From: Steve Magnani <steve@xxxxxxxxxxxxxxx> 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. Worse, an attempt to delete the file causes its directory entry (FID) to be deleted, but because the driver believes that a hard link to the file remains, the Extended File Entry (EFE) and all extents of the file itself remain allocated. Since there is no hard link, after the FID has been deleted all of these blocks are unreachable (leaked). A complete solution to this problem involves walking the File Identifiers in the file's stream directory and freeing all extents allocated to each named stream (each of which involves a walk of arbitrary length). As the complete solution is quite complex, for now just settle for retaining the stream directory attachment during file modification, and being able to reclaim the blocks of the file, its Extended File Entry, and its Stream Directory EFE during file deletion. The UDF structures used by Windows to attach a simple Zone.Identifier named stream to a file are: * A stream directory EFE containing an "in ICB" Zone.Identifier FID, which references * An EFE with "in ICB" stream data For this case, this partial solution reduces the number of blocks leaked during file deletion to just one (the EFE containing the stream data). Signed-off-by: Steven J. Magnani <steve@xxxxxxxxxxxxxxx> --- a/fs/udf/udf_i.h 2019-07-26 11:35:28.257563879 -0500 +++ b/fs/udf/udf_i.h 2019-08-06 14:35:55.579654263 -0500 @@ -42,12 +42,15 @@ struct udf_inode_info { unsigned i_efe : 1; /* extendedFileEntry */ unsigned i_use : 1; /* unallocSpaceEntry */ unsigned i_strat4096 : 1; - unsigned reserved : 26; + unsigned i_streamdir : 1; + unsigned reserved : 25; union { struct short_ad *i_sad; struct long_ad *i_lad; __u8 *i_data; } i_ext; + struct kernel_lb_addr i_locStreamdir; + __u64 i_lenStreams; struct rw_semaphore i_data_sem; struct udf_ext_cache cached_extent; /* Spinlock for protecting extent cache */ --- a/fs/udf/super.c 2019-07-26 11:35:28.253563792 -0500 +++ b/fs/udf/super.c 2019-08-06 15:04:30.851086957 -0500 @@ -151,9 +151,13 @@ static struct inode *udf_alloc_inode(str ei->i_unique = 0; ei->i_lenExtents = 0; + ei->i_lenStreams = 0; ei->i_next_alloc_block = 0; ei->i_next_alloc_goal = 0; ei->i_strat4096 = 0; + ei->i_streamdir = 0; + ei->i_locStreamdir.logicalBlockNum = 0xFFFFFFFF; + ei->i_locStreamdir.partitionReferenceNum = 0xFFFF; init_rwsem(&ei->i_data_sem); ei->cached_extent.lstart = -1; spin_lock_init(&ei->i_extent_cache_lock); --- a/fs/udf/inode.c 2019-07-26 11:35:28.253563792 -0500 +++ b/fs/udf/inode.c 2019-08-06 15:04:30.851086957 -0500 @@ -132,7 +132,7 @@ void udf_evict_inode(struct inode *inode struct udf_inode_info *iinfo = UDF_I(inode); int want_delete = 0; - if (!inode->i_nlink && !is_bad_inode(inode)) { + if ((inode->i_nlink == iinfo->i_streamdir) && !is_bad_inode(inode)) { want_delete = 1; udf_setsize(inode, 0); udf_update_inode(inode, IS_SYNC(inode)); @@ -1485,6 +1485,10 @@ reread: 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; + iinfo->i_locStreamdir.logicalBlockNum = 0xFFFFFFFF; + iinfo->i_locStreamdir.partitionReferenceNum = 0xFFFF; } else { inode->i_blocks = le64_to_cpu(efe->logicalBlocksRecorded) << (inode->i_sb->s_blocksize_bits - 9); @@ -1498,6 +1502,16 @@ reread: 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 +1774,19 @@ static int udf_update_inode(struct inode 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); --- a/fs/udf/ialloc.c 2019-07-26 11:35:28.253563792 -0500 +++ b/fs/udf/ialloc.c 2019-08-06 15:04:30.851086957 -0500 @@ -31,6 +31,7 @@ void udf_free_inode(struct inode *inode) struct super_block *sb = inode->i_sb; struct udf_sb_info *sbi = UDF_SB(sb); struct logicalVolIntegrityDescImpUse *lvidiu = udf_sb_lvidiu(sb); + struct udf_inode_info *iinfo = UDF_I(inode); if (lvidiu) { mutex_lock(&sbi->s_alloc_mutex); @@ -42,7 +43,13 @@ void udf_free_inode(struct inode *inode) mutex_unlock(&sbi->s_alloc_mutex); } - udf_free_blocks(sb, NULL, &UDF_I(inode)->i_location, 0, 1); + udf_free_blocks(sb, NULL, &iinfo->i_location, 0, 1); + if (iinfo->i_streamdir) { + udf_free_blocks(sb, NULL, &iinfo->i_locStreamdir, 0, 1); + udf_warn(inode->i_sb, + "Leaking unsupported stream blocks for inode %lu\n", + inode->i_ino); + } } struct inode *udf_new_inode(struct inode *dir, umode_t mode)
