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2006-06-26ocfs2: do LVB puts in placeMark Fasheh2-5/+10
Don't wait until the AST will be fired to do the LVB copy into the lock resource. Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
2006-06-26ocfs2: mle ref count debuggingKurt Hackel1-9/+20
Signed-off-by: Kurt Hackel <kurt.hackel@oracle.com> Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
2006-06-26ocfs2: allow for an assert message during lock masteryKurt Hackel1-1/+2
Signed-off-by: Kurt Hackel <kurt.hackel@oracle.com> Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
2006-06-26ocfs2: take mle reference during migrationKurt Hackel1-0/+17
Signed-off-by: Kurt Hackel <kurt.hackel@oracle.com> Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
2006-06-26ocfs2: properly initialize the mle structureKurt Hackel1-4/+1
Signed-off-by: Kurt Hackel <kurt.hackel@oracle.com> Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
2006-06-26ocfs2: detach mle from heartbeat eventsKurt Hackel1-0/+2
Signed-off-by: Kurt Hackel <kurt.hackel@oracle.com> Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
2006-06-26ocfs2: mle ref counting fixesKurt Hackel1-19/+90
Signed-off-by: Kurt Hackel <kurt.hackel@oracle.com> Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
2006-06-26ocfs2: better mle debuggingKurt Hackel1-5/+28
Signed-off-by: Kurt Hackel <kurt.hackel@oracle.com> Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
2006-06-26ocfs2: clean up recovery related messagesKurt Hackel1-12/+90
Signed-off-by: Kurt Hackel <kurt.hackel@oracle.com> Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
2006-06-26ocfs2: handle network errors during recoveryKurt Hackel1-17/+36
Signed-off-by: Kurt Hackel <kurt.hackel@oracle.com> Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
2006-06-26ocfs2: only recover one dead node at a timeKurt Hackel1-3/+35
Signed-off-by: Kurt Hackel <kurt.hackel@oracle.com> Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
2006-06-26ocfs2: Better tracking for recovery state changesKurt Hackel1-9/+28
Signed-off-by: Kurt Hackel <kurt.hackel@oracle.com> Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
2006-06-26ocfs2: Fix empty lvb checkKurt Hackel2-5/+16
The check for an empty lvb should check the entire buffer not just the first byte. Signed-off-by: Kurt Hackel <kurt.hackel@oracle.com> Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
2006-06-26ocfs2: fix inverted logic in dlm_is_node_deadKurt Hackel1-1/+1
Signed-off-by: Kurt Hackel <kurt.hackel@oracle.com> Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
2006-06-26ocfs2: recheck lockres master before sending an unlock request.Kurt Hackel1-0/+10
Recovery may have happened and it may now be mastered locally. Signed-off-by: Kurt Hackel <kurt.hackel@oracle.com> Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
2006-06-26ocfs2: add a small delay after a failed migrationKurt Hackel1-2/+5
Otherwise we risk starving other threads. Signed-off-by: Kurt Hackel <kurt.hackel@oracle.com> Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
2006-06-26ocfs2: silence a compile warning in dlm_alloc_pagevec()Mark Fasheh1-2/+2
Reported by Andrew Morton. Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
2006-06-26[PATCH] ocfs2: Alloc at least a page for the DLM hashJoel Becker2-2/+9
The OCFS2 DLM allocates a number of pages for a hash to lookup locks. There was a bug where a PAGE_SIZE bigger than the hash size (eg, 64K pages) would result in zero pages allocated. Signed-off-by: Joel Becker <joel.becker@oracle.com> Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
2006-06-26ocfs2: allocate lockres hash pages in an arrayDaniel Phillips4-13/+46
This allows us to have a hash table greater than a single page which greatly improves dlm performance on some tests. Signed-off-by: Daniel Phillips <phillips@google.com> Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
2006-06-26ocfs2: inline dlm_lockres_get()Mark Fasheh2-6/+6
It's called on every lookup so this might help performance a bit. Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
2006-06-26[PATCH] Clean up ocfs2 hash probe and make it fasterDaniel Phillips1-15/+14
Signed-Off-By: Daniel Phillips <phillips@google.com> Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
2006-06-26ocfs2: calculate lockid hash values outside of the spinlockMark Fasheh4-19/+30
Fixes a performance bug - pointed out by Andrew. Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
2006-06-26ocfs2: move lockres qstr next to hlist_node structureMark Fasheh1-1/+1
Gains us a bit of performance on loads which heavily hit the lockres hash. Patch suggested by Daniel Phillips <phillips@google.com>. Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
2006-06-26Merge git://git.kernel.org/pub/scm/linux/kernel/git/bunk/trivialLinus Torvalds4-7/+7
* git://git.kernel.org/pub/scm/linux/kernel/git/bunk/trivial: typo fixes Clean up 'inline is not at beginning' warnings for usb storage Storage class should be first i386: Trivial typo fixes ixj: make ixj_set_tone_off() static spelling fixes fix paniced->panicked typos Spelling fixes for Documentation/atomic_ops.txt move acknowledgment for Mark Adler to CREDITS remove the bouncing email address of David Campbell
2006-06-26Merge branch 'x86-64'Linus Torvalds1-1/+15
* x86-64: (83 commits) [PATCH] x86_64: x86_64 stack usage debugging [PATCH] x86_64: (resend) x86_64 stack overflow debugging [PATCH] x86_64: msi_apic.c build fix [PATCH] x86_64: i386/x86-64 Add nmi watchdog support for new Intel CPUs [PATCH] x86_64: Avoid broadcasting NMI IPIs [PATCH] x86_64: fix apic error on bootup [PATCH] x86_64: enlarge window for stack growth [PATCH] x86_64: Minor string functions optimizations [PATCH] x86_64: Move export symbols to their C functions [PATCH] x86_64: Standardize i386/x86_64 handling of NMI_VECTOR [PATCH] x86_64: Fix modular pc speaker [PATCH] x86_64: remove sys32_ni_syscall() [PATCH] x86_64: Do not use -ffunction-sections for modules [PATCH] x86_64: Add cpu_relax to apic_wait_icr_idle [PATCH] x86_64: adjust kstack_depth_to_print default [PATCH] i386/x86-64: adjust /proc/interrupts column headings [PATCH] x86_64: Fix race in cpu_local_* on preemptible kernels [PATCH] x86_64: Fix fast check in safe_smp_processor_id [PATCH] x86_64: x86_64 setup.c - printing cmp related boottime information [PATCH] i386/x86-64/ia64: Move polling flag into thread_info_status ... Manual resolve of trivial conflict in arch/i386/kernel/Makefile
2006-06-26[PATCH] x86_64: Add compat_printk and sysctl to turn off compat layer warningsAndi Kleen1-1/+15
Sometimes e.g. with crashme the compat layer warnings can be noisy. Add a way to turn them off by gating all output through compat_printk that checks a global sysctl. The default is not changed. Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26Merge master.kernel.org:/pub/scm/linux/kernel/git/davem/sparc-2.6Linus Torvalds1-903/+255
* master.kernel.org:/pub/scm/linux/kernel/git/davem/sparc-2.6: [SPARC]: Add iomap interfaces. [OPENPROM]: Rewrite driver to use in-kernel device tree. [OPENPROMFS]: Rewrite using in-kernel device tree and seq_file. [SPARC]: Add unique device_node IDs and a ".node" property. [SPARC]: Add of_set_property() interface. [SPARC64]: Export auxio_register to modules. [SPARC64]: Add missing interfaces to dma-mapping.h [SPARC64]: Export _PAGE_IE to modules. [SPARC64]: Allow floppy driver to build modular. [SPARC]: Export x_bus_type to modules. [RIOWATCHDOG]: Fix the build. [CPWATCHDOG]: Fix the build. [PARPORT] sunbpp: Fix typo. [MTD] sun_uflash: Port to new EBUS device layer.
2006-06-26[PATCH] coredump: shutdown current process firstOleg Nesterov1-12/+17
This patch optimizes zap_threads() for the case when there are no ->mm users except the current's thread group. In that case we can avoid 'for_each_process()' loop. It also adds a useful invariant: SIGNAL_GROUP_EXIT (if checked under ->siglock) always implies that all threads (except may be current) have pending SIGKILL. Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Cc: Roland McGrath <roland@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26[PATCH] coredump: some code relocationsOleg Nesterov1-30/+40
This is a preparation for the next patch. No functional changes. Basically, this patch moves '->flags & SIGNAL_GROUP_EXIT' check into zap_threads(), and 'complete(vfork_done)' into coredump_wait outside of ->mmap_sem protected area. Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Cc: Roland McGrath <roland@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26[PATCH] coredump: don't take tasklist_lockOleg Nesterov1-4/+8
This patch removes tasklist_lock from zap_threads(). This is safe wrt: do_exit: The caller holds mm->mmap_sem. This means that task which shares the same ->mm can't pass exit_mm(), so it can't be unhashed from init_task.tasks or ->thread_group lists. fork: None of sub-threads can fork after zap_process(leader). All processes which were created before this point should be visible to zap_threads() because copy_process() adds the new process to the tail of init_task.tasks list, and ->siglock lock/unlock provides a memory barrier. de_thread: It does list_replace_rcu(&leader->tasks, &current->tasks). So zap_threads() will see either old or new leader, it does not matter. However, it can change p->sighand, so we should use lock_task_sighand() in zap_process(). Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26[PATCH] coredump: kill ptrace related stuffOleg Nesterov1-25/+5
With this patch zap_process() sets SIGNAL_GROUP_EXIT while sending SIGKILL to the thread group. This means that a TASK_TRACED task 1. Will be awakened by signal_wake_up(1) 2. Can't sleep again via ptrace_notify() 3. Can't go to do_signal_stop() after return from ptrace_stop() in get_signal_to_deliver() So we can remove all ptrace related stuff from coredump path. Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Roland McGrath <roland@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26[PATCH] coredump: speedup SIGKILL sendingOleg Nesterov1-1/+8
With this patch a thread group is killed atomically under ->siglock. This is faster because we can use sigaddset() instead of force_sig_info() and this is used in further patches. Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Acked-by: Roland McGrath <roland@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26[PATCH] coredump: optimize ->mm users traversalOleg Nesterov1-10/+26
zap_threads() iterates over all threads to find those ones which share current->mm. All threads in the thread group share the same ->mm, so we can skip entire thread group if it has another ->mm. This patch shifts the killing of thread group into the newly added zap_process() function. This looks as unnecessary complication, but it is used in further patches. Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Acked-by: Roland McGrath <roland@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26[PATCH] de_thread: fix lockless do_each_threadOleg Nesterov1-2/+1
We should keep the value of old_leader->tasks.next in de_thread, otherwise we can't do for_each_process/do_each_thread without tasklist_lock held. Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26[PATCH] SELinux: Add sockcreate node to procattr APIEric Paris1-0/+6
Below is a patch to add a new /proc/self/attr/sockcreate A process may write a context into this interface and all subsequent sockets created will be labeled with that context. This is the same idea as the fscreate interface where a process can specify the label of a file about to be created. At this time one envisioned user of this will be xinetd. It will be able to better label sockets for the actual services. At this time all sockets take the label of the creating process, so all xinitd sockets would just be labeled the same. I tested this by creating a tcp sender and listener. The sender was able to write to this new proc file and then create sockets with the specified label. I am able to be sure the new label was used since the avc denial messages kicked out by the kernel included both the new security permission setsockcreate and all the socket denials were for the new label, not the label of the running process. Signed-off-by: Eric Paris <eparis@redhat.com> Signed-off-by: James Morris <jmorris@namei.org> Cc: Chris Wright <chrisw@sous-sol.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26[PATCH] cleanup next_tid()Oleg Nesterov1-7/+7
Try to make next_tid() a bit more readable and deletes unnecessary "pid_alive(pos)" check. Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26[PATCH] simplify/fix first_tid()Oleg Nesterov1-21/+17
first_tid: /* If nr exceeds the number of threads there is nothing todo */ if (nr) { if (nr >= get_nr_threads(leader)) goto done; } This is not reliable: sub-threads can exit after this check, so the 'for' loop below can overlap and proc_task_readdir() can return an already filldir'ed dirents. for (; pos && pid_alive(pos); pos = next_thread(pos)) { if (--nr > 0) continue; Off-by-one error, will return 'leader' when nr == 1. This patch tries to fix these problems and simplify the code. Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26[PATCH] proc: Remove tasklist_lock from proc_task_readdir.Eric W. Biederman1-5/+6
This is just like my previous removal of tasklist_lock from first_tgid, and next_tgid. It simply had to wait until it was rcu safe to walk the thread list. This should be the last instance of the tasklist_lock in proc. So user processes should not be able to influence the tasklist lock hold times. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26[PATCH] proc: Cleanup proc_fd_access_allowedEric W. Biederman1-20/+6
In process of getting proc_fd_access_allowed to work it has developed a few warts. In particular the special case that always allows introspection and the special case to allow inspection of kernel threads. The special case for introspection is needed for /proc/self/mem. The special case for kernel threads really should be overridable by security modules. So consolidate these checks into ptrace.c:may_attach(). The check to always allow introspection is trivial. The check to allow access to kernel threads, and zombies is a little trickier. mem_read and mem_write already verify an mm exists so it isn't needed twice. proc_fd_access_allowed only doesn't want a check to verify task->mm exits, s it prevents all access to kernel threads. So just move the task->mm check into ptrace_attach where it is needed for practical reasons. I did a quick audit and none of the security modules in the kernel seem to care if they are passed a task without an mm into security_ptrace. So the above move should be safe and it allows security modules to come up with more restrictive policy. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Cc: Stephen Smalley <sds@tycho.nsa.gov> Cc: Chris Wright <chrisw@sous-sol.org> Cc: James Morris <jmorris@namei.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26[PATCH] proc: Use sane permission checks on the /proc/<pid>/fd/ symlinksEric W. Biederman1-95/+29
Since 2.2 we have been doing a chroot check to see if it is appropriate to return a read or follow one of these magic symlinks. The chroot check was asking a question about the visibility of files to the calling process and it was actually checking the destination process, and not the files themselves. That test was clearly bogus. In my first pass through I simply fixed the test to check the visibility of the files themselves. That naive approach to fixing the permissions was too strict and resulted in cases where a task could not even see all of it's file descriptors. What has disturbed me about relaxing this check is that file descriptors are per-process private things, and they are occasionaly used a user space capability tokens. Looking a little farther into the symlink path on /proc I did find userid checks and a check for capability (CAP_DAC_OVERRIDE) so there were permissions checking this. But I was still concerned about privacy. Besides /proc there is only one other way to find out this kind of information, and that is ptrace. ptrace has been around for a long time and it has a well established security model. So after thinking about it I finally realized that the permission checks that make sense are the permission checks applied to ptrace_attach. The checks are simple per process, and won't cause nasty surprises for people coming from less capable unices. Unfortunately there is one case that the current ptrace_attach test does not cover: Zombies and kernel threads. Single stepping those kinds of processes is impossible. Being able to see which file descriptors are open on these tasks is important to lsof, fuser and friends. So for these special processes I made the rule you can't find out unless you have CAP_SYS_PTRACE. These proc permission checks should now conform to the principle of least surprise. As well as using much less code to implement :) Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26[PATCH] proc: optimize proc_check_dentry_visibleEric W. Biederman1-13/+16
The code doesn't need to sleep to when making this check so I can just do the comparison and not worry about the reference counts. TODO: While looking at this I realized that my original cleanup did not push the permission check far enough down into the stack. The call of proc_check_dentry_visible needs to move out of the generic proc readlink/follow link code and into the individual get_link instances. Otherwise the shared resources checks are not quite correct (shared files_struct does not require a shared fs_struct), and there are races with unshare. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26[PATCH] proc: Use struct pid not struct task_refEric W. Biederman4-12/+11
Incrementally update my proc-dont-lock-task_structs-indefinitely patches so that they work with struct pid instead of struct task_ref. Mostly this is a straight 1-1 substitution. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26[PATCH] proc: don't lock task_structs indefinitelyEric W. Biederman4-132/+319
Every inode in /proc holds a reference to a struct task_struct. If a directory or file is opened and remains open after the the task exits this pinning continues. With 8K stacks on a 32bit machine the amount pinned per file descriptor is about 10K. Normally I would figure a reasonable per user process limit is about 100 processes. With 80 processes, with a 1000 file descriptors each I can trigger the 00M killer on a 32bit kernel, because I have pinned about 800MB of useless data. This patch replaces the struct task_struct pointer with a pointer to a struct task_ref which has a struct task_struct pointer. The so the pinning of dead tasks does not happen. The code now has to contend with the fact that the task may now exit at any time. Which is a little but not muh more complicated. With this change it takes about 1000 processes each opening up 1000 file descriptors before I can trigger the OOM killer. Much better. [mlp@google.com: task_mmu small fixes] Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Cc: Trond Myklebust <trond.myklebust@fys.uio.no> Cc: Paul Jackson <pj@sgi.com> Cc: Oleg Nesterov <oleg@tv-sign.ru> Cc: Albert Cahalan <acahalan@gmail.com> Signed-off-by: Prasanna Meda <mlp@google.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26[PATCH] proc: make PROC_NUMBUF the buffer size for holding integers as stringsEric W. Biederman1-16/+15
Currently in /proc at several different places we define buffers to hold a process id, or a file descriptor . In most of them we use either a hard coded number or a different define. Modify them all to use PROC_NUMBUF, so the code has a chance of being maintained. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26[PATCH] simply fix first_tgidEric W. Biederman1-15/+13
Like the bug Oleg spotted in first_tid there was also a small off by one error in first_tgid, when a seek was done on the /proc directory. This fixes that and changes the code structure to make it a little more obvious what is going on. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Cc: Oleg Nesterov <oleg@tv-sign.ru> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26[PATCH] proc: Remove tasklist_lock from proc_pid_lookup() and proc_task_lookup()Eric W. Biederman1-4/+4
Since we no longer need the tasklist_lock for get_task_struct the lookup methods no longer need the tasklist_lock. This just depends on my previous patch that makes get_task_struct() rcu safe. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26[PATCH] proc: Remove tasklist_lock from proc_pid_readdirEric W. Biederman1-4/+4
We don't need the tasklist_lock to safely iterate through processes anymore. This depends on my previous to task patches that make get_task_struct rcu safe, and that make next_task() rcu safe. I haven't gotten first_tid/next_tid yet only because next_thread is missing an rcu_dereference. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26[PATCH] proc: refactor reading directories of tasksEric W. Biederman1-105/+163
There are a couple of problems this patch addresses. - /proc/<tgid>/task currently does not work correctly if you stop reading in the middle of a directory. - /proc/ currently requires a full pass through the task list with the tasklist lock held, to determine there are no more processes to read. - The hand rolled integer to string conversion does not properly running out of buffer space. - We seem to be batching reading of pids from the tasklist without reason, and complicating the logic of the code. This patch addresses that by changing how tasks are processed. A first_<task_type> function is built that handles restarts, and a next_<task_type> function is built that just advances to the next task. first_<task_type> when it detects a restart usually uses find_task_by_pid. If that doesn't work because there has been a seek on the directory, or we have already given a complete directory listing, it first checks the number tasks of that type, and only if we are under that count does it walk through all of the tasks to find the one we are interested in. The code that fills in the directory is simpler because there is only a single for loop. The hand rolled integer to string conversion is replaced by snprintf which should handle the the out of buffer case correctly. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26[PATCH] proc: Close the race of a process dying durning lookupEric W. Biederman1-25/+29
proc_lookup and task exiting are not synchronized, although some of the previous code may have suggested that. Every time before we reuse a dentry namei.c calls d_op->derevalidate which prevents us from reusing a stale dcache entry. Unfortunately it does not prevent us from returning a stale dcache entry. This race has been explicitly plugged in proc_pid_lookup but there is nothing to confine it to just that proc lookup function. So to prevent the race I call revalidate explictily in all of the proc lookup functions after I call d_add, and report an error if the revalidate does not succeed. Years ago Al Viro did something similar but those changes got lost in the churn. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26[PATCH] proc: Rewrite the proc dentry flush on exit optimizationEric W. Biederman2-83/+61
To keep the dcache from filling up with dead /proc entries we flush them on process exit. However over the years that code has gotten hairy with a dentry_pointer and a lock in task_struct and misdocumented as a correctness feature. I have rewritten this code to look and see if we have a corresponding entry in the dcache and if so flush it on process exit. This removes the extra fields in the task_struct and allows me to trivially handle the case of a /proc/<tgid>/task/<pid> entry as well as the current /proc/<pid> entries. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>