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* Merge tag 'trace-v5.1-rc6' of ↵Linus Torvalds2019-04-261-0/+1
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull tracing fixes from Steven Rostedt: "Three tracing fixes: - Use "nosteal" for ring buffer splice pages - Memory leak fix in error path of trace_pid_write() - Fix preempt_enable_no_resched() (use preempt_enable()) in ring buffer code" * tag 'trace-v5.1-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: trace: Fix preempt_enable_no_resched() abuse tracing: Fix a memory leak by early error exit in trace_pid_write() tracing: Fix buffer_ref pipe ops
| * tracing: Fix buffer_ref pipe opsJann Horn2019-04-261-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This fixes multiple issues in buffer_pipe_buf_ops: - The ->steal() handler must not return zero unless the pipe buffer has the only reference to the page. But generic_pipe_buf_steal() assumes that every reference to the pipe is tracked by the page's refcount, which isn't true for these buffers - buffer_pipe_buf_get(), which duplicates a buffer, doesn't touch the page's refcount. Fix it by using generic_pipe_buf_nosteal(), which refuses every attempted theft. It should be easy to actually support ->steal, but the only current users of pipe_buf_steal() are the virtio console and FUSE, and they also only use it as an optimization. So it's probably not worth the effort. - The ->get() and ->release() handlers can be invoked concurrently on pipe buffers backed by the same struct buffer_ref. Make them safe against concurrency by using refcount_t. - The pointers stored in ->private were only zeroed out when the last reference to the buffer_ref was dropped. As far as I know, this shouldn't be necessary anyway, but if we do it, let's always do it. Link: http://lkml.kernel.org/r/20190404215925.253531-1-jannh@google.com Cc: Ingo Molnar <mingo@redhat.com> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: stable@vger.kernel.org Fixes: 73a757e63114d ("ring-buffer: Return reader page back into existing ring buffer") Signed-off-by: Jann Horn <jannh@google.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
* | Merge branch 'page-refs' (page ref overflow)Linus Torvalds2019-04-141-4/+6
|\ \ | |/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Merge page ref overflow branch. Jann Horn reported that he can overflow the page ref count with sufficient memory (and a filesystem that is intentionally extremely slow). Admittedly it's not exactly easy. To have more than four billion references to a page requires a minimum of 32GB of kernel memory just for the pointers to the pages, much less any metadata to keep track of those pointers. Jann needed a total of 140GB of memory and a specially crafted filesystem that leaves all reads pending (in order to not ever free the page references and just keep adding more). Still, we have a fairly straightforward way to limit the two obvious user-controllable sources of page references: direct-IO like page references gotten through get_user_pages(), and the splice pipe page duplication. So let's just do that. * branch page-refs: fs: prevent page refcount overflow in pipe_buf_get mm: prevent get_user_pages() from overflowing page refcount mm: add 'try_get_page()' helper function mm: make page ref count overflow check tighter and more explicit
| * fs: prevent page refcount overflow in pipe_buf_getMatthew Wilcox2019-04-141-4/+6
| | | | | | | | | | | | | | | | | | | | | | | | Change pipe_buf_get() to return a bool indicating whether it succeeded in raising the refcount of the page (if the thing in the pipe is a page). This removes another mechanism for overflowing the page refcount. All callers converted to handle a failure. Reported-by: Jann Horn <jannh@google.com> Signed-off-by: Matthew Wilcox <willy@infradead.org> Cc: stable@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | pipe: stop using ->can_mergeJann Horn2019-02-011-7/+0
| | | | | | | | | | | | | | | | | | | | Al Viro pointed out that since there is only one pipe buffer type to which new data can be appended, it isn't necessary to have a ->can_merge field in struct pipe_buf_operations, we can just check for a magic type. Suggested-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Jann Horn <jannh@google.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | splice: don't merge into linked buffersJann Horn2019-02-011-0/+1
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Before this patch, it was possible for two pipes to affect each other after data had been transferred between them with tee(): ============ $ cat tee_test.c int main(void) { int pipe_a[2]; if (pipe(pipe_a)) err(1, "pipe"); int pipe_b[2]; if (pipe(pipe_b)) err(1, "pipe"); if (write(pipe_a[1], "abcd", 4) != 4) err(1, "write"); if (tee(pipe_a[0], pipe_b[1], 2, 0) != 2) err(1, "tee"); if (write(pipe_b[1], "xx", 2) != 2) err(1, "write"); char buf[5]; if (read(pipe_a[0], buf, 4) != 4) err(1, "read"); buf[4] = 0; printf("got back: '%s'\n", buf); } $ gcc -o tee_test tee_test.c $ ./tee_test got back: 'abxx' $ ============ As suggested by Al Viro, fix it by creating a separate type for non-mergeable pipe buffers, then changing the types of buffers in splice_pipe_to_pipe() and link_pipe(). Cc: <stable@vger.kernel.org> Fixes: 7c77f0b3f920 ("splice: implement pipe to pipe splicing") Fixes: 70524490ee2e ("[PATCH] splice: add support for sys_tee()") Suggested-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Jann Horn <jannh@google.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* pipe: reject F_SETPIPE_SZ with size over UINT_MAXEric Biggers2018-02-061-1/+1
| | | | | | | | | | | | | | | | | | | | | | | A pipe's size is represented as an 'unsigned int'. As expected, writing a value greater than UINT_MAX to /proc/sys/fs/pipe-max-size fails with EINVAL. However, the F_SETPIPE_SZ fcntl silently truncates such values to 32 bits, rather than failing with EINVAL as expected. (It *does* fail with EINVAL for values above (1 << 31) but <= UINT_MAX.) Fix this by moving the check against UINT_MAX into round_pipe_size() which is called in both cases. Link: http://lkml.kernel.org/r/20180111052902.14409-6-ebiggers3@gmail.com Signed-off-by: Eric Biggers <ebiggers@google.com> Acked-by: Kees Cook <keescook@chromium.org> Acked-by: Joe Lawrence <joe.lawrence@redhat.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: "Luis R . Rodriguez" <mcgrof@kernel.org> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Mikulas Patocka <mpatocka@redhat.com> Cc: Willy Tarreau <w@1wt.eu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* pipe, sysctl: remove pipe_proc_fn()Eric Biggers2018-02-061-1/+0
| | | | | | | | | | | | | | | | | | | | | | | | pipe_proc_fn() is no longer needed, as it only calls through to proc_dopipe_max_size(). Just put proc_dopipe_max_size() in the ctl_table entry directly, and remove the unneeded EXPORT_SYMBOL() and the ENOSYS stub for it. (The reason the ENOSYS stub isn't needed is that the pipe-max-size ctl_table entry is located directly in 'kern_table' rather than being registered separately. Therefore, the entry is already only defined when the kernel is built with sysctl support.) Link: http://lkml.kernel.org/r/20180111052902.14409-3-ebiggers3@gmail.com Signed-off-by: Eric Biggers <ebiggers@google.com> Acked-by: Kees Cook <keescook@chromium.org> Acked-by: Joe Lawrence <joe.lawrence@redhat.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: "Luis R . Rodriguez" <mcgrof@kernel.org> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Mikulas Patocka <mpatocka@redhat.com> Cc: Willy Tarreau <w@1wt.eu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* pipe, sysctl: drop 'min' parameter from pipe-max-size converterEric Biggers2018-02-061-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Patch series "pipe: buffer limits fixes and cleanups", v2. This series simplifies the sysctl handler for pipe-max-size and fixes another set of bugs related to the pipe buffer limits: - The root user wasn't allowed to exceed the limits when creating new pipes. - There was an off-by-one error when checking the limits, so a limit of N was actually treated as N - 1. - F_SETPIPE_SZ accepted values over UINT_MAX. - Reading the pipe buffer limits could be racy. This patch (of 7): Before validating the given value against pipe_min_size, do_proc_dopipe_max_size_conv() calls round_pipe_size(), which rounds the value up to pipe_min_size. Therefore, the second check against pipe_min_size is redundant. Remove it. Link: http://lkml.kernel.org/r/20180111052902.14409-2-ebiggers3@gmail.com Signed-off-by: Eric Biggers <ebiggers@google.com> Acked-by: Kees Cook <keescook@chromium.org> Acked-by: Joe Lawrence <joe.lawrence@redhat.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: "Luis R . Rodriguez" <mcgrof@kernel.org> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Mikulas Patocka <mpatocka@redhat.com> Cc: Willy Tarreau <w@1wt.eu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* pipe: add proc_dopipe_max_size() to safely assign pipe_max_sizeJoe Lawrence2017-11-171-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | pipe_max_size is assigned directly via procfs sysctl: static struct ctl_table fs_table[] = { ... { .procname = "pipe-max-size", .data = &pipe_max_size, .maxlen = sizeof(int), .mode = 0644, .proc_handler = &pipe_proc_fn, .extra1 = &pipe_min_size, }, ... int pipe_proc_fn(struct ctl_table *table, int write, void __user *buf, size_t *lenp, loff_t *ppos) { ... ret = proc_dointvec_minmax(table, write, buf, lenp, ppos) ... and then later rounded in-place a few statements later: ... pipe_max_size = round_pipe_size(pipe_max_size); ... This leaves a window of time between initial assignment and rounding that may be visible to other threads. (For example, one thread sets a non-rounded value to pipe_max_size while another reads its value.) Similar reads of pipe_max_size are potentially racy: pipe.c :: alloc_pipe_info() pipe.c :: pipe_set_size() Add a new proc_dopipe_max_size() that consolidates reading the new value from the user buffer, verifying bounds, and calling round_pipe_size() with a single assignment to pipe_max_size. Link: http://lkml.kernel.org/r/1507658689-11669-4-git-send-email-joe.lawrence@redhat.com Signed-off-by: Joe Lawrence <joe.lawrence@redhat.com> Reported-by: Mikulas Patocka <mpatocka@redhat.com> Reviewed-by: Mikulas Patocka <mpatocka@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Jens Axboe <axboe@kernel.dk> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* License cleanup: add SPDX GPL-2.0 license identifier to files with no licenseGreg Kroah-Hartman2017-11-021-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* pipe: fix comment in pipe_buf_operationsMiklos Szeredi2016-10-051-8/+3
| | | | | | | Map and unmap ops no longer exist. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* pipe: add pipe_buf_steal() helperMiklos Szeredi2016-10-051-0/+11
| | | | | Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* pipe: add pipe_buf_confirm() helperMiklos Szeredi2016-10-051-1/+11
| | | | | Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* pipe: add pipe_buf_release() helperMiklos Szeredi2016-10-051-0/+14
| | | | | Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* pipe: add pipe_buf_get() helperMiklos Szeredi2016-10-051-0/+11
| | | | | Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* pipe: limit the per-user amount of pages allocated in pipesWilly Tarreau2016-01-191-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | On no-so-small systems, it is possible for a single process to cause an OOM condition by filling large pipes with data that are never read. A typical process filling 4000 pipes with 1 MB of data will use 4 GB of memory. On small systems it may be tricky to set the pipe max size to prevent this from happening. This patch makes it possible to enforce a per-user soft limit above which new pipes will be limited to a single page, effectively limiting them to 4 kB each, as well as a hard limit above which no new pipes may be created for this user. This has the effect of protecting the system against memory abuse without hurting other users, and still allowing pipes to work correctly though with less data at once. The limit are controlled by two new sysctls : pipe-user-pages-soft, and pipe-user-pages-hard. Both may be disabled by setting them to zero. The default soft limit allows the default number of FDs per process (1024) to create pipes of the default size (64kB), thus reaching a limit of 64MB before starting to create only smaller pipes. With 256 processes limited to 1024 FDs each, this results in 1024*64kB + (256*1024 - 1024) * 4kB = 1084 MB of memory allocated for a user. The hard limit is disabled by default to avoid breaking existing applications that make intensive use of pipes (eg: for splicing). Reported-by: socketpair@gmail.com Reported-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Mitigates: CVE-2013-4312 (Linux 2.0+) Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Willy Tarreau <w@1wt.eu> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* Merge branch 'for-linus' of ↵Linus Torvalds2014-04-121-19/+0
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull vfs updates from Al Viro: "The first vfs pile, with deep apologies for being very late in this window. Assorted cleanups and fixes, plus a large preparatory part of iov_iter work. There's a lot more of that, but it'll probably go into the next merge window - it *does* shape up nicely, removes a lot of boilerplate, gets rid of locking inconsistencie between aio_write and splice_write and I hope to get Kent's direct-io rewrite merged into the same queue, but some of the stuff after this point is having (mostly trivial) conflicts with the things already merged into mainline and with some I want more testing. This one passes LTP and xfstests without regressions, in addition to usual beating. BTW, readahead02 in ltp syscalls testsuite has started giving failures since "mm/readahead.c: fix readahead failure for memoryless NUMA nodes and limit readahead pages" - might be a false positive, might be a real regression..." * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (63 commits) missing bits of "splice: fix racy pipe->buffers uses" cifs: fix the race in cifs_writev() ceph_sync_{,direct_}write: fix an oops on ceph_osdc_new_request() failure kill generic_file_buffered_write() ocfs2_file_aio_write(): switch to generic_perform_write() ceph_aio_write(): switch to generic_perform_write() xfs_file_buffered_aio_write(): switch to generic_perform_write() export generic_perform_write(), start getting rid of generic_file_buffer_write() generic_file_direct_write(): get rid of ppos argument btrfs_file_aio_write(): get rid of ppos kill the 5th argument of generic_file_buffered_write() kill the 4th argument of __generic_file_aio_write() lustre: don't open-code kernel_recvmsg() ocfs2: don't open-code kernel_recvmsg() drbd: don't open-code kernel_recvmsg() constify blk_rq_map_user_iov() and friends lustre: switch to kernel_sendmsg() ocfs2: don't open-code kernel_sendmsg() take iov_iter stuff to mm/iov_iter.c process_vm_access: tidy up a bit ...
| * pipe: kill ->map() and ->unmap()Al Viro2014-04-011-19/+0
| | | | | | | | | | | | all pipe_buffer_operations have the same instances of those... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | Merge branch 'master' into for-nextJiri Kosina2014-02-201-0/+2
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| * fuse: fix pipe_buf_operationsMiklos Szeredi2014-01-221-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Having this struct in module memory could Oops when if the module is unloaded while the buffer still persists in a pipe. Since sock_pipe_buf_ops is essentially the same as fuse_dev_pipe_buf_steal merge them into nosteal_pipe_buf_ops (this is the same as default_pipe_buf_ops except stealing the page from the buffer is not allowed). Reported-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Cc: stable@vger.kernel.org
* | treewide: Fix typo in Documentation/DocBookMasanari Iida2014-02-191-1/+1
|/ | | | | | | | | | This patch fix spelling typo in Documentation/DocBook. It is because .html and .xml files are generated by make htmldocs, I have to fix a typo within the source files. Signed-off-by: Masanari Iida <standby24x7@gmail.com> Acked-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
* get rid of the last free_pipe_info() callersAl Viro2013-04-091-2/+1
| | | | | | and rename __free_pipe_info() to free_pipe_info() Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* get rid of alloc_pipe_info() argumentAl Viro2013-04-091-1/+1
| | | | | | not used anymore Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* get rid of pipe->inodeAl Viro2013-04-091-2/+0
| | | | | | | | it's used only as a flag to distinguish normal pipes/FIFOs from the internal per-task one used by file-to-file splice. And pipe->files would work just as well for that purpose... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* pipe: don't use ->i_mutexAl Viro2013-04-091-0/+2
| | | | | | | now it can be done - put mutex into pipe_inode_info, use it instead of ->i_mutex Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* pipe: take allocation and freeing of pipe_inode_info out of ->i_mutexAl Viro2013-04-091-0/+2
| | | | | | | | | | | | | | | | | | * new field - pipe->files; number of struct file over that pipe (all sharing the same inode, of course); protected by inode->i_lock. * pipe_release() decrements pipe->files, clears inode->i_pipe when if the counter has reached 0 (all under ->i_lock) and, in that case, frees pipe after having done pipe_unlock() * fifo_open() starts with grabbing ->i_lock, and either bumps pipe->files if ->i_pipe was non-NULL or allocates a new pipe (dropping and regaining ->i_lock) and rechecks ->i_pipe; if it's still NULL, inserts new pipe there, otherwise bumps ->i_pipe->files and frees the one we'd allocated. At that point we know that ->i_pipe is non-NULL and won't go away, so we can do pipe_lock() on it and proceed as we used to. If we end up failing, decrement pipe->files and if it reaches 0 clear ->i_pipe and free the sucker after pipe_unlock(). Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* Merge branch 'for-linus' of ↵Linus Torvalds2012-08-011-0/+2
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull second vfs pile from Al Viro: "The stuff in there: fsfreeze deadlock fixes by Jan (essentially, the deadlock reproduced by xfstests 068), symlink and hardlink restriction patches, plus assorted cleanups and fixes. Note that another fsfreeze deadlock (emergency thaw one) is *not* dealt with - the series by Fernando conflicts a lot with Jan's, breaks userland ABI (FIFREEZE semantics gets changed) and trades the deadlock for massive vfsmount leak; this is going to be handled next cycle. There probably will be another pull request, but that stuff won't be in it." Fix up trivial conflicts due to unrelated changes next to each other in drivers/{staging/gdm72xx/usb_boot.c, usb/gadget/storage_common.c} * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (54 commits) delousing target_core_file a bit Documentation: Correct s_umount state for freeze_fs/unfreeze_fs fs: Remove old freezing mechanism ext2: Implement freezing btrfs: Convert to new freezing mechanism nilfs2: Convert to new freezing mechanism ntfs: Convert to new freezing mechanism fuse: Convert to new freezing mechanism gfs2: Convert to new freezing mechanism ocfs2: Convert to new freezing mechanism xfs: Convert to new freezing code ext4: Convert to new freezing mechanism fs: Protect write paths by sb_start_write - sb_end_write fs: Skip atime update on frozen filesystem fs: Add freezing handling to mnt_want_write() / mnt_drop_write() fs: Improve filesystem freezing handling switch the protection of percpu_counter list to spinlock nfsd: Push mnt_want_write() outside of i_mutex btrfs: Push mnt_want_write() outside of i_mutex fat: Push mnt_want_write() outside of i_mutex ...
| * consolidate pipe file creationAl Viro2012-07-291-0/+2
| | | | | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | pipe: remove KM_USER0 from commentsCong Wang2012-07-241-5/+3
|/ | | | Signed-off-by: Cong Wang <amwang@redhat.com>
* pipes: add a "packetized pipe" mode for writingLinus Torvalds2012-04-291-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The actual internal pipe implementation is already really about individual packets (called "pipe buffers"), and this simply exposes that as a special packetized mode. When we are in the packetized mode (marked by O_DIRECT as suggested by Alan Cox), a write() on a pipe will not merge the new data with previous writes, so each write will get a pipe buffer of its own. The pipe buffer is then marked with the PIPE_BUF_FLAG_PACKET flag, which in turn will tell the reader side to break the read at that boundary (and throw away any partial packet contents that do not fit in the read buffer). End result: as long as you do writes less than PIPE_BUF in size (so that the pipe doesn't have to split them up), you can now treat the pipe as a packet interface, where each read() system call will read one packet at a time. You can just use a sufficiently big read buffer (PIPE_BUF is sufficient, since bigger than that doesn't guarantee atomicity anyway), and the return value of the read() will naturally give you the size of the packet. NOTE! We do not support zero-sized packets, and zero-sized reads and writes to a pipe continue to be no-ops. Also note that big packets will currently be split at write time, but that the size at which that happens is not really specified (except that it's bigger than PIPE_BUF). Currently that limit is the system page size, but we might want to explicitly support bigger packets some day. The main user for this is going to be the autofs packet interface, allowing us to stop having to care so deeply about exact packet sizes (which have had bugs with 32/64-bit compatibility modes). But user space can create packetized pipes with "pipe2(fd, O_DIRECT)", which will fail with an EINVAL on kernels that do not support this interface. Tested-by: Michael Tokarev <mjt@tls.msk.ru> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: David Miller <davem@davemloft.net> Cc: Ian Kent <raven@themaw.net> Cc: Thomas Meyer <thomas@m3y3r.de> Cc: stable@kernel.org # needed for systemd/autofs interaction fix Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* magic.h: move some FS magic numbers into magic.hMuthu Kumar2012-03-231-2/+0
| | | | | | | | | | | - Move open-coded filesystem magic numbers into magic.h - Rearrange magic.h so that the filesystem-related constants are grouped together. Signed-off-by: Muthukumar R <muthur@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* pipe_fs_i.h: fix kernel-doc warningRandy Dunlap2011-01-101-0/+1
| | | | | | | | | Fix kernel-doc notation warnings in pipe_fs_i.h: Warning(include/linux/pipe_fs_i.h:58): No description found for parameter 'buffers' Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Un-inline get_pipe_info() helper functionLinus Torvalds2010-11-281-12/+1
| | | | | | | | 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>
* Export 'get_pipe_info()' to other usersLinus Torvalds2010-11-281-0/+12
| | | | | | | | | | | | | | | | | | | 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>
* pipe: change /proc/sys/fs/pipe-max-pages to byte sized interfaceJens Axboe2010-06-031-1/+3
| | | | | | | | | | | 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>
* pipe: set lower and upper limit on max pages in the pipe page arrayJens Axboe2010-05-211-0/+2
| | | | | | | | | | | 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>
* pipe: add support for shrinking and growing pipesJens Axboe2010-05-211-4/+7
| | | | | | | | | 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>
* splice: implement default splice_read methodMiklos Szeredi2009-05-111-0/+1
| | | | | | | | | | | | If f_op->splice_read() is not implemented, fall back to a plain read. Use vfs_readv() to read into previously allocated pages. This will allow splice and functions using splice, such as the loop device, to work on all filesystems. This includes "direct_io" files in fuse which bypass the page cache. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* splice: add helpers for locking pipe inodeMiklos Szeredi2009-04-151-0/+5
| | | | | | | | | | | | | | | | | | | | 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>
* pipe: add documentation and commentsJens Axboe2007-07-101-1/+76
| | | | | | | | As per Andrew Mortons request, here's a set of documentation for the generic pipe_buf_operations hooks, the pipe, and pipe_buffer structures. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* pipe: change the ->pin() operation to ->confirm()Jens Axboe2007-07-101-4/+5
| | | | | | | | | | | | The name 'pin' was badly chosen, it doesn't pin a pipe buffer in the most commonly used sense in the kernel. So change the name to 'confirm', after debating this issue with Hugh Dickins a bit. A good return from ->confirm() means that the buffer is really there, and that the contents are good. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* pipe: allow passing around of ops private pointerJens Axboe2007-07-101-0/+1
| | | | | | | | relay needs this for proper consumption handling, and the network receive support needs it as well to lookup the sk_buff on pipe release. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* splice: divorce the splice structure/function definitions from the pipe headerJens Axboe2007-07-101-41/+0
| | | | | | | | | We need to move even more stuff into the header so that folks can use the splice_to_pipe() implementation instead of open-coding a lot of pipe knowledge (see relay implementation), so move to our own header file finally. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* splice: add void cookie to the actor dataJens Axboe2007-07-101-0/+1
| | | | | | We need that for passing driver private info. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* vmsplice: add vmsplice-to-user supportJens Axboe2007-07-101-1/+7
| | | | | | | | A bit of a cheat, it actually just copies the data to userspace. But this makes the interface nice and symmetric and enables people to build on splice, with room for future improvement in performance. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* splice: abstract out actor dataJens Axboe2007-07-101-4/+6
| | | | | | | | | | | | For direct splicing (or private splicing), the output may not be a file. So abstract out the handling into a specified actor function and put the data in the splice_desc structure earlier, so we can build on top of that. This is the first step in better splice handling for drivers, and also for implementing vmsplice _to_ user memory. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* pipe: move pipe_inode_info structure decleration up before it's usedJens Axboe2007-06-081-15/+15
| | | | | | | | There's really no reason it's below the first use of the pointer type, and it'll fail compilation for the network addition (for good reason). So move it up a bit. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* Export __splice_from_pipe()Mark Fasheh2007-03-271-0/+4
| | | | | | | | | Ocfs2 wants to implement it's own splice write actor so that it can better manage cluster / page locks. This lets us re-use the rest of splice write while only providing our own code where it's actually important. Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* [PATCH] reorder struct pipe_buf_operationsEric Dumazet2006-12-131-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | Fields of struct pipe_buf_operations have not a precise layout (ie not optimized to fit cache lines nor reduce cache line ping pongs) The bufs[] array is *large* and is placed near the beginning of the structure, so all following fields have a large offset. This is unfortunate because many archs have smaller instructions when using small offsets relative to a base register. On x86 for example, 7 bits offsets have smaller instruction lengths. Moving bufs[] at the end of pipe_buf_operations permits all fields to have small offsets, and reduce text size, and icache pressure. # size vmlinux.pre vmlinux text data bss dec hex filename 3268989 664356 492196 4425541 438745 vmlinux.pre 3268765 664356 492196 4425317 438665 vmlinux So this patch reduces text size by 224 bytes on my x86_64 machine. Similar results on ia32. Signed-off-by: Eric Dumazet <dada1@cosmosbay.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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