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* [PATCH] check for null vfsmount in dentry_open()Christoph Hellwig2008-03-191-0/+12
| | | | | | | | | | | | | | | Make sure no-one calls dentry_open with a NULL vfsmount argument and crap out with a stacktrace otherwise. A NULL file->f_vfsmnt has always been problematic, but with the per-mount r/o tracking we can't accept anymore at all. [AV] the last place that passed NULL had been eliminated by the previous patch (reiserfs xattr stuff) Acked-by: Al Viro <viro@ZenIV.linux.org.uk> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Dave Hansen <haveblue@us.ibm.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* Make set_fs_{root,pwd} take a struct pathJan Blunck2008-02-141-8/+4
| | | | | | | | | | | In nearly all cases the set_fs_{root,pwd}() calls work on a struct path. Change the function to reflect this and use path_get() here. Signed-off-by: Jan Blunck <jblunck@suse.de> Signed-off-by: Andreas Gruenbacher <agruen@suse.de> Acked-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Introduce path_put()Jan Blunck2008-02-141-11/+11
| | | | | | | | | | | | | | | | | | | * Add path_put() functions for releasing a reference to the dentry and vfsmount of a struct path in the right order * Switch from path_release(nd) to path_put(&nd->path) * Rename dput_path() to path_put_conditional() [akpm@linux-foundation.org: fix cifs] Signed-off-by: Jan Blunck <jblunck@suse.de> Signed-off-by: Andreas Gruenbacher <agruen@suse.de> Acked-by: Christoph Hellwig <hch@lst.de> Cc: <linux-fsdevel@vger.kernel.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Steven French <sfrench@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Embed a struct path into struct nameidata instead of nd->{dentry,mnt}Jan Blunck2008-02-141-15/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This is the central patch of a cleanup series. In most cases there is no good reason why someone would want to use a dentry for itself. This series reflects that fact and embeds a struct path into nameidata. Together with the other patches of this series - it enforced the correct order of getting/releasing the reference count on <dentry,vfsmount> pairs - it prepares the VFS for stacking support since it is essential to have a struct path in every place where the stack can be traversed - it reduces the overall code size: without patch series: text data bss dec hex filename 5321639 858418 715768 6895825 6938d1 vmlinux with patch series: text data bss dec hex filename 5320026 858418 715768 6894212 693284 vmlinux This patch: Switch from nd->{dentry,mnt} to nd->path.{dentry,mnt} everywhere. [akpm@linux-foundation.org: coding-style fixes] [akpm@linux-foundation.org: fix cifs] [akpm@linux-foundation.org: fix smack] Signed-off-by: Jan Blunck <jblunck@suse.de> Signed-off-by: Andreas Gruenbacher <agruen@suse.de> Acked-by: Christoph Hellwig <hch@lst.de> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* remove the unused exports of sys_open/sys_readArjan van de Ven2008-02-081-1/+0
| | | | | | | | | | | These exports (which aren't used and which are in fact dangerous to use because they pretty much form a security hole to use) have been marked _UNUSED since 2.6.24 with removal in 2.6.25. This patch is their final departure from the Linux kernel tree. Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* fs: remove fastcall, it is always emptyHarvey Harrison2008-02-081-2/+2
| | | | | | | [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mark sys_open/sys_read exports unusedArjan van de Ven2007-11-141-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | sys_open / sys_read were used in the early 1.2 days to load firmware from disk inside drivers. Since 2.0 or so this was deprecated behavior, but several drivers still were using this. Since a few years we have a request_firmware() API that implements this in a nice, consistent way. Only some old ISA sound drivers (pre-ALSA) still straggled along for some time.... however with commit c2b1239a9f22f19c53543b460b24507d0e21ea0c the last user is now gone. This is a good thing, since using sys_open / sys_read etc for firmware is a very buggy to dangerous thing to do; these operations put an fd in the process file descriptor table.... which then can be tampered with from other threads for example. For those who don't want the firmware loader, filp_open()/vfs_read are the better APIs to use, without this security issue. The patch below marks sys_open and sys_read unused now that they're really not used anymore, and for deletion in the 2.6.25 timeframe. Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* [PATCH] pass dentry to audit_inode()/audit_inode_child()Al Viro2007-10-211-2/+2
| | | | | | makes caller simpler *and* allows to scan ancestors Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* Implement file posix capabilitiesSerge E. Hallyn2007-10-171-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Implement file posix capabilities. This allows programs to be given a subset of root's powers regardless of who runs them, without having to use setuid and giving the binary all of root's powers. This version works with Kaigai Kohei's userspace tools, found at http://www.kaigai.gr.jp/index.php. For more information on how to use this patch, Chris Friedhoff has posted a nice page at http://www.friedhoff.org/fscaps.html. Changelog: Nov 27: Incorporate fixes from Andrew Morton (security-introduce-file-caps-tweaks and security-introduce-file-caps-warning-fix) Fix Kconfig dependency. Fix change signaling behavior when file caps are not compiled in. Nov 13: Integrate comments from Alexey: Remove CONFIG_ ifdef from capability.h, and use %zd for printing a size_t. Nov 13: Fix endianness warnings by sparse as suggested by Alexey Dobriyan. Nov 09: Address warnings of unused variables at cap_bprm_set_security when file capabilities are disabled, and simultaneously clean up the code a little, by pulling the new code into a helper function. Nov 08: For pointers to required userspace tools and how to use them, see http://www.friedhoff.org/fscaps.html. Nov 07: Fix the calculation of the highest bit checked in check_cap_sanity(). Nov 07: Allow file caps to be enabled without CONFIG_SECURITY, since capabilities are the default. Hook cap_task_setscheduler when !CONFIG_SECURITY. Move capable(TASK_KILL) to end of cap_task_kill to reduce audit messages. Nov 05: Add secondary calls in selinux/hooks.c to task_setioprio and task_setscheduler so that selinux and capabilities with file cap support can be stacked. Sep 05: As Seth Arnold points out, uid checks are out of place for capability code. Sep 01: Define task_setscheduler, task_setioprio, cap_task_kill, and task_setnice to make sure a user cannot affect a process in which they called a program with some fscaps. One remaining question is the note under task_setscheduler: are we ok with CAP_SYS_NICE being sufficient to confine a process to a cpuset? It is a semantic change, as without fsccaps, attach_task doesn't allow CAP_SYS_NICE to override the uid equivalence check. But since it uses security_task_setscheduler, which elsewhere is used where CAP_SYS_NICE can be used to override the uid equivalence check, fixing it might be tough. task_setscheduler note: this also controls cpuset:attach_task. Are we ok with CAP_SYS_NICE being used to confine to a cpuset? task_setioprio task_setnice sys_setpriority uses this (through set_one_prio) for another process. Need same checks as setrlimit Aug 21: Updated secureexec implementation to reflect the fact that euid and uid might be the same and nonzero, but the process might still have elevated caps. Aug 15: Handle endianness of xattrs. Enforce capability version match between kernel and disk. Enforce that no bits beyond the known max capability are set, else return -EPERM. With this extra processing, it may be worth reconsidering doing all the work at bprm_set_security rather than d_instantiate. Aug 10: Always call getxattr at bprm_set_security, rather than caching it at d_instantiate. [morgan@kernel.org: file-caps clean up for linux/capability.h] [bunk@kernel.org: unexport cap_inode_killpriv] Signed-off-by: Serge E. Hallyn <serue@us.ibm.com> Cc: Stephen Smalley <sds@tycho.nsa.gov> Cc: James Morris <jmorris@namei.org> Cc: Chris Wright <chrisw@sous-sol.org> Cc: Andrew Morgan <morgan@kernel.org> Signed-off-by: Andrew Morgan <morgan@kernel.org> Signed-off-by: Adrian Bunk <bunk@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* fs: correct SuS compliance for open of large file without optionsAlan Cox2007-10-171-1/+1
| | | | | | | | | | | | | | | | | The early LFS work that Linux uses favours EFBIG in various places. SuSv3 specifically uses EOVERFLOW for this as noted by Michael (Bug 7253) [EOVERFLOW] The named file is a regular file and the size of the file cannot be represented correctly in an object of type off_t. We should therefore transition to the proper error return code Signed-off-by: Alan Cox <alan@redhat.com> Cc: Theodore Tso <tytso@mit.edu> Cc: Jens Axboe <jens.axboe@oracle.com> Cc: Arjan van de Ven <arjan@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* SELinux: Improve read/write performanceYuichi Nakamura2007-10-171-0/+4
| | | | | | | | | | | | | | It reduces the selinux overhead on read/write by only revalidating permissions in selinux_file_permission if the task or inode labels have changed or the policy has changed since the open-time check. A new LSM hook, security_dentry_open, is added to capture the necessary state at open time to allow this optimization. (see http://marc.info/?l=selinux&m=118972995207740&w=2) Signed-off-by: Yuichi Nakamura<ynakam@hitachisoft.jp> Acked-by: Stephen Smalley <sds@tycho.nsa.gov> Signed-off-by: James Morris <jmorris@namei.org>
* VFS: fix a race in lease-breaking during truncatedavid m. richter2007-07-311-7/+9
| | | | | | | | | | | | It is possible that another process could acquire a new file lease right after break_lease() is called during a truncate, but before lease-granting is disabled by the subsequent get_write_access(). Merely switching the order of the break_lease() and get_write_access() calls prevents this race. Signed-off-by: David M. Richter <richterd@citi.umich.edu> Signed-off-by: "J. Bruce Fields" <bfields@citi.umich.edu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* fallocate syscall interface deficiencyUlrich Drepper2007-07-241-1/+1
| | | | | | | | | | | | | | | | | The fallocate syscall returns ENOSYS in case the filesystem does not support the operation and expects the userlevel code to fill in. This is good in concept. The problem is that the libc code for old kernels should be able to distinguish the case where the syscall is not at all available vs not functioning for a specific mount point. As is this is not possible and we always have to invoke the syscall even if the kernel doesn't support it. I suggest the following patch. Using EOPNOTSUPP is IMO the right thing to do. Cc: Amit Arora <aarora@in.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* sys_fallocate() implementation on i386, x86_64 and powerpcAmit Arora2007-07-171-0/+59
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | fallocate() is a new system call being proposed here which will allow applications to preallocate space to any file(s) in a file system. Each file system implementation that wants to use this feature will need to support an inode operation called ->fallocate(). Applications can use this feature to avoid fragmentation to certain level and thus get faster access speed. With preallocation, applications also get a guarantee of space for particular file(s) - even if later the the system becomes full. Currently, glibc provides an interface called posix_fallocate() which can be used for similar cause. Though this has the advantage of working on all file systems, but it is quite slow (since it writes zeroes to each block that has to be preallocated). Without a doubt, file systems can do this more efficiently within the kernel, by implementing the proposed fallocate() system call. It is expected that posix_fallocate() will be modified to call this new system call first and incase the kernel/filesystem does not implement it, it should fall back to the current implementation of writing zeroes to the new blocks. ToDos: 1. Implementation on other architectures (other than i386, x86_64, and ppc). Patches for s390(x) and ia64 are already available from previous posts, but it was decided that they should be added later once fallocate is in the mainline. Hence not including those patches in this take. 2. Changes to glibc, a) to support fallocate() system call b) to make posix_fallocate() and posix_fallocate64() call fallocate() Signed-off-by: Amit Arora <aarora@in.ibm.com>
* O_CLOEXEC for SCM_RIGHTSUlrich Drepper2007-07-161-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Part two in the O_CLOEXEC saga: adding support for file descriptors received through Unix domain sockets. The patch is once again pretty minimal, it introduces a new flag for recvmsg and passes it just like the existing MSG_CMSG_COMPAT flag. I think this bit is not used otherwise but the networking people will know better. This new flag is not recognized by recvfrom and recv. These functions cannot be used for that purpose and the asymmetry this introduces is not worse than the already existing MSG_CMSG_COMPAT situations. The patch must be applied on the patch which introduced O_CLOEXEC. It has to remove static from the new get_unused_fd_flags function but since scm.c cannot live in a module the function still hasn't to be exported. Here's a test program to make sure the code works. It's so much longer than the actual patch... #include <errno.h> #include <error.h> #include <fcntl.h> #include <stdio.h> #include <string.h> #include <unistd.h> #include <sys/socket.h> #include <sys/un.h> #ifndef O_CLOEXEC # define O_CLOEXEC 02000000 #endif #ifndef MSG_CMSG_CLOEXEC # define MSG_CMSG_CLOEXEC 0x40000000 #endif int main (int argc, char *argv[]) { if (argc > 1) { int fd = atol (argv[1]); printf ("child: fd = %d\n", fd); if (fcntl (fd, F_GETFD) == 0 || errno != EBADF) { puts ("file descriptor valid in child"); return 1; } return 0; } struct sockaddr_un sun; strcpy (sun.sun_path, "./testsocket"); sun.sun_family = AF_UNIX; char databuf[] = "hello"; struct iovec iov[1]; iov[0].iov_base = databuf; iov[0].iov_len = sizeof (databuf); union { struct cmsghdr hdr; char bytes[CMSG_SPACE (sizeof (int))]; } buf; struct msghdr msg = { .msg_iov = iov, .msg_iovlen = 1, .msg_control = buf.bytes, .msg_controllen = sizeof (buf) }; struct cmsghdr *cmsg = CMSG_FIRSTHDR (&msg); cmsg->cmsg_level = SOL_SOCKET; cmsg->cmsg_type = SCM_RIGHTS; cmsg->cmsg_len = CMSG_LEN (sizeof (int)); msg.msg_controllen = cmsg->cmsg_len; pid_t child = fork (); if (child == -1) error (1, errno, "fork"); if (child == 0) { int sock = socket (PF_UNIX, SOCK_STREAM, 0); if (sock < 0) error (1, errno, "socket"); if (bind (sock, (struct sockaddr *) &sun, sizeof (sun)) < 0) error (1, errno, "bind"); if (listen (sock, SOMAXCONN) < 0) error (1, errno, "listen"); int conn = accept (sock, NULL, NULL); if (conn == -1) error (1, errno, "accept"); *(int *) CMSG_DATA (cmsg) = sock; if (sendmsg (conn, &msg, MSG_NOSIGNAL) < 0) error (1, errno, "sendmsg"); return 0; } /* For a test suite this should be more robust like a barrier in shared memory. */ sleep (1); int sock = socket (PF_UNIX, SOCK_STREAM, 0); if (sock < 0) error (1, errno, "socket"); if (connect (sock, (struct sockaddr *) &sun, sizeof (sun)) < 0) error (1, errno, "connect"); unlink (sun.sun_path); *(int *) CMSG_DATA (cmsg) = -1; if (recvmsg (sock, &msg, MSG_CMSG_CLOEXEC) < 0) error (1, errno, "recvmsg"); int fd = *(int *) CMSG_DATA (cmsg); if (fd == -1) error (1, 0, "no descriptor received"); char fdname[20]; snprintf (fdname, sizeof (fdname), "%d", fd); execl ("/proc/self/exe", argv[0], fdname, NULL); puts ("execl failed"); return 1; } [akpm@linux-foundation.org: Fix fastcall inconsistency noted by Michael Buesch] [akpm@linux-foundation.org: build fix] Signed-off-by: Ulrich Drepper <drepper@redhat.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Michael Buesch <mb@bu3sch.de> Cc: Michael Kerrisk <mtk-manpages@gmx.net> Acked-by: David S. Miller <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Introduce O_CLOEXECUlrich Drepper2007-07-161-3/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The problem is as follows: in multi-threaded code (or more correctly: all code using clone() with CLONE_FILES) we have a race when exec'ing. thread #1 thread #2 fd=open() fork + exec fcntl(fd,F_SETFD,FD_CLOEXEC) In some applications this can happen frequently. Take a web browser. One thread opens a file and another thread starts, say, an external PDF viewer. The result can even be a security issue if that open file descriptor refers to a sensitive file and the external program can somehow be tricked into using that descriptor. Just adding O_CLOEXEC support to open() doesn't solve the whole set of problems. There are other ways to create file descriptors (socket, epoll_create, Unix domain socket transfer, etc). These can and should be addressed separately though. open() is such an easy case that it makes not much sense putting the fix off. The test program: #include <errno.h> #include <fcntl.h> #include <stdio.h> #include <unistd.h> #ifndef O_CLOEXEC # define O_CLOEXEC 02000000 #endif int main (int argc, char *argv[]) { int fd; if (argc > 1) { fd = atol (argv[1]); printf ("child: fd = %d\n", fd); if (fcntl (fd, F_GETFD) == 0 || errno != EBADF) { puts ("file descriptor valid in child"); return 1; } return 0; } fd = open ("/proc/self/exe", O_RDONLY | O_CLOEXEC); printf ("in parent: new fd = %d\n", fd); char buf[20]; snprintf (buf, sizeof (buf), "%d", fd); execl ("/proc/self/exe", argv[0], buf, NULL); puts ("execl failed"); return 1; } [kyle@parisc-linux.org: parisc fix] Signed-off-by: Ulrich Drepper <drepper@redhat.com> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: Davide Libenzi <davidel@xmailserver.org> Cc: Michael Kerrisk <mtk-manpages@gmx.net> Cc: Chris Zankel <chris@zankel.net> Signed-off-by: Kyle McMartin <kyle@parisc-linux.org> Acked-by: David S. Miller <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Remove suid/sgid bits on [f]truncate()Linus Torvalds2007-05-081-0/+3
| | | | | | | | .. to match what we do on write(). This way, people who write to files by using [f]truncate + writable mmap have the same semantics as if they were using the write() family of system calls. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* header cleaning: don't include smp_lock.h when not usedRandy Dunlap2007-05-081-1/+0
| | | | | | | | | | | | Remove includes of <linux/smp_lock.h> where it is not used/needed. Suggested by Al Viro. Builds cleanly on x86_64, i386, alpha, ia64, powerpc, sparc, sparc64, and arm (all 59 defconfigs). Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* [PATCH] fdtable: Make fdarray and fdsets equal in sizeVadim Lobanov2006-12-101-2/+1
| | | | | | | | | | | | | | | | | | | | | | | | Currently, each fdtable supports three dynamically-sized arrays of data: the fdarray and two fdsets. The code allows the number of fds supported by the fdarray (fdtable->max_fds) to differ from the number of fds supported by each of the fdsets (fdtable->max_fdset). In practice, it is wasteful for these two sizes to differ: whenever we hit a limit on the smaller-capacity structure, we will reallocate the entire fdtable and all the dynamic arrays within it, so any delta in the memory used by the larger-capacity structure will never be touched at all. Rather than hogging this excess, we shouldn't even allocate it in the first place, and keep the capacities of the fdarray and the fdsets equal. This patch removes fdtable->max_fdset. As an added bonus, most of the supporting code becomes simpler. Signed-off-by: Vadim Lobanov <vlobanov@speakeasy.net> Cc: Christoph Hellwig <hch@lst.de> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Dipankar Sarma <dipankar@in.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] VFS: change struct file to use struct pathJosef "Jeff" Sipek2006-12-081-13/+13
| | | | | | | | | | | | | This patch changes struct file to use struct path instead of having independent pointers to struct dentry and struct vfsmount, and converts all users of f_{dentry,vfsmnt} in fs/ to use f_path.{dentry,mnt}. Additionally, it adds two #define's to make the transition easier for users of the f_dentry and f_vfsmnt. Signed-off-by: Josef "Jeff" Sipek <jsipek@cs.sunysb.edu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] tty: ->signal->tty lockingPeter Zijlstra2006-12-081-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fix the locking of signal->tty. Use ->sighand->siglock to protect ->signal->tty; this lock is already used by most other members of ->signal/->sighand. And unless we are 'current' or the tasklist_lock is held we need ->siglock to access ->signal anyway. (NOTE: sys_unshare() is broken wrt ->sighand locking rules) Note that tty_mutex is held over tty destruction, so while holding tty_mutex any tty pointer remains valid. Otherwise the lifetime of ttys are governed by their open file handles. This leaves some holes for tty access from signal->tty (or any other non file related tty access). It solves the tty SLAB scribbles we were seeing. (NOTE: the change from group_send_sig_info to __group_send_sig_info needs to be examined by someone familiar with the security framework, I think it is safe given the SEND_SIG_PRIV from other __group_send_sig_info invocations) [schwidefsky@de.ibm.com: 3270 fix] [akpm@osdl.org: various post-viro fixes] Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Alan Cox <alan@redhat.com> Cc: Oleg Nesterov <oleg@tv-sign.ru> Cc: Prarit Bhargava <prarit@redhat.com> Cc: Chris Wright <chrisw@sous-sol.org> Cc: Roland McGrath <roland@redhat.com> Cc: Stephen Smalley <sds@tycho.nsa.gov> Cc: James Morris <jmorris@namei.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: Jeff Dike <jdike@addtoit.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Jan Kara <jack@ucw.cz> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] r/o bind mounts: prepare for write access checks: collapse if()Dave Hansen2006-10-011-27/+37
| | | | | | | | | | | | | We're shortly going to be adding a bunch more permission checks in these functions. That requires adding either a bunch of new if() conditions, or some gotos. This patch collapses existing if()s and uses gotos instead to prepare for the upcoming changes. Signed-off-by: Dave Hansen <haveblue@us.ibm.com> Acked-by: Christoph Hellwig <hch@lst.de> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] Create fs/utimes.cAlexey Dobriyan2006-10-011-134/+0
| | | | | | | | | * fs/open.c is getting bit crowdy * preparation to lutimes(2) Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] fix wrong error code on interrupted close syscallsErnie Petrides2006-09-291-1/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The problem is that close() syscalls can call a file system's flush handler, which in turn might sleep interruptibly and ultimately pass back an -ERESTARTSYS return value. This happens for files backed by an interruptible NFS mount under nfs_file_flush() when a large file has just been written and nfs_wait_bit_interruptible() detects that there is a signal pending. I have a test case where the "strace" command is used to attach to a process sleeping in such a close(). Since the SIGSTOP is forced onto the victim process (removing it from the thread's "blocked" mask in force_sig_info()), the RPC wait is interrupted and the close() is terminated early. But the file table entry has already been cleared before the flush handler was called. Thus, when the syscall is restarted, the file descriptor appears closed and an EBADF error is returned (which is wrong). What's worse, there is the hypothetical case where another thread of a multi-threaded application might have reused the file descriptor, in which case that file would be mistakenly closed. The bottom line is that close() syscalls are not restartable, and thus -ERESTARTSYS return values should be mapped to -EINTR. This is consistent with the close(2) manual page. The fix is below. Signed-off-by: Ernie Petrides <petrides@redhat.com> Cc: Roland McGrath <roland@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] vfs: define new lookup flag for chdirMiklos Szeredi2006-09-291-1/+2
| | | | | | | | | | | | | In the "operation does permission checking" model used by fuse, chdir permission is not checked, since there's no chdir method. For this case set a lookup flag, which will be passed to ->permission(), so fuse can distinguish it from permission checks for other operations. Signed-off-by: Miklos Szeredi <miklos@szeredi.hu> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] ftruncate does not always update m/ctimePeter Staubach2006-06-251-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In the course of trying to track down a bug where a file mtime was not being updated correctly, it was discovered that the m/ctime updates were not quite being handled correctly for ftruncate() calls. Quoth SUSv3: open(2): If O_TRUNC is set and the file did previously exist, upon successful completion, open() shall mark for update the st_ctime and st_mtime fields of the file. truncate(2): Upon successful completion, if the file size is changed, this function shall mark for update the st_ctime and st_mtime fields of the file, and the S_ISUID and S_ISGID bits of the file mode may be cleared. ftruncate(2): Upon successful completion, if fildes refers to a regular file, the ftruncate() function shall mark for update the st_ctime and st_mtime fields of the file and the S_ISUID and S_ISGID bits of the file mode may be cleared. If the ftruncate() function is unsuccessful, the file is unaffected. The open(O_TRUNC) and truncate cases were being handled correctly, but the ftruncate case was being handled like the truncate case. The semantics of truncate and ftruncate don't quite match, so ftruncate needs to be handled slightly differently. The attached patch addresses this issue for ftruncate(2). My thanx to Stephen Tweedie and Trond Myklebust for their help in understanding the situation and semantics. Signed-off-by: Peter Staubach <staubach@redhat.com> Cc: "Stephen C. Tweedie" <sct@redhat.com> Cc: Trond Myklebust <trond.myklebust@fys.uio.no> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] vfs: add lock owner argument to flush operationMiklos Szeredi2006-06-231-1/+1
| | | | | | | | | | | | | | | | | | | Pass the POSIX lock owner ID to the flush operation. This is useful for filesystems which don't want to store any locking state in inode->i_flock but want to handle locking/unlocking POSIX locks internally. FUSE is one such filesystem but I think it possible that some network filesystems would need this also. Also add a flag to indicate that a POSIX locking request was generated by close(), so filesystems using the above feature won't send an extra locking request in this case. Signed-off-by: Miklos Szeredi <miklos@szeredi.hu> Cc: Trond Myklebust <trond.myklebust@fys.uio.no> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] VFS: Permit filesystem to perform statfs with a known root dentryDavid Howells2006-06-231-13/+13
| | | | | | | | | | | | | | | | | | | | | Give the statfs superblock operation a dentry pointer rather than a superblock pointer. This complements the get_sb() patch. That reduced the significance of sb->s_root, allowing NFS to place a fake root there. However, NFS does require a dentry to use as a target for the statfs operation. This permits the root in the vfsmount to be used instead. linux/mount.h has been added where necessary to make allyesconfig build successfully. Interest has also been expressed for use with the FUSE and XFS filesystems. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Al Viro <viro@zeniv.linux.org.uk> Cc: Nathan Scott <nathans@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] log more info for directory entry change eventsAmy Griffis2006-06-201-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | When an audit event involves changes to a directory entry, include a PATH record for the directory itself. A few other notable changes: - fixed audit_inode_child() hooks in fsnotify_move() - removed unused flags arg from audit_inode() - added audit log routines for logging a portion of a string Here's some sample output. before patch: type=SYSCALL msg=audit(1149821605.320:26): arch=40000003 syscall=39 success=yes exit=0 a0=bf8d3c7c a1=1ff a2=804e1b8 a3=bf8d3c7c items=1 ppid=739 pid=800 auid=0 uid=0 gid=0 euid=0 suid=0 fsuid=0 egid=0 sgid=0 fsgid=0 tty=ttyS0 comm="mkdir" exe="/bin/mkdir" subj=root:system_r:unconfined_t:s0-s0:c0.c255 type=CWD msg=audit(1149821605.320:26): cwd="/root" type=PATH msg=audit(1149821605.320:26): item=0 name="foo" parent=164068 inode=164010 dev=03:00 mode=040755 ouid=0 ogid=0 rdev=00:00 obj=root:object_r:user_home_t:s0 after patch: type=SYSCALL msg=audit(1149822032.332:24): arch=40000003 syscall=39 success=yes exit=0 a0=bfdd9c7c a1=1ff a2=804e1b8 a3=bfdd9c7c items=2 ppid=714 pid=777 auid=0 uid=0 gid=0 euid=0 suid=0 fsuid=0 egid=0 sgid=0 fsgid=0 tty=ttyS0 comm="mkdir" exe="/bin/mkdir" subj=root:system_r:unconfined_t:s0-s0:c0.c255 type=CWD msg=audit(1149822032.332:24): cwd="/root" type=PATH msg=audit(1149822032.332:24): item=0 name="/root" inode=164068 dev=03:00 mode=040750 ouid=0 ogid=0 rdev=00:00 obj=root:object_r:user_home_dir_t:s0 type=PATH msg=audit(1149822032.332:24): item=1 name="foo" inode=164010 dev=03:00 mode=040755 ouid=0 ogid=0 rdev=00:00 obj=root:object_r:user_home_t:s0 Signed-off-by: Amy Griffis <amy.griffis@hp.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* [PATCH] fs/open.c: unexport sys_openatAdrian Bunk2006-05-151-1/+0
| | | | | | | | Remove the unused EXPORT_SYMBOL_GPL(sys_openat). Signed-off-by: Adrian Bunk <bunk@stusta.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* x86: be careful about tailcall breakage for sys_open[at] tooLinus Torvalds2006-04-181-2/+14
| | | | | | | | | | | | | | Came up through a quick grep for other cases similar to the ftruncate() one in commit 0a489cb3b6a7b277030cdbc97c2c65905db94536. Also, add a comment, so that people who read the code understand why we do what looks like a no-op. (Again, this won't actually matter to any sane user, since libc will save and restore the register gcc stomps on, but it's still wrong to stomp on it) Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* x86: don't allow tail-calls in sys_ftruncate[64]()Linus Torvalds2006-04-181-2/+6
| | | | | | | | | | | | | | | | | | | | Gcc thinks it owns the incoming argument stack, but that's not true for "asmlinkage" functions, and it corrupts the caller-set-up argument stack when it pushes the third argument onto the stack. Which can result in %ebx getting corrupted in user space. Now, normally nobody sane would ever notice, since libc will save and restore %ebx anyway over the system call, but it's still wrong. I'd much rather have "asmlinkage" tell gcc directly that it doesn't own the stack, but no such attribute exists, so we're stuck with our hacky manual "prevent_tail_call()" macro once more (we've had the same issue before with sys_waitpid() and sys_wait4()). Thanks to Hans-Werner Hilse <hilse@sub.uni-goettingen.de> for reporting the issue and testing the fix. Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* Merge branch 'audit.b3' of ↵Linus Torvalds2006-03-251-1/+7
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/viro/audit-current * 'audit.b3' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/audit-current: (22 commits) [PATCH] fix audit_init failure path [PATCH] EXPORT_SYMBOL patch for audit_log, audit_log_start, audit_log_end and audit_format [PATCH] sem2mutex: audit_netlink_sem [PATCH] simplify audit_free() locking [PATCH] Fix audit operators [PATCH] promiscuous mode [PATCH] Add tty to syscall audit records [PATCH] add/remove rule update [PATCH] audit string fields interface + consumer [PATCH] SE Linux audit events [PATCH] Minor cosmetic cleanups to the code moved into auditfilter.c [PATCH] Fix audit record filtering with !CONFIG_AUDITSYSCALL [PATCH] Fix IA64 success/failure indication in syscall auditing. [PATCH] Miscellaneous bug and warning fixes [PATCH] Capture selinux subject/object context information. [PATCH] Exclude messages by message type [PATCH] Collect more inode information during syscall processing. [PATCH] Pass dentry, not just name, in fsnotify creation hooks. [PATCH] Define new range of userspace messages. [PATCH] Filter rule comparators ... Fixed trivial conflict in security/selinux/hooks.c
| * [PATCH] Collect more inode information during syscall processing.Amy Griffis2006-03-201-1/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch augments the collection of inode info during syscall processing. It represents part of the functionality that was provided by the auditfs patch included in RHEL4. Specifically, it: - Collects information for target inodes created or removed during syscalls. Previous code only collects information for the target inode's parent. - Adds the audit_inode() hook to syscalls that operate on a file descriptor (e.g. fchown), enabling audit to do inode filtering for these calls. - Modifies filtering code to check audit context for either an inode # or a parent inode # matching a given rule. - Modifies logging to provide inode # for both parent and child. - Protect debug info from NULL audit_names.name. [AV: folded a later typo fix from the same author] Signed-off-by: Amy Griffis <amy.griffis@hp.com> Signed-off-by: David Woodhouse <dwmw2@infradead.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | [PATCH] Add lookup_instantiate_filp usage warningOleg Drokin2006-03-251-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | I think it would be nice to put an usage warning in header of lookup_instantiate_filp() to indicate it is unsafe to use it on anything but regular files (even that is potentially unsafe, but there your ->open() is usually in your hands anyway), so that others won't fall into the same trap I did. Signed-off-by: Oleg Drokin <green@linuxhacker.ru> Cc: Trond Myklebust <trond.myklebust@fys.uio.no> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* | [PATCH] Shrinks sizeof(files_struct) and better layoutEric Dumazet2006-03-231-4/+4
|/ | | | | | | | | | | | | | | | | | | | | | | | 1) Reduce the size of (struct fdtable) to exactly 64 bytes on 32bits platforms, lowering kmalloc() allocated space by 50%. 2) Reduce the size of (files_struct), using a special 32 bits (or 64bits) embedded_fd_set, instead of a 1024 bits fd_set for the close_on_exec_init and open_fds_init fields. This save some ram (248 bytes per task) as most tasks dont open more than 32 files. D-Cache footprint for such tasks is also reduced to the minimum. 3) Reduce size of allocated fdset. Currently two full pages are allocated, that is 32768 bits on x86 for example, and way too much. The minimum is now L1_CACHE_BYTES. UP and SMP should benefit from this patch, because most tasks will touch only one cache line when open()/close() stdin/stdout/stderr (0/1/2), (next_fd, close_on_exec_init, open_fds_init, fd_array[0 .. 2] being in the same cache line) Signed-off-by: Eric Dumazet <dada1@cosmosbay.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] vfs: *at functions: coreUlrich Drepper2006-01-181-15/+68
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Here is a series of patches which introduce in total 13 new system calls which take a file descriptor/filename pair instead of a single file name. These functions, openat etc, have been discussed on numerous occasions. They are needed to implement race-free filesystem traversal, they are necessary to implement a virtual per-thread current working directory (think multi-threaded backup software), etc. We have in glibc today implementations of the interfaces which use the /proc/self/fd magic. But this code is rather expensive. Here are some results (similar to what Jim Meyering posted before). The test creates a deep directory hierarchy on a tmpfs filesystem. Then rm -fr is used to remove all directories. Without syscall support I get this: real 0m31.921s user 0m0.688s sys 0m31.234s With syscall support the results are much better: real 0m20.699s user 0m0.536s sys 0m20.149s The interfaces are for obvious reasons currently not much used. But they'll be used. coreutils (and Jeff's posixutils) are already using them. Furthermore, code like ftw/fts in libc (maybe even glob) will also start using them. I expect a patch to make follow soon. Every program which is walking the filesystem tree will benefit. Signed-off-by: Ulrich Drepper <drepper@redhat.com> Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Al Viro <viro@ftp.linux.org.uk> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: Michael Kerrisk <mtk-manpages@gmx.net> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] capable/capability.h (fs/)Randy Dunlap2006-01-111-0/+1
| | | | | | | | | fs: Use <linux/capability.h> where capable() is used. Signed-off-by: Randy Dunlap <rdunlap@xenotime.net> Acked-by: Tim Schmielau <tim@physik3.uni-rostock.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] mutex subsystem, semaphore to mutex: VFS, ->i_semJes Sorensen2006-01-091-12/+12
| | | | | | | | | | | | | This patch converts the inode semaphore to a mutex. I have tested it on XFS and compiled as much as one can consider on an ia64. Anyway your luck with it might be different. Modified-by: Ingo Molnar <mingo@elte.hu> (finished the conversion) Signed-off-by: Jes Sorensen <jes@sgi.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* [PATCH] tiny: Uninline some open.c functionsMatt Mackall2006-01-081-3/+3
| | | | | | | | | | | | | | | | | | | | uninline some open.c functions add/remove: 3/0 grow/shrink: 0/6 up/down: 679/-1166 (-487) function old new delta do_sys_truncate - 336 +336 do_sys_ftruncate - 317 +317 __put_unused_fd - 26 +26 put_unused_fd 57 49 -8 sys_close 150 119 -31 sys_ftruncate64 260 26 -234 sys_ftruncate 272 24 -248 sys_truncate 339 25 -314 sys_truncate64 336 5 -331 Signed-off-by: Matt Mackall <mpm@selenic.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] Fix some problems with truncate and mtime semantics.NeilBrown2006-01-081-4/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | SUS requires that when truncating a file to the size that it currently is: truncate and ftruncate should NOT modify ctime or mtime O_TRUNC SHOULD modify ctime and mtime. Currently mtime and ctime are always modified on most local filesystems (side effect of ->truncate) or never modified (on NFS). With this patch: ATTR_CTIME|ATTR_MTIME are sent with ATTR_SIZE precisely when an update of these times is required whether size changes or not (via a new argument to do_truncate). This allows NFS to do the right thing for O_TRUNC. inode_setattr nolonger forces ATTR_MTIME|ATTR_CTIME when the ATTR_SIZE sets the size to it's current value. This allows local filesystems to do the right thing for f?truncate. Also, the logic in inode_setattr is changed a bit so there are two return points. One returns the error from vmtruncate if it failed, the other returns 0 (there can be no other failure). Finally, if vmtruncate succeeds, and ATTR_SIZE is the only change requested, we now fall-through and mark_inode_dirty. If a filesystem did not have a ->truncate function, then vmtruncate will have changed i_size, without marking the inode as 'dirty', and I think this is wrong. Signed-off-by: Neil Brown <neilb@suse.de> Cc: Christoph Hellwig <hch@lst.de> Cc: Trond Myklebust <trond.myklebust@fys.uio.no> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] add a file_permission helperChristoph Hellwig2005-11-091-1/+1
| | | | | | | | | | | | A few more callers of permission() just want to check for a different access pattern on an already open file. This patch adds a wrapper for permission() that takes a file in preparation of per-mount read-only support and to clean up the callers a little. The helper is not intended for new code, everything without the interface set in stone should use vfs_permission() Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] add a vfs_permission helperChristoph Hellwig2005-11-091-6/+6
| | | | | | | | | | | Most permission() calls have a struct nameidata * available. This helper takes that as an argument and thus makes sure we pass it down for lookup intents and prepares for per-mount read-only support where we need a struct vfsmount for checking whether a file is writeable. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] VFS: pass file pointer to filesystem from ftruncate()Miklos Szeredi2005-11-071-3/+7
| | | | | | | | | | | | | | This patch extends the iattr structure with a file pointer memeber, and adds an ATTR_FILE validity flag for this member. This is set if do_truncate() is invoked from ftruncate() or from do_coredump(). The change is source and binary compatible. Signed-off-by: Miklos Szeredi <miklos@szeredi.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] memory leak in dentry_open()Peter Staubach2005-11-071-1/+8
| | | | | | | | | | | There is a memory leak possible in dentry_open(). If get_empty_filp() fails, then the references to dentry and mnt need to be released. The attached patch adds the calls to dput() and mntput() to release these two references. Signed-off-by: Peter Staubach <staubach@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* VFS: Allow the filesystem to return a full file pointer on open intentTrond Myklebust2005-10-181-14/+65
| | | | | | | | | This is needed by NFSv4 for atomicity reasons: our open command is in fact a lookup+open, so we need to be able to propagate open context information from lookup() into the resulting struct file's private_data field. Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
* [PATCH] open returns ENFILE but creates file anywayPeter Staubach2005-09-131-42/+56
| | | | | | | | | | | | | | | | | | | | | | | | | | When open(O_CREAT) is called and the error, ENFILE, is returned, the file may be created anyway. This is counter intuitive, against the SUS V3 specification, and may cause applications to misbehave if they are not coded correctly to handle this semantic. The SUS V3 specification explicitly states "No files shall be created or modified if the function returns -1.". The error, ENFILE, is used to indicate the system wide open file table is full and no more file structs can be allocated. This is due to an ordering problem. The entry in the directory is created before the file struct is allocated. If the allocation for the file struct fails, then the system call must return an error, but the directory entry was already created and can not be safely removed. The solution to this situation is relatively easy. The file struct should be allocated before the directory entry is created. If the allocation fails, then the error can be returned directly. If the creation of the directory entry fails, then the file struct can be easily freed. Signed-off-by: Peter Staubach <staubach@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] files: files struct with RCUDipankar Sarma2005-09-091-4/+4
| | | | | | | | | | | | | | | | | | | | | Patch to eliminate struct files_struct.file_lock spinlock on the reader side and use rcu refcounting rcuref_xxx api for the f_count refcounter. The updates to the fdtable are done by allocating a new fdtable structure and setting files->fdt to point to the new structure. The fdtable structure is protected by RCU thereby allowing lock-free lookup. For fd arrays/sets that are vmalloced, we use keventd to free them since RCU callbacks can't sleep. A global list of fdtable to be freed is not scalable, so we use a per-cpu list. If keventd is already handling the current cpu's work, we use a timer to defer queueing of that work. Since the last publication, this patch has been re-written to avoid using explicit memory barriers and use rcu_assign_pointer(), rcu_dereference() premitives instead. This required that the fd information is kept in a separate structure (fdtable) and updated atomically. Signed-off-by: Dipankar Sarma <dipankar@in.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] files: break up files structDipankar Sarma2005-09-091-17/+24
| | | | | | | | | | | | | | | In order for the RCU to work, the file table array, sets and their sizes must be updated atomically. Instead of ensuring this through too many memory barriers, we put the arrays and their sizes in a separate structure. This patch takes the first step of putting the file table elements in a separate structure fdtable that is embedded withing files_struct. It also changes all the users to refer to the file table using files_fdtable() macro. Subsequent applciation of RCU becomes easier after this. Signed-off-by: Dipankar Sarma <dipankar@in.ibm.com> Signed-Off-By: David Howells <dhowells@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] remove duplicated sys_open32() code from 64bit archsMiklos Szeredi2005-09-071-8/+11
| | | | | | | | | | | | 64 bit architectures all implement their own compatibility sys_open(), when in fact the difference is simply not forcing the O_LARGEFILE flag. So use the a common function instead. Signed-off-by: Miklos Szeredi <miklos@szeredi.hu> Cc: <viro@parcelfarce.linux.theplanet.co.uk> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
generated by cgit v1.1 at 2024-12-26 23:12:50 +0000