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f7ca90b160
Instead of calling aops->get_xip_mem from the fault handler, the filesystem passes a get_block_t that is used to find the appropriate blocks. This requires that all architectures implement copy_user_page(). At the time of writing, mips and arm do not. Patches exist and are in progress. [akpm@linux-foundation.org: remap_file_pages went away] Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com> Reviewed-by: Jan Kara <jack@suse.cz> Cc: Andreas Dilger <andreas.dilger@intel.com> Cc: Boaz Harrosh <boaz@plexistor.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Dave Chinner <david@fromorbit.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Theodore Ts'o <tytso@mit.edu> Cc: Russell King <rmk@arm.linux.org.uk> Cc: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
64 lines
1.4 KiB
C
64 lines
1.4 KiB
C
/*
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* linux/mm/filemap_xip.c
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*
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* Copyright (C) 2005 IBM Corporation
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* Author: Carsten Otte <cotte@de.ibm.com>
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*
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* derived from linux/mm/filemap.c - Copyright (C) Linus Torvalds
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*
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*/
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#include <linux/fs.h>
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#include <linux/backing-dev.h>
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#include <linux/pagemap.h>
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#include <linux/export.h>
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#include <linux/uio.h>
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#include <linux/rmap.h>
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#include <linux/mmu_notifier.h>
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#include <linux/sched.h>
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#include <linux/seqlock.h>
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#include <linux/mutex.h>
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#include <linux/gfp.h>
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#include <asm/tlbflush.h>
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#include <asm/io.h>
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/*
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* truncate a page used for execute in place
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* functionality is analog to block_truncate_page but does use get_xip_mem
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* to get the page instead of page cache
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*/
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int
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xip_truncate_page(struct address_space *mapping, loff_t from)
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{
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pgoff_t index = from >> PAGE_CACHE_SHIFT;
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unsigned offset = from & (PAGE_CACHE_SIZE-1);
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unsigned blocksize;
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unsigned length;
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void *xip_mem;
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unsigned long xip_pfn;
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int err;
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BUG_ON(!mapping->a_ops->get_xip_mem);
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blocksize = 1 << mapping->host->i_blkbits;
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length = offset & (blocksize - 1);
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/* Block boundary? Nothing to do */
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if (!length)
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return 0;
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length = blocksize - length;
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err = mapping->a_ops->get_xip_mem(mapping, index, 0,
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&xip_mem, &xip_pfn);
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if (unlikely(err)) {
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if (err == -ENODATA)
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/* Hole? No need to truncate */
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return 0;
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else
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return err;
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}
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memset(xip_mem + offset, 0, length);
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return 0;
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}
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EXPORT_SYMBOL_GPL(xip_truncate_page);
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