diff options
| -rw-r--r-- | fs/ext4/extents.c | 49 |
1 files changed, 35 insertions, 14 deletions
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c index 4e2bdc26b85c..ca62d748cc65 100644 --- a/fs/ext4/extents.c +++ b/fs/ext4/extents.c @@ -3688,6 +3688,7 @@ static int ext4_ext_fiemap_cb(struct inode *inode, struct ext4_ext_path *path, pgoff_t last_offset; pgoff_t offset; pgoff_t index; + pgoff_t start_index = 0; struct page **pages = NULL; struct buffer_head *bh = NULL; struct buffer_head *head = NULL; @@ -3714,39 +3715,57 @@ out: kfree(pages); return EXT_CONTINUE; } + index = 0; +next_page: /* Try to find the 1st mapped buffer. */ - end = ((__u64)pages[0]->index << PAGE_SHIFT) >> + end = ((__u64)pages[index]->index << PAGE_SHIFT) >> blksize_bits; - if (!page_has_buffers(pages[0])) + if (!page_has_buffers(pages[index])) goto out; - head = page_buffers(pages[0]); + head = page_buffers(pages[index]); if (!head) goto out; + index++; bh = head; do { - if (buffer_mapped(bh)) { + if (end >= newex->ec_block + + newex->ec_len) + /* The buffer is out of + * the request range. + */ + goto out; + + if (buffer_mapped(bh) && + end >= newex->ec_block) { + start_index = index - 1; /* get the 1st mapped buffer. */ - if (end > newex->ec_block + - newex->ec_len) - /* The buffer is out of - * the request range. - */ - goto out; goto found_mapped_buffer; } + bh = bh->b_this_page; end++; } while (bh != head); - /* No mapped buffer found. */ - goto out; + /* No mapped buffer in the range found in this page, + * We need to look up next page. + */ + if (index >= ret) { + /* There is no page left, but we need to limit + * newex->ec_len. + */ + newex->ec_len = end - newex->ec_block; + goto out; + } + goto next_page; } else { /*Find contiguous delayed buffers. */ if (ret > 0 && pages[0]->index == last_offset) head = page_buffers(pages[0]); bh = head; + index = 1; + start_index = 0; } found_mapped_buffer: @@ -3769,7 +3788,7 @@ found_mapped_buffer: end++; } while (bh != head); - for (index = 1; index < ret; index++) { + for (; index < ret; index++) { if (!page_has_buffers(pages[index])) { bh = NULL; break; @@ -3779,8 +3798,10 @@ found_mapped_buffer: bh = NULL; break; } + if (pages[index]->index != - pages[0]->index + index) { + pages[start_index]->index + index + - start_index) { /* Blocks are not contiguous. */ bh = NULL; break; |