a off-by-one problem in the following code.
Version: 2.6.24-rc2
File: fs/sysfs/file.c:118-122
Function: fill_read_buffer
--------------------------------------------------------------------
count = ops->show(kobj, attr_sd->s_attr.attr, buffer->page);
sysfs_put_active_two(attr_sd);
BUG_ON(count > (ssize_t)PAGE_SIZE);
--------------------------------------------------------------------
Because according to the specification of the sysfs and the implement of
the show methods, the show methods return the number of bytes which would
be generated for the given input, excluding the trailing null.So if the
return value of the show methods equals PAGE_SIZE - 1, the buffer is full
in fact. And if the return value equals PAGE_SIZE, the resulting string
was already truncated,or buffer overflow occurred.
This patch fixes an off-by-one error in fill_read_buffer.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Tejun Heo <teheo@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
fix: http://bugzilla.kernel.org/show_bug.cgi?id=3043
only allow coredumping to the same uid that the coredumping
task runs under.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Alan Cox <alan@redhat.com>
Acked-by: Christoph Hellwig <hch@lst.de>
Acked-by: Al Viro <viro@ftp.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
ocfs2_truncate() and ocfs2_remove_inode_range() had reversed their "set
i_size" arguments to ocfs2_truncate_inline(). Fix things so that truncate
sets i_size, and punching a hole ignores it.
This exposed a problem where punching a hole in an inline-data file wasn't
updating the page cache, so fix that too.
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
The existing bug statement didn't take into account unhashed dentries which
might not have a cluster lock on them. This could happen if a node exporting
the file system via NFS is rebooted, re-exported to nfs clients and then
unmounted. It's fine in this case to not have a dentry cluster lock.
Just remove the bug statement and replace it with an error print, which
does the proper checks. Though we want to know if something has happened
which might have prevented a cluster lock from being created, it's
definitely not necessary to panic the machine for this.
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
Enable expensive bitmap scanning only if DEBUG option is enabled.
The bitmap scanning quite loads the CPU and on my machine the write
throughput of dd if=/dev/zero of=/ocfs2/file bs=1M count=500 conv=sync
improves from 37 MB/s to 45.4 MB/s in local mode...
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
If the inode block isn't valid then we don't want to print the value from
that, instead print the block number which was passed in (which should
always be correct). Also, turn this into a debug print for now - folks who
hit an actual problem always have other logs indicating what the source is.
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
It's almost never worth printing in that situation and we keep forgetting to
manually filter it out.
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
Right now we're just setting them from the existing parameters, not the
new ones that a remount specified.
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
* git://git.linux-nfs.org/pub/linux/nfs-2.6:
NFS: Clean up new multi-segment direct I/O changes
NFS: Ensure we return zero if applications attempt to write zero bytes
NFS: Support multiple segment iovecs in the NFS direct I/O path
NFS: Introduce iovec I/O helpers to fs/nfs/direct.c
SUNRPC: Add missing "space" to net/sunrpc/auth_gss.c
SUNRPC: make sunrpc/xprtsock.c:xs_setup_{udp,tcp}() static
NFS: fs/nfs/dir.c should #include "internal.h"
NFS: make nfs_wb_page_priority() static
NFS: mount failure causes bad page state
SUNRPC: remove NFS/RDMA client's binary sysctls
kernel BUG at fs/nfs/namespace.c:108! - can be triggered by bad server
sunrpc: rpc_pipe_poll may miss available data in some cases
sunrpc: return error if unsupported enctype or cksumtype is encountered
sunrpc: gss_pipe_downcall(), don't assume all errors are transient
NFS: Fix the ustat() regression
Simplify calling sequence of nfs_direct_{read,write}_schedule(), and
rename them to reflect their new role.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
A zero byte count direct write request should be a successful no-op, not an
error.
Signed-off-by: Chuck Lever <cel@netapp.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Allow applications to perform asynchronous scatter-gather direct I/O
to NFS files.
Signed-off-by: Chuck Lever <cel@netapp.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Add helpers that iterate over multi-segment iovecs. These will
be used to support multi-segment scatter/gather direct I/O in a
later patch.
Signed-off-by: Chuck Lever <cel@netapp.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Every file should include the headers containing the prototypes for its global
functions (in this case nfs_access_cache_shrinker()).
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
nfs_wb_page_priority() can now become static.
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
While testing a kernel based upon ecd744eec3
(with wrong boot arguments), I got the following bad page state entry while
NFS was trying to mount it's rootfs:
IP-Config: Complete:
device=eth0, addr=192.168.1.101, mask=255.255.255.0, gw=255.255.255.255,
host=192.168.1.101, domain=, nis-domain=(none),
bootserver=192.168.1.100, rootserver=192.168.1.100, rootpath=
Looking up port of RPC 100003/2 on 192.168.1.100
rpcbind: server 192.168.1.100 not responding, timed out
Root-NFS: Unable to get nfsd port number from server, using default
Looking up port of RPC 100005/1 on 192.168.1.100
rpcbind: server 192.168.1.100 not responding, timed out
Root-NFS: Unable to get mountd port number from server, using default
mount: server 192.168.1.100 not responding, timed out
Root-NFS: Server returned error -5 while mounting /nfs/rootfs/
VFS: Unable to mount root fs via NFS, trying floppy.
Bad page state in process 'swapper'
page:c02b1260 flags:0x00000400 mapping:00000000 mapcount:0 count:0
Trying to fix it up, but a reboot is needed
Backtrace:
[<c0023e34>] (dump_stack+0x0/0x14) from [<c0062570>] (bad_page+0x70/0xac)
[<c0062500>] (bad_page+0x0/0xac) from [<c0064914>] (free_hot_cold_page+0x80/0x178)
[<c0064894>] (free_hot_cold_page+0x0/0x178) from [<c0064a74>] (free_hot_page+0x14/0x18)
[<c0064a60>] (free_hot_page+0x0/0x18) from [<c0067078>] (put_page+0xf8/0x154)
[<c0066f80>] (put_page+0x0/0x154) from [<c007dbc8>] (kfree+0xc8/0xd0)
[<c007db00>] (kfree+0x0/0xd0) from [<c00cbb54>] (nfs_get_sb+0x230/0x710)
[<c00cb924>] (nfs_get_sb+0x0/0x710) from [<c0084334>] (vfs_kern_mount+0x58/0xac)[<c00842dc>] (vfs_kern_mount+0x0/0xac) from [<c00843c0>] (do_kern_mount+0x38/0xf4)
[<c0084388>] (do_kern_mount+0x0/0xf4) from [<c0099c7c>] (do_mount+0x1e8/0x614)
...
This seems to be caused by use of an uninitialised structure due to NULL
options being passed to nfs_validate_mount_data(). Ensure that the
parsed mount data is always initialised.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
(Trond: added fix for the same bug in nfs4_validate_mount_data()).
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Srivatsa Vaddagiri noticed occasionally incorrect CPU usage
values in top and tracked it down to stime going below 0 in
task_stime(). Negative values are possible there due to the
sampled nature of stime/utime.
Fix suggested by Balbir Singh.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Tested-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
Reviewed-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Fix RedHat bug 329431
The idea here is separate "conscious" from "unconscious" flushes.
Conscious flushes are those due to a fsync() or close(). Unconscious
ones are flushes that occur as a side effect of some other operation or
due to memory pressure.
Currently, when an error occurs during an unconscious flush (ENOSPC or
EIO), we toss out the page and don't preserve that error to report to
the user when a conscious flush occurs. If after the unconscious flush,
there are no more dirty pages for the inode, the conscious flush will
simply return success even though there were previous errors when writing
out pages. This can lead to data corruption.
The easiest way to reproduce this is to mount up a CIFS share that's
very close to being full or where the user is very close to quota. mv
a file to the share that's slightly larger than the quota allows. The
writes will all succeed (since they go to pagecache). The mv will do a
setattr to set the new file's attributes. This calls
filemap_write_and_wait,
which will return an error since all of the pages can't be written out.
Then later, when the flush and release ops occur, there are no more
dirty pages in pagecache for the file and those operations return 0. mv
then assumes that the file was written out correctly and deletes the
original.
CIFS already has a write_behind_rc variable where it stores the results
from earlier flushes, but that value is only reported in cifs_close.
Since the VFS ignores the return value from the release operation, this
isn't helpful. We should be reporting this error during the flush
operation.
This patch does the following:
1) changes cifs_fsync to use filemap_write_and_wait and cifs_flush and also
sync to check its return code. If it returns successful, they then check
the value of write_behind_rc to see if an earlier flush had reported any
errors. If so, they return that error and clear write_behind_rc.
2) sets write_behind_rc in a few other places where pages are written
out as a side effect of other operations and the code waits on them.
3) changes cifs_setattr to only call filemap_write_and_wait for
ATTR_SIZE changes.
4) makes cifs_writepages accurately distinguish between EIO and ENOSPC
errors when writing out pages.
Some simple testing indicates that the patch works as expected and that
it fixes the reproduceable known problem.
Acked-by: Dave Kleikamp <shaggy@austin.rr.com>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
When retrying kernel_recvmsg() because of a short read, check returned
length against the remaining length, not against total length. This
avoids unneeded session reconnects which would otherwise occur when
kernel_recvmsg() finally returns zero when asked to read zero bytes.
Signed-off-by: Petr Tesarik <ptesarik@suse.cz>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
Hi Trond,
I have discovered that the BUG_ON in nfs_follow_mountpoint:
BUG_ON(IS_ROOT(dentry));
can be triggered by a misbehaving server.
What happens is the client does a lookup and discoveres that the named
directory has a different fsid, so it initiates a mount.
It then performs a GETATTR on the mounted directory and gets a
different fsid again (due to a bug in the NFS server).
This causes nfs_follow_mountpoint to be called on the newly mounted
root, which triggers the BUG_ON.
To duplicate this, have a directory which contains some mountpoints,
and export that directory with the "crossmnt" flag using nfs-utils
1.1.1 (or 1.1.0 I think)
The GETATTR on the root of the mounted filesystem will return the
information for the top exportpoint, while a lookup will return the
correct information. This difference causes the NFS client to BUG.
I think the best way to fix this is to trap this possibility early, so
just before completing the mount in the NFS client, check that it isn't
going to use nfs_mountpoint_inode_operations.
As long as i_op will never change once set (is that true?), this
should be adequately safe.
The following patch shows a possible approach, and it works for me.
i.e. when the NFS server is misbehaving, I get ESTALE on those
mountpoints, while when the NFS server is working correctly, I get
correct behaviour on the client.
NeilBrown
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Since 2.6.18, the superblock sb->s_root has been a dummy dentry with a
dummy inode. This breaks ustat(), which actually uses sb->s_root in a
vfstat() call.
Fix this by making the s_root a dummy alias to the directory inode that was
used when creating the superblock.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Have CIFS_SessSetup call cifs_get_spnego_key when Kerberos is
negotiated. Use the info in the key payload to build a session
setup request packet. Also clean up how the request buffer in
the function is freed on error.
With appropriate user space helper (in samba/source/client). Kerberos
support (secure session establishment can be done now via Kerberos,
previously users would have to use NTLMv2 instead for more secure
session setup).
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
...and populate it with the hostname portion of the UNC string.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
Move all of the kfree's sprinkled in the middle of the function to the
end, and have the code set rc and just goto there on error. Also zero
out the password string before freeing it. Looks like this should also
fix a potential memory leak of the prepath string if an error occurs
near the end of the function.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
With 64KB blocksize, a directory entry can have size 64KB which does not
fit into 16 bits we have for entry lenght. So we store 0xffff instead and
convert value when read from / written to disk. The patch also converts
some places to use ext3_next_entry() when we are changing them anyway.
[akpm@linux-foundation.org: coding-style cleanups]
Signed-off-by: Jan Kara <jack@suse.cz>
Cc: <linux-ext4@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix some warnings with SMBFS_DEBUG_* builds. This patch makes it so that
builds with -Werror don't fail.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
sys_open / sys_read were used in the early 1.2 days to load firmware from
disk inside drivers. Since 2.0 or so this was deprecated behavior, but
several drivers still were using this. Since a few years we have a
request_firmware() API that implements this in a nice, consistent way.
Only some old ISA sound drivers (pre-ALSA) still straggled along for some
time.... however with commit c2b1239a9f the
last user is now gone.
This is a good thing, since using sys_open / sys_read etc for firmware is a
very buggy to dangerous thing to do; these operations put an fd in the
process file descriptor table.... which then can be tampered with from
other threads for example. For those who don't want the firmware loader,
filp_open()/vfs_read are the better APIs to use, without this security
issue.
The patch below marks sys_open and sys_read unused now that they're
really not used anymore, and for deletion in the 2.6.25 timeframe.
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently we special case when we have only the initial pid namespace.
Unfortunately in doing so the copied case for the other namespaces was
broken so we don't properly flush the thread directories :(
So this patch removes the unnecessary special case (removing a usage of
proc_mnt) and corrects the flushing of the thread directories.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Al Viro <viro@ftp.linux.org.uk>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: Sukadev Bhattiprolu <sukadev@us.ibm.com>
Cc: Kirill Korotaev <dev@sw.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This is not a new problem in 2.6.23-git17. 2.6.22/2.6.23 is buggy in the
same way.
Reiserfs could accumulate dirty sub-page-size files until umount time.
They cannot be synced to disk by pdflush routines or explicit `sync'
commands. Only `umount' can do the trick.
The direct cause is: the dirty page's PG_dirty is wrongly _cleared_.
Call trace:
[<ffffffff8027e920>] cancel_dirty_page+0xd0/0xf0
[<ffffffff8816d470>] :reiserfs:reiserfs_cut_from_item+0x660/0x710
[<ffffffff8816d791>] :reiserfs:reiserfs_do_truncate+0x271/0x530
[<ffffffff8815872d>] :reiserfs:reiserfs_truncate_file+0xfd/0x3b0
[<ffffffff8815d3d0>] :reiserfs:reiserfs_file_release+0x1e0/0x340
[<ffffffff802a187c>] __fput+0xcc/0x1b0
[<ffffffff802a1ba6>] fput+0x16/0x20
[<ffffffff8029e676>] filp_close+0x56/0x90
[<ffffffff8029fe0d>] sys_close+0xad/0x110
[<ffffffff8020c41e>] system_call+0x7e/0x83
Fix the bug by removing the cancel_dirty_page() call. Tests show that
it causes no bad behaviors on various write sizes.
=== for the patient ===
Here are more detailed demonstrations of the problem.
1) the page has both PG_dirty(D)/PAGECACHE_TAG_DIRTY(d) after being written to;
and then only PAGECACHE_TAG_DIRTY(d) remains after the file is closed.
------------------------------ screen 0 ------------------------------
[T0] root /home/wfg# cat > /test/tiny
[T1] hi
[T2] root /home/wfg#
------------------------------ screen 1 ------------------------------
[T1] root /home/wfg# echo /test/tiny > /proc/filecache
[T1] root /home/wfg# cat /proc/filecache
# file /test/tiny
# flags R:referenced A:active M:mmap U:uptodate D:dirty W:writeback O:owner B:buffer d:dirty w:writeback
# idx len state refcnt
0 1 ___UD__Bd_ 2
[T2] root /home/wfg# cat /proc/filecache
# file /test/tiny
# flags R:referenced A:active M:mmap U:uptodate D:dirty W:writeback O:owner B:buffer d:dirty w:writeback
# idx len state refcnt
0 1 ___U___Bd_ 2
2) note the non-zero 'cancelled_write_bytes' after /tmp/hi is copied.
------------------------------ screen 0 ------------------------------
[T0] root /home/wfg# echo hi > /tmp/hi
[T1] root /home/wfg# cp /tmp/hi /dev/stdin /test
[T2] hi
[T3] root /home/wfg#
------------------------------ screen 1 ------------------------------
[T1] root /proc/4397# cd /proc/`pidof cp`
[T1] root /proc/4713# cat io
rchar: 8396
wchar: 3
syscr: 20
syscw: 1
read_bytes: 0
write_bytes: 20480
cancelled_write_bytes: 4096
[T2] root /proc/4713# cat io
rchar: 8399
wchar: 6
syscr: 21
syscw: 2
read_bytes: 0
write_bytes: 24576
cancelled_write_bytes: 4096
//Question: the 'write_bytes' is a bit more than expected ;-)
Tested-by: Maxim Levitsky <maximlevitsky@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: Fengguang Wu <wfg@mail.ustc.edu.cn>
Reviewed-by: Chris Mason <chris.mason@oracle.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
