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* /proc/*/oom_score oops re badnessAlexey Dobriyan2007-05-081-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Eternal quest to make while true; do cat /proc/fs/xfs/stat >/dev/null 2>/dev/null; done while true; do find /proc -type f 2>/dev/null | xargs cat >/dev/null 2>/dev/null; done while true; do modprobe xfs; rmmod xfs; done work reliably continues and now kernel oopses in the following way: BUG: unable to handle ... at virtual address 6b6b6b6b EIP is at badness process: cat proc_oom_score proc_info_read sys_fstat64 vfs_read proc_info_read sys_read Failing code is prefetch hidden in list_for_each_entry() in badness(). badness() is reachable from two points. One is proc_oom_score, another is out_of_memory() => select_bad_process() => badness(). Second path grabs tasklist_lock, while first doesn't. Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* VFS: delay the dentry name generation on sockets and pipesEric Dumazet2007-05-082-6/+43
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 1) Introduces a new method in 'struct dentry_operations'. This method called d_dname() might be called from d_path() to build a pathname for special filesystems. It is called without locks. Future patches (if we succeed in having one common dentry for all pipes/sockets) may need to change prototype of this method, but we now use : char *d_dname(struct dentry *dentry, char *buffer, int buflen); 2) Adds a dynamic_dname() helper function that eases d_dname() implementations 3) Defines d_dname method for sockets : No more sprintf() at socket creation. This is delayed up to the moment someone does an access to /proc/pid/fd/... 4) Defines d_dname method for pipes : No more sprintf() at pipe creation. This is delayed up to the moment someone does an access to /proc/pid/fd/... A benchmark consisting of 1.000.000 calls to pipe()/close()/close() gives a *nice* speedup on my Pentium(M) 1.6 Ghz : 3.090 s instead of 3.450 s Signed-off-by: Eric Dumazet <dada1@cosmosbay.com> Acked-by: Christoph Hellwig <hch@infradead.org> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* add file position info to procMiklos Szeredi2007-05-081-18/+114
| | | | | | | | | | | | | | | | | | | | | | Add support for finding out the current file position, open flags and possibly other info in the future. These new entries are added: /proc/PID/fdinfo/FD /proc/PID/task/TID/fdinfo/FD For each fd the information is provided in the following format: pos: 1234 flags: 0100002 [bunk@stusta.de: make struct proc_fdinfo_file_operations static] Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Cc: Alexey Dobriyan <adobriyan@sw.ru> Signed-off-by: Adrian Bunk <bunk@stusta.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* procfs: reorder struct pid_dentry to save space on 64bit archs, and constify ↵Eric Dumazet2007-05-081-26/+27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | them Change the order of fields of struct pid_entry (file fs/proc/base.c) in order to avoid a hole on 64bit archs. (8 bytes saved per object) Also change all pid_entry arrays to be const qualified, to make clear they must not be modified. Before (on x86_64) : # size fs/proc/base.o text data bss dec hex filename 15549 2192 0 17741 454d fs/proc/base.o After : # size fs/proc/base.o text data bss dec hex filename 17229 176 0 17405 43fd fs/proc/base.o Thats 336 bytes saved on kernel size on x86_64 Signed-off-by: Eric Dumazet <dada1@cosmosbay.com> Acked-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* proc: maps protectionKees Cook2007-05-084-1/+29
| | | | | | | | | | | | | | | | | | | | | | | | | | The /proc/pid/ "maps", "smaps", and "numa_maps" files contain sensitive information about the memory location and usage of processes. Issues: - maps should not be world-readable, especially if programs expect any kind of ASLR protection from local attackers. - maps cannot just be 0400 because "-D_FORTIFY_SOURCE=2 -O2" makes glibc check the maps when %n is in a *printf call, and a setuid(getuid()) process wouldn't be able to read its own maps file. (For reference see http://lkml.org/lkml/2006/1/22/150) - a system-wide toggle is needed to allow prior behavior in the case of non-root applications that depend on access to the maps contents. This change implements a check using "ptrace_may_attach" before allowing access to read the maps contents. To control this protection, the new knob /proc/sys/kernel/maps_protect has been added, with corresponding updates to the procfs documentation. [akpm@linux-foundation.org: build fixes] [akpm@linux-foundation.org: New sysctl numbers are old hat] Signed-off-by: Kees Cook <kees@outflux.net> 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>
* namei.c: remove utterly outdated commentChristoph Hellwig2007-05-081-11/+0
| | | | | | | | | We don't have a routine called namei() anymore since at least 2.3.x, and the comment is just totally out of sync with the current lookup logic. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* vfs: remove superflous sb == NULL checksChristoph Hellwig2007-05-082-4/+2
| | | | | | | | inode->i_sb is always set, not need to check for it. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* proc: remove pathetic ->deleted WARN_ONAlexey Dobriyan2007-05-081-2/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | WARN_ON(de && de->deleted); is sooo unreliable. Why? proc_lookup remove_proc_entry =========== ================= lock_kernel(); spin_lock(&proc_subdir_lock); [find proc entry] spin_unlock(&proc_subdir_lock); spin_lock(&proc_subdir_lock); [find proc entry] proc_get_inode ============== WARN_ON(de && de->deleted); ... if (!atomic_read(&de->count)) free_proc_entry(de); else de->deleted = 1; So, if you have some strange oops [1], and doesn't see this WARN_ON it means nothing. [1] try_module_get() of module which doesn't exist, two lines below should suffice, or not? Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Fix race between proc_readdir and remove_proc_entryDarrick J. Wong2007-05-081-2/+9
| | | | | | | | | | | | | | | | | | | | | | | | Fix the following race: proc_readdir remove_proc_entry ============ ================= spin_lock(&proc_subdir_lock); [choose PDE to start filldir from] spin_unlock(&proc_subdir_lock); spin_lock(&proc_subdir_lock); [find PDE] [free PDE, refcount is 0] spin_unlock(&proc_subdir_lock); /* boom */ if (filldir(dirent, de->name, ... [de_put on error path --adobriyan] Signed-off-by: Darrick J. Wong <djwong@us.ibm.com> Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Fix race between proc_get_inode() and remove_proc_entry()Alexey Dobriyan2007-05-082-8/+6
| | | | | | | | | | | | | | | | | | | | | | proc_lookup remove_proc_entry =========== ================= lock_kernel(); spin_lock(&proc_subdir_lock); [find PDE with refcount 0] spin_unlock(&proc_subdir_lock); spin_lock(&proc_subdir_lock); [find PDE with refcount 0] [check refcount and free PDE] spin_unlock(&proc_subdir_lock); proc_get_inode: de_get(de); /* boom */ Signed-off-by: Alexey Dobriyan <adobriyan@openvz.org> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Oleg Nesterov <oleg@tv-sign.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* add filesystem subtype supportMiklos Szeredi2007-05-084-6/+48
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There's a slight problem with filesystem type representation in fuse based filesystems. From the kernel's view, there are just two filesystem types: fuse and fuseblk. From the user's view there are lots of different filesystem types. The user is not even much concerned if the filesystem is fuse based or not. So there's a conflict of interest in how this should be represented in fstab, mtab and /proc/mounts. The current scheme is to encode the real filesystem type in the mount source. So an sshfs mount looks like this: sshfs#user@server:/ /mnt/server fuse rw,nosuid,nodev,... This url-ish syntax works OK for sshfs and similar filesystems. However for block device based filesystems (ntfs-3g, zfs) it doesn't work, since the kernel expects the mount source to be a real device name. A possibly better scheme would be to encode the real type in the type field as "type.subtype". So fuse mounts would look like this: /dev/hda1 /mnt/windows fuseblk.ntfs-3g rw,... user@server:/ /mnt/server fuse.sshfs rw,nosuid,nodev,... This patch adds the necessary code to the kernel so that this can be correctly displayed in /proc/mounts. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* epoll: optimizations and cleanupsDavide Libenzi2007-05-081-147/+86
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Epoll is doing multiple passes over the ready set at the moment, because of the constraints over the f_op->poll() call. Looking at the code again, I noticed that we already hold the epoll semaphore in read, and this (together with other locking conditions that hold while doing an epoll_wait()) can lead to a smarter way [1] to "ship" events to userspace (in a single pass). This is a stress application that can be used to test the new code. It spwans multiple thread and call epoll_wait() and epoll_ctl() from many threads. Stress tested on my dual Opteron 254 w/out any problems. http://www.xmailserver.org/totalmess.c This is not a benchmark, just something that tries to stress and exploit possible problems with the new code. Also, I made a stupid micro-benchmark: http://www.xmailserver.org/epwbench.c [1] Considering that epoll must be thread-safe, there are five ways we can be hit during an epoll_wait() transfer loop (ep_send_events()): 1) The epoll fd going away and calling ep_free This just can't happen, since we did an fget() in sys_epoll_wait 2) An epoll_ctl(EPOLL_CTL_DEL) This can't happen because epoll_ctl() gets ep->sem in write, and we're holding it in read during ep_send_events() 3) An fd stored inside the epoll fd going away This can't happen because in eventpoll_release_file() we get ep->sem in write, and we're holding it in read during ep_send_events() 4) Another epoll_wait() happening on another thread They both can be inside ep_send_events() at the same time, we get (splice) the ready-list under the spinlock, so each one will get its own ready list. Note that an fd cannot be at the same time inside more than one ready list, because ep_poll_callback() will not re-queue it if it sees it already linked: if (ep_is_linked(&epi->rdllink)) goto is_linked; Another case that can happen, is two concurrent epoll_wait(), coming in with a userspace event buffer of size, say, ten. Suppose there are 50 event ready in the list. The first epoll_wait() will "steal" the whole list, while the second, seeing no events, will go to sleep. But at the end of ep_send_events() in the first epoll_wait(), we will re-inject surplus ready fds, and we will trigger the proper wake_up to the second epoll_wait(). 5) ep_poll_callback() hitting us asyncronously This is the tricky part. As I said above, the ep_is_linked() test done inside ep_poll_callback(), will guarantee us that until the item will result linked to a list, ep_poll_callback() will not try to re-queue it again (read, write data on any of its members). When we do a list_del() in ep_send_events(), the item will still satisfy the ep_is_linked() test (whatever data is written in prev/next, it'll never be its own pointer), so ep_poll_callback() will still leave us alone. It's only after the eventual smp_mb()+INIT_LIST_HEAD(&epi->rdllink) that it'll become visible to ep_poll_callback(), but at the point we're already past it. [akpm@osdl.org: 80 cols] Signed-off-by: Davide Libenzi <davidel@xmailserver.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* ext3: dirindex error pointer issuesDmitriy Monakhov2007-05-082-22/+30
| | | | | | | | | | | | | | | | | | | | | | | | - ext3_dx_find_entry() exit with out setting proper error pointer - do_split() exit with out setting proper error pointer it is realy painful because many callers contain folowing code: de = do_split(handle,dir, &bh, frame, &hinfo, &retval); if (!(de)) return retval; <<< WOW retval wasn't changed by do_split(), so caller failed <<< but return SUCCESS :) - Rearrange do_split() error path. Current error path is realy ugly, all this up and down jump stuff doesn't make code easy to understand. [dmonakhov@sw.ru: fix annoying fake error messages] Signed-off-by: Monakhov Dmitriy <dmonakhov@openvz.org> Cc: Andreas Dilger <adilger@clusterfs.com> Cc: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Monakhov Dmitriy <dmonakhov@openvz.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge sys_clone()/sys_unshare() nsproxy and namespace handlingBadari Pulavarty2007-05-081-23/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | sys_clone() and sys_unshare() both makes copies of nsproxy and its associated namespaces. But they have different code paths. This patch merges all the nsproxy and its associated namespace copy/clone handling (as much as possible). Posted on container list earlier for feedback. - Create a new nsproxy and its associated namespaces and pass it back to caller to attach it to right process. - Changed all copy_*_ns() routines to return a new copy of namespace instead of attaching it to task->nsproxy. - Moved the CAP_SYS_ADMIN checks out of copy_*_ns() routines. - Removed unnessary !ns checks from copy_*_ns() and added BUG_ON() just incase. - Get rid of all individual unshare_*_ns() routines and make use of copy_*_ns() instead. [akpm@osdl.org: cleanups, warning fix] [clg@fr.ibm.com: remove dup_namespaces() declaration] [serue@us.ibm.com: fix CONFIG_IPC_NS=n, clone(CLONE_NEWIPC) retval] [akpm@linux-foundation.org: fix build with CONFIG_SYSVIPC=n] Signed-off-by: Badari Pulavarty <pbadari@us.ibm.com> Signed-off-by: Serge Hallyn <serue@us.ibm.com> Cc: Cedric Le Goater <clg@fr.ibm.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: <containers@lists.osdl.org> Signed-off-by: Cedric Le Goater <clg@fr.ibm.com> Cc: Oleg Nesterov <oleg@tv-sign.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* exec: fix remove_arg_zeroNick Piggin2007-05-081-16/+34
| | | | | | | | | | | | | | | | | | | | | | | | | | Petr Tesarik discovered a problem in remove_arg_zero(). He writes: When a script is loaded, load_script() replaces argv[0] with the name of the interpreter and the filename passed to the exec syscall. However, there is no guarantee that the length of the interpreter name plus the length of the filename is greater than the length of the original argv[0]. If the difference happens to cross a page boundary, setup_arg_pages() will call put_dirty_page() [aka install_arg_page()] with an address outside the VMA. Therefore, remove_arg_zero() must free all pages which would be unused after the argument is removed. So, rewrite the remove_arg_zero function without gotos, with a few comments, and with the commonly used explicit index/offset. This fixes the problem and makes it easier to understand as well. [a.p.zijlstra@chello.nl: add comment] Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: Petr Tesarik <ptesarik@suse.cz> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* reiserfs: correct misspelled "REISERFS_PROC_INFO" to "CONFIG_REISERFS_PROC_INFO"Robert P. J. Day2007-05-081-1/+1
| | | | | | | | | Correct the misspelling of the preprocessor check of a Kconfig option to refer to CONFIG_REISERFS_PROC_INFO and not just the incorrect REISERFS_PROC_INFO. Signed-off-by: Robert P. J. Day <rpjday@mindspring.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* reiserfs: shrink superblock if no xattrsAlexey Dobriyan2007-05-081-2/+4
| | | | | | | | | | | | | | | | | | | | | | | | This makes in-core superblock fit into one cacheline here. Before: struct dentry * xattr_root; /* 124 4 */ /* --- cacheline 1 boundary (128 bytes) --- */ struct rw_semaphore xattr_dir_sem; /* 128 12 */ int j_errno; /* 140 4 */ }; /* size: 144, cachelines: 2 */ /* sum members: 142, holes: 1, sum holes: 2 */ /* last cacheline: 16 bytes */ After: int j_errno; /* 124 4 */ /* --- cacheline 1 boundary (128 bytes) --- */ }; /* size: 128, cachelines: 1 */ /* sum members: 126, holes: 1, sum holes: 2 */ Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Cc: <reiserfs-dev@namesys.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* reiserfs: possible null pointer dereference during resizeDmitriy Monakhov2007-05-081-0/+4
| | | | | | | | | | sb_read may return NULL, let's explicitly check it. If so free new bitmap blocks array, after this we may safely exit as it done above during bitmap allocation. Signed-off-by: Dmitriy Monakhov <dmonakhov@openvz.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* freevxfs: possible null pointer dereference fixDmitriy Monakhov2007-05-082-2/+2
| | | | | | | | | sb_read may return NULL, so let's explicitly check it. Signed-off-by: Dmitriy Monakhov <dmonakhov@openvz.org> 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>
* is_power_of_2 in fs/block_dev.cVignesh Babu BM2007-05-081-1/+2
| | | | | | | | Replace (n & (n-1)) in the context of power of 2 checks with is_power_of_2 Signed-off-by: vignesh babu <vignesh.babu@wipro.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* is_power_of_2 in fs/hfsVignesh Babu BM2007-05-082-2/+4
| | | | | | | | | Replace (n & (n-1)) in the context of power of 2 checks with is_power_of_2 Signed-off-by: vignesh babu <vignesh.babu@wipro.com> Cc: Roman Zippel <zippel@linux-m68k.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* is_power_of_2 in fatVignesh Babu BM2007-05-081-4/+3
| | | | | | | | | | Replacing (n & (n-1)) in the context of power of 2 checks with is_power_of_2 Signed-off-by: vignesh babu <vignesh.babu@wipro.com> Acked-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* devpts: add fsnotify create eventFlorin Malita2007-05-081-1/+4
| | | | | | | | | | | | | | Currently, devpts doesn't generate an fsnotify event upon pts creation because the regular vfs paths aren't involved. Deallocation, on the other hand, correctly generates a nameremove event thanks to the d_delete() invocation in devpts_pty_kill(). This patch adds the missing fsnotify_create() trigger in devpts_pty_new(). Signed-off-by: Florin Malita <fmalita@gmail.com> Acked-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* use use SEEK_MAX to validate user lseek argumentsChris Snook2007-05-081-2/+2
| | | | | | | | | Add SEEK_MAX and use it to validate lseek arguments from userspace. Signed-off-by: Chris Snook <csnook@redhat.com> Acked-by: David Howells <dhowells@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* use symbolic constants in generic lseek codeChris Snook2007-05-081-6/+6
| | | | | | | | | Convert magic numbers to SEEK_* values from fs.h Signed-off-by: Chris Snook <csnook@redhat.com> Acked-by: David Howells <dhowells@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: shrink parent dentries when shrinking slabAndrew Morton2007-05-081-1/+1
| | | | | | | | | | | | | | | | Teach the dentry slab shrinker to aggressively shrink parent dentries when shrinking the dentry cache. This is done to attempt to improve the situation where the dentry slab cache gets a lot of internal fragmentation due to pages containing directory dentries. It is expected that this change will cause some of those dentries to be reaped earlier, and with less scanning. Needs careful testing. Cc: Miklos Szeredi <mszeredi@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* fix quadratic behavior of shrink_dcache_parent()Miklos Szeredi2007-05-081-37/+67
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The time shrink_dcache_parent() takes, grows quadratically with the depth of the tree under 'parent'. This starts to get noticable at about 10,000. These kinds of depths don't occur normally, and filesystems which invoke shrink_dcache_parent() via d_invalidate() seem to have other depth dependent timings, so it's not even easy to expose this problem. However with FUSE it's easy to create a deep tree and d_invalidate() will also get called. This can make a syscall hang for a very long time. This is the original discovery of the problem by Russ Cox: http://article.gmane.org/gmane.comp.file-systems.fuse.devel/3826 The following patch fixes the quadratic behavior, by optionally allowing prune_dcache() to prune ancestors of a dentry in one go, instead of doing it one at a time. Common code in dput() and prune_one_dentry() is extracted into a new helper function d_kill(). shrink_dcache_parent() as well as shrink_dcache_sb() are converted to use the ancestry-pruner option. Only for shrink_dcache_memory() is this behavior not desirable, so it keeps using the old algorithm. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Maneesh Soni <maneesh@in.ibm.com> Acked-by: "Paul E. McKenney" <paulmck@us.ibm.com> Cc: Dipankar Sarma <dipankar@in.ibm.com> Cc: Neil Brown <neilb@suse.de> Cc: Trond Myklebust <trond.myklebust@fys.uio.no> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* reduce size of task_struct on 64-bit machinesWilliam Cohen2007-05-081-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | This past week I was playing around with that pahole tool (http://oops.ghostprotocols.net:81/acme/dwarves/) and looking at the size of various struct in the kernel. I was surprised by the size of the task_struct on x86_64, approaching 4K. I looked through the fields in task_struct and found that a number of them were declared as "unsigned long" rather than "unsigned int" despite them appearing okay as 32-bit sized fields. On x86_64 "unsigned long" ends up being 8 bytes in size and forces 8 byte alignment. Is there a reason there a reason they are "unsigned long"? The patch below drops the size of the struct from 3808 bytes (60 64-byte cachelines) to 3760 bytes (59 64-byte cachelines). A couple other fields in the task struct take a signficant amount of space: struct thread_struct thread; 688 struct held_lock held_locks[30]; 1680 CONFIG_LOCKDEP is turned on in the .config [akpm@linux-foundation.org: fix printk warnings] Cc: <linux-arch@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* ext2/3/4: fix file date underflow on ext2 3 filesystems on 64 bit systemsMarkus Rechberger2007-05-083-9/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Taken from http://bugzilla.kernel.org/show_bug.cgi?id=5079 signed long ranges from -2.147.483.648 to 2.147.483.647 on x86 32bit 10000011110110100100111110111101 .. -2,082,844,739 10000011110110100100111110111101 .. 2,212,122,557 <- this currently gets stored on the disk but when converting it to a 64bit signed long value it loses its sign and becomes positive. Cc: Andreas Dilger <adilger@dilger.ca> Cc: <linux-ext4@vger.kernel.org> Andreas says: This patch is now treating timestamps with the high bit set as negative times (before Jan 1, 1970). This means we lose 1/2 of the possible range of timestamps (lopping off 68 years before unix timestamp overflow - now only 30 years away :-) to handle the extremely rare case of setting timestamps into the distant past. If we are only interested in fixing the underflow case, we could just limit the values to 0 instead of storing negative values. At worst this will skew the timestamp by a few hours for timezones in the far east (files would still show Jan 1, 1970 in "ls -l" output). That said, it seems 32-bit systems (mine at least) allow files to be set into the past (01/01/1907 works fine) so it seems this patch is bringing the x86_64 behaviour into sync with other kernels. On the plus side, we have a patch that is ready to add nanosecond timestamps to ext3 and as an added bonus adds 2 high bits to the on-disk timestamp so this extends the maximum date to 2242. Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Allow access to /proc/$PID/fd after setuid()Alexey Dobriyan2007-05-081-0/+18
| | | | | | | | | | | | | | | | | | | | | | /proc/$PID/fd has r-x------ permissions, so if process does setuid(), it will not be able to access /proc/*/fd/. This breaks fstatat() emulation in glibc. open("foo", O_RDONLY|O_DIRECTORY) = 4 setuid32(65534) = 0 stat64("/proc/self/fd/4/bar", 0xbfafb298) = -1 EACCES (Permission denied) Signed-off-by: Alexey Dobriyan <adobriyan@openvz.org> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: James Morris <jmorris@namei.org> Cc: Chris Wright <chrisw@sous-sol.org> Cc: Ulrich Drepper <drepper@redhat.com> Cc: Oleg Nesterov <oleg@tv-sign.ru> Acked-By: Kirill Korotaev <dev@openvz.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* block_write_full_page(): report ENOSPCAndrew Morton2007-05-081-0/+1
| | | | | | | | block_write_full_page() forgot to propagate ENPSOC into the address_space. Cc: Guillaume Chazarain <guichaz@yahoo.fr> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Factor outstanding I/O error handlingGuillaume Chazarain2007-05-082-18/+3
| | | | | | | | | | Cleanup: setting an outstanding error on a mapping was open coded too many times. Factor it out in mapping_set_error(). Signed-off-by: Guillaume Chazarain <guichaz@yahoo.fr> Cc: Steven Whitehouse <swhiteho@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* uml: hostfs style fixesJeff Dike2007-05-083-171/+167
| | | | | | | | | hostfs needed some style goodness. Signed-off-by: Jeff Dike <jdike@linux.intel.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* uml: make hostfs_setattr() support operations on unlinked open filesAlberto Bertogli2007-05-083-44/+74
| | | | | | | | | | | | | | | | | | This patch allows hostfs_setattr() to work on unlinked open files by calling set_attr() (the userspace part) with the inode's fd. Without this, applications that depend on doing attribute changes to unlinked open files will fail. It works by using the fd versions instead of the path ones (for example fchmod() instead of chmod(), fchown() instead of chown()) when an fd is available. Signed-off-by: Alberto Bertogli <albertito@gmail.com> Signed-off-by: Jeff Dike <jdike@linux.intel.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: move common segment checks to separate helper functionDmitriy Monakhov2007-05-082-37/+6
| | | | | | | | | | [akpm@linux-foundation.org: cleanup] Signed-off-by: Monakhov Dmitriy <dmonakhov@openvz.org> Cc: Christoph Hellwig <hch@lst.de> Acked-by: Anton Altaparmakov <aia21@cam.ac.uk> Acked-by: David Chinner <dgc@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branch 'server-cluster-locking-api' of git://linux-nfs.org/~bfields/linuxLinus Torvalds2007-05-0712-200/+524
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * 'server-cluster-locking-api' of git://linux-nfs.org/~bfields/linux: gfs2: nfs lock support for gfs2 lockd: add code to handle deferred lock requests lockd: always preallocate block in nlmsvc_lock() lockd: handle test_lock deferrals lockd: pass cookie in nlmsvc_testlock lockd: handle fl_grant callbacks lockd: save lock state on deferral locks: add fl_grant callback for asynchronous lock return nfsd4: Convert NFSv4 to new lock interface locks: add lock cancel command locks: allow {vfs,posix}_lock_file to return conflicting lock locks: factor out generic/filesystem switch from setlock code locks: factor out generic/filesystem switch from test_lock locks: give posix_test_lock same interface as ->lock locks: make ->lock release private data before returning in GETLK case locks: create posix-to-flock helper functions locks: trivial removal of unnecessary parentheses
| * gfs2: nfs lock support for gfs2Marc Eshel2007-05-062-10/+104
| | | | | | | | | | | | | | | | Add NFS lock support to GFS2. Signed-off-by: Marc Eshel <eshel@almaden.ibm.com> Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu> Acked-by: Steven Whitehouse <swhiteho@redhat.com>
| * lockd: add code to handle deferred lock requestsMarc Eshel2007-05-064-7/+40
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Rewrite nlmsvc_lock() to use the asynchronous interface. As with testlock, we answer nlm requests in nlmsvc_lock by first looking up the block and then using the results we find in the block if B_QUEUED is set, and calling vfs_lock_file() otherwise. If this a new lock request and we get -EINPROGRESS return on a non-blocking request then we defer the request. Also modify nlmsvc_unlock() to call the filesystem method if appropriate. Signed-off-by: Marc Eshel <eshel@almaden.ibm.com> Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
| * lockd: always preallocate block in nlmsvc_lock()Marc Eshel2007-05-061-23/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Normally we could skip ever having to allocate a block in the case where the client asks for a non-blocking lock, or asks for a blocking lock that succeeds immediately. However we're going to want to always look up a block first in order to check whether we're revisiting a deferred lock call, and to be prepared to handle the case where the filesystem returns -EINPROGRESS--in that case we want to make sure the lock we've given the filesystem is the one embedded in the block that we'll use to track the deferred request. Signed-off-by: Marc Eshel <eshel@almaden.ibm.com> Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
| * lockd: handle test_lock deferralsMarc Eshel2007-05-063-16/+73
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Rewrite nlmsvc_testlock() to use the new asynchronous interface: instead of immediately doing a posix_test_lock(), we first look for a matching block. If the subsequent test_lock returns anything other than -EINPROGRESS, we then remove the block we've found and return the results. If it returns -EINPROGRESS, then we defer the lock request. In the case where the block we find in the first step has B_QUEUED set, we bypass the vfs_test_lock entirely, instead using the block to decide how to respond: with nlm_lck_denied if B_TIMED_OUT is set. with nlm_granted if B_GOT_CALLBACK is set. by dropping if neither B_TIMED_OUT nor B_GOT_CALLBACK is set Signed-off-by: Marc Eshel <eshel@almaden.ibm.com> Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
| * lockd: pass cookie in nlmsvc_testlockMarc Eshel2007-05-063-4/+5
| | | | | | | | | | | | | | | | | | | | Change NLM internal interface to pass more information for test lock; we need this to make sure the cookie information is pushed down to the place where we do request deferral, which is handled for testlock by the following patch. Signed-off-by: Marc Eshel <eshel@almaden.ibm.com> Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
| * lockd: handle fl_grant callbacksMarc Eshel2007-05-061-4/+87
| | | | | | | | | | | | | | Add code to handle file system callback when the lock is finally granted. Signed-off-by: Marc Eshel <eshel@almaden.ibm.com> Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
| * lockd: save lock state on deferralMarc Eshel2007-05-061-0/+25
| | | | | | | | | | | | | | | | | | | | | | | | | | We need to keep some state for a pending asynchronous lock request, so this patch adds that state to struct nlm_block. This also adds a function which defers the request, by calling rqstp->rq_chandle.defer and storing the resulting deferred request in a nlm_block structure which we insert into lockd's global block list. That new function isn't called yet, so it's dead code until a later patch. Signed-off-by: Marc Eshel <eshel@almaden.ibm.com> Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
| * locks: add fl_grant callback for asynchronous lock returnMarc Eshel2007-05-061-0/+19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Acquiring a lock on a cluster filesystem may require communication with remote hosts, and to avoid blocking lockd or nfsd threads during such communication, we allow the results to be returned asynchronously. When a ->lock() call needs to block, the file system will return -EINPROGRESS, and then later return the results with a call to the routine in the fl_grant field of the lock_manager_operations struct. This differs from the case when ->lock returns -EAGAIN to a blocking lock request; in that case, the filesystem calls fl_notify when the lock is granted, and the caller retries the original lock. So while fl_notify is merely a hint to the caller that it should retry, fl_grant actually communicates the final result of the lock operation (with the lock already acquired in the succesful case). Therefore fl_grant takes a lock, a status and, for the test lock case, a conflicting lock. We also allow fl_grant to return an error to the filesystem, to handle the case where the fl_grant requests arrives after the lock manager has already given up waiting for it. Signed-off-by: Marc Eshel <eshel@almaden.ibm.com> Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
| * nfsd4: Convert NFSv4 to new lock interfaceMarc Eshel2007-05-061-7/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | Convert NFSv4 to the new lock interface. We don't define any callback for now, so we're not taking advantage of the asynchronous feature--that's less critical for the multi-threaded nfsd then it is for the single-threaded lockd. But this does allow a cluster filesystems to export cluster-coherent locking to NFS. Note that it's cluster filesystems that are the issue--of the filesystems that define lock methods (nfs, cifs, etc.), most are not exportable by nfsd. Signed-off-by: Marc Eshel <eshel@almaden.ibm.com> Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
| * locks: add lock cancel commandMarc Eshel2007-05-061-0/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Lock managers need to be able to cancel pending lock requests. In the case where the exported filesystem manages its own locks, it's not sufficient just to call posix_unblock_lock(); we need to let the filesystem know what's happening too. We do this by adding a new fcntl lock command: FL_CANCELLK. Some day this might also be made available to userspace applications that could benefit from an asynchronous locking api. Signed-off-by: Marc Eshel <eshel@almaden.ibm.com> Signed-off-by: "J. Bruce Fields" <bfields@citi.umich.edu>
| * locks: allow {vfs,posix}_lock_file to return conflicting lockMarc Eshel2007-05-064-33/+30
| | | | | | | | | | | | | | | | | | | | | | | | The nfsv4 protocol's lock operation, in the case of a conflict, returns information about the conflicting lock. It's unclear how clients can use this, so for now we're not going so far as to add a filesystem method that can return a conflicting lock, but we may as well return something in the local case when it's easy to. Signed-off-by: Marc Eshel <eshel@almaden.ibm.com> Signed-off-by: "J. Bruce Fields" <bfields@citi.umich.edu>
| * locks: factor out generic/filesystem switch from setlock codeMarc Eshel2007-05-061-32/+36
| | | | | | | | | | | | | | | | | | | | | | Factor out the code that switches between generic and filesystem-specific lock methods; eventually we want to call this from lock managers (lockd and nfsd) too; currently they only call the generic methods. This patch does that for all the setlk code. Signed-off-by: Marc Eshel <eshel@almaden.ibm.com> Signed-off-by: "J. Bruce Fields" <bfields@citi.umich.edu>
| * locks: factor out generic/filesystem switch from test_lockJ. Bruce Fields2007-05-061-13/+25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Factor out the code that switches between generic and filesystem-specific lock methods; eventually we want to call this from lock managers (lockd and nfsd) too; currently they only call the generic methods. This patch does that for test_lock. Note that this hasn't been necessary until recently, because the few filesystems that define ->lock() (nfs, cifs...) aren't exportable via NFS. However GFS (and, in the future, other cluster filesystems) need to implement their own locking to get cluster-coherent locking, and also want to be able to export locking to NFS (lockd and NFSv4). So we accomplish this by factoring out code such as this and exporting it for the use of lockd and nfsd. Signed-off-by: "J. Bruce Fields" <bfields@citi.umich.edu>
| * locks: give posix_test_lock same interface as ->lockMarc Eshel2007-05-067-50/+31
| | | | | | | | | | | | | | | | | | posix_test_lock() and ->lock() do the same job but have gratuitously different interfaces. Modify posix_test_lock() so the two agree, simplifying some code in the process. Signed-off-by: Marc Eshel <eshel@almaden.ibm.com> Signed-off-by: "J. Bruce Fields" <bfields@citi.umich.edu>
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