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authorStefan Brüns <stefan.bruens@rwth-aachen.de>2016-09-06 05:36:55 +0300
committerDongjin Kim <tobetter@gmail.com>2020-02-10 16:44:41 +0300
commited8d7675e16468c467182f6472a788f32d48f3b7 (patch)
tree51c2c6570869331757be62ecf4ef6e9a62c48b0a
parent72d88d57cd379e7af9cf27b8144627bbbaed1507 (diff)
downloadu-boot-ed8d7675e16468c467182f6472a788f32d48f3b7.tar.xz
ext4: Correct block number handling, empty block vs. error code
read_allocated block may return block number 0, which is just an indicator a chunk of the file is not backed by a block, i.e. it is sparse. During file deletions, just continue with the next logical block, for other operations treat blocknumber <= 0 as an error. For writes, blocknumber 0 should never happen, as U-Boot always allocates blocks for the whole file. Reading already handles this correctly, i.e. the read buffer is 0-fillled. Not treating block 0 as sparse block leads to FS corruption, e.g. ./sandbox/u-boot -c 'host bind 0 ./sandbox/test/fs/3GB.ext4.img ; ext4write host 0 0 /2.5GB.file 1 ' The 2.5GB.file from the fs test is actually a sparse file. Signed-off-by: Stefan Brüns <stefan.bruens@rwth-aachen.de>
-rw-r--r--fs/ext4/ext4_common.c6
-rw-r--r--fs/ext4/ext4_write.c11
2 files changed, 13 insertions, 4 deletions
diff --git a/fs/ext4/ext4_common.c b/fs/ext4/ext4_common.c
index f43746e5aa..ff5dbde4e1 100644
--- a/fs/ext4/ext4_common.c
+++ b/fs/ext4/ext4_common.c
@@ -542,7 +542,7 @@ static int search_dir(struct ext2_inode *parent_inode, char *dirname)
/* get the block no allocated to a file */
for (blk_idx = 0; blk_idx < directory_blocks; blk_idx++) {
blknr = read_allocated_block(parent_inode, blk_idx);
- if (blknr == 0)
+ if (blknr <= 0)
goto fail;
/* read the directory block */
@@ -836,7 +836,7 @@ int ext4fs_filename_unlink(char *filename)
/* read the block no allocated to a file */
for (blk_idx = 0; blk_idx < directory_blocks; blk_idx++) {
blknr = read_allocated_block(g_parent_inode, blk_idx);
- if (blknr == 0)
+ if (blknr <= 0)
break;
inodeno = unlink_filename(filename, blknr);
if (inodeno != -1)
@@ -1593,7 +1593,7 @@ long int read_allocated_block(struct ext2_inode *inode, int fileblock)
if (status == 0) {
printf("** SI ext2fs read block (indir 1)"
"failed. **\n");
- return 0;
+ return -1;
}
ext4fs_indir1_blkno =
__le32_to_cpu(inode->b.blocks.
diff --git a/fs/ext4/ext4_write.c b/fs/ext4/ext4_write.c
index 5934316664..df53774ce4 100644
--- a/fs/ext4/ext4_write.c
+++ b/fs/ext4/ext4_write.c
@@ -464,6 +464,10 @@ static int ext4fs_delete_file(int inodeno)
/* release data blocks */
for (i = 0; i < no_blocks; i++) {
blknr = read_allocated_block(&inode, i);
+ if (blknr == 0)
+ continue;
+ if (blknr < 0)
+ goto fail;
bg_idx = blknr / blk_per_grp;
if (fs->blksz == 1024) {
remainder = blknr % blk_per_grp;
@@ -721,6 +725,10 @@ void ext4fs_deinit(void)
fs->curr_blkno = 0;
}
+/*
+ * Write data to filesystem blocks. Uses same optimization for
+ * contigous sectors as ext4fs_read_file
+ */
static int ext4fs_write_file(struct ext2_inode *file_inode,
int pos, unsigned int len, char *buf)
{
@@ -754,7 +762,7 @@ static int ext4fs_write_file(struct ext2_inode *file_inode,
int blockend = fs->blksz;
int skipfirst = 0;
blknr = read_allocated_block(file_inode, i);
- if (blknr < 0)
+ if (blknr <= 0)
return -1;
blknr = blknr << log2_fs_blocksize;
@@ -933,6 +941,7 @@ int ext4fs_write(const char *fname, unsigned char *buffer,
/* copy the file content into data blocks */
if (ext4fs_write_file(file_inode, 0, sizebytes, (char *)buffer) == -1) {
printf("Error in copying content\n");
+ /* FIXME: Deallocate data blocks */
goto fail;
}
ibmap_idx = parent_inodeno / le32_to_cpu(ext4fs_root->sblock.inodes_per_group);