mm: write iovec cleanup
Hide some of the open-coded nr_segs tests into the iovec helpers. This is all to simplify generic_file_buffered_write, because that gets more complex in the next patch. 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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committed by
Linus Torvalds
parent
eb2be18931
commit
4a9e5ef1f4
@@ -15,7 +15,6 @@
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#include <linux/rmap.h>
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#include <linux/sched.h>
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#include <asm/tlbflush.h>
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#include "filemap.h"
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/*
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* We do use our own empty page to avoid interference with other users
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@@ -288,6 +287,7 @@ __xip_file_write(struct file *filp, const char __user *buf,
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unsigned long index;
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unsigned long offset;
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size_t copied;
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char *kaddr;
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offset = (pos & (PAGE_CACHE_SIZE -1)); /* Within page */
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index = pos >> PAGE_CACHE_SHIFT;
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@@ -295,14 +295,6 @@ __xip_file_write(struct file *filp, const char __user *buf,
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if (bytes > count)
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bytes = count;
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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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fault_in_pages_readable(buf, bytes);
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page = a_ops->get_xip_page(mapping,
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index*(PAGE_SIZE/512), 0);
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if (IS_ERR(page) && (PTR_ERR(page) == -ENODATA)) {
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@@ -319,8 +311,13 @@ __xip_file_write(struct file *filp, const char __user *buf,
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break;
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}
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copied = filemap_copy_from_user(page, offset, buf, bytes);
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fault_in_pages_readable(buf, bytes);
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kaddr = kmap_atomic(page, KM_USER0);
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copied = bytes -
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__copy_from_user_inatomic_nocache(kaddr, buf, bytes);
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kunmap_atomic(kaddr, KM_USER0);
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flush_dcache_page(page);
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if (likely(copied > 0)) {
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status = copied;
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