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* flag parameters: timerfd_createUlrich Drepper2008-07-241-2/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The timerfd_create syscall already has a flags parameter. It just is unused so far. This patch changes this by introducing the TFD_CLOEXEC flag to set the close-on-exec flag for the returned file descriptor. A new name TFD_CLOEXEC is introduced which in this implementation must have the same value as O_CLOEXEC. The following test must be adjusted for architectures other than x86 and x86-64 and in case the syscall numbers changed. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ #include <fcntl.h> #include <stdio.h> #include <time.h> #include <unistd.h> #include <sys/syscall.h> #ifndef __NR_timerfd_create # ifdef __x86_64__ # define __NR_timerfd_create 283 # elif defined __i386__ # define __NR_timerfd_create 322 # else # error "need __NR_timerfd_create" # endif #endif #define TFD_CLOEXEC O_CLOEXEC int main (void) { int fd = syscall (__NR_timerfd_create, CLOCK_REALTIME, 0); if (fd == -1) { puts ("timerfd_create(0) failed"); return 1; } int coe = fcntl (fd, F_GETFD); if (coe == -1) { puts ("fcntl failed"); return 1; } if (coe & FD_CLOEXEC) { puts ("timerfd_create(0) set close-on-exec flag"); return 1; } close (fd); fd = syscall (__NR_timerfd_create, CLOCK_REALTIME, TFD_CLOEXEC); if (fd == -1) { puts ("timerfd_create(TFD_CLOEXEC) failed"); return 1; } coe = fcntl (fd, F_GETFD); if (coe == -1) { puts ("fcntl failed"); return 1; } if ((coe & FD_CLOEXEC) == 0) { puts ("timerfd_create(TFD_CLOEXEC) set close-on-exec flag"); return 1; } close (fd); puts ("OK"); return 0; } ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Signed-off-by: Ulrich Drepper <drepper@redhat.com> Acked-by: Davide Libenzi <davidel@xmailserver.org> Cc: Michael Kerrisk <mtk.manpages@googlemail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* flag parameters: eventfdUlrich Drepper2008-07-241-2/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch adds the new eventfd2 syscall. It extends the old eventfd syscall by one parameter which is meant to hold a flag value. In this patch the only flag support is EFD_CLOEXEC which causes the close-on-exec flag for the returned file descriptor to be set. A new name EFD_CLOEXEC is introduced which in this implementation must have the same value as O_CLOEXEC. The following test must be adjusted for architectures other than x86 and x86-64 and in case the syscall numbers changed. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ #include <fcntl.h> #include <stdio.h> #include <unistd.h> #include <sys/syscall.h> #ifndef __NR_eventfd2 # ifdef __x86_64__ # define __NR_eventfd2 290 # elif defined __i386__ # define __NR_eventfd2 328 # else # error "need __NR_eventfd2" # endif #endif #define EFD_CLOEXEC O_CLOEXEC int main (void) { int fd = syscall (__NR_eventfd2, 1, 0); if (fd == -1) { puts ("eventfd2(0) failed"); return 1; } int coe = fcntl (fd, F_GETFD); if (coe == -1) { puts ("fcntl failed"); return 1; } if (coe & FD_CLOEXEC) { puts ("eventfd2(0) sets close-on-exec flag"); return 1; } close (fd); fd = syscall (__NR_eventfd2, 1, EFD_CLOEXEC); if (fd == -1) { puts ("eventfd2(EFD_CLOEXEC) failed"); return 1; } coe = fcntl (fd, F_GETFD); if (coe == -1) { puts ("fcntl failed"); return 1; } if ((coe & FD_CLOEXEC) == 0) { puts ("eventfd2(EFD_CLOEXEC) does not set close-on-exec flag"); return 1; } close (fd); puts ("OK"); return 0; } ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ [akpm@linux-foundation.org: add sys_ni stub] Signed-off-by: Ulrich Drepper <drepper@redhat.com> Acked-by: Davide Libenzi <davidel@xmailserver.org> Cc: Michael Kerrisk <mtk.manpages@googlemail.com> Cc: <linux-arch@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* flag parameters: signalfdUlrich Drepper2008-07-242-6/+22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch adds the new signalfd4 syscall. It extends the old signalfd syscall by one parameter which is meant to hold a flag value. In this patch the only flag support is SFD_CLOEXEC which causes the close-on-exec flag for the returned file descriptor to be set. A new name SFD_CLOEXEC is introduced which in this implementation must have the same value as O_CLOEXEC. The following test must be adjusted for architectures other than x86 and x86-64 and in case the syscall numbers changed. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ #include <fcntl.h> #include <signal.h> #include <stdio.h> #include <unistd.h> #include <sys/syscall.h> #ifndef __NR_signalfd4 # ifdef __x86_64__ # define __NR_signalfd4 289 # elif defined __i386__ # define __NR_signalfd4 327 # else # error "need __NR_signalfd4" # endif #endif #define SFD_CLOEXEC O_CLOEXEC int main (void) { sigset_t ss; sigemptyset (&ss); sigaddset (&ss, SIGUSR1); int fd = syscall (__NR_signalfd4, -1, &ss, 8, 0); if (fd == -1) { puts ("signalfd4(0) failed"); return 1; } int coe = fcntl (fd, F_GETFD); if (coe == -1) { puts ("fcntl failed"); return 1; } if (coe & FD_CLOEXEC) { puts ("signalfd4(0) set close-on-exec flag"); return 1; } close (fd); fd = syscall (__NR_signalfd4, -1, &ss, 8, SFD_CLOEXEC); if (fd == -1) { puts ("signalfd4(SFD_CLOEXEC) failed"); return 1; } coe = fcntl (fd, F_GETFD); if (coe == -1) { puts ("fcntl failed"); return 1; } if ((coe & FD_CLOEXEC) == 0) { puts ("signalfd4(SFD_CLOEXEC) does not set close-on-exec flag"); return 1; } close (fd); puts ("OK"); return 0; } ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ [akpm@linux-foundation.org: add sys_ni stub] Signed-off-by: Ulrich Drepper <drepper@redhat.com> Acked-by: Davide Libenzi <davidel@xmailserver.org> Cc: Michael Kerrisk <mtk.manpages@googlemail.com> Cc: <linux-arch@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* flag parameters: anon_inode_getfd extensionUlrich Drepper2008-07-245-8/+10
| | | | | | | | | | | | | | | This patch just extends the anon_inode_getfd interface to take an additional parameter with a flag value. The flag value is passed on to get_unused_fd_flags in anticipation for a use with the O_CLOEXEC flag. No actual semantic changes here, the changed callers all pass 0 for now. [akpm@linux-foundation.org: KVM fix] Signed-off-by: Ulrich Drepper <drepper@redhat.com> Acked-by: Davide Libenzi <davidel@xmailserver.org> Cc: Michael Kerrisk <mtk.manpages@googlemail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* binfmt_misc: use simple_read_from_buffer()Akinobu Mita2008-07-241-17/+3
| | | | | | Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* fs: check for statfs overflowJon Tollefson2008-07-242-5/+6
| | | | | | | | | | | | Adds a check for an overflow in the filesystem size so if someone is checking with statfs() on a 16G blocksize hugetlbfs in a 32bit binary that it will report back EOVERFLOW instead of a size of 0. Acked-by: Nishanth Aravamudan <nacc@us.ibm.com> Signed-off-by: Jon Tollefson <kniht@linux.vnet.ibm.com> Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* hugetlbfs: per mount huge page sizesAndi Kleen2008-07-241-9/+36
| | | | | | | | | | | | | | | | | | | | | | Add the ability to configure the hugetlb hstate used on a per mount basis. - Add a new pagesize= option to the hugetlbfs mount that allows setting the page size - This option causes the mount code to find the hstate corresponding to the specified size, and sets up a pointer to the hstate in the mount's superblock. - Change the hstate accessors to use this information rather than the global_hstate they were using (requires a slight change in mm/memory.c so we don't NULL deref in the error-unmap path -- see comments). [np: take hstate out of hugetlbfs inode and vma->vm_private_data] Acked-by: Adam Litke <agl@us.ibm.com> Acked-by: Nishanth Aravamudan <nacc@us.ibm.com> Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* hugetlb: modular state for hugetlb page sizeAndi Kleen2008-07-241-22/+30
| | | | | | | | | | | | | | | | | | | | | | | | | | The goal of this patchset is to support multiple hugetlb page sizes. This is achieved by introducing a new struct hstate structure, which encapsulates the important hugetlb state and constants (eg. huge page size, number of huge pages currently allocated, etc). The hstate structure is then passed around the code which requires these fields, they will do the right thing regardless of the exact hstate they are operating on. This patch adds the hstate structure, with a single global instance of it (default_hstate), and does the basic work of converting hugetlb to use the hstate. Future patches will add more hstate structures to allow for different hugetlbfs mounts to have different page sizes. [akpm@linux-foundation.org: coding-style fixes] Acked-by: Adam Litke <agl@us.ibm.com> Acked-by: Nishanth Aravamudan <nacc@us.ibm.com> Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* vmallocinfo: add NUMA informationEric Dumazet2008-07-241-2/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Christoph recently added /proc/vmallocinfo file to get information about vmalloc allocations. This patch adds NUMA specific information, giving number of pages allocated on each memory node. This should help to check that vmalloc() is able to respect NUMA policies. Example of output on a four nodes machine (one cpu per node) 1) network hash tables are evenly spreaded on four nodes (OK) (Same point for inodes and dentries hash tables) 2) iptables tables (x_tables) are correctly allocated on each cpu node (OK). 3) sys_swapon() allocates its memory from one node only. 4) each loaded module is using memory on one node. Sysadmins could tune their setup to change points 3) and 4) if necessary. grep "pages=" /proc/vmallocinfo 0xffffc20000000000-0xffffc20000201000 2101248 alloc_large_system_hash+0x204/0x2c0 pages=512 vmalloc N0=128 N1=128 N2=128 N3=128 0xffffc20000201000-0xffffc20000302000 1052672 alloc_large_system_hash+0x204/0x2c0 pages=256 vmalloc N0=64 N1=64 N2=64 N3=64 0xffffc2000031a000-0xffffc2000031d000 12288 alloc_large_system_hash+0x204/0x2c0 pages=2 vmalloc N1=1 N2=1 0xffffc2000031f000-0xffffc2000032b000 49152 cramfs_uncompress_init+0x2e/0x80 pages=11 vmalloc N0=3 N1=3 N2=2 N3=3 0xffffc2000033e000-0xffffc20000341000 12288 sys_swapon+0x640/0xac0 pages=2 vmalloc N0=2 0xffffc20000341000-0xffffc20000344000 12288 xt_alloc_table_info+0xfe/0x130 [x_tables] pages=2 vmalloc N0=2 0xffffc20000344000-0xffffc20000347000 12288 xt_alloc_table_info+0xfe/0x130 [x_tables] pages=2 vmalloc N1=2 0xffffc20000347000-0xffffc2000034a000 12288 xt_alloc_table_info+0xfe/0x130 [x_tables] pages=2 vmalloc N2=2 0xffffc2000034a000-0xffffc2000034d000 12288 xt_alloc_table_info+0xfe/0x130 [x_tables] pages=2 vmalloc N3=2 0xffffc20004381000-0xffffc20004402000 528384 alloc_large_system_hash+0x204/0x2c0 pages=128 vmalloc N0=32 N1=32 N2=32 N3=32 0xffffc20004402000-0xffffc20004803000 4198400 alloc_large_system_hash+0x204/0x2c0 pages=1024 vmalloc vpages N0=256 N1=256 N2=256 N3=256 0xffffc20004803000-0xffffc20004904000 1052672 alloc_large_system_hash+0x204/0x2c0 pages=256 vmalloc N0=64 N1=64 N2=64 N3=64 0xffffc20004904000-0xffffc20004bec000 3047424 sys_swapon+0x640/0xac0 pages=743 vmalloc vpages N0=743 0xffffffffa0000000-0xffffffffa000f000 61440 sys_init_module+0xc27/0x1d00 pages=14 vmalloc N1=14 0xffffffffa000f000-0xffffffffa0014000 20480 sys_init_module+0xc27/0x1d00 pages=4 vmalloc N0=4 0xffffffffa0014000-0xffffffffa0017000 12288 sys_init_module+0xc27/0x1d00 pages=2 vmalloc N0=2 0xffffffffa0017000-0xffffffffa0022000 45056 sys_init_module+0xc27/0x1d00 pages=10 vmalloc N1=10 0xffffffffa0022000-0xffffffffa0028000 24576 sys_init_module+0xc27/0x1d00 pages=5 vmalloc N3=5 0xffffffffa0028000-0xffffffffa0050000 163840 sys_init_module+0xc27/0x1d00 pages=39 vmalloc N1=39 0xffffffffa0050000-0xffffffffa0052000 8192 sys_init_module+0xc27/0x1d00 pages=1 vmalloc N1=1 0xffffffffa0052000-0xffffffffa0056000 16384 sys_init_module+0xc27/0x1d00 pages=3 vmalloc N1=3 0xffffffffa0056000-0xffffffffa0081000 176128 sys_init_module+0xc27/0x1d00 pages=42 vmalloc N3=42 0xffffffffa0081000-0xffffffffa00ae000 184320 sys_init_module+0xc27/0x1d00 pages=44 vmalloc N3=44 0xffffffffa00ae000-0xffffffffa00b1000 12288 sys_init_module+0xc27/0x1d00 pages=2 vmalloc N3=2 0xffffffffa00b1000-0xffffffffa00b9000 32768 sys_init_module+0xc27/0x1d00 pages=7 vmalloc N0=7 0xffffffffa00b9000-0xffffffffa00c4000 45056 sys_init_module+0xc27/0x1d00 pages=10 vmalloc N3=10 0xffffffffa00c6000-0xffffffffa00e0000 106496 sys_init_module+0xc27/0x1d00 pages=25 vmalloc N2=25 0xffffffffa00e0000-0xffffffffa00f1000 69632 sys_init_module+0xc27/0x1d00 pages=16 vmalloc N2=16 0xffffffffa00f1000-0xffffffffa00f4000 12288 sys_init_module+0xc27/0x1d00 pages=2 vmalloc N3=2 0xffffffffa00f4000-0xffffffffa00f7000 12288 sys_init_module+0xc27/0x1d00 pages=2 vmalloc N3=2 [akpm@linux-foundation.org: fix comment] Signed-off-by: Eric Dumazet <dada1@cosmosbay.com> Cc: Christoph Lameter <cl@linux-foundation.org> Cc: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* SYNC_FILE_RANGE_WRITE may and will block. Document that.Pavel Machek2008-07-241-1/+2
| | | | | | | [akpm@linux-foundation.org: fix comment text] Signed-off-by: Pavel Machek <pavel@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* hugetlb: guarantee that COW faults for a process that called ↵Mel Gorman2008-07-241-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | mmap(MAP_PRIVATE) on hugetlbfs will succeed After patch 2 in this series, a process that successfully calls mmap() for a MAP_PRIVATE mapping will be guaranteed to successfully fault until a process calls fork(). At that point, the next write fault from the parent could fail due to COW if the child still has a reference. We only reserve pages for the parent but a copy must be made to avoid leaking data from the parent to the child after fork(). Reserves could be taken for both parent and child at fork time to guarantee faults but if the mapping is large it is highly likely we will not have sufficient pages for the reservation, and it is common to fork only to exec() immediatly after. A failure here would be very undesirable. Note that the current behaviour of mainline with MAP_PRIVATE pages is pretty bad. The following situation is allowed to occur today. 1. Process calls mmap(MAP_PRIVATE) 2. Process calls mlock() to fault all pages and makes sure it succeeds 3. Process forks() 4. Process writes to MAP_PRIVATE mapping while child still exists 5. If the COW fails at this point, the process gets SIGKILLed even though it had taken care to ensure the pages existed This patch improves the situation by guaranteeing the reliability of the process that successfully calls mmap(). When the parent performs COW, it will try to satisfy the allocation without using reserves. If that fails the parent will steal the page leaving any children without a page. Faults from the child after that point will result in failure. If the child COW happens first, an attempt will be made to allocate the page without reserves and the child will get SIGKILLed on failure. To summarise the new behaviour: 1. If the original mapper performs COW on a private mapping with multiple references, it will attempt to allocate a hugepage from the pool or the buddy allocator without using the existing reserves. On fail, VMAs mapping the same area are traversed and the page being COW'd is unmapped where found. It will then steal the original page as the last mapper in the normal way. 2. The VMAs the pages were unmapped from are flagged to note that pages with data no longer exist. Future no-page faults on those VMAs will terminate the process as otherwise it would appear that data was corrupted. A warning is printed to the console that this situation occured. 2. If the child performs COW first, it will attempt to satisfy the COW from the pool if there are enough pages or via the buddy allocator if overcommit is allowed and the buddy allocator can satisfy the request. If it fails, the child will be killed. If the pool is large enough, existing applications will not notice that the reserves were a factor. Existing applications depending on the no-reserves been set are unlikely to exist as for much of the history of hugetlbfs, pages were prefaulted at mmap(), allocating the pages at that point or failing the mmap(). [npiggin@suse.de: fix CONFIG_HUGETLB=n build] Signed-off-by: Mel Gorman <mel@csn.ul.ie> Acked-by: Adam Litke <agl@us.ibm.com> Cc: Andy Whitcroft <apw@shadowen.org> Cc: William Lee Irwin III <wli@holomorphy.com> Cc: Hugh Dickins <hugh@veritas.com> Cc: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* hugetlb: reserve huge pages for reliable MAP_PRIVATE hugetlbfs mappings ↵Mel Gorman2008-07-241-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | until fork() This patch reserves huge pages at mmap() time for MAP_PRIVATE mappings in a similar manner to the reservations taken for MAP_SHARED mappings. The reserve count is accounted both globally and on a per-VMA basis for private mappings. This guarantees that a process that successfully calls mmap() will successfully fault all pages in the future unless fork() is called. The characteristics of private mappings of hugetlbfs files behaviour after this patch are; 1. The process calling mmap() is guaranteed to succeed all future faults until it forks(). 2. On fork(), the parent may die due to SIGKILL on writes to the private mapping if enough pages are not available for the COW. For reasonably reliable behaviour in the face of a small huge page pool, children of hugepage-aware processes should not reference the mappings; such as might occur when fork()ing to exec(). 3. On fork(), the child VMAs inherit no reserves. Reads on pages already faulted by the parent will succeed. Successful writes will depend on enough huge pages being free in the pool. 4. Quotas of the hugetlbfs mount are checked at reserve time for the mapper and at fault time otherwise. Before this patch, all reads or writes in the child potentially needs page allocations that can later lead to the death of the parent. This applies to reads and writes of uninstantiated pages as well as COW. After the patch it is only a write to an instantiated page that causes problems. Signed-off-by: Mel Gorman <mel@csn.ul.ie> Acked-by: Adam Litke <agl@us.ibm.com> Cc: Andy Whitcroft <apw@shadowen.org> Cc: William Lee Irwin III <wli@holomorphy.com> Cc: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* fix soft lock up at NFS mount via per-SB LRU-list of unused dentriesKentaro Makita2008-07-242-155/+181
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [Summary] Split LRU-list of unused dentries to one per superblock to avoid soft lock up during NFS mounts and remounting of any filesystem. Previously I posted here: http://lkml.org/lkml/2008/3/5/590 [Descriptions] - background dentry_unused is a list of dentries which are not referenced. dentry_unused grows up when references on directories or files are released. This list can be very long if there is huge free memory. - the problem When shrink_dcache_sb() is called, it scans all dentry_unused linearly under spin_lock(), and if dentry->d_sb is differnt from given superblock, scan next dentry. This scan costs very much if there are many entries, and very ineffective if there are many superblocks. IOW, When we need to shrink unused dentries on one dentry, but scans unused dentries on all superblocks in the system. For example, we scan 500 dentries to unmount a filesystem, but scans 1,000,000 or more unused dentries on other superblocks. In our case , At mounting NFS*, shrink_dcache_sb() is called to shrink unused dentries on NFS, but scans 100,000,000 unused dentries on superblocks in the system such as local ext3 filesystems. I hear NFS mounting took 1 min on some system in use. * : NFS uses virtual filesystem in rpc layer, so NFS is affected by this problem. 100,000,000 is possible number on large systems. Per-superblock LRU of unused dentried can reduce the cost in reasonable manner. - How to fix I found this problem is solved by David Chinner's "Per-superblock unused dentry LRU lists V3"(1), so I rebase it and add some fix to reclaim with fairness, which is in Andrew Morton's comments(2). 1) http://lkml.org/lkml/2006/5/25/318 2) http://lkml.org/lkml/2006/5/25/320 Split LRU-list of unused dentries to each superblocks. Then, NFS mounting will check dentries under a superblock instead of all. But this spliting will break LRU of dentry-unused. So, I've attempted to make reclaim unused dentrins with fairness by calculate number of dentries to scan on this sb based on following way number of dentries to scan on this sb = count * (number of dentries on this sb / number of dentries in the machine) - ToDo - I have to measuring performance number and do stress tests. - When unmount occurs during prune_dcache(), scanning on same superblock, It is unable to reach next superblock because it is gone away. We restart scannig superblock from first one, it causes unfairness of reclaim unused dentries on first superblock. But I think this happens very rarely. - Test Results Result on 6GB boxes with excessive unused dentries. Without patch: $ cat /proc/sys/fs/dentry-state 10181835 10180203 45 0 0 0 # mount -t nfs 10.124.60.70:/work/kernel-src nfs real 0m1.830s user 0m0.001s sys 0m1.653s With this patch: $ cat /proc/sys/fs/dentry-state 10236610 10234751 45 0 0 0 # mount -t nfs 10.124.60.70:/work/kernel-src nfs real 0m0.106s user 0m0.002s sys 0m0.032s [akpm@linux-foundation.org: fix comments] Signed-off-by: Kentaro Makita <k-makita@np.css.fujitsu.com> Cc: Neil Brown <neilb@suse.de> Cc: Trond Myklebust <trond.myklebust@fys.uio.no> Cc: David Chinner <dgc@sgi.com> Cc: "J. Bruce Fields" <bfields@fieldses.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: remove double indirection on tlb parameter to free_pgd_range() & CoJan Beulich2008-07-241-2/+2
| | | | | | | | | | | | | | | | | | The double indirection here is not needed anywhere and hence (at least) confusing. Signed-off-by: Jan Beulich <jbeulich@novell.com> Cc: Hugh Dickins <hugh@veritas.com> Cc: Nick Piggin <npiggin@suse.de> Cc: Christoph Lameter <cl@linux-foundation.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: "Luck, Tony" <tony.luck@intel.com> Cc: Paul Mundt <lethal@linux-sh.org> Cc: "David S. Miller" <davem@davemloft.net> Acked-by: Jeremy Fitzhardinge <jeremy@goop.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm/vmstat.c: proper externsAdrian Bunk2008-07-241-4/+0
| | | | | | | | | This patch adds proper extern declarations for five variables in include/linux/vmstat.h 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>
* Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6Linus Torvalds2008-07-221-6/+5
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6: (82 commits) ipw2200: Call netif_*_queue() interfaces properly. netxen: Needs to include linux/vmalloc.h [netdrvr] atl1d: fix !CONFIG_PM build r6040: rework init_one error handling r6040: bump release number to 0.18 r6040: handle RX fifo full and no descriptor interrupts r6040: change the default waiting time r6040: use definitions for magic values in descriptor status r6040: completely rework the RX path r6040: call napi_disable when puting down the interface and set lp->dev accordingly. mv643xx_eth: fix NETPOLL build r6040: rework the RX buffers allocation routine r6040: fix scheduling while atomic in r6040_tx_timeout r6040: fix null pointer access and tx timeouts r6040: prefix all functions with r6040 rndis_host: support WM6 devices as modems at91_ether: use netstats in net_device structure sfc: Create one RX queue and interrupt per CPU package by default sfc: Use a separate workqueue for resets sfc: I2C adapter initialisation fixes ...
| * netns: make get_proc_net() staticAdrian Bunk2008-07-221-6/+5
| | | | | | | | | | | | | | | | get_proc_net() can now become static. Signed-off-by: Adrian Bunk <bunk@kernel.org> Acked-by: Pavel Emelyanov <xemul@openvz.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* | Merge git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core-2.6Linus Torvalds2008-07-227-32/+173
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core-2.6: (79 commits) arm: bus_id -> dev_name() and dev_set_name() conversions sparc64: fix up bus_id changes in sparc core code 3c59x: handle pci_name() being const MTD: handle pci_name() being const HP iLO driver sysdev: Convert the x86 mce tolerant sysdev attribute to generic attribute sysdev: Add utility functions for simple int/ulong variable sysdev attributes sysdev: Pass the attribute to the low level sysdev show/store function driver core: Suppress sysfs warnings for device_rename(). kobject: Transmit return value of call_usermodehelper() to caller sysfs-rules.txt: reword API stability statement debugfs: Implement debugfs_remove_recursive() HOWTO: change email addresses of James in HOWTO always enable FW_LOADER unless EMBEDDED=y uio-howto.tmpl: use unique output names uio-howto.tmpl: use standard copyright/legal markings sysfs: don't call notify_change sysdev: fix debugging statements in registration code. kobject: should use kobject_put() in kset-example kobject: reorder kobject to save space on 64 bit builds ...
| * | driver core: Suppress sysfs warnings for device_rename().Cornelia Huck2008-07-213-10/+69
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | driver core: Suppress sysfs warnings for device_rename(). Renaming network devices to an already existing name is not something we want sysfs to print a scary warning for, since the callers can deal with this correctly. So let's introduce sysfs_create_link_nowarn() which gets rid of the common warning. Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
| * | debugfs: Implement debugfs_remove_recursive()Haavard Skinnemoen2008-07-211-18/+96
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | debugfs_remove_recursive() will remove a dentry and all its children. Drivers can use this to zap their whole debugfs tree so that they don't need to keep track of every single debugfs dentry they created. It may fail to remove the whole tree in certain cases: sh-3.2# rmmod atmel-mci < /sys/kernel/debug/mmc0/ios/clock mmc0: card b368 removed atmel_mci atmel_mci.0: Lost dma0chan1, falling back to PIO sh-3.2# ls /sys/kernel/debug/mmc0/ ios But I'm not sure if that case can be handled in any sane manner. Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com> Cc: Pierre Ossman <drzeus-list@drzeus.cx> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
| * | sysfs: don't call notify_changeMiklos Szeredi2008-07-211-1/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | sysfs_chmod_file() calls notify_change() to change the permission bits on a sysfs file. Replace with explicit call to sysfs_setattr() and fsnotify_change(). This is equivalent, except that security_inode_setattr() is not called. This function is called by drivers, so the security checks do not make any sense. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
| * | driver core: remove KOBJ_NAME_LEN defineKay Sievers2008-07-211-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | Kobjects do not have a limit in name size since a while, so stop pretending that they do. Signed-off-by: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
| * | device create: coda: convert device_create to device_create_drvdataGreg Kroah-Hartman2008-07-211-2/+3
| |/ | | | | | | | | | | | | | | | | device_create() is race-prone, so use the race-free device_create_drvdata() instead as device_create() is going away. Cc: Jan Harkes <jaharkes@cs.cmu.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* | proc: fix /proc/*/pagemap some moreAlexey Dobriyan2008-07-221-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | struct pagemap_walk was placed on stack, some hooks are initialized, the rest (->pgd_entry, ->pud_entry, ->pte_entry) are valid but junk. Reported-by: Eric Sesterhenn <snakebyte@gmx.de> Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Cc: "Vegard Nossum" <vegard.nossum@gmail.com> Cc: <stable@kernel.org> [2.6.25.x, 2.6.26.x] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | execve filename: document and export via auxiliary vectorJohn Reiser2008-07-221-0/+1
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The Linux kernel puts the filename argument of execve() into the new address space. Many developers are surprised to learn this. Those who know and could use it, object "But it's not documented." Those who want to use it dislike the expression (char *)(1+ strlen(env[-1+ n_env]) + env[-1+ n_env]) because it requires locating the last original environment variable, and assumes that the filename follows the characters. This patch documents the insertion of the filename, and makes it easier to find by adding a new tag AT_EXECFN in the ElfXX_auxv_t; see <elf.h>. In many cases readlink("/proc/self/exe",) gives the same answer. But if all the original pages get unmapped, then the kernel erases the symlink for /proc/self/exe. This can happen when a program decompressor does a good job of cleaning up after uncompressing directly to memory, so that the address space of the target program looks the same as if compression had never happened. One example is http://upx.sourceforge.net . One notable use of the underlying concept (what path containED the executable) is glibc expanding $ORIGIN in DT_RUNPATH. In practice for the near term, it may be a good idea for user-mode code to use both /proc/self/exe and AT_EXECFN as fall-back methods for each other. /proc/self/exe can fail due to unmapping, AT_EXECFN can fail because it won't be present on non-new systems. The auxvec or {AT_EXECFN}.d_val also can get overwritten, although in nearly all cases this would be the result of a bug. The runtime cost is one NEW_AUX_ENT using two words of stack space. The underlying value is maintained already as bprm->exec; setup_arg_pages() in fs/exec.c slides it for stack_shift, etc. Signed-off-by: John Reiser <jreiser@BitWagon.com> Cc: Roland McGrath <roland@redhat.com> Cc: Jakub Jelinek <jakub@redhat.com> Cc: Ulrich Drepper <drepper@redhat.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branch 'for-2.6.27' of git://linux-nfs.org/~bfields/linuxLinus Torvalds2008-07-2017-501/+596
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * 'for-2.6.27' of git://linux-nfs.org/~bfields/linux: (51 commits) nfsd: nfs4xdr.c do-while is not a compound statement nfsd: Use C99 initializers in fs/nfsd/nfs4xdr.c lockd: Pass "struct sockaddr *" to new failover-by-IP function lockd: get host reference in nlmsvc_create_block() instead of callers lockd: minor svclock.c style fixes lockd: eliminate duplicate nlmsvc_lookup_host call from nlmsvc_lock lockd: eliminate duplicate nlmsvc_lookup_host call from nlmsvc_testlock lockd: nlm_release_host() checks for NULL, caller needn't file lock: reorder struct file_lock to save space on 64 bit builds nfsd: take file and mnt write in nfs4_upgrade_open nfsd: document open share bit tracking nfsd: tabulate nfs4 xdr encoding functions nfsd: dprint operation names svcrdma: Change WR context get/put to use the kmem cache svcrdma: Create a kmem cache for the WR contexts svcrdma: Add flush_scheduled_work to module exit function svcrdma: Limit ORD based on client's advertised IRD svcrdma: Remove unused wait q from svcrdma_xprt structure svcrdma: Remove unneeded spin locks from __svc_rdma_free svcrdma: Add dma map count and WARN_ON ...
| * nfsd: nfs4xdr.c do-while is not a compound statementHarvey Harrison2008-07-181-2/+2
| | | | | | | | | | | | | | | | | | The WRITEMEM macro produces sparse warnings of the form: fs/nfsd/nfs4xdr.c:2668:2: warning: do-while statement is not a compound statement Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com> Cc: Benny Halevy <bhalevy@panasas.com> Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
| * nfsd: Use C99 initializers in fs/nfsd/nfs4xdr.cJ. Bruce Fields2008-07-181-74/+74
| | | | | | | | | | | | | | | | Thanks to problem report and original patch from Harvey Harrison. Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu> Cc: Harvey Harrison <harvey.harrison@gmail.com> Cc: Benny Halevy <bhalevy@panasas.com>
| * lockd: Pass "struct sockaddr *" to new failover-by-IP functionChuck Lever2008-07-152-14/+33
| | | | | | | | | | | | | | | | | | | | | | | | | | Pass a more generic socket address type to nlmsvc_unlock_all_by_ip() to allow for future support of IPv6. Also provide additional sanity checking in failover_unlock_ip() when constructing the server's IP address. As an added bonus, provide clean kerneldoc comments on related NLM interfaces which were recently added. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
| * lockd: get host reference in nlmsvc_create_block() instead of callersJ. Bruce Fields2008-07-151-3/+2
| | | | | | | | | | | | | | | | | | | | | | It may not be obvious (till you look at the definition of nlm_alloc_call()) that a function like nlmsvc_create_block() should consume a reference on success or failure, so I find it clearer if it takes the reference it needs itself. And both callers already do this immediately before the call anyway. Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
| * lockd: minor svclock.c style fixesJ. Bruce Fields2008-07-151-5/+5
| | | | | | | | Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
| * lockd: eliminate duplicate nlmsvc_lookup_host call from nlmsvc_lockJeff Layton2008-07-153-10/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | nlmsvc_lock calls nlmsvc_lookup_host to find a nlm_host struct. The callers of this function, however, call nlmsvc_retrieve_args or nlm4svc_retrieve_args, which also return a nlm_host struct. Change nlmsvc_lock to take a host arg instead of calling nlmsvc_lookup_host itself and change the callers to pass a pointer to the nlm_host they've already found. Since nlmsvc_testlock() now just uses the caller's reference, we no longer need to get or release it. Signed-off-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
| * lockd: eliminate duplicate nlmsvc_lookup_host call from nlmsvc_testlockJeff Layton2008-07-153-11/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | nlmsvc_testlock calls nlmsvc_lookup_host to find a nlm_host struct. The callers of this functions, however, call nlmsvc_retrieve_args or nlm4svc_retrieve_args, which also return a nlm_host struct. Change nlmsvc_testlock to take a host arg instead of calling nlmsvc_lookup_host itself and change the callers to pass a pointer to the nlm_host they've already found. We take a reference to host in the place where nlmsvc_testlock() previous did a new lookup, so the reference counting is unchanged from before. Signed-off-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
| * lockd: nlm_release_host() checks for NULL, caller needn'tJeff Layton2008-07-152-4/+2
| | | | | | | | | | | | | | No need to check for a NULL argument twice. Signed-off-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
| * nfsd: take file and mnt write in nfs4_upgrade_openBenny Halevy2008-07-071-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | testing with newpynfs revealed this warning: Jul 3 07:32:50 buml kernel: writeable file with no mnt_want_write() Jul 3 07:32:50 buml kernel: ------------[ cut here ]------------ Jul 3 07:32:50 buml kernel: WARNING: at /usr0/export/dev/bhalevy/git/linux-pnfs-bh-nfs41/include/linux/fs.h:855 drop_file_write_access+0x6b/0x7e() Jul 3 07:32:50 buml kernel: Modules linked in: nfsd auth_rpcgss exportfs nfs lockd nfs_acl sunrpc Jul 3 07:32:50 buml kernel: Call Trace: Jul 3 07:32:50 buml kernel: 6eaadc88: [<6002f471>] warn_on_slowpath+0x54/0x8e Jul 3 07:32:50 buml kernel: 6eaadcc8: [<601b790d>] printk+0xa0/0x793 Jul 3 07:32:50 buml kernel: 6eaadd38: [<601b6205>] __mutex_lock_slowpath+0x1db/0x1ea Jul 3 07:32:50 buml kernel: 6eaadd68: [<7107d4d5>] nfs4_preprocess_seqid_op+0x2a6/0x31c [nfsd] Jul 3 07:32:50 buml kernel: 6eaadda8: [<60078dc9>] drop_file_write_access+0x6b/0x7e Jul 3 07:32:50 buml kernel: 6eaaddc8: [<710804e4>] nfsd4_open_downgrade+0x114/0x1de [nfsd] Jul 3 07:32:50 buml kernel: 6eaade08: [<71076215>] nfsd4_proc_compound+0x1ba/0x2dc [nfsd] Jul 3 07:32:50 buml kernel: 6eaade48: [<71068221>] nfsd_dispatch+0xe5/0x1c2 [nfsd] Jul 3 07:32:50 buml kernel: 6eaade88: [<71312f81>] svc_process+0x3fd/0x714 [sunrpc] Jul 3 07:32:50 buml kernel: 6eaadea8: [<60039a81>] kernel_sigprocmask+0xf3/0x100 Jul 3 07:32:50 buml kernel: 6eaadee8: [<7106874b>] nfsd+0x182/0x29b [nfsd] Jul 3 07:32:50 buml kernel: 6eaadf48: [<60021cc9>] run_kernel_thread+0x41/0x4a Jul 3 07:32:50 buml kernel: 6eaadf58: [<710685c9>] nfsd+0x0/0x29b [nfsd] Jul 3 07:32:50 buml kernel: 6eaadf98: [<60021cb0>] run_kernel_thread+0x28/0x4a Jul 3 07:32:50 buml kernel: 6eaadfc8: [<60013829>] new_thread_handler+0x72/0x9c Jul 3 07:32:50 buml kernel: Jul 3 07:32:50 buml kernel: ---[ end trace 2426dd7cb2fba3bf ]--- Bruce Fields suggested this (Thanks!): maybe we need to be doing a mnt_want_write on open_upgrade and mnt_put_write on downgrade? This patch adds a call to mnt_want_write and file_take_write (which is doing the actual work). The counter-calls mnt_drop_write a file_release_write are now being properly called by drop_file_write_access in the exact path printed by the warning above. Signed-off-by: Benny Halevy <bhalevy@panasas.com> Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
| * nfsd: document open share bit trackingJ. Bruce Fields2008-07-071-0/+18
| | | | | | | | | | | | | | It's not immediately obvious from the code why we're doing this. Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu> Cc: Benny Halevy <bhalevy@panasas.com>
| * nfsd: tabulate nfs4 xdr encoding functionsBenny Halevy2008-07-041-114/+91
| | | | | | | | | | | | | | | | | | | | | | In preparation for minorversion 1 All encoders now return an nfserr status (typically their nfserr argument). Unsupported ops go through nfsd4_encode_operation too, so use nfsd4_encode_noop to encode nothing for their reply body. Signed-off-by: Benny Halevy <bhalevy@panasas.com> Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
| * Merge branch 'for-bfields' of git://linux-nfs.org/~tomtucker/xprt-switch-2.6 ↵J. Bruce Fields2008-07-03119-1481/+1913
| |\ | | | | | | | | | into for-2.6.27
| * | nfsd: dprint operation namesBenny Halevy2008-07-021-2/+50
| | | | | | | | | | | | | | | Signed-off-by: Benny Halevy <bhalevy@panasas.com> Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
| * | nfsd: nfs4 minorversion decoder vectorsBenny Halevy2008-07-021-3/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | Have separate vectors of operation decoders for each minorversion. Obsolete ops in newer minorversions have default implementation returning nfserr_opnotsupp. Signed-off-by: Benny Halevy <bhalevy@panasas.com> Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
| * | nfsd: unsupported nfs4 ops should fail with nfserr_opnotsuppBenny Halevy2008-07-021-0/+9
| | | | | | | | | | | | | | | | | | | | | nfserr_opnotsupp should be returned for unsupported nfs4 ops rather than nfserr_op_illegal. Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
| * | nfsd: tabulate nfs4 xdr decoding functionsBenny Halevy2008-07-021-105/+48
| | | | | | | | | | | | | | | | | | | | | In preparation for minorversion 1 Signed-off-by: Benny Halevy <bhalevy@panasas.com> Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
| * | nfsd: return nfserr_minor_vers_mismatch when compound minorversion != 0Benny Halevy2008-07-021-7/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Check minorversion once before decoding any operation and reject with nfserr_minor_vers_mismatch if != 0 (this still happens in nfsd4_proc_compound). In this case return a zero length resultdata array as required by RFC3530. minorversion 1 processing will have its own vector of decoders. Signed-off-by: Benny Halevy <bhalevy@panasas.com> Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
| * | nfsd: clean up mnt_want_write callsMiklos Szeredi2008-07-011-14/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | Multiple mnt_want_write() calls in the switch statement looks really ugly. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Acked-by: Christoph Hellwig <hch@infradead.org> Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
| * | nfsd: treat all shutdown signals as equivalentJeff Layton2008-06-301-25/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | knfsd currently uses 2 signal masks when processing requests. A "loose" mask (SHUTDOWN_SIGS) that it uses when receiving network requests, and then a more "strict" mask (ALLOWED_SIGS, which is just SIGKILL) that it allows when doing the actual operation on the local storage. This is apparently unnecessarily complicated. The underlying filesystem should be able to sanely handle a signal in the middle of an operation. This patch removes the signal mask handling from knfsd altogether. When knfsd is started as a kthread, all signals are ignored. It then allows all of the signals in SHUTDOWN_SIGS. There's no need to set the mask as well. Signed-off-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
| * | nfsd: fix spurious EACCESS in reconnect_path()Neil Brown2008-06-301-3/+26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Thanks to Frank Van Maarseveen for the original problem report: "A privileged process on an NFS client which drops privileges after using them to change the current working directory, will experience incorrect EACCES after an NFS server reboot. This problem can also occur after memory pressure on the server, particularly when the client side is quiet for some time." This occurs because the filehandle points to a directory whose parents are no longer in the dentry cache, and we're attempting to reconnect the directory to its parents without adequate permissions to perform lookups in the parent directories. We can therefore fix the problem by acquiring the necessary capabilities before attempting the reconnection. We do this only in the no_subtree_check case, since the documented behavior of the subtree_check export option requires the server to check that the user has lookup permissions on all parents. The subtree_check case still has a problem, since reconnect_path() unnecessarily requires both read and lookup permissions on all parent directories. However, a fix in that case would be more delicate, and use of subtree_check is already discouraged for other reasons. Signed-off-by: Neil Brown <neilb@suse.de> Cc: Frank van Maarseveen <frankvm@frankvm.com> Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
| * | nfsd: rename MAY_ flagsMiklos Szeredi2008-06-239-84/+92
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Rename nfsd_permission() specific MAY_* flags to NFSD_MAY_* to make it clear, that these are not used outside nfsd, and to avoid name and number space conflicts with the VFS. [comment from hch: rename MAY_READ, MAY_WRITE and MAY_EXEC as well] Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
| * | knfsd: nfsd: Handle ERESTARTSYS from syscalls.NeilBrown2008-06-231-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | OCFS2 can return -ERESTARTSYS from write requests (and possibly elsewhere) if there is a signal pending. If nfsd is shutdown (by sending a signal to each thread) while there is still an IO load from the client, each thread could handle one last request with a signal pending. This can result in -ERESTARTSYS which is not understood by nfserrno() and so is reflected back to the client as nfserr_io aka -EIO. This is wrong. Instead, interpret ERESTARTSYS to mean "try again later" by returning nfserr_jukebox. The client will resend and - if the server is restarted - the write will (hopefully) be successful and everyone will be happy. The symptom that I narrowed down to this was: copy a large file via NFS to an OCFS2 filesystem, and restart the nfs server during the copy. The 'cp' might get an -EIO, and the file will be corrupted - presumably holes in the middle where writes appeared to fail. Signed-off-by: Neil Brown <neilb@suse.de> Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
| * | nfsd: fix race in nfsd_nrthreads()Neil Brown2008-06-231-4/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | We need the nfsd_mutex before accessing nfsd_serv->sv_nrthreads or we can't even guarantee nfsd_serv will still be there. Signed-off-by: Neil Brown <neilb@suse.de> Acked-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
| * | lockd: close potential race with rapid lockd_up/lockd_down cycleJeff Layton2008-06-231-20/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If lockd_down is called very rapidly after lockd_up returns, then there is a slim chance that lockd() will never be called. kthread() will return before calling the function, so we'll end up never actually calling the cleanup functions for the thread. Signed-off-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
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