Merge Paulus' tree

[karo-tx-linux.git] / fs / ntfs / file.c

diff --git a/fs/ntfs/file.c b/fs/ntfs/file.c
index cdedc84e1372459b0b5710a44018bf904a4d6e90..7275338918132fe31eed51bddf2d48485d52c1b9 100644 (file)
--- a/fs/ntfs/file.c
+++ b/fs/ntfs/file.c
@@ -78,12 +78,8 @@ static int ntfs_file_open(struct inode *vi, struct file *filp)
  * Extend the initialized size of an attribute described by the ntfs inode @ni
  * to @new_init_size bytes.  This involves zeroing any non-sparse space between
  * the old initialized size and @new_init_size both in the page cache and on
- * disk (if relevant complete pages are zeroed in the page cache then these may
- * simply be marked dirty for later writeout).  There is one caveat and that is
- * that if any uptodate page cache pages between the old initialized size and
- * the smaller of @new_init_size and the file size (vfs inode->i_size) are in
- * memory, these need to be marked dirty without being zeroed since they could
- * be non-zero due to mmap() based writes.
+ * disk (if relevant complete pages are already uptodate in the page cache then
+ * these are simply marked dirty).
  *
  * As a side-effect, the file size (vfs inode->i_size) may be incremented as,
  * in the resident attribute case, it is tied to the initialized size and, in
@@ -98,10 +94,10 @@ static int ntfs_file_open(struct inode *vi, struct file *filp)
  * with new data via mmap() based writes, so we cannot just zero it.  And since
  * POSIX specifies that the behaviour of resizing a file whilst it is mmap()ped
  * is unspecified, we choose not to do zeroing and thus we do not need to touch
- * the page at all.  For a more detailed explanation see ntfs_truncate() which
- * is in fs/ntfs/inode.c.
+ * the page at all.  For a more detailed explanation see ntfs_truncate() in
+ * fs/ntfs/inode.c.
  *
- * @cached_page and @lru_pvec are just optimisations for dealing with multiple
+ * @cached_page and @lru_pvec are just optimizations for dealing with multiple
  * pages.
  *
  * Return 0 on success and -errno on error.  In the case that an error is
@@ -110,9 +106,8 @@ static int ntfs_file_open(struct inode *vi, struct file *filp)
  * this is the case, the necessary zeroing will also have happened and that all
  * metadata is self-consistent.
  *
- * Locking: This function locks the mft record of the base ntfs inode and
- * maintains the lock throughout execution of the function.  This is required
- * so that the initialized size of the attribute can be modified safely.
+ * Locking: i_sem on the vfs inode corrseponsind to the ntfs inode @ni must be
+ *         held by the caller.
  */
 static int ntfs_attr_extend_initialized(ntfs_inode *ni, const s64 new_init_size,
                struct page **cached_page, struct pagevec *lru_pvec)
@@ -673,10 +668,10 @@ map_buffer_cached:
                                 * to, we need to read it in before the write,
                                 * i.e. now.
                                 */
-                               if (!buffer_uptodate(bh) && ((bh_pos < pos &&
-                                               bh_end > pos) ||
-                                               (bh_end > end &&
-                                               bh_end > end))) {
+                               if (!buffer_uptodate(bh) && bh_pos < end &&
+                                               bh_end > pos &&
+                                               (bh_pos < pos ||
+                                               bh_end > end)) {
                                        /*
                                         * If the buffer is fully or partially
                                         * within the initialized size, do an
@@ -789,10 +784,11 @@ retry_remap:
                                                blocksize_bits);
                                cdelta = 0;
                                /*
-                                * If the number of remaining clusters in the
-                                * @pages is smaller or equal to the number of
-                                * cached clusters, unlock the runlist as the
-                                * map cache will be used from now on.
+                                * If the number of remaining clusters touched
+                                * by the write is smaller or equal to the
+                                * number of cached clusters, unlock the
+                                * runlist as the map cache will be used from
+                                * now on.
                                 */
                                if (likely(vcn + vcn_len >= cend)) {
                                        if (rl_write_locked) {
@@ -1836,7 +1832,7 @@ static ssize_t ntfs_file_buffered_write(struct kiocb *iocb,
        VCN last_vcn;
        LCN lcn;
        unsigned long flags;
-       size_t bytes, iov_ofs;
+       size_t bytes, iov_ofs = 0;      /* Offset in the current iovec. */
        ssize_t status, written;
        unsigned nr_pages;
        int err;
@@ -1988,8 +1984,6 @@ static ssize_t ntfs_file_buffered_write(struct kiocb *iocb,
        last_vcn = -1;
        if (likely(nr_segs == 1))
                buf = iov->iov_base;
-       else
-               iov_ofs = 0;    /* Offset in the current iovec. */
        do {
                VCN vcn;
                pgoff_t idx, start_idx;