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* splice: don't pass the address of ->f_pos to methodsAl Viro2013-06-201-8/+16
| | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* aio: don't include aio.h in sched.hKent Overstreet2013-05-071-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | Faster kernel compiles by way of fewer unnecessary includes. [akpm@linux-foundation.org: fix fallout] [akpm@linux-foundation.org: fix build] Signed-off-by: Kent Overstreet <koverstreet@google.com> Cc: Zach Brown <zab@redhat.com> Cc: Felipe Balbi <balbi@ti.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Mark Fasheh <mfasheh@suse.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Jens Axboe <axboe@kernel.dk> Cc: Asai Thambi S P <asamymuthupa@micron.com> Cc: Selvan Mani <smani@micron.com> Cc: Sam Bradshaw <sbradshaw@micron.com> Cc: Jeff Moyer <jmoyer@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Benjamin LaHaise <bcrl@kvack.org> Reviewed-by: "Theodore Ts'o" <tytso@mit.edu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* aio: remove retry-based AIOZach Brown2013-05-071-31/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This removes the retry-based AIO infrastructure now that nothing in tree is using it. We want to remove retry-based AIO because it is fundemantally unsafe. It retries IO submission from a kernel thread that has only assumed the mm of the submitting task. All other task_struct references in the IO submission path will see the kernel thread, not the submitting task. This design flaw means that nothing of any meaningful complexity can use retry-based AIO. This removes all the code and data associated with the retry machinery. The most significant benefit of this is the removal of the locking around the unused run list in the submission path. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Kent Overstreet <koverstreet@google.com> Signed-off-by: Zach Brown <zab@redhat.com> Cc: Zach Brown <zab@redhat.com> Cc: Felipe Balbi <balbi@ti.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Mark Fasheh <mfasheh@suse.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Jens Axboe <axboe@kernel.dk> Cc: Asai Thambi S P <asamymuthupa@micron.com> Cc: Selvan Mani <smani@micron.com> Cc: Sam Bradshaw <sbradshaw@micron.com> Acked-by: Jeff Moyer <jmoyer@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Benjamin LaHaise <bcrl@kvack.org> Reviewed-by: "Theodore Ts'o" <tytso@mit.edu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* kill fs/read_write.hAl Viro2013-05-041-1/+4
| | | | | | | fs/compat.c doesn't need it anymore, so let's just move the remaining contents (two typedefs) into fs/read_write.c Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* Merge branch 'for-linus' of ↵Linus Torvalds2013-05-011-2/+203
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull VFS updates from Al Viro, Misc cleanups all over the place, mainly wrt /proc interfaces (switch create_proc_entry to proc_create(), get rid of the deprecated create_proc_read_entry() in favor of using proc_create_data() and seq_file etc). 7kloc removed. * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (204 commits) don't bother with deferred freeing of fdtables proc: Move non-public stuff from linux/proc_fs.h to fs/proc/internal.h proc: Make the PROC_I() and PDE() macros internal to procfs proc: Supply a function to remove a proc entry by PDE take cgroup_open() and cpuset_open() to fs/proc/base.c ppc: Clean up scanlog ppc: Clean up rtas_flash driver somewhat hostap: proc: Use remove_proc_subtree() drm: proc: Use remove_proc_subtree() drm: proc: Use minor->index to label things, not PDE->name drm: Constify drm_proc_list[] zoran: Don't print proc_dir_entry data in debug reiserfs: Don't access the proc_dir_entry in r_open(), r_start() r_show() proc: Supply an accessor for getting the data from a PDE's parent airo: Use remove_proc_subtree() rtl8192u: Don't need to save device proc dir PDE rtl8187se: Use a dir under /proc/net/r8180/ proc: Add proc_mkdir_data() proc: Move some bits from linux/proc_fs.h to linux/{of.h,signal.h,tty.h} proc: Move PDE_NET() to fs/proc/proc_net.c ...
| * lift sb_start_write() out of ->write()Al Viro2013-04-091-10/+14
| | | | | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * switch compat readv/writev variants to COMPAT_SYSCALL_DEFINEAl Viro2013-04-091-2/+195
| | | | | | | | | | | | ... and take to fs/read_write.c Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * lift sb_start_write/sb_end_write out of ->aio_write()Al Viro2013-04-091-2/+6
| | | | | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | Merge branch 'for-linus' of ↵Linus Torvalds2013-05-011-22/+46
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal Pull compat cleanup from Al Viro: "Mostly about syscall wrappers this time; there will be another pile with patches in the same general area from various people, but I'd rather push those after both that and vfs.git pile are in." * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal: syscalls.h: slightly reduce the jungles of macros get rid of union semop in sys_semctl(2) arguments make do_mremap() static sparc: no need to sign-extend in sync_file_range() wrapper ppc compat wrappers for add_key(2) and request_key(2) are pointless x86: trim sys_ia32.h x86: sys32_kill and sys32_mprotect are pointless get rid of compat_sys_semctl() and friends in case of ARCH_WANT_OLD_COMPAT_IPC merge compat sys_ipc instances consolidate compat lookup_dcookie() convert vmsplice to COMPAT_SYSCALL_DEFINE switch getrusage() to COMPAT_SYSCALL_DEFINE switch epoll_pwait to COMPAT_SYSCALL_DEFINE convert sendfile{,64} to COMPAT_SYSCALL_DEFINE switch signalfd{,4}() to COMPAT_SYSCALL_DEFINE make SYSCALL_DEFINE<n>-generated wrappers do asmlinkage_protect make HAVE_SYSCALL_WRAPPERS unconditional consolidate cond_syscall and SYSCALL_ALIAS declarations teach SYSCALL_DEFINE<n> how to deal with long long/unsigned long long get rid of duplicate logics in __SC_....[1-6] definitions
| * | convert sendfile{,64} to COMPAT_SYSCALL_DEFINEAl Viro2013-03-031-2/+42
| | | | | | | | | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | teach SYSCALL_DEFINE<n> how to deal with long long/unsigned long longAl Viro2013-03-031-20/+4
| | | | | | | | | | | | | | | | | | | | | ... and convert a bunch of SYSCALL_DEFINE ones to SYSCALL_DEFINE<n>, killing the boilerplate crap around them. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | | fs/read_write.c: fix generic_file_llseek() commentMing Lei2013-04-291-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit ef3d0fd27e90 ("vfs: do (nearly) lockless generic_file_llseek") has removed i_mutex from generic_file_llseek, so update the comment accordingly. Signed-off-by: Ming Lei <tom.leiming@gmail.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | vfs/splice: Fix missed checks in new __kernel_write() helperAl Viro2013-03-271-0/+3
| |/ |/| | | | | | | | | | | | | | | | | | | | | | | | | Commit 06ae43f34bcc ("Don't bother with redoing rw_verify_area() from default_file_splice_from()") lost the checks to test existence of the write/aio_write methods. My apologies ;-/ Eventually, we want that in fs/splice.c side of things (no point repeating it for every buffer, after all), but for now this is the obvious minimal fix. Reported-by: Dave Jones <davej@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | Don't bother with redoing rw_verify_area() from default_file_splice_from()Al Viro2013-03-211-0/+25
|/ | | | | | | | | | default_file_splice_from() ends up calling vfs_write() (via very convoluted callchain). It's an overkill, since we already have done rw_verify_area() in the caller by the time we call vfs_write() we are under set_fs(KERNEL_DS), so access_ok() is also pointless. Add a new helper (__kernel_write()), use it instead of kernel_write() in there. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* Merge branch 'for-linus' of ↵Linus Torvalds2013-03-021-1/+8
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal Pull signal/compat fixes from Al Viro: "Fixes for several regressions introduced in the last signal.git pile, along with fixing bugs in truncate and ftruncate compat (on just about anything biarch at least one of those two had been done wrong)." * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal: compat: restore timerfd settime and gettime compat syscalls [regression] braino in "sparc: convert to ksignal" fix compat truncate/ftruncate switch lseek to COMPAT_SYSCALL_DEFINE lseek() and truncate() on sparc really need sign extension
| * switch lseek to COMPAT_SYSCALL_DEFINEAl Viro2013-02-241-1/+8
| | | | | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | new helper: file_inode(file)Al Viro2013-02-221-4/+4
|/ | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* sendfile: allows bypassing of notifier eventsScott Wolchok2012-12-201-0/+2
| | | | | | | | | | | | | | | | | do_sendfile() in fs/read_write.c does not call the fsnotify functions, unlike its neighbors. This manifests as a lack of inotify ACCESS events when a file is sent using sendfile(2). Addresses https://bugzilla.kernel.org/show_bug.cgi?id=12812 [akpm@linux-foundation.org: use fsnotify_modify(out.file), not fsnotify_access(), per Dave] Signed-off-by: Alan Cox <alan@linux.intel.com> Cc: Dave Chinner <david@fromorbit.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Scott Wolchok <swolchok@umich.edu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* lseek: the "whence" argument is called "whence"Andrew Morton2012-12-171-20/+20
| | | | | | | | | But the kernel decided to call it "origin" instead. Fix most of the sites. Acked-by: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* compat: fs: Generic compat_sys_sendfile implementationCatalin Marinas2012-10-021-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | This function is used by sparc, powerpc and arm64 for compat support. The patch adds a generic implementation which calls do_sendfile() directly and avoids set_fs(). The sparc architecture has wrappers for the sign extensions while powerpc relies on the compiler to do the this. The patch adds wrappers for powerpc to handle the u32->int type conversion. compat_sys_sendfile64() can be replaced by a sys_sendfile() call since compat_loff_t has the same size as off_t on a 64-bit system. On powerpc, the patch also changes the 64-bit sendfile call from sys_sendile64 to sys_sendfile. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: David S. Miller <davem@davemloft.net> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* switch simple cases of fget_light to fdgetAl Viro2012-09-261-99/+77
| | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* vfs: allow custom EOF in generic_file_llseek codeEric Sandeen2012-07-231-8/+10
| | | | | | | | | | | | | | | | | | | | | | | | For ext3/4 htree directories, using the vfs llseek function with SEEK_END goes to i_size like for any other file, but in reality we want the maximum possible hash value. Recent changes in ext4 have cut & pasted generic_file_llseek() back into fs/ext4/dir.c, but replicating this core code seems like a bad idea, especially since the copy has already diverged from the vfs. This patch updates generic_file_llseek_size to accept both a custom maximum offset, and a custom EOF position. With this in place, ext4_dir_llseek can pass in the appropriate maximum hash position for both maxsize and eof, and get what it wants. As far as I know, this does not fix any bugs - nfs in the kernel doesn't use SEEK_END, and I don't know of any user who does. But some ext4 folks seem keen on doing the right thing here, and I can't really argue. (Patch also fixes up some comments slightly) Signed-off-by: Eric Sandeen <sandeen@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* aio/vfs: cleanup of rw_copy_check_uvector() and compat_rw_copy_check_uvector()Christopher Yeoh2012-05-311-4/+3
| | | | | | | | | | | | | | | | | | A cleanup of rw_copy_check_uvector and compat_rw_copy_check_uvector after changes made to support CMA in an earlier patch. Rather than having an additional check_access parameter to these functions, the first paramater type is overloaded to allow the caller to specify CHECK_IOVEC_ONLY which means check that the contents of the iovec are valid, but do not check the memory that they point to. This is used by process_vm_readv/writev where we need to validate that a iovec passed to the syscall is valid but do not want to check the memory that it points to at this point because it refers to an address space in another process. Signed-off-by: Chris Yeoh <yeohc@au1.ibm.com> Reviewed-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* fs: reduce the use of module.h wherever possiblePaul Gortmaker2012-02-281-1/+1
| | | | | | | | | | For files only using THIS_MODULE and/or EXPORT_SYMBOL, map them onto including export.h -- or if the file isn't even using those, then just delete the include. Fix up any implicit include dependencies that were being masked by module.h along the way. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
* Cross Memory AttachChristopher Yeoh2011-10-311-3/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The basic idea behind cross memory attach is to allow MPI programs doing intra-node communication to do a single copy of the message rather than a double copy of the message via shared memory. The following patch attempts to achieve this by allowing a destination process, given an address and size from a source process, to copy memory directly from the source process into its own address space via a system call. There is also a symmetrical ability to copy from the current process's address space into a destination process's address space. - Use of /proc/pid/mem has been considered, but there are issues with using it: - Does not allow for specifying iovecs for both src and dest, assuming preadv or pwritev was implemented either the area read from or written to would need to be contiguous. - Currently mem_read allows only processes who are currently ptrace'ing the target and are still able to ptrace the target to read from the target. This check could possibly be moved to the open call, but its not clear exactly what race this restriction is stopping (reason appears to have been lost) - Having to send the fd of /proc/self/mem via SCM_RIGHTS on unix domain socket is a bit ugly from a userspace point of view, especially when you may have hundreds if not (eventually) thousands of processes that all need to do this with each other - Doesn't allow for some future use of the interface we would like to consider adding in the future (see below) - Interestingly reading from /proc/pid/mem currently actually involves two copies! (But this could be fixed pretty easily) As mentioned previously use of vmsplice instead was considered, but has problems. Since you need the reader and writer working co-operatively if the pipe is not drained then you block. Which requires some wrapping to do non blocking on the send side or polling on the receive. In all to all communication it requires ordering otherwise you can deadlock. And in the example of many MPI tasks writing to one MPI task vmsplice serialises the copying. There are some cases of MPI collectives where even a single copy interface does not get us the performance gain we could. For example in an MPI_Reduce rather than copy the data from the source we would like to instead use it directly in a mathops (say the reduce is doing a sum) as this would save us doing a copy. We don't need to keep a copy of the data from the source. I haven't implemented this, but I think this interface could in the future do all this through the use of the flags - eg could specify the math operation and type and the kernel rather than just copying the data would apply the specified operation between the source and destination and store it in the destination. Although we don't have a "second user" of the interface (though I've had some nibbles from people who may be interested in using it for intra process messaging which is not MPI). This interface is something which hardware vendors are already doing for their custom drivers to implement fast local communication. And so in addition to this being useful for OpenMPI it would mean the driver maintainers don't have to fix things up when the mm changes. There was some discussion about how much faster a true zero copy would go. Here's a link back to the email with some testing I did on that: http://marc.info/?l=linux-mm&m=130105930902915&w=2 There is a basic man page for the proposed interface here: http://ozlabs.org/~cyeoh/cma/process_vm_readv.txt This has been implemented for x86 and powerpc, other architecture should mainly (I think) just need to add syscall numbers for the process_vm_readv and process_vm_writev. There are 32 bit compatibility versions for 64-bit kernels. For arch maintainers there are some simple tests to be able to quickly verify that the syscalls are working correctly here: http://ozlabs.org/~cyeoh/cma/cma-test-20110718.tgz Signed-off-by: Chris Yeoh <yeohc@au1.ibm.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: David Howells <dhowells@redhat.com> Cc: James Morris <jmorris@namei.org> Cc: <linux-man@vger.kernel.org> Cc: <linux-arch@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* vfs: add generic_file_llseek_sizeAndi Kleen2011-10-281-9/+28
| | | | | | | | | | | Add a generic_file_llseek variant to the VFS that allows passing in the maximum file size of the file system, instead of always using maxbytes from the superblock. This can be used to eliminate some cut'n'paste seek code in ext4. Signed-off-by: Andi Kleen <ak@linux.intel.com> Signed-off-by: Christoph Hellwig <hch@lst.de>
* vfs: do (nearly) lockless generic_file_llseekAndi Kleen2011-10-281-44/+41
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The i_mutex lock use of generic _file_llseek hurts. Independent processes accessing the same file synchronize over a single lock, even though they have no need for synchronization at all. Under high utilization this can cause llseek to scale very poorly on larger systems. This patch does some rethinking of the llseek locking model: First the 64bit f_pos is not necessarily atomic without locks on 32bit systems. This can already cause races with read() today. This was discussed on linux-kernel in the past and deemed acceptable. The patch does not change that. Let's look at the different seek variants: SEEK_SET: Doesn't really need any locking. If there's a race one writer wins, the other loses. For 32bit the non atomic update races against read() stay the same. Without a lock they can also happen against write() now. The read() race was deemed acceptable in past discussions, and I think if it's ok for read it's ok for write too. => Don't need a lock. SEEK_END: This behaves like SEEK_SET plus it reads the maximum size too. Reading the maximum size would have the 32bit atomic problem. But luckily we already have a way to read the maximum size without locking (i_size_read), so we can just use that instead. Without i_mutex there is no synchronization with write() anymore, however since the write() update is atomic on 64bit it just behaves like another racy SEEK_SET. On non atomic 32bit it's the same as SEEK_SET. => Don't need a lock, but need to use i_size_read() SEEK_CUR: This has a read-modify-write race window on the same file. One could argue that any application doing unsynchronized seeks on the same file is already broken. But for the sake of not adding a regression here I'm using the file->f_lock to synchronize this. Using this lock is much better than the inode mutex because it doesn't synchronize between processes. => So still need a lock, but can use a f_lock. This patch implements this new scheme in generic_file_llseek. I dropped generic_file_llseek_unlocked and changed all callers. Signed-off-by: Andi Kleen <ak@linux.intel.com> Signed-off-by: Christoph Hellwig <hch@lst.de>
* fs: add missing unlock in default_llseek()Dan Carpenter2011-07-261-4/+8
| | | | | | | | | A recent change in linux-next, 982d816581 "fs: add SEEK_HOLE and SEEK_DATA flags" added some direct returns on error, but it should have been a goto out. Signed-off-by: Dan Carpenter <error27@gmail.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* fs: add SEEK_HOLE and SEEK_DATA flagsJosef Bacik2011-07-201-3/+41
| | | | | | | | | | | | | | | | | | | | | | | | | | This just gets us ready to support the SEEK_HOLE and SEEK_DATA flags. Turns out using fiemap in things like cp cause more problems than it solves, so lets try and give userspace an interface that doesn't suck. We need to match solaris here, and the definitions are *o* If /whence/ is SEEK_HOLE, the offset of the start of the next hole greater than or equal to the supplied offset is returned. The definition of a hole is provided near the end of the DESCRIPTION. *o* If /whence/ is SEEK_DATA, the file pointer is set to the start of the next non-hole file region greater than or equal to the supplied offset. So in the generic case the entire file is data and there is a virtual hole at the end. That means we will just return i_size for SEEK_HOLE and will return the same offset for SEEK_DATA. This is how Solaris does it so we have to do it the same way. Thanks, Signed-off-by: Josef Bacik <josef@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* fix signedness mess in rw_verify_area() on 64bit architecturesAl Viro2011-01-121-16/+11
| | | | | | ... and clean the unsigned-f_pos code, while we are at it. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* BKL: remove extraneous #include <smp_lock.h>Arnd Bergmann2010-11-171-1/+0
| | | | | | | | | | The big kernel lock has been removed from all these files at some point, leaving only the #include. Remove this too as a cleanup. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* readv/writev: do the same MAX_RW_COUNT truncation that read/write doesLinus Torvalds2010-10-291-29/+33
| | | | | | | | | | We used to protect against overflow, but rather than return an error, do what read/write does, namely to limit the total size to MAX_RW_COUNT. This is not only more consistent, but it also means that any broken low-level read/write routine that still keeps counts in 'int' can't break. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* vfs: introduce FMODE_UNSIGNED_OFFSET for allowing negative f_posKAMEZAWA Hiroyuki2010-10-251-4/+24
| | | | | | | | | | | | | | | | | | Now, rw_verify_area() checsk f_pos is negative or not. And if negative, returns -EINVAL. But, some special files as /dev/(k)mem and /proc/<pid>/mem etc.. has negative offsets. And we can't do any access via read/write to the file(device). So introduce FMODE_UNSIGNED_OFFSET to allow negative file offsets. Signed-off-by: Wu Fengguang <fengguang.wu@intel.com> Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Al Viro <viro@ZenIV.linux.org.uk> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* vfs: make no_llseek the defaultArnd Bergmann2010-10-151-1/+0
| | | | | | | | | | | | | | | | | | | | All file operations now have an explicit .llseek operation pointer, so we can change the default action for future code. This makes changes the default from default_llseek to no_llseek, which always returns -ESPIPE if a user tries to seek on a file without a .llseek operation. The name of the default_llseek function remains unchanged, if anyone thinks we should change it, please speak up. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Cc: Christoph Hellwig <hch@infradead.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: linux-fsdevel@vger.kernel.org
* vfs: don't use BKL in default_llseekArnd Bergmann2010-10-151-2/+2
| | | | | | | | | | | | | | There are currently 191 users of default_llseek. Nine of these are in device drivers that use the big kernel lock. None of these ever touch file->f_pos outside of llseek or file_pos_write. Consequently, we never rely on the BKL in the default_llseek function and can replace that with i_mutex, which is also used in generic_file_llseek. Signed-off-by: Arnd Bergmann <arnd@arndb.de>
* fsnotify: pass a file instead of an inode to open, read, and writeEric Paris2010-07-281-4/+4
| | | | | | | | | | fanotify, the upcoming notification system actually needs a struct path so it can do opens in the context of listeners, and it needs a file so it can get f_flags from the original process. Close was the only operation that already was passing a struct file to the notification hook. This patch passes a file for access, modify, and open as well as they are easily available to these hooks. Signed-off-by: Eric Paris <eparis@redhat.com>
* vfs: introduce noop_llseek()jan Blunck2010-05-271-0/+17
| | | | | | | | | | | | | | This is an implementation of ->llseek useable for the rare special case when userspace expects the seek to succeed but the (device) file is actually not able to perform the seek. In this case you use noop_llseek() instead of falling back to the default implementation of ->llseek. Signed-off-by: Jan Blunck <jblunck@suse.de> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Christoph Hellwig <hch@lst.de> 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>
* do_sync_read/write() should set kiocb.ki_nbytes to be consistentDavid Howells2010-03-241-0/+2
| | | | | | | | do_sync_read/write() should set kiocb.ki_nbytes to be consistent with do_sync_readv_writev(). Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* sendfile(): check f_op.splice_write() rather than f_op.sendpage()Changli Gao2009-11-041-2/+0
| | | | | | | | | | | | sendfile(2) was reworked with the splice infrastructure, but it still checks f_op.sendpage() instead of f_op.splice_write() wrongly. Although if f_op.sendpage() exists, f_op.splice_write() always exists at the same time currently, the assumption will be broken in future silently. This patch also brings a side effect: sendfile(2) can work with any output file. Some security checks related to f_op are added too. Signed-off-by: Changli Gao <xiaosuo@gmail.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* vfs: remove redundant position check in do_sendfileJeff Layton2009-09-241-3/+0
| | | | | | | | | | | | | | As Johannes Weiner pointed out, one of the range checks in do_sendfile is redundant and is already checked in rw_verify_area. Signed-off-by: Jeff Layton <jlayton@redhat.com> Reviewed-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Christoph Hellwig <hch@lst.de> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Robert Love <rlove@google.com> Cc: Mandeep Singh Baines <msb@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* splice: implement default splice_read methodMiklos Szeredi2009-05-111-6/+1
| | | | | | | | | | | | If f_op->splice_read() is not implemented, fall back to a plain read. Use vfs_readv() to read into previously allocated pages. This will allow splice and functions using splice, such as the loop device, to work on all filesystems. This includes "direct_io" files in fuse which bypass the page cache. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* Make non-compat preadv/pwritev use native register sizeLinus Torvalds2009-04-041-4/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Instead of always splitting the file offset into 32-bit 'high' and 'low' parts, just split them into the largest natural word-size - which in C terms is 'unsigned long'. This allows 64-bit architectures to avoid the unnecessary 32-bit shifting and masking for native format (while the compat interfaces will obviously always have to do it). This also changes the order of 'high' and 'low' to be "low first". Why? Because when we have it like this, the 64-bit system calls now don't use the "pos_high" argument at all, and it makes more sense for the native system call to simply match the user-mode prototype. This results in a much more natural calling convention, and allows the compiler to generate much more straightforward code. On x86-64, we now generate testq %rcx, %rcx # pos_l js .L122 #, movq %rcx, -48(%rbp) # pos_l, pos from the C source loff_t pos = pos_from_hilo(pos_h, pos_l); ... if (pos < 0) return -EINVAL; and the 'pos_h' register isn't even touched. It used to generate code like mov %r8d, %r8d # pos_low, pos_low salq $32, %rcx #, tmp71 movq %r8, %rax # pos_low, pos.386 orq %rcx, %rax # tmp71, pos.386 js .L122 #, movq %rax, -48(%rbp) # pos.386, pos which isn't _that_ horrible, but it does show how the natural word size is just a more sensible interface (same arguments will hold in the user level glibc wrapper function, of course, so the kernel side is just half of the equation!) Note: in all cases the user code wrapper can again be the same. You can just do #define HALF_BITS (sizeof(unsigned long)*4) __syscall(PWRITEV, fd, iov, count, offset, (offset >> HALF_BITS) >> HALF_BITS); or something like that. That way the user mode wrapper will also be nicely passing in a zero (it won't actually have to do the shifts, the compiler will understand what is going on) for the last argument. And that is a good idea, even if nobody will necessarily ever care: if we ever do move to a 128-bit lloff_t, this particular system call might be left alone. Of course, that will be the least of our worries if we really ever need to care, so this may not be worth really caring about. [ Fixed for lost 'loff_t' cast noticed by Andrew Morton ] Acked-by: Gerd Hoffmann <kraxel@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: linux-api@vger.kernel.org Cc: linux-arch@vger.kernel.org Cc: Ingo Molnar <mingo@elte.hu> Cc: Ralf Baechle <ralf@linux-mips.org>> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* preadv/pwritev: Add preadv and pwritev system calls.Gerd Hoffmann2009-04-021-0/+50
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch adds preadv and pwritev system calls. These syscalls are a pretty straightforward combination of pread and readv (same for write). They are quite useful for doing vectored I/O in threaded applications. Using lseek+readv instead opens race windows you'll have to plug with locking. Other systems have such system calls too, for example NetBSD, check here: http://www.daemon-systems.org/man/preadv.2.html The application-visible interface provided by glibc should look like this to be compatible to the existing implementations in the *BSD family: ssize_t preadv(int d, const struct iovec *iov, int iovcnt, off_t offset); ssize_t pwritev(int d, const struct iovec *iov, int iovcnt, off_t offset); This prototype has one problem though: On 32bit archs is the (64bit) offset argument unaligned, which the syscall ABI of several archs doesn't allow to do. At least s390 needs a wrapper in glibc to handle this. As we'll need a wrappers in glibc anyway I've decided to push problem to glibc entriely and use a syscall prototype which works without arch-specific wrappers inside the kernel: The offset argument is explicitly splitted into two 32bit values. The patch sports the actual system call implementation and the windup in the x86 system call tables. Other archs follow as separate patches. Signed-off-by: Gerd Hoffmann <kraxel@redhat.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: <linux-api@vger.kernel.org> Cc: <linux-arch@vger.kernel.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* [CVE-2009-0029] System call wrappers part 20Heiko Carstens2009-01-141-6/+7
| | | | Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
* [CVE-2009-0029] System call wrappers part 19Heiko Carstens2009-01-141-4/+4
| | | | Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
* [CVE-2009-0029] System call wrappers part 16Heiko Carstens2009-01-141-2/+2
| | | | Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
* [CVE-2009-0029] System call wrapper special casesHeiko Carstens2009-01-141-4/+20
| | | | | | | | | | | | System calls with an unsigned long long argument can't be converted with the standard wrappers since that would include a cast to long, which in turn means that we would lose the upper 32 bit on 32 bit architectures. Also semctl can't use the standard wrapper since it has a 'union' parameter. So we handle them as special case and add some extra wrappers instead. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
* [CVE-2009-0029] Convert all system calls to return a longHeiko Carstens2009-01-141-9/+9
| | | | | | | | | Convert all system calls to return a long. This should be a NOP since all converted types should have the same size anyway. With the exception of sys_exit_group which returned void. But that doesn't matter since the system call doesn't return. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
* vfs: lseek(fd, 0, SEEK_CUR) race conditionAlain Knaff2009-01-051-0/+13
| | | | | | | | | | | | | | | | | | This patch fixes a race condition in lseek. While it is expected that unpredictable behaviour may result while repositioning the offset of a file descriptor concurrently with reading/writing to the same file descriptor, this should not happen when merely *reading* the file descriptor's offset. Unfortunately, the only portable way in Unix to read a file descriptor's offset is lseek(fd, 0, SEEK_CUR); however executing this concurrently with read/write may mess up the position. [with fixes from akpm] Signed-off-by: Alain Knaff <alain@knaff.lu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* [PATCH] generic_file_llseek tidyupsChristoph Hellwig2008-10-231-18/+40
| | | | | | | | Add kerneldoc for generic_file_llseek and generic_file_llseek_unlocked, use sane variable names and unclutter the code. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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