From c3912f75ff2909eadb5c919274139f9fa6cdfe36 Mon Sep 17 00:00:00 2001 From: Sascha Hauer Date: Tue, 29 Oct 2019 09:38:52 +0100 Subject: fs: ext4: Fix handling of sparse files MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Adoption of U-Boot commit: | commit f81db56f2fd6dc16efeaec2961121244765a1f11 | Author: Stefan Brüns | Date: Sat Nov 5 22:17:14 2016 +0100 | | ext4: Fix handling of sparse files | | A sparse file may have regions not mapped by any extents, at the start | or at the end of the file, or anywhere between, thus not finding a | matching extent region is never an error. | | Found by python filesystem tests. Signed-off-by: Sascha Hauer --- fs/ext4/ext4_common.c | 28 ++++++++++++++-------------- 1 file changed, 14 insertions(+), 14 deletions(-) (limited to 'fs') diff --git a/fs/ext4/ext4_common.c b/fs/ext4/ext4_common.c index 55e837b4bd..2703b55e99 100644 --- a/fs/ext4/ext4_common.c +++ b/fs/ext4/ext4_common.c @@ -167,10 +167,11 @@ long int read_allocated_block(struct ext2fs_node *node, int fileblock) log2_blksz = LOG2_EXT2_BLOCK_SIZE(node->data); if (le32_to_cpu(inode->flags) & EXT4_EXTENTS_FL) { + long int startblock, endblock; char *buf = zalloc(blksz); struct ext4_extent_header *ext_block; struct ext4_extent *extent; - int i = -1; + int i; if (!buf) return -ENOMEM; @@ -186,28 +187,27 @@ long int read_allocated_block(struct ext2fs_node *node, int fileblock) extent = (struct ext4_extent *)(ext_block + 1); - do { - i++; - if (i >= le16_to_cpu(ext_block->eh_entries)) - break; - } while (fileblock >= le32_to_cpu(extent[i].ee_block)); + for (i = 0; i < le16_to_cpu(ext_block->eh_entries); i++) { + startblock = le32_to_cpu(extent[i].ee_block); + endblock = startblock + le16_to_cpu(extent[i].ee_len); - if (--i >= 0) { - fileblock -= le32_to_cpu(extent[i].ee_block); - if (fileblock >= le16_to_cpu(extent[i].ee_len)) { + if (startblock > fileblock) { + /* Sparse file */ free(buf); return 0; } - start = le16_to_cpu(extent[i].ee_start_hi); - start = (start << 32) + + if (fileblock < endblock) { + start = le16_to_cpu(extent[i].ee_start_hi); + start = (start << 32) + le32_to_cpu(extent[i].ee_start_lo); - free(buf); - return fileblock + start; + free(buf); + return (fileblock - startblock) + start; + } } free(buf); - return -EIO; + return 0; } if (fileblock < INDIRECT_BLOCKS) { -- cgit v1.2.3