udf: reduce leakage of blocks related to named streams
Windows is capable of creating UDF files having named streams.
One example is the "Zone.Identifier" stream attached automatically
to files downloaded from a network. See:
https://msdn.microsoft.com/en-us/library/dn392609.aspx
Modification of a file having one or more named streams in Linux causes
the stream directory to become detached from the file, essentially leaking
all blocks pertaining to the file's streams.
Fix by saving off information about an inode's streams when reading it,
for later use when its on-disk data is updated.
Link: https://lore.kernel.org/r/20190814125002.10869-1-steve@digidescorp.com
Signed-off-by: Steven J. Magnani <steve@digidescorp.com>
Signed-off-by: Jan Kara <jack@suse.cz>
diff --git a/fs/udf/inode.c b/fs/udf/inode.c
index 9bb1831..54eee39 100644
--- a/fs/udf/inode.c
+++ b/fs/udf/inode.c
@@ -1485,6 +1485,8 @@ static int udf_read_inode(struct inode *inode, bool hidden_inode)
iinfo->i_lenEAttr = le32_to_cpu(fe->lengthExtendedAttr);
iinfo->i_lenAlloc = le32_to_cpu(fe->lengthAllocDescs);
iinfo->i_checkpoint = le32_to_cpu(fe->checkpoint);
+ iinfo->i_streamdir = 0;
+ iinfo->i_lenStreams = 0;
} else {
inode->i_blocks = le64_to_cpu(efe->logicalBlocksRecorded) <<
(inode->i_sb->s_blocksize_bits - 9);
@@ -1498,6 +1500,16 @@ static int udf_read_inode(struct inode *inode, bool hidden_inode)
iinfo->i_lenEAttr = le32_to_cpu(efe->lengthExtendedAttr);
iinfo->i_lenAlloc = le32_to_cpu(efe->lengthAllocDescs);
iinfo->i_checkpoint = le32_to_cpu(efe->checkpoint);
+
+ /* Named streams */
+ iinfo->i_streamdir = (efe->streamDirectoryICB.extLength != 0);
+ iinfo->i_locStreamdir =
+ lelb_to_cpu(efe->streamDirectoryICB.extLocation);
+ iinfo->i_lenStreams = le64_to_cpu(efe->objectSize);
+ if (iinfo->i_lenStreams >= inode->i_size)
+ iinfo->i_lenStreams -= inode->i_size;
+ else
+ iinfo->i_lenStreams = 0;
}
inode->i_generation = iinfo->i_unique;
@@ -1760,9 +1772,19 @@ static int udf_update_inode(struct inode *inode, int do_sync)
iinfo->i_ext.i_data,
inode->i_sb->s_blocksize -
sizeof(struct extendedFileEntry));
- efe->objectSize = cpu_to_le64(inode->i_size);
+ efe->objectSize =
+ cpu_to_le64(inode->i_size + iinfo->i_lenStreams);
efe->logicalBlocksRecorded = cpu_to_le64(lb_recorded);
+ if (iinfo->i_streamdir) {
+ struct long_ad *icb_lad = &efe->streamDirectoryICB;
+
+ icb_lad->extLocation =
+ cpu_to_lelb(iinfo->i_locStreamdir);
+ icb_lad->extLength =
+ cpu_to_le32(inode->i_sb->s_blocksize);
+ }
+
udf_adjust_time(iinfo, inode->i_atime);
udf_adjust_time(iinfo, inode->i_mtime);
udf_adjust_time(iinfo, inode->i_ctime);