- 02 Apr, 2009 15 commits
-
-
Gerd Hoffmann authored
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>
-
Gerd Hoffmann authored
Factor out some code from compat_sys_writev() which can be shared with the upcoming compat_sys_pwritev(). Signed-off-by:
-
Gerd Hoffmann authored
This patch series: Implement the preadv() and pwritev() syscalls. *BSD has this syscall for quite some time. Test code: #if 0 set -x gcc -Wall -O2 -o preadv $0 exit 0 #endif /* * preadv demo / test * * (c) 2008 Gerd Hoffmann <kraxel@redhat.com> * * build with "sh $thisfile" */ #include <stdio.h> #include <stdlib.h> #include <unistd.h> #include <errno.h> #include <inttypes.h> #include <sys/uio.h> /* ----------------------------------------------------------------- */ /* syscall windup */ #include <sys/syscall.h> #if 0 /* WARNING: Be sure you know what you are doing if you enable this. * linux syscall code isn't upstream yet, syscall numbers are subject * to change */ # ifndef __NR_preadv # ifdef __i386__ # define __NR_preadv 333 # define __NR_pwritev 334 # endif # ifdef __x86_64__ # define __NR_preadv 295 # define __NR_pwritev 296 # endif # endif #endif #ifndef __NR_preadv # error preadv/pwritev syscall numbers are unknown #endif static ssize_t preadv(int fd, const struct iovec *iov, int iovcnt, off_t offset) { uint32_t pos_high = (offset >> 32) & 0xffffffff; uint32_t pos_low = offset & 0xffffffff; return syscall(__NR_preadv, fd, iov, iovcnt, pos_high, pos_low); } static ssize_t pwritev(int fd, const struct iovec *iov, int iovcnt, off_t offset) { uint32_t pos_high = (offset >> 32) & 0xffffffff; uint32_t pos_low = offset & 0xffffffff; return syscall(__NR_pwritev, fd, iov, iovcnt, pos_high, pos_low); } /* ----------------------------------------------------------------- */ /* demo/test app */ static char filename[] = "/tmp/preadv-XXXXXX"; static char outbuf[11] = "0123456789"; static char inbuf[11] = "----------"; static struct iovec ovec[2] = {{ .iov_base = outbuf + 5, .iov_len = 5, },{ .iov_base = outbuf + 0, .iov_len = 5, }}; static struct iovec ivec[3] = {{ .iov_base = inbuf + 6, .iov_len = 2, },{ .iov_base = inbuf + 4, .iov_len = 2, },{ .iov_base = inbuf + 2, .iov_len = 2, }}; void cleanup(void) { unlink(filename); } int main(int argc, char **argv) { int fd, rc; fd = mkstemp(filename); if (-1 == fd) { perror("mkstemp"); exit(1); } atexit(cleanup); /* write to file: "56789-01234" */ rc = pwritev(fd, ovec, 2, 0); if (rc < 0) { perror("pwritev"); exit(1); } /* read from file: "78-90-12" */ rc = preadv(fd, ivec, 3, 2); if (rc < 0) { perror("preadv"); exit(1); } printf("result : %s\n", inbuf); printf("expected: %s\n", "--129078--"); exit(0); } This patch: Factor out some code from compat_sys_readv() which can be shared with the upcoming compat_sys_preadv(). Signed-off-by: -
David VomLehn authored
Decompression errors can arise due to corruption of compressed blocks on flash or in memory. This patch propagates errors detected during decompression back to the block layer. Signed-off-by:
David VomLehn <dvomlehn@cisco.com> Signed-off-by:
-
Mike Frysinger authored
Signed-off-by:
Mike Frysinger <vapier.adi@gmail.com> Signed-off-by:
Bryan Wu <cooloney@kernel.org> Cc: David Howells <dhowells@redhat.com> Cc: Greg Ungerer <gerg@snapgear.com> Signed-off-by:
-
Roel Kluin authored
hppfs_read_file() may return (ssize_t) -ENOMEM, or -EFAULT. When stored in size_t 'count', these errors will not be noticed, a large value will be added to *ppos. Signed-off-by:
Roel Kluin <roel.kluin@gmail.com> Signed-off-by:
-
Jan Kara authored
Sometimes block_write_begin() can map buffers in a page but later we fail to copy data into those buffers (because the source page has been paged out in the mean time). We then end up with !uptodate mapped buffers. To add a bit more to the confusion, block_write_end() does not commit any data (and thus does not any mark buffers as uptodate) if we didn't succeed with copying all the data. Commit f4fc66a8 (ext3: convert to new aops) missed these cases and thus we were inserting non-uptodate buffers to transaction's list which confuses JBD code and it reports IO errors, aborts a transaction and generally makes users afraid about their data ;-P. This patch fixes the problem by reorganizing ext3_..._write_end() code to first call block_write_end() to mark buffers with valid data uptodate and after that we file only uptodate buffers to transaction's lists. We also fix a problem where we could leave blocks allocated beyond i_size (i_disksize in fact) because of failed write. We now add inode to orphan list when write fails (to be safe in case we crash) and then truncate blocks beyond i_size in a separate transaction. Signed-off-by:
Jan Kara <jack@suse.cz> Reviewed-by:
Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: <linux-ext4@vger.kernel.org> Signed-off-by:
-
Bryan Donlan authored
ext3_iget() returns -ESTALE if invoked on a deleted inode, in order to report errors to NFS properly. However, in ext[234]_lookup(), this -ESTALE can be propagated to userspace if the filesystem is corrupted such that a directory entry references a deleted inode. This leads to a misleading error message - "Stale NFS file handle" - and confusion on the part of the admin. The bug can be easily reproduced by creating a new filesystem, making a link to an unused inode using debugfs, then mounting and attempting to ls -l said link. This patch thus changes ext3_lookup to return -EIO if it receives -ESTALE from ext3_iget(), as ext3 does for other filesystem metadata corruption; and also invokes the appropriate ext*_error functions when this case is detected. Signed-off-by:
Bryan Donlan <bdonlan@gmail.com> Cc: <linux-ext4@vger.kernel.org> Signed-off-by:
-
Wei Yongjun authored
Use unsigned instead of int for the parameter which carries a blocksize. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by:
Wei Yongjun <yjwei@cn.fujitsu.com> Cc: Theodore Ts'o <tytso@mit.edu> Signed-off-by:
-
Jan Kara authored
On 32-bit system with CONFIG_LBD getblk can fail because provided block number is too big. Make JBD gracefully handle that. Signed-off-by:
-
Cyrus Massoumi authored
Reformat ext3/ioctl.c to make it look more like ext4/ioctl.c and remove the BKL around ext3_ioctl(). Signed-off-by:
Cyrus Massoumi <cyrusm@gmx.net> Cc: <linux-ext4@vger.kernel.org> Acked-by:
Jan Kara <jack@ucw.cz> Signed-off-by:
-
Nikanth Karthikesan authored
Check bh->b_blocknr only if BH_Mapped is set. akpm: I doubt if b_blocknr is ever uninitialised here, but it could conceivably cause a problem if we're doing a lookup for block zero. Signed-off-by:
Nikanth Karthikesan <knikanth@suse.de> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by:
-
Jeff Layton authored
The dirtied_when value on an inode is supposed to represent the first time that an inode has one of its pages dirtied. This value is in units of jiffies. It's used in several places in the writeback code to determine when to write out an inode. The problem is that these checks assume that dirtied_when is updated periodically. If an inode is continuously being used for I/O it can be persistently marked as dirty and will continue to age. Once the time compared to is greater than or equal to half the maximum of the jiffies type, the logic of the time_*() macros inverts and the opposite of what is needed is returned. On 32-bit architectures that's just under 25 days (assuming HZ == 1000). As the least-recently dirtied inode, it'll end up being the first one that pdflush will try to write out. sync_sb_inodes does this check: /* Was this inode dirtied after sync_sb_inodes was called? */ if (time_after(inode->dirtied_when, start)) break; ...but now dirtied_when appears to be in the future. sync_sb_inodes bails out without attempting to write any dirty inodes. When this occurs, pdflush will stop writing out inodes for this superblock. Nothing can unwedge it until jiffies moves out of the problematic window. This patch fixes this problem by changing the checks against dirtied_when to also check whether it appears to be in the future. If it does, then we consider the value to be far in the past. This should shrink the problematic window of time to such a small period (30s) as not to matter. Signed-off-by:
Jeff Layton <jlayton@redhat.com> Signed-off-by:
Wu Fengguang <fengguang.wu@intel.com> Acked-by:
Ian Kent <raven@themaw.net> Cc: Jens Axboe <jens.axboe@oracle.com> Signed-off-by:
-
Wu Fengguang authored
clear_inode() will switch inode state from I_FREEING to I_CLEAR, and do so _outside_ of inode_lock. So any I_FREEING testing is incomplete without a coupled testing of I_CLEAR. So add I_CLEAR tests to drop_pagecache_sb(), generic_sync_sb_inodes() and add_dquot_ref(). Masayoshi MIZUMA discovered the bug in drop_pagecache_sb() and Jan Kara reminds fixing the other two cases. Masayoshi MIZUMA has a nice panic flow: ===================================================================== [process A] | [process B] | | | prune_icache() | drop_pagecache() | spin_lock(&inode_lock) | drop_pagecache_sb() | inode->i_state |= I_FREEING; | | | spin_unlock(&inode_lock) | V | | | spin_lock(&inode_lock) | V | | | dispose_list() | | | list_del() | | | clear_inode() | | | inode->i_state = I_CLEAR | | | | | V | | | if (inode->i_state & (I_FREEING|I_WILL_FREE)) | | | continue; <==== NOT MATCH | | | | | | (DANGER from here on! Accessing disposing inode!) | | | | | | __iget() | | | list_move() <===== PANIC on poisoned list !! V V | (time) ===================================================================== Reported-by:Masayoshi MIZUMA <m.mizuma@jp.fujitsu.com> Reviewed-by:
-
David Howells authored
Fix a number of issues with the per-MM VMA patch: (1) Make mmap_pages_allocated an atomic_long_t, just in case this is used on a NOMMU system with more than 2G pages. Makes no difference on a 32-bit system. (2) Report vma->vm_pgoff * PAGE_SIZE as a 64-bit value, not a 32-bit value, lest it overflow. (3) Move the allocation of the vm_area_struct slab back for fork.c. (4) Use KMEM_CACHE() for both vm_area_struct and vm_region slabs. (5) Use BUG_ON() rather than if () BUG(). (6) Make the default validate_nommu_regions() a static inline rather than a #define. (7) Make free_page_series()'s objection to pages with a refcount != 1 more informative. (8) Adjust the __put_nommu_region() banner comment to indicate that the semaphore must be held for writing. (9) Limit the number of warnings about munmaps of non-mmapped regions. Reported-by:David Howells <dhowells@redhat.com> Cc: Greg Ungerer <gerg@snapgear.com> Signed-off-by:
-
- 01 Apr, 2009 25 commits
-
-
Mans Rullgard authored
This fixes unaligned accesses in nsm_init_private() when creating nlm_reboot keys. Signed-off-by:
Mans Rullgard <mans@mansr.com> Reviewed-by:
Chuck Lever <chuck.lever@oracle.com> Signed-off-by:
Trond Myklebust <Trond.Myklebust@netapp.com>
-
Ian Kent authored
A deadlock can occur when user space uses a signal (autofs version 4 uses SIGCHLD for this) to effect expire completion. The order of events is: Expire process completes, but before being able to send SIGCHLD to it's parent ... Another process walks onto a different mount point and drops the directory inode semaphore prior to sending the request to the daemon as it must ... A third process does an lstat on on the expired mount point causing it to wait on expire completion (unfortunately) holding the directory semaphore. The mount request then arrives at the daemon which does an lstat and, deadlock. For some time I was concerned about releasing the directory semaphore around the expire wait in autofs4_lookup as well as for the mount call back. I finally realized that the last round of changes in this function made the expiring dentry and the lookup dentry separate and distinct so the check and possible wait can be done anywhere prior to the mount call back. This patch moves the check to just before the mount call back and inside the directory inode mutex release. Signed-off-by:
-
Ian Kent authored
A significant portion of the autofs_dev_ioctl_expire() and autofs4_expire_multi() functions is duplicated code. This patch cleans that up. Signed-off-by:
Jeff Moyer <jmoyer@redhat.com> Signed-off-by:
-
Johannes Weiner authored
Use kzfree() instead of memset() + kfree(). Signed-off-by:
Johannes Weiner <hannes@cmpxchg.org> Reviewed-by:
Pekka Enberg <penberg@cs.helsinki.fi> Acked-by:
Tyler Hicks <tyhicks@linux.vnet.ibm.com> Signed-off-by:
-
Wu Fengguang authored
Addresses http://bugzilla.kernel.org/show_bug.cgi?id=12843 "I use ramfs instead of tmpfs for /tmp because I don't use swap on my laptop. Some apps need 1777 mode for /tmp directory, but ramfs does not support 'mode=' mount option." Reported-by:
Avan Anishchuk <matimatik@gmail.com> Signed-off-by:
-
Davide Libenzi authored
Introduce keyed event wakeups inside the eventfd code. Signed-off-by:
Davide Libenzi <davidel@xmailserver.org> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: Ingo Molnar <mingo@elte.hu> Cc: David Miller <davem@davemloft.net> Cc: William Lee Irwin III <wli@movementarian.org> Signed-off-by:
-
Davide Libenzi authored
Use the events hint now sent by some devices, to avoid unnecessary wakeups for events that are of no interest for the caller. This code handles both devices that are sending keyed events, and the ones that are not (and event the ones that sometimes send events, and sometimes don't). [akpm@linux-foundation.org: coding-style fixes] Signed-off-by:
-
Davide Libenzi authored
People started using eventfd in a semaphore-like way where before they were using pipes. That is, counter-based resource access. Where a "wait()" returns immediately by decrementing the counter by one, if counter is greater than zero. Otherwise will wait. And where a "post(count)" will add count to the counter releasing the appropriate amount of waiters. If eventfd the "post" (write) part is fine, while the "wait" (read) does not dequeue 1, but the whole counter value. The problem with eventfd is that a read() on the fd returns and wipes the whole counter, making the use of it as semaphore a little bit more cumbersome. You can do a read() followed by a write() of COUNTER-1, but IMO it's pretty easy and cheap to make this work w/out extra steps. This patch introduces a new eventfd flag that tells eventfd to only dequeue 1 from the counter, allowing simple read/write to make it behave like a semaphore. Simple test here: http://www.xmailserver.org/eventfd-sem.c To be back-compatible with earlier kernels, userspace applications should probe for the availability of this feature via #ifdef EFD_SEMAPHORE fd = eventfd2 (CNT, EFD_SEMAPHORE); if (fd == -1 && errno == EINVAL) <fallback> #else <fallback> #endif Signed-off-by:
Michael Kerrisk <mtk.manpages@gmail.com> Cc: Ulrich Drepper <drepper@redhat.com> Signed-off-by:
-
Tony Battersby authored
eventpoll.c uses void * in one place for no obvious reason; change it to use the real type instead. Signed-off-by:
Tony Battersby <tonyb@cybernetics.com> Acked-by:
-
Tony Battersby authored
ep_modify() doesn't need to set event.data from within the ep->lock spinlock as the comment suggests. The only place event.data is used is ep_send_events_proc(), and this is protected by ep->mtx instead of ep->lock. Also update the comment for mutex_lock() at the top of ep_scan_ready_list(), which mentions epoll_ctl(EPOLL_CTL_DEL) but not epoll_ctl(EPOLL_CTL_MOD). ep_modify() can also use spin_lock_irq() instead of spin_lock_irqsave(). Signed-off-by:
-
Tony Battersby authored
xchg in ep_unregister_pollwait() is unnecessary because it is protected by either epmutex or ep->mtx (the same protection as ep_remove()). If xchg was necessary, it would be insufficient to protect against problems: if multiple concurrent calls to ep_unregister_pollwait() were possible then a second caller that returns without doing anything because nwait == 0 could return before the waitqueues are removed by the first caller, which looks like it could lead to problematic races with ep_poll_callback(). So remove xchg and add comments about the locking. Signed-off-by:
-
Tony Battersby authored
If epoll_wait returns -EFAULT, the event that was being returned when the fault was encountered will be forgotten. This is not a big deal since EFAULT will happen only if a buggy userspace program passes in a bad address, in which case what happens later usually doesn't matter. However, it is easy to remember the event for later, and this patch makes a simple change to do that. Signed-off-by:
-
Tony Battersby authored
ep_call_nested() (formerly ep_poll_safewake()) uses "current" (without dereferencing it) to detect callback recursion, but it may be called from irq context where the use of current is generally discouraged. It would be better to use get_cpu() and put_cpu() to detect the callback recursion. Signed-off-by:
-
Davide Libenzi authored
Remove debugging code from epoll. There's no need for it to be included into mainline code. Signed-off-by:
-
Davide Libenzi authored
Signed-off-by:
-
Davide Libenzi authored
Fix a bug inside the epoll's f_op->poll() code, that returns POLLIN even though there are no actual ready monitored fds. The bug shows up if you add an epoll fd inside another fd container (poll, select, epoll). The problem is that callback-based wake ups used by epoll does not carry (patches will follow, to fix this) any information about the events that actually happened. So the callback code, since it can't call the file* ->poll() inside the callback, chains the file* into a ready-list. So, suppose you added an fd with EPOLLOUT only, and some data shows up on the fd, the file* mapped by the fd will be added into the ready-list (via wakeup callback). During normal epoll_wait() use, this condition is sorted out at the time we're actually able to call the file*'s f_op->poll(). Inside the old epoll's f_op->poll() though, only a quick check !list_empty(ready-list) was performed, and this could have led to reporting POLLIN even though no ready fds would show up at a following epoll_wait(). In order to correctly report the ready status for an epoll fd, the ready-list must be checked to see if any really available fd+event would be ready in a following epoll_wait(). Operation (calling f_op->poll() from inside f_op->poll()) that, like wake ups, must be handled with care because of the fact that epoll fds can be added to other epoll fds. Test code: /* * epoll_test by Davide Libenzi (Simple code to test epoll internals) * Copyright (C) 2008 Davide Libenzi * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA * * Davide Libenzi <davidel@xmailserver.org> * */ #include <sys/types.h> #include <unistd.h> #include <stdio.h> #include <stdlib.h> #include <string.h> #include <errno.h> #include <signal.h> #include <limits.h> #include <poll.h> #include <sys/epoll.h> #include <sys/wait.h> #define EPWAIT_TIMEO (1 * 1000) #ifndef POLLRDHUP #define POLLRDHUP 0x2000 #endif #define EPOLL_MAX_CHAIN 100L #define EPOLL_TF_LOOP (1 << 0) struct epoll_test_cfg { long size; long flags; }; static int xepoll_create(int n) { int epfd; if ((epfd = epoll_create(n)) == -1) { perror("epoll_create"); exit(2); } return epfd; } static void xepoll_ctl(int epfd, int cmd, int fd, struct epoll_event *evt) { if (epoll_ctl(epfd, cmd, fd, evt) < 0) { perror("epoll_ctl"); exit(3); } } static void xpipe(int *fds) { if (pipe(fds)) { perror("pipe"); exit(4); } } static pid_t xfork(void) { pid_t pid; if ((pid = fork()) == (pid_t) -1) { perror("pipe"); exit(5); } return pid; } static int run_forked_proc(int (*proc)(void *), void *data) { int status; pid_t pid; if ((pid = xfork()) == 0) exit((*proc)(data)); if (waitpid(pid, &status, 0) != pid) { perror("waitpid"); return -1; } return WIFEXITED(status) ? WEXITSTATUS(status): -2; } static int check_events(int fd, int timeo) { struct pollfd pfd; fprintf(stdout, "Checking events for fd %d\n", fd); memset(&pfd, 0, sizeof(pfd)); pfd.fd = fd; pfd.events = POLLIN | POLLOUT; if (poll(&pfd, 1, timeo) < 0) { perror("poll()"); return 0; } if (pfd.revents & POLLIN) fprintf(stdout, "\tPOLLIN\n"); if (pfd.revents & POLLOUT) fprintf(stdout, "\tPOLLOUT\n"); if (pfd.revents & POLLERR) fprintf(stdout, "\tPOLLERR\n"); if (pfd.revents & POLLHUP) fprintf(stdout, "\tPOLLHUP\n"); if (pfd.revents & POLLRDHUP) fprintf(stdout, "\tPOLLRDHUP\n"); return pfd.revents; } static int epoll_test_tty(void *data) { int epfd, ifd = fileno(stdin), res; struct epoll_event evt; if (check_events(ifd, 0) != POLLOUT) { fprintf(stderr, "Something is cooking on STDIN (%d)\n", ifd); return 1; } epfd = xepoll_create(1); fprintf(stdout, "Created epoll fd (%d)\n", epfd); memset(&evt, 0, sizeof(evt)); evt.events = EPOLLIN; xepoll_ctl(epfd, EPOLL_CTL_ADD, ifd, &evt); if (check_events(epfd, 0) & POLLIN) { res = epoll_wait(epfd, &evt, 1, 0); if (res == 0) { fprintf(stderr, "Epoll fd (%d) is ready when it shouldn't!\n", epfd); return 2; } } return 0; } static int epoll_wakeup_chain(void *data) { struct epoll_test_cfg *tcfg = data; int i, res, epfd, bfd, nfd, pfds[2]; pid_t pid; struct epoll_event evt; memset(&evt, 0, sizeof(evt)); evt.events = EPOLLIN; epfd = bfd = xepoll_create(1); for (i = 0; i < tcfg->size; i++) { nfd = xepoll_create(1); xepoll_ctl(bfd, EPOLL_CTL_ADD, nfd, &evt); bfd = nfd; } xpipe(pfds); if (tcfg->flags & EPOLL_TF_LOOP) { xepoll_ctl(bfd, EPOLL_CTL_ADD, epfd, &evt); /* * If we're testing for loop, we want that the wakeup * triggered by the write to the pipe done in the child * process, triggers a fake event. So we add the pipe * read size with EPOLLOUT events. This will trigger * an addition to the ready-list, but no real events * will be there. The the epoll kernel code will proceed * in calling f_op->poll() of the epfd, triggering the * loop we want to test. */ evt.events = EPOLLOUT; } xepoll_ctl(bfd, EPOLL_CTL_ADD, pfds[0], &evt); /* * The pipe write must come after the poll(2) call inside * check_events(). This tests the nested wakeup code in * fs/eventpoll.c:ep_poll_safewake() * By having the check_events() (hence poll(2)) happens first, * we have poll wait queue filled up, and the write(2) in the * child will trigger the wakeup chain. */ if ((pid = xfork()) == 0) { sleep(1); write(pfds[1], "w", 1); exit(0); } res = check_events(epfd, 2000) & POLLIN; if (waitpid(pid, NULL, 0) != pid) { perror("waitpid"); return -1; } return res; } static int epoll_poll_chain(void *data) { struct epoll_test_cfg *tcfg = data; int i, res, epfd, bfd, nfd, pfds[2]; pid_t pid; struct epoll_event evt; memset(&evt, 0, sizeof(evt)); evt.events = EPOLLIN; epfd = bfd = xepoll_create(1); for (i = 0; i < tcfg->size; i++) { nfd = xepoll_create(1); xepoll_ctl(bfd, EPOLL_CTL_ADD, nfd, &evt); bfd = nfd; } xpipe(pfds); if (tcfg->flags & EPOLL_TF_LOOP) { xepoll_ctl(bfd, EPOLL_CTL_ADD, epfd, &evt); /* * If we're testing for loop, we want that the wakeup * triggered by the write to the pipe done in the child * process, triggers a fake event. So we add the pipe * read size with EPOLLOUT events. This will trigger * an addition to the ready-list, but no real events * will be there. The the epoll kernel code will proceed * in calling f_op->poll() of the epfd, triggering the * loop we want to test. */ evt.events = EPOLLOUT; } xepoll_ctl(bfd, EPOLL_CTL_ADD, pfds[0], &evt); /* * The pipe write mush come before the poll(2) call inside * check_events(). This tests the nested f_op->poll calls code in * fs/eventpoll.c:ep_eventpoll_poll() * By having the pipe write(2) happen first, we make the kernel * epoll code to load the ready lists, and the following poll(2) * done inside check_events() will test nested poll code in * ep_eventpoll_poll(). */ if ((pid = xfork()) == 0) { write(pfds[1], "w", 1); exit(0); } sleep(1); res = check_events(epfd, 1000) & POLLIN; if (waitpid(pid, NULL, 0) != pid) { perror("waitpid"); return -1; } return res; } int main(int ac, char **av) { int error; struct epoll_test_cfg tcfg; fprintf(stdout, "\n********** Testing TTY events\n"); error = run_forked_proc(epoll_test_tty, NULL); fprintf(stdout, error == 0 ? "********** OK\n": "********** FAIL (%d)\n", error); tcfg.size = 3; tcfg.flags = 0; fprintf(stdout, "\n********** Testing short wakeup chain\n"); error = run_forked_proc(epoll_wakeup_chain, &tcfg); fprintf(stdout, error == POLLIN ? "********** OK\n": "********** FAIL (%d)\n", error); tcfg.size = EPOLL_MAX_CHAIN; tcfg.flags = 0; fprintf(stdout, "\n********** Testing long wakeup chain (HOLD ON)\n"); error = run_forked_proc(epoll_wakeup_chain, &tcfg); fprintf(stdout, error == 0 ? "********** OK\n": "********** FAIL (%d)\n", error); tcfg.size = 3; tcfg.flags = 0; fprintf(stdout, "\n********** Testing short poll chain\n"); error = run_forked_proc(epoll_poll_chain, &tcfg); fprintf(stdout, error == POLLIN ? "********** OK\n": "********** FAIL (%d)\n", error); tcfg.size = EPOLL_MAX_CHAIN; tcfg.flags = 0; fprintf(stdout, "\n********** Testing long poll chain (HOLD ON)\n"); error = run_forked_proc(epoll_poll_chain, &tcfg); fprintf(stdout, error == 0 ? "********** OK\n": "********** FAIL (%d)\n", error); tcfg.size = 3; tcfg.flags = EPOLL_TF_LOOP; fprintf(stdout, "\n********** Testing loopy wakeup chain (HOLD ON)\n"); error = run_forked_proc(epoll_wakeup_chain, &tcfg); fprintf(stdout, error == 0 ? "********** OK\n": "********** FAIL (%d)\n", error); tcfg.size = 3; tcfg.flags = EPOLL_TF_LOOP; fprintf(stdout, "\n********** Testing loopy poll chain (HOLD ON)\n"); error = run_forked_proc(epoll_poll_chain, &tcfg); fprintf(stdout, error == 0 ? "********** OK\n": "********** FAIL (%d)\n", error); return 0; } Signed-off-by: -
Harvey Harrison authored
The base versions handle constant folding now and are shorter than these private wrappers, use them directly. Signed-off-by:
Harvey Harrison <harvey.harrison@gmail.com> Cc: Anton Altaparmakov <aia21@cantab.net> Signed-off-by:
-
Eric Sandeen authored
Now that the filesystem freeze operation has been elevated to the VFS, and is just an ioctl away, some sort of safety net for unintentionally frozen root filesystems may be in order. The timeout thaw originally proposed did not get merged, but perhaps something like this would be useful in emergencies. For example, freeze /path/to/mountpoint may freeze your root filesystem if you forgot that you had that unmounted. I chose 'j' as the last remaining character other than 'h' which is sort of reserved for help (because help is generated on any unknown character). I've tested this on a non-root fs with multiple (nested) freezers, as well as on a system rendered unresponsive due to a frozen root fs. [randy.dunlap@oracle.com: emergency thaw only if CONFIG_BLOCK enabled] Signed-off-by:
Eric Sandeen <sandeen@redhat.com> Cc: Takashi Sato <t-sato@yk.jp.nec.com> Signed-off-by:
Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by:
-
KAMEZAWA Hiroyuki authored
try_to_free_pages() is used for the direct reclaim of up to SWAP_CLUSTER_MAX pages when watermarks are low. The caller to alloc_pages_nodemask() can specify a nodemask of nodes that are allowed to be used but this is not passed to try_to_free_pages(). This can lead to unnecessary reclaim of pages that are unusable by the caller and int the worst case lead to allocation failure as progress was not been make where it is needed. This patch passes the nodemask used for alloc_pages_nodemask() to try_to_free_pages(). Reviewed-by:
KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Acked-by:
Mel Gorman <mel@csn.ul.ie> Signed-off-by:
KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Rik van Riel <riel@redhat.com> Signed-off-by:
-
Johannes Weiner authored
Instead of open-coding the lru-list-add pagevec batching when expanding a file mapping from zero, defer to the appropriate page cache function that also takes care of adding the page to the lru list. This is cleaner, saves code and reduces the stack footprint by 16 words worth of pagevec. Signed-off-by:
-
Hugh Dickins authored
Fix warnings and return values in sysfs bin_page_mkwrite(), fixing fs/sysfs/bin.c: In function `bin_page_mkwrite': fs/sysfs/bin.c:250: warning: passing argument 2 of `bb->vm_ops->page_mkwrite' from incompatible pointer type fs/sysfs/bin.c: At top level: fs/sysfs/bin.c:280: warning: initialization from incompatible pointer type Expects to have my [PATCH next] sysfs: fix some bin_vm_ops errors Signed-off-by:
Hugh Dickins <hugh@veritas.com> Cc: Nick Piggin <npiggin@suse.de> Cc: "Eric W. Biederman" <ebiederm@aristanetworks.com> Signed-off-by:
-
Nick Piggin authored
page_mkwrite is called with neither the page lock nor the ptl held. This means a page can be concurrently truncated or invalidated out from underneath it. Callers are supposed to prevent truncate races themselves, however previously the only thing they can do in case they hit one is to raise a SIGBUS. A sigbus is wrong for the case that the page has been invalidated or truncated within i_size (eg. hole punched). Callers may also have to perform memory allocations in this path, where again, SIGBUS would be wrong. The previous patch ("mm: page_mkwrite change prototype to match fault") made it possible to properly specify errors. Convert the generic buffer.c code and btrfs to return sane error values (in the case of page removed from pagecache, VM_FAULT_NOPAGE will cause the fault handler to exit without doing anything, and the fault will be retried properly). This fixes core code, and converts btrfs as a template/example. All other filesystems defining their own page_mkwrite should be fixed in a similar manner. Acked-by:Chris Mason <chris.mason@oracle.com> Signed-off-by:
Nick Piggin <npiggin@suse.de> Signed-off-by:
-
Nick Piggin authored
Change the page_mkwrite prototype to take a struct vm_fault, and return VM_FAULT_xxx flags. There should be no functional change. This makes it possible to return much more detailed error information to the VM (and also can provide more information eg. virtual_address to the driver, which might be important in some special cases). This is required for a subsequent fix. And will also make it easier to merge page_mkwrite() with fault() in future. Signed-off-by:
-
Ravikiran G Thirumalai authored
Allow non root users with sufficient mlock rlimits to be able to allocate hugetlb backed shm for now. Deprecate this though. This is being deprecated because the mlock based rlimit checks for SHM_HUGETLB is not consistent with mmap based huge page allocations. Signed-off-by:
Ravikiran Thirumalai <kiran@scalex86.org> Reviewed-by:
-
Ravikiran G Thirumalai authored
Fix hugetlb subsystem so that non root users belonging to hugetlb_shm_group can actually allocate hugetlb backed shm. Currently non root users cannot even map one large page using SHM_HUGETLB when they belong to the gid in /proc/sys/vm/hugetlb_shm_group. This is because allocation size is verified against RLIMIT_MEMLOCK resource limit even if the user belongs to hugetlb_shm_group. This patch 1. Fixes hugetlb subsystem so that users with CAP_IPC_LOCK and users belonging to hugetlb_shm_group don't need to be restricted with RLIMIT_MEMLOCK resource limits 2. This patch also disables mlock based rlimit checking (which will be reinstated and marked deprecated in a subsequent patch). Signed-off-by:
-
