The patch titled
     From: Nick Piggin <[EMAIL PROTECTED]>
has been removed from the -mm tree.  Its filename was
     mm-generic_file_buffered_write-iovec-cleanup.patch

This patch was dropped because it is obsolete

------------------------------------------------------
Subject: From: Nick Piggin <[EMAIL PROTECTED]>
From: Nick Piggin <[EMAIL PROTECTED]>
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To: Andrew Morton <[EMAIL PROTECTED]>
Cc: Linux Kernel <[email protected]>,
        Linux Filesystems <[email protected]>,
        Nick Piggin <[EMAIL PROTECTED]>,
        Linux Memory Management <[EMAIL PROTECTED]>
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Subject: [patch 8/9] mm: generic_file_buffered_write iovec cleanup
Date: Sun,  4 Feb 2007 09:50:57 +0100 (CET)
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        version=3.0.2

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 <[EMAIL PROTECTED]>

Index: linux-2.6/mm/filemap.h
===================================================================
--- linux-2.6.orig/mm/filemap.h
+++ linux-2.6/mm/filemap.h
@@ -22,82 +22,82 @@ __filemap_copy_from_user_iovec_inatomic(
 
 /*
  * Copy as much as we can into the page and return the number of bytes which
- * were sucessfully copied.  If a fault is encountered then clear the page
- * out to (offset+bytes) and return the number of bytes which were copied.
- *
- * NOTE: For this to work reliably we really want 
copy_from_user_inatomic_nocache
- * to *NOT* zero any tail of the buffer that it failed to copy.  If it does,
- * and if the following non-atomic copy succeeds, then there is a small window
- * where the target page contains neither the data before the write, nor the
- * data after the write (it contains zero).  A read at this time will see
- * data that is inconsistent with any ordering of the read and the write.
- * (This has been detected in practice).
+ * were sucessfully copied.  If a fault is encountered then return the number 
of
+ * bytes which were copied.
  */
 static inline size_t
-filemap_copy_from_user(struct page *page, unsigned long offset,
-                       const char __user *buf, unsigned bytes)
+filemap_copy_from_user_atomic(struct page *page, unsigned long offset,
+                       const struct iovec *iov, unsigned long nr_segs,
+                       size_t base, size_t bytes)
 {
        char *kaddr;
-       int left;
+       size_t copied;
 
        kaddr = kmap_atomic(page, KM_USER0);
-       left = __copy_from_user_inatomic_nocache(kaddr + offset, buf, bytes);
+       if (likely(nr_segs == 1)) {
+               int left;
+               char __user *buf = iov->iov_base + base;
+               left = __copy_from_user_inatomic_nocache(kaddr + offset,
+                                                       buf, bytes);
+               copied = bytes - left;
+       } else {
+               copied = __filemap_copy_from_user_iovec_inatomic(kaddr + offset,
+                                                       iov, base, bytes);
+       }
        kunmap_atomic(kaddr, KM_USER0);
 
-       if (left != 0) {
-               /* Do it the slow way */
-               kaddr = kmap(page);
-               left = __copy_from_user_nocache(kaddr + offset, buf, bytes);
-               kunmap(page);
-       }
-       return bytes - left;
+       return copied;
 }
 
 /*
- * This has the same sideeffects and return value as filemap_copy_from_user().
- * The difference is that on a fault we need to memset the remainder of the
- * page (out to offset+bytes), to emulate filemap_copy_from_user()'s
- * single-segment behaviour.
+ * This has the same sideeffects and return value as
+ * filemap_copy_from_user_atomic().
+ * The difference is that it attempts to resolve faults.
  */
 static inline size_t
-filemap_copy_from_user_iovec(struct page *page, unsigned long offset,
-                       const struct iovec *iov, size_t base, size_t bytes)
+filemap_copy_from_user(struct page *page, unsigned long offset,
+                       const struct iovec *iov, unsigned long nr_segs,
+                        size_t base, size_t bytes)
 {
        char *kaddr;
        size_t copied;
 
-       kaddr = kmap_atomic(page, KM_USER0);
-       copied = __filemap_copy_from_user_iovec_inatomic(kaddr + offset, iov,
-                                                        base, bytes);
-       kunmap_atomic(kaddr, KM_USER0);
-       if (copied != bytes) {
-               kaddr = kmap(page);
-               copied = __filemap_copy_from_user_iovec_inatomic(kaddr + 
offset, iov,
-                                                                base, bytes);
-               if (bytes - copied)
-                       memset(kaddr + offset + copied, 0, bytes - copied);
-               kunmap(page);
+       kaddr = kmap(page);
+       if (likely(nr_segs == 1)) {
+               int left;
+               char __user *buf = iov->iov_base + base;
+               left = __copy_from_user_nocache(kaddr + offset, buf, bytes);
+               copied = bytes - left;
+       } else {
+               copied = __filemap_copy_from_user_iovec_inatomic(kaddr + offset,
+                                                       iov, base, bytes);
        }
+       kunmap(page);
        return copied;
 }
 
 static inline void
-filemap_set_next_iovec(const struct iovec **iovp, size_t *basep, size_t bytes)
+filemap_set_next_iovec(const struct iovec **iovp, unsigned long nr_segs,
+                                                size_t *basep, size_t bytes)
 {
-       const struct iovec *iov = *iovp;
-       size_t base = *basep;
-
-       while (bytes) {
-               int copy = min(bytes, iov->iov_len - base);
-
-               bytes -= copy;
-               base += copy;
-               if (iov->iov_len == base) {
-                       iov++;
-                       base = 0;
+       if (likely(nr_segs == 1)) {
+               *basep += bytes;
+       } else {
+               const struct iovec *iov = *iovp;
+               size_t base = *basep;
+
+               while (bytes) {
+                       int copy = min(bytes, iov->iov_len - base);
+
+                       bytes -= copy;
+                       base += copy;
+                       if (iov->iov_len == base) {
+                               iov++;
+                               base = 0;
+                       }
                }
+               *iovp = iov;
+               *basep = base;
        }
-       *iovp = iov;
-       *basep = base;
 }
 #endif
Index: linux-2.6/mm/filemap.c
===================================================================
--- linux-2.6.orig/mm/filemap.c
+++ linux-2.6/mm/filemap.c
@@ -2049,12 +2049,7 @@ generic_file_buffered_write(struct kiocb
        /*
         * handle partial DIO write.  Adjust cur_iov if needed.
         */
-       if (likely(nr_segs == 1))
-               buf = iov->iov_base + written;
-       else {
-               filemap_set_next_iovec(&cur_iov, &iov_offset, written);
-               buf = cur_iov->iov_base + iov_offset;
-       }
+       filemap_set_next_iovec(&cur_iov, nr_segs, &iov_offset, written);
 
        do {
                struct page *page;
@@ -2064,6 +2059,7 @@ generic_file_buffered_write(struct kiocb
                size_t bytes;           /* Bytes to write to page */
                size_t copied;          /* Bytes copied from user */
 
+               buf = cur_iov->iov_base + iov_offset;
                offset = (pos & (PAGE_CACHE_SIZE - 1));
                index = pos >> PAGE_CACHE_SHIFT;
                bytes = PAGE_CACHE_SIZE - offset;
@@ -2095,13 +2091,10 @@ generic_file_buffered_write(struct kiocb
                if (unlikely(status))
                        goto fs_write_aop_error;
 
-               if (likely(nr_segs == 1))
-                       copied = filemap_copy_from_user(page, offset,
-                                                       buf, bytes);
-               else
-                       copied = filemap_copy_from_user_iovec(page, offset,
-                                               cur_iov, iov_offset, bytes);
+               copied = filemap_copy_from_user(page, offset,
+                                       cur_iov, nr_segs, iov_offset, bytes);
                flush_dcache_page(page);
+
                status = a_ops->commit_write(file, page, offset, offset+bytes);
                if (unlikely(status < 0))
                        goto fs_write_aop_error;
@@ -2112,20 +2105,11 @@ generic_file_buffered_write(struct kiocb
                if (unlikely(status > 0)) /* filesystem did partial write */
                        copied = status;
 
-               if (likely(copied > 0)) {
-                       written += copied;
-                       count -= copied;
-                       pos += copied;
-                       buf += copied;
-                       if (unlikely(nr_segs > 1)) {
-                               filemap_set_next_iovec(&cur_iov,
-                                               &iov_offset, copied);
-                               if (count)
-                                       buf = cur_iov->iov_base + iov_offset;
-                       } else {
-                               iov_offset += copied;
-                       }
-               }
+               written += copied;
+               count -= copied;
+               pos += copied;
+               filemap_set_next_iovec(&cur_iov, nr_segs, &iov_offset, copied);
+
                unlock_page(page);
                mark_page_accessed(page);
                page_cache_release(page);

Patches currently in -mm which might be from [EMAIL PROTECTED] are

mm-only-mm-debug-write-deadlocks.patch
mm-fix-pagecache-write-deadlocks.patch
mm-fix-pagecache-write-deadlocks-comment.patch
mm-fix-pagecache-write-deadlocks-mm-pagecache-write-deadlocks-efault-fix.patch
mm-fix-pagecache-write-deadlocks-zerolength-fix.patch
mm-fix-pagecache-write-deadlocks-stale-holes-fix.patch
fs-prepare_write-fixes.patch
fs-prepare_write-fixes-fuse-fix.patch
fs-prepare_write-fixes-jffs-fix.patch
fs-prepare_write-fixes-fat-fix.patch
fs-fix-cont-vs-deadlock-patches.patch
git-block.patch
buffer-memorder-fix.patch
sched-avoid-div-in-rebalance_tick.patch

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