mm: clean up buffered write code
Rename some variables and fix some types. Signed-off-by: Andrew Morton <akpm@osdl.org> 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>
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6814d7a912
commit
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35
mm/filemap.c
35
mm/filemap.c
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@ -1838,16 +1838,15 @@ generic_file_buffered_write(struct kiocb *iocb, const struct iovec *iov,
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size_t count, ssize_t written)
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{
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struct file *file = iocb->ki_filp;
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struct address_space * mapping = file->f_mapping;
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struct address_space *mapping = file->f_mapping;
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const struct address_space_operations *a_ops = mapping->a_ops;
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struct inode *inode = mapping->host;
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long status = 0;
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struct page *page;
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struct page *cached_page = NULL;
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size_t bytes;
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struct pagevec lru_pvec;
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const struct iovec *cur_iov = iov; /* current iovec */
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size_t iov_base = 0; /* offset in the current iovec */
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size_t iov_offset = 0; /* offset in the current iovec */
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char __user *buf;
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pagevec_init(&lru_pvec, 0);
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@ -1858,31 +1857,33 @@ generic_file_buffered_write(struct kiocb *iocb, const struct iovec *iov,
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if (likely(nr_segs == 1))
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buf = iov->iov_base + written;
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else {
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filemap_set_next_iovec(&cur_iov, &iov_base, written);
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buf = cur_iov->iov_base + iov_base;
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filemap_set_next_iovec(&cur_iov, &iov_offset, written);
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buf = cur_iov->iov_base + iov_offset;
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}
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do {
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unsigned long index;
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unsigned long offset;
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unsigned long maxlen;
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size_t copied;
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pgoff_t index; /* Pagecache index for current page */
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unsigned long offset; /* Offset into pagecache page */
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unsigned long maxlen; /* Bytes remaining in current iovec */
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size_t bytes; /* Bytes to write to page */
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size_t copied; /* Bytes copied from user */
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offset = (pos & (PAGE_CACHE_SIZE -1)); /* Within page */
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offset = (pos & (PAGE_CACHE_SIZE - 1));
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index = pos >> PAGE_CACHE_SHIFT;
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bytes = PAGE_CACHE_SIZE - offset;
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if (bytes > count)
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bytes = count;
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maxlen = cur_iov->iov_len - iov_offset;
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if (maxlen > bytes)
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maxlen = bytes;
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/*
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* Bring in the user page that we will copy from _first_.
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* Otherwise there's a nasty deadlock on copying from the
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* same page as we're writing to, without it being marked
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* up-to-date.
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*/
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maxlen = cur_iov->iov_len - iov_base;
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if (maxlen > bytes)
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maxlen = bytes;
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fault_in_pages_readable(buf, maxlen);
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page = __grab_cache_page(mapping,index,&cached_page,&lru_pvec);
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@ -1913,7 +1914,7 @@ generic_file_buffered_write(struct kiocb *iocb, const struct iovec *iov,
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buf, bytes);
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else
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copied = filemap_copy_from_user_iovec(page, offset,
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cur_iov, iov_base, bytes);
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cur_iov, iov_offset, bytes);
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flush_dcache_page(page);
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status = a_ops->commit_write(file, page, offset, offset+bytes);
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if (status == AOP_TRUNCATED_PAGE) {
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@ -1931,12 +1932,12 @@ generic_file_buffered_write(struct kiocb *iocb, const struct iovec *iov,
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buf += status;
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if (unlikely(nr_segs > 1)) {
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filemap_set_next_iovec(&cur_iov,
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&iov_base, status);
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&iov_offset, status);
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if (count)
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buf = cur_iov->iov_base +
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iov_base;
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iov_offset;
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} else {
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iov_base += status;
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iov_offset += status;
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}
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}
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}
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