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path: root/fs/pipe.c
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2011-01-20Fix broken "pipe: use event aware wakeups" optimizationLinus Torvalds
Commit e462c448fdc8 ("pipe: use event aware wakeups") optimized the pipe event wakeup calls to avoid wakeups if the events do not match the requested set. However, the optimization was buggy, in that it didn't actually use the correct sets for the events: when we make room for more data to be written, the pipe poll() routine will return both the POLLOUT _and_ POLLWRNORM bits. Similarly for read. And most critically, when a pipe is released, that will potentially result in POLLHUP|POLLERR (depending on whether it was the last reader or writer), not just the regular POLLIN|POLLOUT. This bug showed itself as a hung gnome-screensaver-dialog process, stuck forever (or at least until it was poked by a signal or by being traced) in a poll() system call. Cc: Davide Libenzi <davidel@xmailserver.org> Cc: David S. Miller <davem@davemloft.net> Cc: Eric Dumazet <eric.dumazet@gmail.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-16sanitize vfsmount refcounting changesAl Viro
Instead of splitting refcount between (per-cpu) mnt_count and (SMP-only) mnt_longrefs, make all references contribute to mnt_count again and keep track of how many are longterm ones. Accounting rules for longterm count: * 1 for each fs_struct.root.mnt * 1 for each fs_struct.pwd.mnt * 1 for having non-NULL ->mnt_ns * decrement to 0 happens only under vfsmount lock exclusive That allows nice common case for mntput() - since we can't drop the final reference until after mnt_longterm has reached 0 due to the rules above, mntput() can grab vfsmount lock shared and check mnt_longterm. If it turns out to be non-zero (which is the common case), we know that this is not the final mntput() and can just blindly decrement percpu mnt_count. Otherwise we grab vfsmount lock exclusive and do usual decrement-and-check of percpu mnt_count. For fs_struct.c we have mnt_make_longterm() and mnt_make_shortterm(); namespace.c uses the latter in places where we don't already hold vfsmount lock exclusive and opencodes a few remaining spots where we need to manipulate mnt_longterm. Note that we mostly revert the code outside of fs/namespace.c back to what we used to have; in particular, normal code doesn't need to care about two kinds of references, etc. And we get to keep the optimization Nick's variant had bought us... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-01-13Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6 * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6: (41 commits) fs: add documentation on fallocate hole punching Gfs2: fail if we try to use hole punch Btrfs: fail if we try to use hole punch Ext4: fail if we try to use hole punch Ocfs2: handle hole punching via fallocate properly XFS: handle hole punching via fallocate properly fs: add hole punching to fallocate vfs: pass struct file to do_truncate on O_TRUNC opens (try #2) fix signedness mess in rw_verify_area() on 64bit architectures fs: fix kernel-doc for dcache::prepend_path fs: fix kernel-doc for dcache::d_validate sanitize ecryptfs ->mount() switch afs move internal-only parts of ncpfs headers to fs/ncpfs switch ncpfs switch 9p pass default dentry_operations to mount_pseudo() switch hostfs switch affs switch configfs ...
2011-01-13pipe: use event aware wakeupsDavide Libenzi
Send the events the wakeup refers to, so that epoll, and even the new poll code in fs/select.c can avoid wakeups if the events do not match the requested set. Signed-off-by: Davide Libenzi <davidel@xmailserver.org> Acked-by: David S. Miller <davem@davemloft.net> Acked-by: Eric Dumazet <eric.dumazet@gmail.com> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-12pass default dentry_operations to mount_pseudo()Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-01-07fs: scale mntget/mntputNick Piggin
The problem that this patch aims to fix is vfsmount refcounting scalability. We need to take a reference on the vfsmount for every successful path lookup, which often go to the same mount point. The fundamental difficulty is that a "simple" reference count can never be made scalable, because any time a reference is dropped, we must check whether that was the last reference. To do that requires communication with all other CPUs that may have taken a reference count. We can make refcounts more scalable in a couple of ways, involving keeping distributed counters, and checking for the global-zero condition less frequently. - check the global sum once every interval (this will delay zero detection for some interval, so it's probably a showstopper for vfsmounts). - keep a local count and only taking the global sum when local reaches 0 (this is difficult for vfsmounts, because we can't hold preempt off for the life of a reference, so a counter would need to be per-thread or tied strongly to a particular CPU which requires more locking). - keep a local difference of increments and decrements, which allows us to sum the total difference and hence find the refcount when summing all CPUs. Then, keep a single integer "long" refcount for slow and long lasting references, and only take the global sum of local counters when the long refcount is 0. This last scheme is what I implemented here. Attached mounts and process root and working directory references are "long" references, and everything else is a short reference. This allows scalable vfsmount references during path walking over mounted subtrees and unattached (lazy umounted) mounts with processes still running in them. This results in one fewer atomic op in the fastpath: mntget is now just a per-CPU inc, rather than an atomic inc; and mntput just requires a spinlock and non-atomic decrement in the common case. However code is otherwise bigger and heavier, so single threaded performance is basically a wash. Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07fs: improve scalability of pseudo filesystemsNick Piggin
Regardless of how much we possibly try to scale dcache, there is likely always going to be some fundamental contention when adding or removing children under the same parent. Pseudo filesystems do not seem need to have connected dentries because by definition they are disconnected. Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07fs: dcache reduce branches in lookup pathNick Piggin
Reduce some branches and memory accesses in dcache lookup by adding dentry flags to indicate common d_ops are set, rather than having to check them. This saves a pointer memory access (dentry->d_op) in common path lookup situations, and saves another pointer load and branch in cases where we have d_op but not the particular operation. Patched with: git grep -E '[.>]([[:space:]])*d_op([[:space:]])*=' | xargs sed -e 's/\([^\t ]*\)->d_op = \(.*\);/d_set_d_op(\1, \2);/' -e 's/\([^\t ]*\)\.d_op = \(.*\);/d_set_d_op(\&\1, \2);/' -i Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07fs: avoid inode RCU freeing for pseudo fsNick Piggin
Pseudo filesystems that don't put inode on RCU list or reachable by rcu-walk dentries do not need to RCU free their inodes. Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2010-11-28Un-inline get_pipe_info() helper functionLinus Torvalds
This avoids some include-file hell, and the function isn't really important enough to be inlined anyway. Reported-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-11-28Export 'get_pipe_info()' to other usersLinus Torvalds
And in particular, use it in 'pipe_fcntl()'. The other pipe functions do not need to use the 'careful' version, since they are only ever called for things that are already known to be pipes. The normal read/write/ioctl functions are called through the file operations structures, so if a file isn't a pipe, they'd never get called. But pipe_fcntl() is special, and called directly from the generic fcntl code, and needs to use the same careful function that the splice code is using. Cc: Jens Axboe <jaxboe@fusionio.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Dave Jones <davej@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-29convert get_sb_pseudo() usersAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-10-25fs: do not assign default i_ino in new_inodeChristoph Hellwig
Instead of always assigning an increasing inode number in new_inode move the call to assign it into those callers that actually need it. For now callers that need it is estimated conservatively, that is the call is added to all filesystems that do not assign an i_ino by themselves. For a few more filesystems we can avoid assigning any inode number given that they aren't user visible, and for others it could be done lazily when an inode number is actually needed, but that's left for later patches. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-10-21pipe: fix failure to return error code on ->confirm()Nicolas Kaiser
The arguments were transposed, we want to assign the error code to 'ret', which is being returned. Signed-off-by: Nicolas Kaiser <nikai@nikai.net> Cc: stable@kernel.org Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-06-10pipe: fix check in "set size" fcntlMiklos Szeredi
As it stands this check compares the number of pages to the page size. This makes no sense and makes the fcntl fail in almost any sane case. Fix it by checking if nr_pages is not zero (it can become zero only if arg is too big and round_pipe_size() overflows). Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-06-10pipe: fix pipe buffer resizingMiklos Szeredi
pipe_set_size() needs to copy pipe bufs from the old circular buffer to the new. The current code gets this wrong in multiple ways, resulting in oops. Test program is available here: http://www.kernel.org/pub/linux/kernel/people/mszeredi/piperesize/ Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-06-03pipe: change /proc/sys/fs/pipe-max-pages to byte sized interfaceJens Axboe
This changes the interface to be based on bytes instead. The API matches that of F_SETPIPE_SZ in that it rounds up the passed in size so that the resulting page array is a power-of-2 in size. The proc file is renamed to /proc/sys/fs/pipe-max-size to reflect this change. Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-06-03pipe: change the privilege required for growing a pipe beyond system maxJens Axboe
Change it to CAP_SYS_RESOURCE, as that more accurately models what we want to control. Suggested-by: Michael Kerrisk <mtk.manpages@googlemail.com> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-06-03pipe: adjust minimum pipe size to 1 pageJens Axboe
We don't need to pages to guarantee the POSIX requirement that upto a page size write must be atomic to an empty pipe. Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-06-01Merge branch 'master' into for-linusJens Axboe
Conflicts: fs/pipe.c Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-05-30Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse: mm: export generic_pipe_buf_*() to modules fuse: support splice() reading from fuse device fuse: allow splice to move pages mm: export remove_from_page_cache() to modules mm: export lru_cache_add_*() to modules fuse: support splice() writing to fuse device fuse: get page reference for readpages fuse: use get_user_pages_fast() fuse: remove unneeded variable
2010-05-27fs: Add missing mutex_unlockJulia Lawall
Add a mutex_unlock missing on the error path. At other exists from the function that return an error flag, the mutex is unlocked, so do the same here. The semantic match that finds this problem is as follows: (http://coccinelle.lip6.fr/) // <smpl> @@ expression E1; @@ * mutex_lock(E1,...); <+... when != E1 if (...) { ... when != E1 * return ...; } ...+> * mutex_unlock(E1,...); // </smpl> Signed-off-by: Julia Lawall <julia@diku.dk> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-05-26mm: export generic_pipe_buf_*() to modulesMiklos Szeredi
This is needed by fuse device code which wants to create pipe buffers. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2010-05-24pipe: make F_{GET,SET}PIPE_SZ deal with byte sizesJens Axboe
Instead of requiring an exact number of pages as the argument and return value, change the API to deal with number of bytes instead. This also relaxes the requirement that the passed in size must result in a power-of-2 page array size. Round up to the nearest power-of-2 automatically and return the resulting size of the pipe on success. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2010-05-24pipe: F_SETPIPE_SZ should return -EPERM for non-rootJens Axboe
If the passed in size is larger than what has been set as the system wide limit and the user is not root, we want to return permission denied (not invalid value). Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2010-05-21pipe: set lower and upper limit on max pages in the pipe page arrayJens Axboe
We need at least two to guarantee proper POSIX behaviour, so never allow a smaller limit than that. Also expose a /proc/sys/fs/pipe-max-pages sysctl file that allows root to define a sane upper limit. Make it default to 16 times the default size, which is 16 pages. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2010-05-21pipe: add support for shrinking and growing pipesJens Axboe
This patch adds F_GETPIPE_SZ and F_SETPIPE_SZ fcntl() actions for growing and shrinking the size of a pipe and adjusts pipe.c and splice.c (and relay and network splice) usage to work with these larger (or smaller) pipes. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-12-17fs: no games with DCACHE_UNHASHEDNick Piggin
Filesystems outside the regular namespace do not have to clear DCACHE_UNHASHED in order to have a working /proc/$pid/fd/XXX. Nothing in proc prevents the fd link from being used if its dentry is not in the hash. Also, it does not get put into the dcache hash if DCACHE_UNHASHED is clear; that depends on the filesystem calling d_add or d_rehash. So delete the misleading comments and needless code. Acked-by: Miklos Szeredi <mszeredi@suse.cz> Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-12-16switch create_read_pipe() to alloc_file()Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-12-16switch alloc_file() to passing struct pathAl Viro
... and have the caller grab both mnt and dentry; kill leak in infiniband, while we are at it. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-10-22fs: pipe.c null pointer dereferenceEarl Chew
This patch fixes a null pointer exception in pipe_rdwr_open() which generates the stack trace: > Unable to handle kernel NULL pointer dereference at 0000000000000028 RIP: > [<ffffffff802899a5>] pipe_rdwr_open+0x35/0x70 > [<ffffffff8028125c>] __dentry_open+0x13c/0x230 > [<ffffffff8028143d>] do_filp_open+0x2d/0x40 > [<ffffffff802814aa>] do_sys_open+0x5a/0x100 > [<ffffffff8021faf3>] sysenter_do_call+0x1b/0x67 The failure mode is triggered by an attempt to open an anonymous pipe via /proc/pid/fd/* as exemplified by this script: ============================================================= while : ; do { echo y ; sleep 1 ; } | { while read ; do echo z$REPLY; done ; } & PID=$! OUT=$(ps -efl | grep 'sleep 1' | grep -v grep | { read PID REST ; echo $PID; } ) OUT="${OUT%% *}" DELAY=$((RANDOM * 1000 / 32768)) usleep $((DELAY * 1000 + RANDOM % 1000 )) echo n > /proc/$OUT/fd/1 # Trigger defect done ============================================================= Note that the failure window is quite small and I could only reliably reproduce the defect by inserting a small delay in pipe_rdwr_open(). For example: static int pipe_rdwr_open(struct inode *inode, struct file *filp) { msleep(100); mutex_lock(&inode->i_mutex); Although the defect was observed in pipe_rdwr_open(), I think it makes sense to replicate the change through all the pipe_*_open() functions. The core of the change is to verify that inode->i_pipe has not been released before attempting to manipulate it. If inode->i_pipe is no longer present, return ENOENT to indicate so. The comment about potentially using atomic_t for i_pipe->readers and i_pipe->writers has also been removed because it is no longer relevant in this context. The inode->i_mutex lock must be used so that inode->i_pipe can be dealt with correctly. Signed-off-by: Earl Chew <earl_chew@agilent.com> Cc: stable@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-07-22lockdep: Fix lockdep annotation for pipe_double_lock()Peter Zijlstra
The presumed use of the pipe_double_lock() routine is to lock 2 locks in a deadlock free way by ordering the locks by their address. However it fails to keep the specified lock classes in order and explicitly annotates a deadlock. Rectify this. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Miklos Szeredi <mszeredi@suse.cz> LKML-Reference: <1248163763.15751.11098.camel@twins>
2009-05-11splice: implement default splice_read methodMiklos Szeredi
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>
2009-04-15splice: add helpers for locking pipe inodeMiklos Szeredi
There are lots of sequences like this, especially in splice code: if (pipe->inode) mutex_lock(&pipe->inode->i_mutex); /* do something */ if (pipe->inode) mutex_unlock(&pipe->inode->i_mutex); so introduce helpers which do the conditional locking and unlocking. Also replace the inode_double_lock() call with a pipe_double_lock() helper to avoid spreading the use of this functionality beyond the pipe code. This patch is just a cleanup, and should cause no behavioral changes. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-03-27Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6 * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6: (37 commits) fs: avoid I_NEW inodes Merge code for single and multiple-instance mounts Remove get_init_pts_sb() Move common mknod_ptmx() calls into caller Parse mount options just once and copy them to super block Unroll essentials of do_remount_sb() into devpts vfs: simple_set_mnt() should return void fs: move bdev code out of buffer.c constify dentry_operations: rest constify dentry_operations: configfs constify dentry_operations: sysfs constify dentry_operations: JFS constify dentry_operations: OCFS2 constify dentry_operations: GFS2 constify dentry_operations: FAT constify dentry_operations: FUSE constify dentry_operations: procfs constify dentry_operations: ecryptfs constify dentry_operations: CIFS constify dentry_operations: AFS ...
2009-03-27constify dentry_operations: restAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-03-27do_pipe cleanup: drop its last user in arch/alpha/Cheng Renquan
The last user of do_pipe is in arch/alpha/, after replacing it with do_pipe_flags, the do_pipe can be totally dropped. Signed-off-by: Cheng Renquan <crquan@gmail.com> Acked-by: Richard Henderson <rth@twiddle.net> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-03-16Rationalize fasync return valuesJonathan Corbet
Most fasync implementations do something like: return fasync_helper(...); But fasync_helper() will return a positive value at times - a feature used in at least one place. Thus, a number of other drivers do: err = fasync_helper(...); if (err < 0) return err; return 0; In the interests of consistency and more concise code, it makes sense to map positive return values onto zero where ->fasync() is called. Cc: Al Viro <viro@ZenIV.linux.org.uk> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2009-03-12pipe_rdwr_fasync: fix the error handling to prevent the leak/crashOleg Nesterov
If the second fasync_helper() fails, pipe_rdwr_fasync() returns the error but leaves the file on ->fasync_readers. This was always wrong, but since 233e70f4228e78eb2f80dc6650f65d3ae3dbf17c "saner FASYNC handling on file close" we have the new problem. Because in this case setfl() doesn't set FASYNC bit, __fput() will not do ->fasync(0), and we leak fasync_struct with ->fa_file pointing to the freed file. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Cc: Al Viro <viro@ZenIV.linux.org.uk> Cc: Andi Kleen <andi@firstfloor.org> Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-14[CVE-2009-0029] System call wrappers part 33Heiko Carstens
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2009-01-14[CVE-2009-0029] System call wrappers part 32Heiko Carstens
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2009-01-14[CVE-2009-0029] Remove __attribute__((weak)) from sys_pipe/sys_pipe2Heiko Carstens
Remove __attribute__((weak)) from common code sys_pipe implemantation. IA64, ALPHA, SUPERH (32bit) and SPARC (32bit) have own implemantations with the same name. Just rename them. For sys_pipe2 there is no architecture specific implementation. Cc: Richard Henderson <rth@twiddle.net> Cc: David S. Miller <davem@davemloft.net> Cc: Paul Mundt <lethal@linux-sh.org> Cc: Tony Luck <tony.luck@intel.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2009-01-04sanitize audit_fd_pair()Al Viro
* no allocations * return void Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-11-14CRED: Wrap task credential accesses in the filesystem subsystemDavid Howells
Wrap access to task credentials so that they can be separated more easily from the task_struct during the introduction of COW creds. Change most current->(|e|s|fs)[ug]id to current_(|e|s|fs)[ug]id(). Change some task->e?[ug]id to task_e?[ug]id(). In some places it makes more sense to use RCU directly rather than a convenient wrapper; these will be addressed by later patches. Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: James Morris <jmorris@namei.org> Acked-by: Serge Hallyn <serue@us.ibm.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: James Morris <jmorris@namei.org>
2008-11-01saner FASYNC handling on file closeAl Viro
As it is, all instances of ->release() for files that have ->fasync() need to remember to evict file from fasync lists; forgetting that creates a hole and we actually have a bunch that *does* forget. So let's keep our lives simple - let __fput() check FASYNC in file->f_flags and call ->fasync() there if it's been set. And lose that crap in ->release() instances - leaving it there is still valid, but we don't have to bother anymore. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-26[PATCH] reuse xxx_fifo_fops for xxx_pipe_fopsDenys Vlasenko
Merge fifo and pipe file_operations. Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-07-24flag parameters: NONBLOCK in pipeUlrich Drepper
This patch adds O_NONBLOCK support to pipe2. It is minimally more involved than the patches for eventfd et.al but still trivial. The interfaces of the create_write_pipe and create_read_pipe helper functions were changed and the one other caller as well. The following test must be adjusted for architectures other than x86 and x86-64 and in case the syscall numbers changed. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ #include <fcntl.h> #include <stdio.h> #include <unistd.h> #include <sys/syscall.h> #ifndef __NR_pipe2 # ifdef __x86_64__ # define __NR_pipe2 293 # elif defined __i386__ # define __NR_pipe2 331 # else # error "need __NR_pipe2" # endif #endif int main (void) { int fds[2]; if (syscall (__NR_pipe2, fds, 0) == -1) { puts ("pipe2(0) failed"); return 1; } for (int i = 0; i < 2; ++i) { int fl = fcntl (fds[i], F_GETFL); if (fl == -1) { puts ("fcntl failed"); return 1; } if (fl & O_NONBLOCK) { printf ("pipe2(0) set non-blocking mode for fds[%d]\n", i); return 1; } close (fds[i]); } if (syscall (__NR_pipe2, fds, O_NONBLOCK) == -1) { puts ("pipe2(O_NONBLOCK) failed"); return 1; } for (int i = 0; i < 2; ++i) { int fl = fcntl (fds[i], F_GETFL); if (fl == -1) { puts ("fcntl failed"); return 1; } if ((fl & O_NONBLOCK) == 0) { printf ("pipe2(O_NONBLOCK) does not set non-blocking mode for fds[%d]\n", i); return 1; } close (fds[i]); } puts ("OK"); return 0; } ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Signed-off-by: Ulrich Drepper <drepper@redhat.com> Acked-by: Davide Libenzi <davidel@xmailserver.org> Cc: Michael Kerrisk <mtk.manpages@googlemail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-24flag parameters: pipeUlrich Drepper
This patch introduces the new syscall pipe2 which is like pipe but it also takes an additional parameter which takes a flag value. This patch implements the handling of O_CLOEXEC for the flag. I did not add support for the new syscall for the architectures which have a special sys_pipe implementation. I think the maintainers of those archs have the chance to go with the unified implementation but that's up to them. The implementation introduces do_pipe_flags. I did that instead of changing all callers of do_pipe because some of the callers are written in assembler. I would probably screw up changing the assembly code. To avoid breaking code do_pipe is now a small wrapper around do_pipe_flags. Once all callers are changed over to do_pipe_flags the old do_pipe function can be removed. The following test must be adjusted for architectures other than x86 and x86-64 and in case the syscall numbers changed. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ #include <fcntl.h> #include <stdio.h> #include <unistd.h> #include <sys/syscall.h> #ifndef __NR_pipe2 # ifdef __x86_64__ # define __NR_pipe2 293 # elif defined __i386__ # define __NR_pipe2 331 # else # error "need __NR_pipe2" # endif #endif int main (void) { int fd[2]; if (syscall (__NR_pipe2, fd, 0) != 0) { puts ("pipe2(0) failed"); return 1; } for (int i = 0; i < 2; ++i) { int coe = fcntl (fd[i], F_GETFD); if (coe == -1) { puts ("fcntl failed"); return 1; } if (coe & FD_CLOEXEC) { printf ("pipe2(0) set close-on-exit for fd[%d]\n", i); return 1; } } close (fd[0]); close (fd[1]); if (syscall (__NR_pipe2, fd, O_CLOEXEC) != 0) { puts ("pipe2(O_CLOEXEC) failed"); return 1; } for (int i = 0; i < 2; ++i) { int coe = fcntl (fd[i], F_GETFD); if (coe == -1) { puts ("fcntl failed"); return 1; } if ((coe & FD_CLOEXEC) == 0) { printf ("pipe2(O_CLOEXEC) does not set close-on-exit for fd[%d]\n", i); return 1; } } close (fd[0]); close (fd[1]); puts ("OK"); return 0; } ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Signed-off-by: Ulrich Drepper <drepper@redhat.com> Acked-by: Davide Libenzi <davidel@xmailserver.org> Cc: Michael Kerrisk <mtk.manpages@googlemail.com> Cc: <linux-arch@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-06-23[patch 1/4] vfs: path_{get,put}() cleanupsJan Blunck
Here are some more places where path_{get,put}() can be used instead of dput()/mntput() pair. Signed-off-by: Jan Blunck <jblunck@suse.de> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Jens Axboe <jens.axboe@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-05-08sys_pipe(): fix file descriptor leaksUlrich Drepper
Remember to close the files if copy_to_user() failed. Spotted by dm.n9107@gmail.com. Signed-off-by: Ulrich Drepper <drepper@redhat.com> Cc: DM <dm.n9107@gmail.com> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>