Don't put requests into the background when a fatal interrupt occurs while the
request is in userspace. This removes a major wart from the implementation.
Backgrounding of requests was introduced to allow breaking of deadlocks.
However now the same can be achieved by aborting the filesystem through the
'abort' sysfs attribute.
This is a change in the interface, but should not cause problems, since these
kinds of deadlocks never happen during normal operation.
Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The following patches add POSIX file locking to the fuse interface.
Additional changes ralated to this are:
- asynchronous interrupt of requests by SIGKILL no longer supported
- separate control filesystem, instead of using sysfs objects
- add support for synchronously interrupting requests
Details are documented in Documentation/filesystems/fuse.txt throughout the
patches.
This patch:
Have fuse.h use MISC_MAJOR rather than a hardcoded '10'.
Signed-off-by: Jan Engelhardt <jengelh@gmx.de>
Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Make another couple of alterations to the memory barrier document following
suggestions by Alan Stern and in co-operation with Paul McKenney:
(*) Rework the point of introduction of memory barriers and the description
of what they are to reiterate why they're needed.
(*) Modify a statement about the use of data dependency barriers to note that
other barriers can be used instead (as they imply DD-barriers).
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-By: Paul E. McKenney <paulmck@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Another bunch of checks in the char drivers .put_char() and .write()
routines, where tty can never be NULL. This patch removes these checks to
save some code. Coverity choked at those with the following bug ids:
isicom.c 767, 766
specialix.c 773, 774
synclink_cs.c 779, 781
synclink_gt.c 784, 785
synclinkmp.c 784, 785
Signed-off-by: Eric Sesterhenn <snakebyte@gmx.de>
Cc: Paul Fulghum <paulkf@microgate.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
I've found a case where invalid dentrys in a mount tree, waiting to be
cleaned up by d_invalidate, prevent the expected expire.
In this case dentrys created during a lookup for which a mount fails or has
no entry in the mount map contribute to the d_count of the parent dentry.
These dentrys may not be invalidated prior to comparing the interanl usage
count of valid autofs dentrys against the dentry d_count which makes a
mount tree appear busy so it doesn't expire.
Signed-off-by: Ian Kent <raven@themaw.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
coverity choked at another two !tty checks, in places where tty can
never be NULL. Since it removes some code we should remove
these checks. (Coverity ids #763,#762)
Signed-off-by Eric Sesterhenn <snakebyte@gmx.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
coverity choked at two !tty checks, in places where tty can never be NULL.
Since it removes some code we should remove these checks. (Coverity ids
#763,#762)
[akpm@osdl.org: even cleaner!]
Signed-off-by: Eric Sesterhenn <snakebyte@gmx.de>
Acked-by: Alan Cox <alan@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
An update to the RCU documentation calling out the
self-limiting-update-rate advantages of synchronize_rcu(), and describing
how to use call_rcu() in a way that results in self-limiting updates.
Self-limiting updates are important to avoiding RCU-induced OOM in face of
denial-of-service attacks.
Signed-off-by: Paul E. McKenney <paulmck@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Backoff readahead size exponentially on I/O error.
Michael Tokarev <mjt@tls.msk.ru> described the problem as:
[QUOTE]
Suppose there's a CD-rom with a scratch/etc, one sector is unreadable.
In order to "fix" it, one have to read it and write to another CD-rom,
or something.. or just ignore the error (if it's just a skip in a video
stream). Let's assume the unreadable block is number U.
But current behavior is just insane. An application requests block
number N, which is before U. Kernel tries to read-ahead blocks N..U.
Cdrom drive tries to read it, re-read it.. for some time. Finally,
when all the N..U-1 blocks are read, kernel returns block number N
(as requested) to an application, successefully.
Now an app requests block number N+1, and kernel tries to read
blocks N+1..U+1. Retrying again as in previous step.
And so on, up to when an app requests block number U-1. And when,
finally, it requests block U, it receives read error.
So, kernel currentry tries to re-read the same failing block as
many times as the current readahead value (256 (times?) by default).
This whole process already killed my cdrom drive (I posted about it
to LKML several months ago) - literally, the drive has fried, and
does not work anymore. Ofcourse that problem was a bug in firmware
(or whatever) of the drive *too*, but.. main problem with that is
current readahead logic as described above.
[/QUOTE]
Which was confirmed by Jens Axboe <axboe@suse.de>:
[QUOTE]
For ide-cd, it tends do only end the first part of the request on a
medium error. So you may see a lot of repeats :/
[/QUOTE]
With this patch, retries are expected to be reduced from, say, 256, to 5.
[akpm@osdl.org: cleanups]
Signed-off-by: Wu Fengguang <wfg@mail.ustc.edu.cn>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Priority: not critical.
Mark 3 functions __init. Saves a little memory.
This makes these functions' calls to AdvWaitEEPCmd() (which is __init)
be clean (i.e., eliminates text -> init -> text call chain).
Fix multiple section mismatch warnings:
WARNING: drivers/scsi/advansys.o - Section mismatch: reference to .init.text: from .text between 'AdvSet3550EEPConfig' (at offset 0x7a22) and 'AdvSet38C0800EEPConfig'
WARNING: drivers/scsi/advansys.o - Section mismatch: reference to .init.text: from .text between 'AdvSet3550EEPConfig' (at offset 0x7a4e) and 'AdvSet38C0800EEPConfig'
WARNING: drivers/scsi/advansys.o - Section mismatch: reference to .init.text: from .text between 'AdvSet3550EEPConfig' (at offset 0x7a79) and 'AdvSet38C0800EEPConfig'
WARNING: drivers/scsi/advansys.o - Section mismatch: reference to .init.text: from .text between 'AdvSet3550EEPConfig' (at offset 0x7aa2) and 'AdvSet38C0800EEPConfig'
WARNING: drivers/scsi/advansys.o - Section mismatch: reference to .init.text: from .text between 'AdvSet3550EEPConfig' (at offset 0x7abb) and 'AdvSet38C0800EEPConfig'
WARNING: drivers/scsi/advansys.o - Section mismatch: reference to .init.text: from .text between 'AdvSet38C0800EEPConfig' (at offset 0x7ae0) and 'AdvSet38C1600EEPConfig'
WARNING: drivers/scsi/advansys.o - Section mismatch: reference to .init.text: from .text between 'AdvSet38C0800EEPConfig' (at offset 0x7b0c) and 'AdvSet38C1600EEPConfig'
WARNING: drivers/scsi/advansys.o - Section mismatch: reference to .init.text: from .text between 'AdvSet38C0800EEPConfig' (at offset 0x7b37) and 'AdvSet38C1600EEPConfig'
WARNING: drivers/scsi/advansys.o - Section mismatch: reference to .init.text: from .text between 'AdvSet38C0800EEPConfig' (at offset 0x7b60) and 'AdvSet38C1600EEPConfig'
WARNING: drivers/scsi/advansys.o - Section mismatch: reference to .init.text: from .text between 'AdvSet38C0800EEPConfig' (at offset 0x7b79) and 'AdvSet38C1600EEPConfig'
WARNING: drivers/scsi/advansys.o - Section mismatch: reference to .init.text: from .text between 'AdvSet38C1600EEPConfig' (at offset 0x7b9e) and 'AdvExeScsiQueue'
WARNING: drivers/scsi/advansys.o - Section mismatch: reference to .init.text: from .text between 'AdvSet38C1600EEPConfig' (at offset 0x7bca) and 'AdvExeScsiQueue'
WARNING: drivers/scsi/advansys.o - Section mismatch: reference to .init.text: from .text between 'AdvSet38C1600EEPConfig' (at offset 0x7bf5) and 'AdvExeScsiQueue'
WARNING: drivers/scsi/advansys.o - Section mismatch: reference to .init.text: from .text between 'AdvSet38C1600EEPConfig' (at offset 0x7c1e) and 'AdvExeScsiQueue'
WARNING: drivers/scsi/advansys.o - Section mismatch: reference to .init.text: from .text between 'AdvSet38C1600EEPConfig' (at offset 0x7c37) and 'AdvExeScsiQueue'
Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
Cc: James Bottomley <James.Bottomley@steeleye.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Priority: tossup.
In theory some of these (previously) __init functions could be called
after init, but that problem has not been observed AFAIK.
There were 2 cases of cleanup_module() (module_exit) calling __init
functions (clear_requested_irq() & have_requested_irq()).
These are more serious, but still not observed AFAIK.
Fix sections mismatch:
WARNING: drivers/char/ip2/ip2main.o - Section mismatch: reference to .init.text: from .text between 'cleanup_module' (at offset 0x228b) and 'ip2_loadmain'
WARNING: drivers/char/ip2/ip2main.o - Section mismatch: reference to .init.text: from .text between 'cleanup_module' (at offset 0x22ae) and 'ip2_loadmain'
WARNING: drivers/char/ip2/ip2main.o - Section mismatch: reference to .init.text: from .text between 'ip2_loadmain' (at offset 0x2501) and 'set_irq'
WARNING: drivers/char/ip2/ip2main.o - Section mismatch: reference to .init.text: from .text between 'ip2_loadmain' (at offset 0x25de) and 'set_irq'
WARNING: drivers/char/ip2/ip2main.o - Section mismatch: reference to .init.text: from .text between 'ip2_loadmain' (at offset 0x2698) and 'set_irq'
WARNING: drivers/char/ip2/ip2main.o - Section mismatch: reference to .init.text: from .text between 'ip2_loadmain' (at offset 0x2922) and 'set_irq'
WARNING: drivers/char/ip2/ip2main.o - Section mismatch: reference to .init.text: from .text between 'ip2_loadmain' (at offset 0x299e) and 'set_irq'
Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Priority: not critical.
Make __mcdx_init() __init and static. Saves a little memory.
Fix section mismatch warning and make the function static while there:
WARNING: drivers/cdrom/mcdx.o - Section mismatch: reference to .init.text: from .text between 'init_module' (at offset 0x8be) and 'mcdx_transfer'
Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
Cc: Jens Axboe <axboe@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Priority: not critical.
Change 3 functions from __init to __devinit.
Could be an init/probe problem in theory, but not observed, so not
high priority IMO.
Fix section mismatch warnings:
WARNING: drivers/video/tridentfb.o - Section mismatch: reference to .init.text: from .text between 'trident_pci_probe' (at offset 0x1aad) and 'trident_pci_remove'
WARNING: drivers/video/tridentfb.o - Section mismatch: reference to .init.text: from .text between 'trident_pci_probe' (at offset 0x1b22) and 'trident_pci_remove'
WARNING: drivers/video/tridentfb.o - Section mismatch: reference to .init.text: from .text between 'trident_pci_probe' (at offset 0x1b31) and 'trident_pci_remove'
Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
netdev->set_config can be called at any time, so these references
to __initdata would be a real problem.
However, problem has not been observed AFAIK.
Fix section mismatch warnings:
WARNING: drivers/net/wan/sdla.o - Section mismatch: reference to .init.data: from .text between 'sdla_set_config' (at offset 0x1b8e) and 'sdla_stats'
WARNING: drivers/net/wan/sdla.o - Section mismatch: reference to .init.data: from .text between 'sdla_set_config' (at offset 0x1e76) and 'sdla_stats'
Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
In the course of trying to track down a bug where a file mtime was not
being updated correctly, it was discovered that the m/ctime updates were
not quite being handled correctly for ftruncate() calls.
Quoth SUSv3:
open(2):
If O_TRUNC is set and the file did previously exist, upon
successful completion, open() shall mark for update the st_ctime
and st_mtime fields of the file.
truncate(2):
Upon successful completion, if the file size is changed, this
function shall mark for update the st_ctime and st_mtime fields
of the file, and the S_ISUID and S_ISGID bits of the file mode
may be cleared.
ftruncate(2):
Upon successful completion, if fildes refers to a regular file,
the ftruncate() function shall mark for update the st_ctime and
st_mtime fields of the file and the S_ISUID and S_ISGID bits of
the file mode may be cleared. If the ftruncate() function is
unsuccessful, the file is unaffected.
The open(O_TRUNC) and truncate cases were being handled correctly, but the
ftruncate case was being handled like the truncate case. The semantics of
truncate and ftruncate don't quite match, so ftruncate needs to be handled
slightly differently.
The attached patch addresses this issue for ftruncate(2).
My thanx to Stephen Tweedie and Trond Myklebust for their help in
understanding the situation and semantics.
Signed-off-by: Peter Staubach <staubach@redhat.com>
Cc: "Stephen C. Tweedie" <sct@redhat.com>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
I'm testing glibc on MIPS64, little-endian, N32, O32 and N64 multilibs.
Among the NPTL test failures seen are some arising from sigsuspend problems
for N32: it blocks the wrong signals, so SIGCANCEL (SIGRTMIN) is blocked
despite glibc's carefully excluding it from sets of signals to block.
Specifically, testing suggests it blocks signal N^32 instead of signal N,
so (in the example tested) blocking SIGUSR1 (17) blocks signal 49 instead.
glibc's sigset_t uses an array of unsigned long, as does the kernel.
In both cases, signal N+1 is represented as
(1UL << (N % (8 * sizeof (unsigned long)))) in word number
(N / (8 * sizeof (unsigned long))).
Thus the N32 glibc uses an array of 32-bit words and the N64 kernel uses an
array of 64-bit words. For little-endian, the layout is the same, with
signals 1-32 in the first 4 bytes, signals 33-64 in the second, etc.; for
big-endian, userspace has that layout while in the kernel each 8 bytes have
the two halves swapped from the userspace layout.
The N32 sigsuspend syscall uses sigset_from_compat to convert the userspace
sigset to kernel format. If __COMPAT_ENDIAN_SWAP__ is *not* set, this uses
logic of the form
set->sig[0] = compat->sig[0] | (((long)compat->sig[1]) << 32 )
to convert the userspace sigset to a kernel one. This looks correct to me
for both big and little endian, given that in userspace compat->sig[1] will
represent signals 33-64, and so will the high 32 bits of set->sig[0] in the
kernel. If however __COMPAT_ENDIAN_SWAP__ *is* set, as it is for
__MIPSEL__, it uses
set->sig[0] = compat->sig[1] | (((long)compat->sig[0]) << 32 );
which seems incorrect for both big and little endian, and would
explain the observed symptoms.
This code is the only use of __COMPAT_ENDIAN_SWAP__, so if incorrect
then that macro serves no purpose, in which case something like the
following patch would seem appropriate to remove it.
Signed-off-by: Joseph Myers <joseph@codesourcery.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The variables nlen and rlen are defined/initialized but not used in
ext3_add_entry().
Signed-off-by: Johann Lombardi <johann.lombardi@bull.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Finding "init_module" high stack usage problems is challenging when there
are over 1600 "init_module" functions in the kernel tree, so make
checkstack.pl print out the filename where the stack usage occurs. This is
useful for code built as loadable modules.
For built-in code, it just prints the kernel image file name, like
"vmlinux". Examples:
(before patch:)
0x0000000d callback: 1928
0xffffffff81678c09 huft_build: 1560
0x0018 init_module: 1512
(after patch:)
0x0000000d callback [divacapi]: 1928
0xffffffff81678c09 huft_build [vmlinux]: 1560
0x0018 init_module [hdaps]: 1512
Also change one if-series to use elsif to cut down on unneeded tests.
Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
Acked-by: Joern Engel <joern@wh.fh-wedel.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Miklos Szeredi
Jan Engelhardt
David Howells
Eric Sesterhenn
Niels Kristian Bech Jensen
Ian Kent
Anton Blanchard
Paul E. McKenney
Wu Fengguang
David Woodhouse
Randy Dunlap
Peter Staubach
akpm@osdl.org
Johann Lombardi
Florin Malita
Stephen Hemminger
Atsushi Nemoto