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path: root/fs/ramfs/file-nommu.c
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2006-10-01[PATCH] Streamline generic_file_* interfaces and filemap cleanupsBadari Pulavarty
This patch cleans up generic_file_*_read/write() interfaces. Christoph Hellwig gave me the idea for this clean ups. In a nutshell, all filesystems should set .aio_read/.aio_write methods and use do_sync_read/ do_sync_write() as their .read/.write methods. This allows us to cleanup all variants of generic_file_* routines. Final available interfaces: generic_file_aio_read() - read handler generic_file_aio_write() - write handler generic_file_aio_write_nolock() - no lock write handler __generic_file_aio_write_nolock() - internal worker routine Signed-off-by: Badari Pulavarty <pbadari@us.ibm.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-10[PATCH] NOMMU: Fix execution off of ramfs with mmap()David Howells
Fix execution through the FDPIC binfmt of programs stored on ramfs by preventing the ramfs mmap() returning successfully on a private mapping of a ramfs file. This causes NOMMU mmap to make a copy of the mapped portion of the file and map that instead. This could be improved by granting direct mapping access to read-only private mappings for which the data is stored on a contiguous run of pages. However, this is only likely to be the case if the file was extended with truncate before being written. ramfs is left to map the file directly for shared mappings so that SYSV IPC and POSIX shared memory both still work. Signed-off-by: David Howells <dhowells@redhat.com> Cc: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-28[PATCH] mark address_space_operations constChristoph Hellwig
Same as with already do with the file operations: keep them in .rodata and prevents people from doing runtime patching. Signed-off-by: Christoph Hellwig <hch@lst.de> Cc: Steven French <sfrench@us.ibm.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] mm: nommu use compound pagesNick Piggin
Now that compound page handling is properly fixed in the VM, move nommu over to using compound pages rather than rolling their own refcounting. nommu vm page refcounting is broken anyway, but there is no need to have divergent code in the core VM now, nor when it gets fixed. Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: David Howells <dhowells@redhat.com> (Needs testing, please). Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-06[PATCH] NOMMU: Provide shared-writable mmap support on ramfsDavid Howells
The attached patch makes ramfs support shared-writable mmaps by: (1) Attempting to perform a contiguous block allocation to the requested size when truncate attempts to increase the file from zero size, such as happens when: fd = shm_open("/file/on/ramfs", ...): ftruncate(fd, size_requested); addr = mmap(NULL, subsize, PROT_READ|PROT_WRITE|PROT_EXEC, MAP_SHARED, fd, offset); (2) Permitting any shared-writable mapping over any contiguous set of extant pages. get_unmapped_area() will return the address into the actual ramfs pages. The mapping may start anywhere and be of any size, but may not go over the end of file. Multiple mappings may overlap in any way. (3) Not permitting a file to be shrunk if it would truncate any shared mappings (private mappings are copied). Thus this patch provides support for POSIX shared memory on NOMMU kernels, with certain limitations such as there being a large enough block of pages available to support the allocation and it only working on directly mappable filesystems. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>