Merge tag 'v3.10.108' into update

[GitHub/mt8127/android_kernel_alcatel_ttab.git] / fs / ext4 / file.c

diff --git a/fs/ext4/file.c b/fs/ext4/file.c
index ec9770f425381a25e8758e9b53abc26f2ba5bdfa..ed2badabebf0074fc95f1fcae76600c75381f91f 100644 (file)
--- a/fs/ext4/file.c
+++ b/fs/ext4/file.c
@@ -325,47 +325,27 @@ static int ext4_find_unwritten_pgoff(struct inode *inode,
                num = min_t(pgoff_t, end - index, PAGEVEC_SIZE);
                nr_pages = pagevec_lookup(&pvec, inode->i_mapping, index,
                                          (pgoff_t)num);
-               if (nr_pages == 0) {
-                       if (whence == SEEK_DATA)
-                               break;
-
-                       BUG_ON(whence != SEEK_HOLE);
-                       /*
-                        * If this is the first time to go into the loop and
-                        * offset is not beyond the end offset, it will be a
-                        * hole at this offset
-                        */
-                       if (lastoff == startoff || lastoff < endoff)
-                               found = 1;
+               if (nr_pages == 0)
                        break;
-               }
-
-               /*
-                * If this is the first time to go into the loop and
-                * offset is smaller than the first page offset, it will be a
-                * hole at this offset.
-                */
-               if (lastoff == startoff && whence == SEEK_HOLE &&
-                   lastoff < page_offset(pvec.pages[0])) {
-                       found = 1;
-                       break;
-               }
 
                for (i = 0; i < nr_pages; i++) {
                        struct page *page = pvec.pages[i];
                        struct buffer_head *bh, *head;
 
                        /*
-                        * If the current offset is not beyond the end of given
-                        * range, it will be a hole.
+                        * If current offset is smaller than the page offset,
+                        * there is a hole at this offset.
                         */
-                       if (lastoff < endoff && whence == SEEK_HOLE &&
-                           page->index > end) {
+                       if (whence == SEEK_HOLE && lastoff < endoff &&
+                           lastoff < page_offset(pvec.pages[i])) {
                                found = 1;
                                *offset = lastoff;
                                goto out;
                        }
 
+                       if (page->index > end)
+                               goto out;
+
                        lock_page(page);
 
                        if (unlikely(page->mapping != inode->i_mapping)) {
@@ -382,6 +362,8 @@ static int ext4_find_unwritten_pgoff(struct inode *inode,
                                lastoff = page_offset(page);
                                bh = head = page_buffers(page);
                                do {
+                                       if (lastoff + bh->b_size <= startoff)
+                                               goto next;
                                        if (buffer_uptodate(bh) ||
                                            buffer_unwritten(bh)) {
                                                if (whence == SEEK_DATA)
@@ -396,6 +378,7 @@ static int ext4_find_unwritten_pgoff(struct inode *inode,
                                                unlock_page(page);
                                                goto out;
                                        }
+next:
                                        lastoff += bh->b_size;
                                        bh = bh->b_this_page;
                                } while (bh != head);
@@ -405,20 +388,18 @@ static int ext4_find_unwritten_pgoff(struct inode *inode,
                        unlock_page(page);
                }
 
-               /*
-                * The no. of pages is less than our desired, that would be a
-                * hole in there.
-                */
-               if (nr_pages < num && whence == SEEK_HOLE) {
-                       found = 1;
-                       *offset = lastoff;
+               /* The no. of pages is less than our desired, we are done. */
+               if (nr_pages < num)
                        break;
-               }
 
                index = pvec.pages[i - 1]->index + 1;
                pagevec_release(&pvec);
        } while (index <= end);
 
+       if (whence == SEEK_HOLE && lastoff < endoff) {
+               found = 1;
+               *offset = lastoff;
+       }
 out:
        pagevec_release(&pvec);
        return found;
@@ -440,7 +421,7 @@ static loff_t ext4_seek_data(struct file *file, loff_t offset, loff_t maxsize)
        mutex_lock(&inode->i_mutex);
 
        isize = i_size_read(inode);
-       if (offset >= isize) {
+       if (offset < 0 || offset >= isize) {
                mutex_unlock(&inode->i_mutex);
                return -ENXIO;
        }
@@ -523,7 +504,7 @@ static loff_t ext4_seek_hole(struct file *file, loff_t offset, loff_t maxsize)
        mutex_lock(&inode->i_mutex);
 
        isize = i_size_read(inode);
-       if (offset >= isize) {
+       if (offset < 0 || offset >= isize) {
                mutex_unlock(&inode->i_mutex);
                return -ENXIO;
        }