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2019-06-11fs: stream_open - opener for stream-like files so that read and write can ↵Kirill Smelkov
run simultaneously without deadlock commit 10dce8af34226d90fa56746a934f8da5dcdba3df upstream. Commit 9c225f2655e3 ("vfs: atomic f_pos accesses as per POSIX") added locking for file.f_pos access and in particular made concurrent read and write not possible - now both those functions take f_pos lock for the whole run, and so if e.g. a read is blocked waiting for data, write will deadlock waiting for that read to complete. This caused regression for stream-like files where previously read and write could run simultaneously, but after that patch could not do so anymore. See e.g. commit 581d21a2d02a ("xenbus: fix deadlock on writes to /proc/xen/xenbus") which fixes such regression for particular case of /proc/xen/xenbus. The patch that added f_pos lock in 2014 did so to guarantee POSIX thread safety for read/write/lseek and added the locking to file descriptors of all regular files. In 2014 that thread-safety problem was not new as it was already discussed earlier in 2006. However even though 2006'th version of Linus's patch was adding f_pos locking "only for files that are marked seekable with FMODE_LSEEK (thus avoiding the stream-like objects like pipes and sockets)", the 2014 version - the one that actually made it into the tree as 9c225f2655e3 - is doing so irregardless of whether a file is seekable or not. See https://lore.kernel.org/lkml/53022DB1.4070805@gmail.com/ https://lwn.net/Articles/180387 https://lwn.net/Articles/180396 for historic context. The reason that it did so is, probably, that there are many files that are marked non-seekable, but e.g. their read implementation actually depends on knowing current position to correctly handle the read. Some examples: kernel/power/user.c snapshot_read fs/debugfs/file.c u32_array_read fs/fuse/control.c fuse_conn_waiting_read + ... drivers/hwmon/asus_atk0110.c atk_debugfs_ggrp_read arch/s390/hypfs/inode.c hypfs_read_iter ... Despite that, many nonseekable_open users implement read and write with pure stream semantics - they don't depend on passed ppos at all. And for those cases where read could wait for something inside, it creates a situation similar to xenbus - the write could be never made to go until read is done, and read is waiting for some, potentially external, event, for potentially unbounded time -> deadlock. Besides xenbus, there are 14 such places in the kernel that I've found with semantic patch (see below): drivers/xen/evtchn.c:667:8-24: ERROR: evtchn_fops: .read() can deadlock .write() drivers/isdn/capi/capi.c:963:8-24: ERROR: capi_fops: .read() can deadlock .write() drivers/input/evdev.c:527:1-17: ERROR: evdev_fops: .read() can deadlock .write() drivers/char/pcmcia/cm4000_cs.c:1685:7-23: ERROR: cm4000_fops: .read() can deadlock .write() net/rfkill/core.c:1146:8-24: ERROR: rfkill_fops: .read() can deadlock .write() drivers/s390/char/fs3270.c:488:1-17: ERROR: fs3270_fops: .read() can deadlock .write() drivers/usb/misc/ldusb.c:310:1-17: ERROR: ld_usb_fops: .read() can deadlock .write() drivers/hid/uhid.c:635:1-17: ERROR: uhid_fops: .read() can deadlock .write() net/batman-adv/icmp_socket.c:80:1-17: ERROR: batadv_fops: .read() can deadlock .write() drivers/media/rc/lirc_dev.c:198:1-17: ERROR: lirc_fops: .read() can deadlock .write() drivers/leds/uleds.c:77:1-17: ERROR: uleds_fops: .read() can deadlock .write() drivers/input/misc/uinput.c:400:1-17: ERROR: uinput_fops: .read() can deadlock .write() drivers/infiniband/core/user_mad.c:985:7-23: ERROR: umad_fops: .read() can deadlock .write() drivers/gnss/core.c:45:1-17: ERROR: gnss_fops: .read() can deadlock .write() In addition to the cases above another regression caused by f_pos locking is that now FUSE filesystems that implement open with FOPEN_NONSEEKABLE flag, can no longer implement bidirectional stream-like files - for the same reason as above e.g. read can deadlock write locking on file.f_pos in the kernel. FUSE's FOPEN_NONSEEKABLE was added in 2008 in a7c1b990f715 ("fuse: implement nonseekable open") to support OSSPD. OSSPD implements /dev/dsp in userspace with FOPEN_NONSEEKABLE flag, with corresponding read and write routines not depending on current position at all, and with both read and write being potentially blocking operations: See https://github.com/libfuse/osspd https://lwn.net/Articles/308445 https://github.com/libfuse/osspd/blob/14a9cff0/osspd.c#L1406 https://github.com/libfuse/osspd/blob/14a9cff0/osspd.c#L1438-L1477 https://github.com/libfuse/osspd/blob/14a9cff0/osspd.c#L1479-L1510 Corresponding libfuse example/test also describes FOPEN_NONSEEKABLE as "somewhat pipe-like files ..." with read handler not using offset. However that test implements only read without write and cannot exercise the deadlock scenario: https://github.com/libfuse/libfuse/blob/fuse-3.4.2-3-ga1bff7d/example/poll.c#L124-L131 https://github.com/libfuse/libfuse/blob/fuse-3.4.2-3-ga1bff7d/example/poll.c#L146-L163 https://github.com/libfuse/libfuse/blob/fuse-3.4.2-3-ga1bff7d/example/poll.c#L209-L216 I've actually hit the read vs write deadlock for real while implementing my FUSE filesystem where there is /head/watch file, for which open creates separate bidirectional socket-like stream in between filesystem and its user with both read and write being later performed simultaneously. And there it is semantically not easy to split the stream into two separate read-only and write-only channels: https://lab.nexedi.com/kirr/wendelin.core/blob/f13aa600/wcfs/wcfs.go#L88-169 Let's fix this regression. The plan is: 1. We can't change nonseekable_open to include &~FMODE_ATOMIC_POS - doing so would break many in-kernel nonseekable_open users which actually use ppos in read/write handlers. 2. Add stream_open() to kernel to open stream-like non-seekable file descriptors. Read and write on such file descriptors would never use nor change ppos. And with that property on stream-like files read and write will be running without taking f_pos lock - i.e. read and write could be running simultaneously. 3. With semantic patch search and convert to stream_open all in-kernel nonseekable_open users for which read and write actually do not depend on ppos and where there is no other methods in file_operations which assume @offset access. 4. Add FOPEN_STREAM to fs/fuse/ and open in-kernel file-descriptors via steam_open if that bit is present in filesystem open reply. It was tempting to change fs/fuse/ open handler to use stream_open instead of nonseekable_open on just FOPEN_NONSEEKABLE flags, but grepping through Debian codesearch shows users of FOPEN_NONSEEKABLE, and in particular GVFS which actually uses offset in its read and write handlers https://codesearch.debian.net/search?q=-%3Enonseekable+%3D https://gitlab.gnome.org/GNOME/gvfs/blob/1.40.0-6-gcbc54396/client/gvfsfusedaemon.c#L1080 https://gitlab.gnome.org/GNOME/gvfs/blob/1.40.0-6-gcbc54396/client/gvfsfusedaemon.c#L1247-1346 https://gitlab.gnome.org/GNOME/gvfs/blob/1.40.0-6-gcbc54396/client/gvfsfusedaemon.c#L1399-1481 so if we would do such a change it will break a real user. 5. Add stream_open and FOPEN_STREAM handling to stable kernels starting from v3.14+ (the kernel where 9c225f2655 first appeared). This will allow to patch OSSPD and other FUSE filesystems that provide stream-like files to return FOPEN_STREAM | FOPEN_NONSEEKABLE in their open handler and this way avoid the deadlock on all kernel versions. This should work because fs/fuse/ ignores unknown open flags returned from a filesystem and so passing FOPEN_STREAM to a kernel that is not aware of this flag cannot hurt. In turn the kernel that is not aware of FOPEN_STREAM will be < v3.14 where just FOPEN_NONSEEKABLE is sufficient to implement streams without read vs write deadlock. This patch adds stream_open, converts /proc/xen/xenbus to it and adds semantic patch to automatically locate in-kernel places that are either required to be converted due to read vs write deadlock, or that are just safe to be converted because read and write do not use ppos and there are no other funky methods in file_operations. Regarding semantic patch I've verified each generated change manually - that it is correct to convert - and each other nonseekable_open instance left - that it is either not correct to convert there, or that it is not converted due to current stream_open.cocci limitations. The script also does not convert files that should be valid to convert, but that currently have .llseek = noop_llseek or generic_file_llseek for unknown reason despite file being opened with nonseekable_open (e.g. drivers/input/mousedev.c) Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Yongzhi Pan <panyongzhi@gmail.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: David Vrabel <david.vrabel@citrix.com> Cc: Juergen Gross <jgross@suse.com> Cc: Miklos Szeredi <miklos@szeredi.hu> Cc: Tejun Heo <tj@kernel.org> Cc: Kirill Tkhai <ktkhai@virtuozzo.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Christoph Hellwig <hch@lst.de> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Julia Lawall <Julia.Lawall@lip6.fr> Cc: Nikolaus Rath <Nikolaus@rath.org> Cc: Han-Wen Nienhuys <hanwen@google.com> Signed-off-by: Kirill Smelkov <kirr@nexedi.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-04-05vfs: fix preadv64v2 and pwritev64v2 compat syscalls with offset == -1Aurelien Jarno
[ Upstream commit cc4b1242d7e3b42eed73881fc749944146493e4f ] The preadv2 and pwritev2 syscalls are supposed to emulate the readv and writev syscalls when offset == -1. Therefore the compat code should check for offset before calling do_compat_preadv64 and do_compat_pwritev64. This is the case for the preadv2 and pwritev2 syscalls, but handling of offset == -1 is missing in their 64-bit equivalent. This patch fixes that, calling do_compat_readv and do_compat_writev when offset == -1. This fixes the following glibc tests on x32: - misc/tst-preadvwritev2 - misc/tst-preadvwritev64v2 Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: H.J. Lu <hjl.tools@gmail.com> Signed-off-by: Aurelien Jarno <aurelien@aurel32.net> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-02-06fs: add the fsnotify call to vfs_iter_writeJimmy Durand Wesolowski
A bug has been discovered when redirecting splice output to regular files on EXT4 and tmpfs. Other filesystems might be affected. This commit fixes the issue for stable series kernel, using one of the change introduced during the rewrite and refactoring of vfs_iter_write in 4.13, specifically in the commit abbb65899aec ("fs: implement vfs_iter_write using do_iter_write"). This issue affects v4.4 and v4.9 stable series of kernels. Without this fix for v4.4 and v4.9 stable, the following upstream commits (and their dependencies would need to be backported): * commit abbb65899aec ("fs: implement vfs_iter_write using do_iter_write") * commit 18e9710ee59c ("fs: implement vfs_iter_read using do_iter_read") * commit edab5fe38c2c ("fs: move more code into do_iter_read/do_iter_write") * commit 19c735868dd0 ("fs: remove __do_readv_writev") * commit 26c87fb7d10d ("fs: remove do_compat_readv_writev") * commit 251b42a1dc64 ("fs: remove do_readv_writev") as well as the following dependencies: * commit bb7462b6fd64 ("vfs: use helpers for calling f_op->{read,write}_iter()") * commit 0f78d06ac1e9 ("vfs: pass type instead of fn to do_{loop,iter}_readv_writev()") * commit 7687a7a4435f ("vfs: extract common parts of {compat_,}do_readv_writev()") In order to reduce the changes, this commit uses only the part of commit abbb65899aec ("fs: implement vfs_iter_write using do_iter_write") that fixes the issue. This issue and the reproducer can be found on https://bugzilla.kernel.org/show_bug.cgi?id=85381 Reported-by: Richard Li <richardpku@gmail.com> Reported-by: Chad Miller <millchad@amazon.com> Reviewed-by: Stefan Nuernberger <snu@amazon.de> Reviewed-by: Frank Becker <becke@amazon.de> Signed-off-by: Jimmy Durand Wesolowski <jdw@amazon.de>
2017-10-12vfs: deny copy_file_range() for non regular filesAmir Goldstein
commit 11cbfb10775aa2a01cee966d118049ede9d0bdf2 upstream. There is no in-tree file system that implements copy_file_range() for non regular files. Deny an attempt to copy_file_range() a directory with EISDIR and any other non regualr file with EINVAL to conform with behavior of vfs_{clone,dedup}_file_range(). This change is needed prior to converting sb_start_write() to file_start_write() in the vfs helper. Cc: linux-api@vger.kernel.org Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Amir Goldstein <amir73il@gmail.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Cc: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-10-05vfs: Return -ENXIO for negative SEEK_HOLE / SEEK_DATA offsetsAndreas Gruenbacher
commit fc46820b27a2d9a46f7e90c9ceb4a64a1bc5fab8 upstream. In generic_file_llseek_size, return -ENXIO for negative offsets as well as offsets beyond EOF. This affects filesystems which don't implement SEEK_HOLE / SEEK_DATA internally, possibly because they don't support holes. Fixes xfstest generic/448. Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-24fs: pass on flags in compat_writevChristoph Hellwig
commit 20223f0f39ea9d31ece08f04ac79f8c4e8d98246 upstream. Fixes: 793b80ef14af ("vfs: pass a flags argument to vfs_readv/vfs_writev") Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-10-14iov_iter: kernel-doc import_iovec() and rw_copy_check_uvector()Vegard Nossum
Both import_iovec() and rw_copy_check_uvector() take an array (typically small and on-stack) which is used to hold an iovec array copy from userspace. This is to avoid an expensive memory allocation in the fast path (i.e. few iovec elements). The caller may have to check whether these functions actually used the provided buffer or allocated a new one -- but this differs between the too. Let's just add a kernel doc to clarify what the semantics are for each function. Signed-off-by: Vegard Nossum <vegard.nossum@oracle.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-07-15x86/syscalls: Add compat_sys_preadv64v2/compat_sys_pwritev64v2H.J. Lu
Don't use the same syscall numbers for 2 different syscalls: 534 x32 preadv compat_sys_preadv64 535 x32 pwritev compat_sys_pwritev64 534 x32 preadv2 compat_sys_preadv2 535 x32 pwritev2 compat_sys_pwritev2 Add compat_sys_preadv64v2() and compat_sys_pwritev64v2() so that 64-bit offset is passed in one 64-bit register on x32, similar to compat_sys_preadv64() and compat_sys_pwritev64(). Signed-off-by: H.J. Lu <hjl.tools@gmail.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/CAMe9rOovCMf-RQfx_n1U_Tu_DX1BYkjtFr%3DQ4-_PFVSj9BCzUA@mail.gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-05-18Merge branch 'work.iov_iter' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull iov_iter cleanups from Al Viro. * 'work.iov_iter' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: fold checks into iterate_and_advance() rw_verify_area(): saner calling conventions aio: remove a pointless assignment
2016-05-17Merge branch 'work.preadv2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull vfs cleanups from Al Viro: "More cleanups from Christoph" * 'work.preadv2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: nfsd: use RWF_SYNC fs: add RWF_DSYNC aand RWF_SYNC ceph: use generic_write_sync fs: simplify the generic_write_sync prototype fs: add IOCB_SYNC and IOCB_DSYNC direct-io: remove the offset argument to dio_complete direct-io: eliminate the offset argument to ->direct_IO xfs: eliminate the pos variable in xfs_file_dio_aio_write filemap: remove the pos argument to generic_file_direct_write filemap: remove pos variables in generic_file_read_iter
2016-05-02give readdir(2)/getdents(2)/etc. uniform exclusion with lseek()Al Viro
same as read() on regular files has, and for the same reason. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-05-01fs: add RWF_DSYNC aand RWF_SYNCChristoph Hellwig
This is the per-I/O equivalent of O_DSYNC and O_SYNC, and very useful for all kinds of file servers and storage targets. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-04-03rw_verify_area(): saner calling conventionsAl Viro
Lift length capping into the few callers that care about it. Most of them treat all non-negatives as "success" and ignore the capped value, and with good reasons. Make rw_verify_area() return 0 on success. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-03-18Merge branches 'work.lookups', 'work.misc' and 'work.preadv2' into for-nextAl Viro
2016-03-04vfs: add the RWF_HIPRI flag for preadv2/pwritev2Christoph Hellwig
This adds a flag that tells the file system that this is a high priority request for which it's worth to poll the hardware. The flag is purely advisory and can be ignored if not supported. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Stephen Bates <stephen.bates@pmcs.com> Tested-by: Stephen Bates <stephen.bates@pmcs.com> Acked-by: Jeff Moyer <jmoyer@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-03-04vfs: vfs: Define new syscalls preadv2,pwritev2Milosz Tanski
New syscalls that take an flag argument. No flags are added yet in this patch. Signed-off-by: Milosz Tanski <milosz@adfin.com> [hch: rebased on top of my kiocb changes] Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Stephen Bates <stephen.bates@pmcs.com> Tested-by: Stephen Bates <stephen.bates@pmcs.com> Acked-by: Jeff Moyer <jmoyer@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-03-04vfs: pass a flags argument to vfs_readv/vfs_writevChristoph Hellwig
This way we can set kiocb flags also from the sync read/write path for the read_iter/write_iter operations. For now there is no way to pass flags to plain read/write operations as there is no real need for that, and all flags passed are explicitly rejected for these files. Signed-off-by: Milosz Tanski <milosz@adfin.com> [hch: rebased on top of my kiocb changes] Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Stephen Bates <stephen.bates@pmcs.com> Tested-by: Stephen Bates <stephen.bates@pmcs.com> Acked-by: Jeff Moyer <jmoyer@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-02-27fs: return -EOPNOTSUPP if clone is not supportedChristoph Hellwig
-EBADF is a rather confusing error if an operations is not supported, and nfsd gets rather upset about it. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-02-20fs: allow no_seek_end_llseek to actually seekWouter van Kesteren
The user-visible impact of the issue is for example that without this patch sensors-detect breaks when trying to seek in /dev/cpu/0/cpuid. '~0ULL' is a 'unsigned long long' that when converted to a loff_t, which is signed, gets turned into -1. later in vfs_setpos we have 'if (offset > maxsize)', which makes it always return EINVAL. Fixes: b25472f9b961 ("new helpers: no_seek_end_llseek{,_size}()") Signed-off-by: Wouter van Kesteren <woutershep@gmail.com> Reviewed-by: Andreas Dilger <adilger@dilger.ca> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-01-22vfs: abort dedupe loop if fatal signals are pendingDarrick J. Wong
If the program running dedupe receives a fatal signal during the dedupe loop, we should bail out to avoid tying up the system. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-01-22wrappers for ->i_mutex accessAl Viro
parallel to mutex_{lock,unlock,trylock,is_locked,lock_nested}, inode_foo(inode) being mutex_foo(&inode->i_mutex). Please, use those for access to ->i_mutex; over the coming cycle ->i_mutex will become rwsem, with ->lookup() done with it held only shared. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-01-12Merge branch 'work.misc' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull misc vfs updates from Al Viro: "All kinds of stuff. That probably should've been 5 or 6 separate branches, but by the time I'd realized how large and mixed that bag had become it had been too close to -final to play with rebasing. Some fs/namei.c cleanups there, memdup_user_nul() introduction and switching open-coded instances, burying long-dead code, whack-a-mole of various kinds, several new helpers for ->llseek(), assorted cleanups and fixes from various people, etc. One piece probably deserves special mention - Neil's lookup_one_len_unlocked(). Similar to lookup_one_len(), but gets called without ->i_mutex and tries to avoid ever taking it. That, of course, means that it's not useful for any directory modifications, but things like getting inode attributes in nfds readdirplus are fine with that. I really should've asked for moratorium on lookup-related changes this cycle, but since I hadn't done that early enough... I *am* asking for that for the coming cycle, though - I'm going to try and get conversion of i_mutex to rwsem with ->lookup() done under lock taken shared. There will be a patch closer to the end of the window, along the lines of the one Linus had posted last May - mechanical conversion of ->i_mutex accesses to inode_lock()/inode_unlock()/inode_trylock()/ inode_is_locked()/inode_lock_nested(). To quote Linus back then: ----- | This is an automated patch using | | sed 's/mutex_lock(&\(.*\)->i_mutex)/inode_lock(\1)/' | sed 's/mutex_unlock(&\(.*\)->i_mutex)/inode_unlock(\1)/' | sed 's/mutex_lock_nested(&\(.*\)->i_mutex,[ ]*I_MUTEX_\([A-Z0-9_]*\))/inode_lock_nested(\1, I_MUTEX_\2)/' | sed 's/mutex_is_locked(&\(.*\)->i_mutex)/inode_is_locked(\1)/' | sed 's/mutex_trylock(&\(.*\)->i_mutex)/inode_trylock(\1)/' | | with a very few manual fixups ----- I'm going to send that once the ->i_mutex-affecting stuff in -next gets mostly merged (or when Linus says he's about to stop taking merges)" * 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (63 commits) nfsd: don't hold i_mutex over userspace upcalls fs:affs:Replace time_t with time64_t fs/9p: use fscache mutex rather than spinlock proc: add a reschedule point in proc_readfd_common() logfs: constify logfs_block_ops structures fcntl: allow to set O_DIRECT flag on pipe fs: __generic_file_splice_read retry lookup on AOP_TRUNCATED_PAGE fs: xattr: Use kvfree() [s390] page_to_phys() always returns a multiple of PAGE_SIZE nbd: use ->compat_ioctl() fs: use block_device name vsprintf helper lib/vsprintf: add %*pg format specifier fs: use gendisk->disk_name where possible poll: plug an unused argument to do_poll amdkfd: don't open-code memdup_user() cdrom: don't open-code memdup_user() rsxx: don't open-code memdup_user() mtip32xx: don't open-code memdup_user() [um] mconsole: don't open-code memdup_user_nul() [um] hostaudio: don't open-code memdup_user() ...
2016-01-01vfs: hoist the btrfs deduplication ioctl to the vfsDarrick J. Wong
Hoist the btrfs EXTENT_SAME ioctl up to the VFS and make the name more systematic (FIDEDUPERANGE). Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-01-01vfs: wire up compat ioctl for CLONE/CLONE_RANGEDarrick J. Wong
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-12-23new helpers: no_seek_end_llseek{,_size}()Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-12-07vfs: pull btrfs clone API to vfs layerChristoph Hellwig
The btrfs clone ioctls are now adopted by other file systems, with NFS and CIFS already having support for them, and XFS being under active development. To avoid growth of various slightly incompatible implementations, add one to the VFS. Note that clones are different from file copies in several ways: - they are atomic vs other writers - they support whole file clones - they support 64-bit legth clones - they do not allow partial success (aka short writes) - clones are expected to be a fast metadata operation Because of that it would be rather cumbersome to try to piggyback them on top of the recent clone_file_range infrastructure. The converse isn't true and the clone_file_range system call could try clone file range as a first attempt to copy, something that further patches will enable. Based on earlier work from Peng Tao. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-12-07locks: new locks_mandatory_area calling conventionChristoph Hellwig
Pass a loff_t end for the last byte instead of the 32-bit count parameter to allow full file clones even on 32-bit architectures. While we're at it also simplify the read/write selection. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: J. Bruce Fields <bfields@fieldses.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-12-01vfs: Add vfs_copy_file_range() support for pagecache copiesAnna Schumaker
This allows us to have an in-kernel copy mechanism that avoids frequent switches between kernel and user space. This is especially useful so NFSD can support server-side copies. The default (flags=0) means to first attempt copy acceleration, but use the pagecache if that fails. Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Padraig Brady <P@draigBrady.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-12-01vfs: add copy_file_range syscall and vfs helperZach Brown
Add a copy_file_range() system call for offloading copies between regular files. This gives an interface to underlying layers of the storage stack which can copy without reading and writing all the data. There are a few candidates that should support copy offloading in the nearer term: - btrfs shares extent references with its clone ioctl - NFS has patches to add a COPY command which copies on the server - SCSI has a family of XCOPY commands which copy in the device This system call avoids the complexity of also accelerating the creation of the destination file by operating on an existing destination file descriptor, not a path. Currently the high level vfs entry point limits copy offloading to files on the same mount and super (and not in the same file). This can be relaxed if we get implementations which can copy between file systems safely. Signed-off-by: Zach Brown <zab@redhat.com> [Anna Schumaker: Change -EINVAL to -EBADF during file verification, Change flags parameter from int to unsigned int, Add function to include/linux/syscalls.h, Check copy len after file open mode, Don't forbid ranges inside the same file, Use rw_verify_area() to veriy ranges, Use file_out rather than file_in, Add COPY_FR_REFLINK flag] Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-04-11new_sync_write(): discard ->ki_pos unless the return value is positiveAl Viro
That allows ->write_iter() instances much more convenient life wrt iocb->ki_pos (and fixes several filesystems with borderline POSIX violations when zero-length write succeeds and changes the current position). Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-04-11->aio_read and ->aio_write removedAl Viro
no remaining users Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-04-11kill do_sync_read/do_sync_writeAl Viro
all remaining instances of aio_{read,write} (all 4 of them) have explicit ->read and ->write resp.; do_sync_read/do_sync_write is never called by __vfs_read/__vfs_write anymore and no other users had been left. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-04-11make new_sync_{read,write}() staticAl Viro
All places outside of core VFS that checked ->read and ->write for being NULL or called the methods directly are gone now, so NULL {read,write} with non-NULL {read,write}_iter will do the right thing in all cases. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-04-11export __vfs_read()Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-04-11new helper: __vfs_write()Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-04-11switch {compat_,}do_readv_writev() to {compat_,}import_iovec()Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-04-11lift iov_iter into {compat_,}do_readv_writev()Al Viro
get it closer to matching {compat_,}rw_copy_check_uvector(). Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-03-25fs: move struct kiocb to fs.hChristoph Hellwig
struct kiocb now is a generic I/O container, so move it to fs.h. Also do a #include diet for aio.h while we're at it. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-03-13fs: don't allow to complete sync iocbs through aio_completeChristoph Hellwig
The AIO interface is fairly complex because it tries to allow filesystems to always work async and then wakeup a synchronous caller through aio_complete. It turns out that basically no one was doing this to avoid the complexity and context switches, and we've already fixed up the remaining users and can now get rid of this case. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-03-12fs: remove ki_nbytesChristoph Hellwig
There is no need to pass the total request length in the kiocb, as we already get passed in through the iov_iter argument. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-02-17Merge branch 'iov_iter' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull iov_iter updates from Al Viro: "More iov_iter work - missing counterpart of iov_iter_init() for bvec-backed ones and vfs_read_iter()/vfs_write_iter() - wrappers for sync calls of ->read_iter()/->write_iter()" * 'iov_iter' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: fs: add vfs_iter_{read,write} helpers new helper: iov_iter_bvec()
2015-01-29fs: add vfs_iter_{read,write} helpersChristoph Hellwig
Simple helpers that pass an arbitrary iov_iter to filesystems. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-01-16locks: convert posix locks to file_lock_contextJeff Layton
Signed-off-by: Jeff Layton <jlayton@primarydata.com> Acked-by: Christoph Hellwig <hch@lst.de>
2014-12-14Merge branch 'next' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security Pull security layer updates from James Morris: "In terms of changes, there's general maintenance to the Smack, SELinux, and integrity code. The IMA code adds a new kconfig option, IMA_APPRAISE_SIGNED_INIT, which allows IMA appraisal to require signatures. Support for reading keys from rootfs before init is call is also added" * 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (23 commits) selinux: Remove security_ops extern security: smack: fix out-of-bounds access in smk_parse_smack() VFS: refactor vfs_read() ima: require signature based appraisal integrity: provide a hook to load keys when rootfs is ready ima: load x509 certificate from the kernel integrity: provide a function to load x509 certificate from the kernel integrity: define a new function integrity_read_file() Security: smack: replace kzalloc with kmem_cache for inode_smack Smack: Lock mode for the floor and hat labels ima: added support for new kernel cmdline parameter ima_template_fmt ima: allocate field pointers array on demand in template_desc_init_fields() ima: don't allocate a copy of template_fmt in template_desc_init_fields() ima: display template format in meas. list if template name length is zero ima: added error messages to template-related functions ima: use atomic bit operations to protect policy update interface ima: ignore empty and with whitespaces policy lines ima: no need to allocate entry for comment ima: report policy load status ima: use path names cache ...
2014-11-17VFS: refactor vfs_read()Dmitry Kasatkin
integrity_kernel_read() duplicates the file read operations code in vfs_read(). This patch refactors vfs_read() code creating a helper function __vfs_read(). It is used by both vfs_read() and integrity_kernel_read(). Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-10-09cachefiles_write_page(): switch to __kernel_write()Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-05-06switch simple generic_file_aio_read() users to ->read_iter()Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-05-06new methods: ->read_iter() and ->write_iter()Al Viro
Beginning to introduce those. Just the callers for now, and it's clumsier than it'll eventually become; once we finish converting aio_read and aio_write instances, the things will get nicer. For now, these guys are in parallel to ->aio_read() and ->aio_write(); they take iocb and iov_iter, with everything in iov_iter already validated. File offset is passed in iocb->ki_pos, iov/nr_segs - in iov_iter. Main concerns in that series are stack footprint and ability to split the damn thing cleanly. [fix from Peter Ujfalusi <peter.ujfalusi@ti.com> folded] Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-05-06replace checking for ->read/->aio_read presence with check in ->f_modeAl Viro
Since we are about to introduce new methods (read_iter/write_iter), the tests in a bunch of places would have to grow inconveniently. Check once (at open() time) and store results in ->f_mode as FMODE_CAN_READ and FMODE_CAN_WRITE resp. It might end up being a temporary measure - once everything switches from ->aio_{read,write} to ->{read,write}_iter it might make sense to return to open-coded checks. We'll see... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-03-31Merge branch 'compat' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux Pull s390 compat wrapper rework from Heiko Carstens: "S390 compat system call wrapper simplification work. The intention of this work is to get rid of all hand written assembly compat system call wrappers on s390, which perform proper sign or zero extension, or pointer conversion of compat system call parameters. Instead all of this should be done with C code eg by using Al's COMPAT_SYSCALL_DEFINEx() macro. Therefore all common code and s390 specific compat system calls have been converted to the COMPAT_SYSCALL_DEFINEx() macro. In order to generate correct code all compat system calls may only have eg compat_ulong_t parameters, but no unsigned long parameters. Those patches which change parameter types from unsigned long to compat_ulong_t parameters are separate in this series, but shouldn't cause any harm. The only compat system calls which intentionally have 64 bit parameters (preadv64 and pwritev64) in support of the x86/32 ABI haven't been changed, but are now only available if an architecture defines __ARCH_WANT_COMPAT_SYS_PREADV64/PWRITEV64. System calls which do not have a compat variant but still need proper zero extension on s390, like eg "long sys_brk(unsigned long brk)" will get a proper wrapper function with the new s390 specific COMPAT_SYSCALL_WRAPx() macro: COMPAT_SYSCALL_WRAP1(brk, unsigned long, brk); which generates the following code (simplified): asmlinkage long sys_brk(unsigned long brk); asmlinkage long compat_sys_brk(long brk) { return sys_brk((u32)brk); } Given that the C file which contains all the COMPAT_SYSCALL_WRAP lines includes both linux/syscall.h and linux/compat.h, it will generate build errors, if the declaration of sys_brk() doesn't match, or if there exists a non-matching compat_sys_brk() declaration. In addition this will intentionally result in a link error if somewhere else a compat_sys_brk() function exists, which probably should have been used instead. Two more BUILD_BUG_ONs make sure the size and type of each compat syscall parameter can be handled correctly with the s390 specific macros. I converted the compat system calls step by step to verify the generated code is correct and matches the previous code. In fact it did not always match, however that was always a bug in the hand written asm code. In result we get less code, less bugs, and much more sanity checking" * 'compat' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (44 commits) s390/compat: add copyright statement compat: include linux/unistd.h within linux/compat.h s390/compat: get rid of compat wrapper assembly code s390/compat: build error for large compat syscall args mm/compat: convert to COMPAT_SYSCALL_DEFINE with changing parameter types kexec/compat: convert to COMPAT_SYSCALL_DEFINE with changing parameter types net/compat: convert to COMPAT_SYSCALL_DEFINE with changing parameter types ipc/compat: convert to COMPAT_SYSCALL_DEFINE with changing parameter types fs/compat: convert to COMPAT_SYSCALL_DEFINE with changing parameter types ipc/compat: convert to COMPAT_SYSCALL_DEFINE fs/compat: convert to COMPAT_SYSCALL_DEFINE security/compat: convert to COMPAT_SYSCALL_DEFINE mm/compat: convert to COMPAT_SYSCALL_DEFINE net/compat: convert to COMPAT_SYSCALL_DEFINE kernel/compat: convert to COMPAT_SYSCALL_DEFINE fs/compat: optional preadv64/pwrite64 compat system calls ipc/compat_sys_msgrcv: change msgtyp type from long to compat_long_t s390/compat: partial parameter conversion within syscall wrappers s390/compat: automatic zero, sign and pointer conversion of syscalls s390/compat: add sync_file_range and fallocate compat syscalls ...
generated by cgit v1.2.3 (git 2.0.4) at 2024-05-26 03:49:24 +0000