Gitweb:     
http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=64649a58919e66ec21792dbb6c48cb3da22cbd7f
Commit:     64649a58919e66ec21792dbb6c48cb3da22cbd7f
Parent:     5fe172370687e03cc6ba8dca990b75db18ff9bb3
Author:     Nick Piggin <[EMAIL PROTECTED]>
AuthorDate: Tue Oct 16 01:24:56 2007 -0700
Committer:  Linus Torvalds <[EMAIL PROTECTED]>
CommitDate: Tue Oct 16 09:42:54 2007 -0700

    mm: trim more holes
    
    If prepare_write fails with AOP_TRUNCATED_PAGE, or if commit_write fails, 
then
    we may have failed the write operation despite prepare_write having
    instantiated blocks past i_size.  Fix this, and consolidate the trimming 
into
    one place.
    
    Signed-off-by: Nick Piggin <[EMAIL PROTECTED]>
    Signed-off-by: Andrew Morton <[EMAIL PROTECTED]>
    Signed-off-by: Linus Torvalds <[EMAIL PROTECTED]>
---
 mm/filemap.c |   80 +++++++++++++++++++++++++++++-----------------------------
 1 files changed, 40 insertions(+), 40 deletions(-)

diff --git a/mm/filemap.c b/mm/filemap.c
index 0c54fc9..73b98c6 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -1895,22 +1895,9 @@ generic_file_buffered_write(struct kiocb *iocb, const 
struct iovec *iov,
                }
 
                status = a_ops->prepare_write(file, page, offset, offset+bytes);
-               if (unlikely(status)) {
-                       loff_t isize = i_size_read(inode);
+               if (unlikely(status))
+                       goto fs_write_aop_error;
 
-                       if (status != AOP_TRUNCATED_PAGE)
-                               unlock_page(page);
-                       page_cache_release(page);
-                       if (status == AOP_TRUNCATED_PAGE)
-                               continue;
-                       /*
-                        * prepare_write() may have instantiated a few blocks
-                        * outside i_size.  Trim these off again.
-                        */
-                       if (pos + bytes > isize)
-                               vmtruncate(inode, isize);
-                       break;
-               }
                if (likely(nr_segs == 1))
                        copied = filemap_copy_from_user(page, offset,
                                                        buf, bytes);
@@ -1919,40 +1906,53 @@ generic_file_buffered_write(struct kiocb *iocb, const 
struct iovec *iov,
                                                cur_iov, iov_offset, bytes);
                flush_dcache_page(page);
                status = a_ops->commit_write(file, page, offset, offset+bytes);
-               if (status == AOP_TRUNCATED_PAGE) {
-                       page_cache_release(page);
-                       continue;
+               if (unlikely(status < 0 || status == AOP_TRUNCATED_PAGE))
+                       goto fs_write_aop_error;
+               if (unlikely(copied != bytes)) {
+                       status = -EFAULT;
+                       goto fs_write_aop_error;
                }
+               if (unlikely(status > 0)) /* filesystem did partial write */
+                       copied = status;
+
                if (likely(copied > 0)) {
-                       if (!status)
-                               status = copied;
-
-                       if (status >= 0) {
-                               written += status;
-                               count -= status;
-                               pos += status;
-                               buf += status;
-                               if (unlikely(nr_segs > 1)) {
-                                       filemap_set_next_iovec(&cur_iov,
-                                                       &iov_offset, status);
-                                       if (count)
-                                               buf = cur_iov->iov_base +
-                                                       iov_offset;
-                               } else {
-                                       iov_offset += status;
-                               }
+                       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;
                        }
                }
-               if (unlikely(copied != bytes))
-                       if (status >= 0)
-                               status = -EFAULT;
                unlock_page(page);
                mark_page_accessed(page);
                page_cache_release(page);
-               if (status < 0)
-                       break;
                balance_dirty_pages_ratelimited(mapping);
                cond_resched();
+               continue;
+
+fs_write_aop_error:
+               if (status != AOP_TRUNCATED_PAGE)
+                       unlock_page(page);
+               page_cache_release(page);
+
+               /*
+                * prepare_write() may have instantiated a few blocks
+                * outside i_size.  Trim these off again. Don't need
+                * i_size_read because we hold i_mutex.
+                */
+               if (pos + bytes > inode->i_size)
+                       vmtruncate(inode, inode->i_size);
+               if (status == AOP_TRUNCATED_PAGE)
+                       continue;
+               else
+                       break;
+
        } while (count);
        *ppos = pos;
 
-
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