- 20 7月, 2007 3 次提交
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由 Nick Piggin 提交于
Change ->fault prototype. We now return an int, which contains VM_FAULT_xxx code in the low byte, and FAULT_RET_xxx code in the next byte. FAULT_RET_ code tells the VM whether a page was found, whether it has been locked, and potentially other things. This is not quite the way he wanted it yet, but that's changed in the next patch (which requires changes to arch code). This means we no longer set VM_CAN_INVALIDATE in the vma in order to say that a page is locked which requires filemap_nopage to go away (because we can no longer remain backward compatible without that flag), but we were going to do that anyway. struct fault_data is renamed to struct vm_fault as Linus asked. address is now a void __user * that we should firmly encourage drivers not to use without really good reason. The page is now returned via a page pointer in the vm_fault struct. Signed-off-by: NNick Piggin <npiggin@suse.de> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Nick Piggin 提交于
Nonlinear mappings are (AFAIKS) simply a virtual memory concept that encodes the virtual address -> file offset differently from linear mappings. ->populate is a layering violation because the filesystem/pagecache code should need to know anything about the virtual memory mapping. The hitch here is that the ->nopage handler didn't pass down enough information (ie. pgoff). But it is more logical to pass pgoff rather than have the ->nopage function calculate it itself anyway (because that's a similar layering violation). Having the populate handler install the pte itself is likewise a nasty thing to be doing. This patch introduces a new fault handler that replaces ->nopage and ->populate and (later) ->nopfn. Most of the old mechanism is still in place so there is a lot of duplication and nice cleanups that can be removed if everyone switches over. The rationale for doing this in the first place is that nonlinear mappings are subject to the pagefault vs invalidate/truncate race too, and it seemed stupid to duplicate the synchronisation logic rather than just consolidate the two. After this patch, MAP_NONBLOCK no longer sets up ptes for pages present in pagecache. Seems like a fringe functionality anyway. NOPAGE_REFAULT is removed. This should be implemented with ->fault, and no users have hit mainline yet. [akpm@linux-foundation.org: cleanup] [randy.dunlap@oracle.com: doc. fixes for readahead] [akpm@linux-foundation.org: build fix] Signed-off-by: NNick Piggin <npiggin@suse.de> Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com> Cc: Mark Fasheh <mark.fasheh@oracle.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Nick Piggin 提交于
Fix the race between invalidate_inode_pages and do_no_page. Andrea Arcangeli identified a subtle race between invalidation of pages from pagecache with userspace mappings, and do_no_page. The issue is that invalidation has to shoot down all mappings to the page, before it can be discarded from the pagecache. Between shooting down ptes to a particular page, and actually dropping the struct page from the pagecache, do_no_page from any process might fault on that page and establish a new mapping to the page just before it gets discarded from the pagecache. The most common case where such invalidation is used is in file truncation. This case was catered for by doing a sort of open-coded seqlock between the file's i_size, and its truncate_count. Truncation will decrease i_size, then increment truncate_count before unmapping userspace pages; do_no_page will read truncate_count, then find the page if it is within i_size, and then check truncate_count under the page table lock and back out and retry if it had subsequently been changed (ptl will serialise against unmapping, and ensure a potentially updated truncate_count is actually visible). Complexity and documentation issues aside, the locking protocol fails in the case where we would like to invalidate pagecache inside i_size. do_no_page can come in anytime and filemap_nopage is not aware of the invalidation in progress (as it is when it is outside i_size). The end result is that dangling (->mapping == NULL) pages that appear to be from a particular file may be mapped into userspace with nonsense data. Valid mappings to the same place will see a different page. Andrea implemented two working fixes, one using a real seqlock, another using a page->flags bit. He also proposed using the page lock in do_no_page, but that was initially considered too heavyweight. However, it is not a global or per-file lock, and the page cacheline is modified in do_no_page to increment _count and _mapcount anyway, so a further modification should not be a large performance hit. Scalability is not an issue. This patch implements this latter approach. ->nopage implementations return with the page locked if it is possible for their underlying file to be invalidated (in that case, they must set a special vm_flags bit to indicate so). do_no_page only unlocks the page after setting up the mapping completely. invalidation is excluded because it holds the page lock during invalidation of each page (and ensures that the page is not mapped while holding the lock). This also allows significant simplifications in do_no_page, because we have the page locked in the right place in the pagecache from the start. Signed-off-by: NNick Piggin <npiggin@suse.de> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 11 7月, 2007 1 次提交
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由 Mark Fasheh 提交于
Implement cluster consistent shared writeable mappings using the ->page_mkwrite() callback. Signed-off-by: NMark Fasheh <mark.fasheh@oracle.com>
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- 27 4月, 2007 1 次提交
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由 Mark Fasheh 提交于
This will be turned back on once we can do allocation in ->page_mkwrite(). Signed-off-by: NMark Fasheh <mark.fasheh@oracle.com>
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- 08 12月, 2006 1 次提交
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由 Sunil Mushran 提交于
This allows users to format an ocfs2 file system with a special flag, OCFS2_FEATURE_INCOMPAT_LOCAL_MOUNT. When the file system sees this flag, it will not use any cluster services, nor will it require a cluster configuration, thus acting like a 'local' file system. Signed-off-by: NSunil Mushran <sunil.mushran@oracle.com> Signed-off-by: NMark Fasheh <mark.fasheh@oracle.com>
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- 02 12月, 2006 1 次提交
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由 Tiger Yang 提交于
Conditionally update atime in ocfs2_file_aio_read(), ocfs2_readdir() and ocfs2_mmap(). Signed-off-by: NTiger Yang <tiger.yang@oracle.com> Signed-off-by: NMark Fasheh <mark.fasheh@oracle.com>
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- 30 6月, 2006 1 次提交
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由 Joel Becker 提交于
Give gcc the chance to compile out the debug logging code in ocfs2. This saves some size at the expense of being able to debug the code. Signed-off-by: NJoel Becker <joel.becker@oracle.com> Signed-off-by: NMark Fasheh <mark.fasheh@oracle.com>
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- 11 1月, 2006 1 次提交
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由 Christoph Hellwig 提交于
To allow various options to work per-mount instead of per-sb we need a struct vfsmount when updating ctime and mtime. This preparation patch replaces the inode_update_time routine with a file_update_atime routine so we can easily get at the vfsmount. (and the file makes more sense in this context anyway). Also get rid of the unused second argument - we always want to update the ctime when calling this routine. Signed-off-by: NChristoph Hellwig <hch@lst.de> Cc: Al Viro <viro@ftp.linux.org.uk> Cc: Anton Altaparmakov <aia21@cantab.net> Signed-off-by: NAndrew Morton <akpm@osdl.org> Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
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- 04 1月, 2006 1 次提交
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由 Mark Fasheh 提交于
The OCFS2 file system module. Signed-off-by: NMark Fasheh <mark.fasheh@oracle.com> Signed-off-by: NKurt Hackel <kurt.hackel@oracle.com>
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