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2006-06-23[PATCH] VFS: Permit filesystem to override root dentry on mountDavid Howells
Extend the get_sb() filesystem operation to take an extra argument that permits the VFS to pass in the target vfsmount that defines the mountpoint. The filesystem is then required to manually set the superblock and root dentry pointers. For most filesystems, this should be done with simple_set_mnt() which will set the superblock pointer and then set the root dentry to the superblock's s_root (as per the old default behaviour). The get_sb() op now returns an integer as there's now no need to return the superblock pointer. This patch permits a superblock to be implicitly shared amongst several mount points, such as can be done with NFS to avoid potential inode aliasing. In such a case, simple_set_mnt() would not be called, and instead the mnt_root and mnt_sb would be set directly. The patch also makes the following changes: (*) the get_sb_*() convenience functions in the core kernel now take a vfsmount pointer argument and return an integer, so most filesystems have to change very little. (*) If one of the convenience function is not used, then get_sb() should normally call simple_set_mnt() to instantiate the vfsmount. This will always return 0, and so can be tail-called from get_sb(). (*) generic_shutdown_super() now calls shrink_dcache_sb() to clean up the dcache upon superblock destruction rather than shrink_dcache_anon(). This is required because the superblock may now have multiple trees that aren't actually bound to s_root, but that still need to be cleaned up. The currently called functions assume that the whole tree is rooted at s_root, and that anonymous dentries are not the roots of trees which results in dentries being left unculled. However, with the way NFS superblock sharing are currently set to be implemented, these assumptions are violated: the root of the filesystem is simply a dummy dentry and inode (the real inode for '/' may well be inaccessible), and all the vfsmounts are rooted on anonymous[*] dentries with child trees. [*] Anonymous until discovered from another tree. (*) The documentation has been adjusted, including the additional bit of changing ext2_* into foo_* in the documentation. [akpm@osdl.org: convert ipath_fs, do other stuff] Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Al Viro <viro@zeniv.linux.org.uk> Cc: Nathan Scott <nathans@sgi.com> Cc: Roland Dreier <rolandd@cisco.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-28[PATCH] Make most file operations structs in fs/ constArjan van de Ven
This is a conversion to make the various file_operations structs in fs/ const. Basically a regexp job, with a few manual fixups The goal is both to increase correctness (harder to accidentally write to shared datastructures) and reducing the false sharing of cachelines with things that get dirty in .data (while .rodata is nicely read only and thus cache clean) Signed-off-by: Arjan van de Ven <arjan@infradead.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-22[PATCH] convert hugetlbfs_counter to atomicChen, Kenneth W
Implementation of hugetlbfs_counter() is functionally equivalent to atomic_inc_return(). Use the simpler atomic form. Signed-off-by: Ken Chen <kenneth.w.chen@intel.com> Cc: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-22[PATCH] hugepage: Strict page reservation for hugepage inodesDavid Gibson
These days, hugepages are demand-allocated at first fault time. There's a somewhat dubious (and racy) heuristic when making a new mmap() to check if there are enough available hugepages to fully satisfy that mapping. A particularly obvious case where the heuristic breaks down is where a process maps its hugepages not as a single chunk, but as a bunch of individually mmap()ed (or shmat()ed) blocks without touching and instantiating the pages in between allocations. In this case the size of each block is compared against the total number of available hugepages. It's thus easy for the process to become overcommitted, because each block mapping will succeed, although the total number of hugepages required by all blocks exceeds the number available. In particular, this defeats such a program which will detect a mapping failure and adjust its hugepage usage downward accordingly. The patch below addresses this problem, by strictly reserving a number of physical hugepages for hugepage inodes which have been mapped, but not instatiated. MAP_SHARED mappings are thus "safe" - they will fail on mmap(), not later with an OOM SIGKILL. MAP_PRIVATE mappings can still trigger an OOM. (Actually SHARED mappings can technically still OOM, but only if the sysadmin explicitly reduces the hugepage pool between mapping and instantiation) This patch appears to address the problem at hand - it allows DB2 to start correctly, for instance, which previously suffered the failure described above. This patch causes no regressions on the libhugetblfs testsuite, and makes a test (designed to catch this problem) pass which previously failed (ppc64, POWER5). Signed-off-by: David Gibson <dwg@au1.ibm.com> Cc: William Lee Irwin III <wli@holomorphy.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-01[PATCH] mm: hugepage accounting fixHugh Dickins
2.6.15's hugepage faulting introduced huge_pages_needed accounting into hugetlbfs: to count how many pages are already in cache, for spot check on how far a new mapping may be allowed to extend the file. But it's muddled: each hugepage found covers HPAGE_SIZE, not PAGE_SIZE. Once pages were already in cache, it would overshoot, wrap its hugepages count backwards, and so fail a harmless repeat mapping with -ENOMEM. Fixes the problem found by Don Dupuis. Signed-off-by: Hugh Dickins <hugh@veritas.com> Acked-By: Adam Litke <agl@us.ibm.com> Acked-by: William Irwin <wli@holomorphy.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-14[PATCH] Add tmpfs options for memory placement policiesRobin Holt
Anything that writes into a tmpfs filesystem is liable to disproportionately decrease the available memory on a particular node. Since there's no telling what sort of application (e.g. dd/cp/cat) might be dropping large files there, this lets the admin choose the appropriate default behavior for their site's situation. Introduce a tmpfs mount option which allows specifying a memory policy and a second option to specify the nodelist for that policy. With the default policy, tmpfs will behave as it does today. This patch adds support for preferred, bind, and interleave policies. The default policy will cause pages to be added to tmpfs files on the node which is doing the writing. Some jobs expect a single process to create and manage the tmpfs files. This results in a node which has a significantly reduced number of free pages. With this patch, the administrator can specify the policy and nodes for that policy where they would prefer allocations. This patch was originally written by Brent Casavant and Hugh Dickins. I added support for the bind and preferred policies and the mpol_nodelist mount option. Signed-off-by: Brent Casavant <bcasavan@sgi.com> Signed-off-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: Robin Holt <holt@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-11[PATCH] capable/capability.h (fs/)Randy Dunlap
fs: Use <linux/capability.h> where capable() is used. Signed-off-by: Randy Dunlap <rdunlap@xenotime.net> Acked-by: Tim Schmielau <tim@physik3.uni-rostock.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-09[PATCH] mutex subsystem, semaphore to mutex: VFS, ->i_semJes Sorensen
This patch converts the inode semaphore to a mutex. I have tested it on XFS and compiled as much as one can consider on an ia64. Anyway your luck with it might be different. Modified-by: Ingo Molnar <mingo@elte.hu> (finished the conversion) Signed-off-by: Jes Sorensen <jes@sgi.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2006-01-06[PATCH] Hugetlb: Copy on Write supportDavid Gibson
Implement copy-on-write support for hugetlb mappings so MAP_PRIVATE can be supported. This helps us to safely use hugetlb pages in many more applications. The patch makes the following changes. If needed, I also have it broken out according to the following paragraphs. 1. Add a pair of functions to set/clear write access on huge ptes. The writable check in make_huge_pte is moved out to the caller for use by COW later. 2. Hugetlb copy-on-write requires special case handling in the following situations: - copy_hugetlb_page_range() - Copied pages must be write protected so a COW fault will be triggered (if necessary) if those pages are written to. - find_or_alloc_huge_page() - Only MAP_SHARED pages are added to the page cache. MAP_PRIVATE pages still need to be locked however. 3. Provide hugetlb_cow() and calls from hugetlb_fault() and hugetlb_no_page() which handles the COW fault by making the actual copy. 4. Remove the check in hugetlbfs_file_map() so that MAP_PRIVATE mmaps will be allowed. Make MAP_HUGETLB exempt from the depricated VM_RESERVED mapping check. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Adam Litke <agl@us.ibm.com> Cc: William Lee Irwin III <wli@holomorphy.com> Cc: "Seth, Rohit" <rohit.seth@intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-22[PATCH] Fix hugetlbfs_statfs() reporting of block limitsDavid Gibson
Currently, if a hugetlbfs is mounted without limits (the default), statfs() will return -1 for max/free/used blocks. This does not appear to be in line with normal convention: simple_statfs() and shmem_statfs() both return 0 in similar cases. Worse, it confuses the translation logic in put_compat_statfs(), causing it to return -EOVERFLOW on such a mount. This patch alters hugetlbfs_statfs() to return 0 for max/free/used blocks on a mount without limits. Note that we need the test in the patch below, rather than just using 0 in the sbinfo structure, because the -1 marked in the free blocks field is used internally to tell the Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-09[PATCH] fs/hugetlbfs/inode.c: make a function staticAdrian Bunk
This patch makes a needlessly global function static. Signed-off-by: Adrian Bunk <bunk@stusta.de> Acked-by: William Irwin <wli@holomorphy.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-10-29[PATCH] hugetlb: overcommit accounting checkAdam Litke
Basic overcommit checking for hugetlb_file_map() based on an implementation used with demand faulting in SLES9. Since demand faulting can't guarantee the availability of pages at mmap time, this patch implements a basic sanity check to ensure that the number of huge pages required to satisfy the mmap are currently available. Despite the obvious race, I think it is a good start on doing proper accounting. I'd like to work towards an accounting system that mimics the semantics of normal pages (especially for the MAP_PRIVATE/COW case). That work is underway and builds on what this patch starts. Huge page shared memory segments are simpler and still maintain their commit on shmget semantics. Signed-off-by: Adam Litke <agl@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-10-29[PATCH] hugetlb: demand fault handlerAdam Litke
Below is a patch to implement demand faulting for huge pages. The main motivation for changing from prefaulting to demand faulting is so that huge page memory areas can be allocated according to NUMA policy. Thanks to consolidated hugetlb code, switching the behavior requires changing only one fault handler. The bulk of the patch just moves the logic from hugelb_prefault() to hugetlb_pte_fault() and find_get_huge_page(). Signed-off-by: Adam Litke <agl@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-10-29[PATCH] cleanup hugelbfs_forget_inodeChristoph Hellwig
Reformat hugelbfs_forget_inode and add the missing but harmless write_inode_now call. It looks the same as generic_forget_inode now except for the call to truncate_hugepages instead of truncate_inode_pages. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-10-29[PATCH] kill hugelbfs_do_delete_inodeChristoph Hellwig
hugetlbfs_do_delete_inode is the same as generic_delete_inode now, so remove it in favour of the latter. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-10-29[PATCH] hugetlbfs: clean up hugetlbfs_delete_inodeChristoph Hellwig
Make hugetlbfs looks the same as generic_detelte_inode, fixing a bunch of missing updates to it at the same time. Rename it to hugetlbfs_do_delete_inode and add a real hugetlbfs_delete_inode that implements ->delete_inode. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-10-29[PATCH] hugetlbfs: move free_inodes accountingChristoph Hellwig
Move hugetlbfs accounting into ->alloc_inode / ->destroy_inode. This keeps the code simpler, fixes a loeak where a failing inode allocation wouldn't decrement the counter and moves hugetlbfs_delete_inode and hugetlbfs_forget_inode closer to their generic counterparts. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-10-29[PATCH] mm: unmap_vmas with inner ptlockHugh Dickins
Remove the page_table_lock from around the calls to unmap_vmas, and replace the pte_offset_map in zap_pte_range by pte_offset_map_lock: all callers are now safe to descend without page_table_lock. Don't attempt fancy locking for hugepages, just take page_table_lock in unmap_hugepage_range. Which makes zap_hugepage_range, and the hugetlb test in zap_page_range, redundant: unmap_vmas calls unmap_hugepage_range anyway. Nor does unmap_vmas have much use for its mm arg now. The tlb_start_vma and tlb_end_vma in unmap_page_range are now called without page_table_lock: if they're implemented at all, they typically come down to flush_cache_range (usually done outside page_table_lock) and flush_tlb_range (which we already audited for the mprotect case). Signed-off-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-21[PATCH] Avoiding mmap fragmentationWolfgang Wander
Ingo recently introduced a great speedup for allocating new mmaps using the free_area_cache pointer which boosts the specweb SSL benchmark by 4-5% and causes huge performance increases in thread creation. The downside of this patch is that it does lead to fragmentation in the mmap-ed areas (visible via /proc/self/maps), such that some applications that work fine under 2.4 kernels quickly run out of memory on any 2.6 kernel. The problem is twofold: 1) the free_area_cache is used to continue a search for memory where the last search ended. Before the change new areas were always searched from the base address on. So now new small areas are cluttering holes of all sizes throughout the whole mmap-able region whereas before small holes tended to close holes near the base leaving holes far from the base large and available for larger requests. 2) the free_area_cache also is set to the location of the last munmap-ed area so in scenarios where we allocate e.g. five regions of 1K each, then free regions 4 2 3 in this order the next request for 1K will be placed in the position of the old region 3, whereas before we appended it to the still active region 1, placing it at the location of the old region 2. Before we had 1 free region of 2K, now we only get two free regions of 1K -> fragmentation. The patch addresses thes issues by introducing yet another cache descriptor cached_hole_size that contains the largest known hole size below the current free_area_cache. If a new request comes in the size is compared against the cached_hole_size and if the request can be filled with a hole below free_area_cache the search is started from the base instead. The results look promising: Whereas 2.6.12-rc4 fragments quickly and my (earlier posted) leakme.c test program terminates after 50000+ iterations with 96 distinct and fragmented maps in /proc/self/maps it performs nicely (as expected) with thread creation, Ingo's test_str02 with 20000 threads requires 0.7s system time. Taking out Ingo's patch (un-patch available per request) by basically deleting all mentions of free_area_cache from the kernel and starting the search for new memory always at the respective bases we observe: leakme terminates successfully with 11 distinctive hardly fragmented areas in /proc/self/maps but thread creating is gringdingly slow: 30+s(!) system time for Ingo's test_str02 with 20000 threads. Now - drumroll ;-) the appended patch works fine with leakme: it ends with only 7 distinct areas in /proc/self/maps and also thread creation seems sufficiently fast with 0.71s for 20000 threads. Signed-off-by: Wolfgang Wander <wwc@rentec.com> Credit-to: "Richard Purdie" <rpurdie@rpsys.net> Signed-off-by: Ken Chen <kenneth.w.chen@intel.com> Acked-by: Ingo Molnar <mingo@elte.hu> (partly) Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-04-16Linux-2.6.12-rc2Linus Torvalds
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!