FreeBSD/Linux Kernel Cross Reference
sys/fs/ntfs/ChangeLog

     ToDo/Notes:
             - Find and fix bugs.
             - The only places in the kernel where a file is resized are
               ntfs_file_write*() and ntfs_truncate() for both of which i_mutex is
               held.  Just have to be careful in read-/writepage and other helpers
               not running under i_mutex that we play nice.  Also need to be careful
               with initialized_size extension in ntfs_file_write*() and writepage.
               UPDATE: The only things that need to be checked are the compressed
               write and the other attribute resize/write cases like index
              attributes, etc.  For now none of these are implemented so are safe.
            - Implement filling in of holes in aops.c::ntfs_writepage() and its
              helpers.
            - Implement mft.c::sync_mft_mirror_umount().  We currently will just
              leave the volume dirty on umount if the final iput(vol->mft_ino)
              causes a write of any mirrored mft records due to the mft mirror
              inode having been discarded already.  Whether this can actually ever
              happen is unclear however so it is worth waiting until someone hits
              the problem.
    
    2.1.29 - Fix a deadlock at mount time.
    
            - During mount the VFS holds s_umount lock on the superblock.  So when
              we try to empty the journal $LogFile contents by calling
              ntfs_attr_set() when the machine does not have much memory and the
              journal is large ntfs_attr_set() results in the VM trying to balance
              dirty pages which in turn tries to that the s_umount lock and thus we
              get a deadlock.  The solution is to not use ntfs_attr_set() and
              instead do the zeroing by hand at the block level rather than page
              cache level.
            - Fix sparse warnings.
    
    2.1.28 - Fix a deadlock.
    
            - Fix deadlock in fs/ntfs/inode.c::ntfs_put_inode().  Thanks to Sergey
              Vlasov for the report and detailed analysis of the deadlock.  The fix
              involved getting rid of ntfs_put_inode() altogether and hence NTFS no
              longer has a ->put_inode super operation.
    
    2.1.27 - Various bug fixes and cleanups.
    
            - Fix two compiler warnings on Alpha.  Thanks to Andrew Morton for
              reporting them.
            - Fix an (innocent) off-by-one error in the runlist code.
            - Fix a buggette in an "should be impossible" case handling where we
              continued the attribute lookup loop instead of aborting it.
            - Use buffer_migrate_page() for the ->migratepage function of all ntfs
              address space operations.
            - Fix comparison of $MFT and $MFTMirr to not bail out when there are
              unused, invalid mft records which are the same in both $MFT and
              $MFTMirr.
            - Add support for sparse files which have a compression unit of 0.
            - Remove all the make_bad_inode() calls.  This should only be called
              from read inode and new inode code paths.
            - Limit name length in fs/ntfs/unistr.c::ntfs_nlstoucs() to maximum
              allowed by NTFS, i.e. 255 Unicode characters, not including the
              terminating NULL (which is not stored on disk).
            - Improve comments on file attribute flags in fs/ntfs/layout.h.
            - Fix a bug in fs/ntfs/inode.c::ntfs_read_locked_index_inode() where we
              forgot to update a temporary variable so loading index inodes which
              have an index allocation attribute failed.
            - Add a missing call to flush_dcache_mft_record_page() in
              fs/ntfs/inode.c::ntfs_write_inode().
            - Handle the recently introduced -ENAMETOOLONG return value from
              fs/ntfs/unistr.c::ntfs_nlstoucs() in fs/ntfs/namei.c::ntfs_lookup().
            - Semaphore to mutex conversion.  (Ingo Molnar)
    
    2.1.26 - Minor bug fixes and updates.
    
            - Fix a potential overflow in file.c where a cast to s64 was missing in
              a left shift of a page index.
            - The struct inode has had its i_sem semaphore changed to a mutex named
              i_mutex.
            - We have struct kmem_cache now so use it instead of the typedef
              kmem_cache_t.  (Pekka Enberg)
            - Implement support for sector sizes above 512 bytes (up to the maximum
              supported by NTFS which is 4096 bytes).
            - Do more detailed reporting of why we cannot mount read-write by
              special casing the VOLUME_MODIFIED_BY_CHKDSK flag.
            - Miscellaneous updates to layout.h.
            - Cope with attribute list attribute having invalid flags.  Windows
              copes with this and even chkdsk does not detect or fix this so we
              have to cope with it, too.  Thanks to Pawel Kot for reporting the
              problem.
    
    2.1.25 - (Almost) fully implement write(2) and truncate(2).
    
            - Change ntfs_map_runlist_nolock(), ntfs_attr_find_vcn_nolock() and
              {__,}ntfs_cluster_free() to also take an optional attribute search
              context as argument.  This allows calling these functions with the
              mft record mapped.  Update all callers.
            - Fix potential deadlock in ntfs_mft_data_extend_allocation_nolock()
              error handling by passing in the active search context when calling
              ntfs_cluster_free().
            - Change ntfs_cluster_alloc() to take an extra boolean parameter
              specifying whether the cluster are being allocated to extend an
              attribute or to fill a hole.
            - Change ntfs_attr_make_non_resident() to call ntfs_cluster_alloc()
              with @is_extension set to TRUE and remove the runlist terminator
              fixup code as this is now done by ntfs_cluster_alloc().
           - Change ntfs_attr_make_non_resident to take the attribute value size
             as an extra parameter.  This is needed since we need to know the size
             before we can map the mft record and our callers always know it.  The
             reason we cannot simply read the size from the vfs inode i_size is
             that this is not necessarily uptodate.  This happens when
             ntfs_attr_make_non_resident() is called in the ->truncate call path.
           - Fix ntfs_attr_make_non_resident() to update the vfs inode i_blocks
             which is zero for a resident attribute but should no longer be zero
             once the attribute is non-resident as it then has real clusters
             allocated.
           - Add fs/ntfs/attrib.[hc]::ntfs_attr_extend_allocation(), a function to
             extend the allocation of an attributes.  Optionally, the data size,
             but not the initialized size can be extended, too.
           - Implement fs/ntfs/inode.[hc]::ntfs_truncate().  It only supports
             uncompressed and unencrypted files and it never creates sparse files
             at least for the moment (making a file sparse requires us to modify
             its directory entries and we do not support directory operations at
             the moment).  Also, support for highly fragmented files, i.e. ones
             whose data attribute is split across multiple extents, is severly
             limited.  When such a case is encountered, EOPNOTSUPP is returned.
           - Enable ATTR_SIZE attribute changes in ntfs_setattr().  This completes
             the initial implementation of file truncation.  Now both open(2)ing
             a file with the O_TRUNC flag and the {,f}truncate(2) system calls
             will resize a file appropriately.  The limitations are that only
             uncompressed and unencrypted files are supported.  Also, there is
             only very limited support for highly fragmented files (the ones whose
             $DATA attribute is split into multiple attribute extents).
           - In attrib.c::ntfs_attr_set() call balance_dirty_pages_ratelimited()
             and cond_resched() in the main loop as we could be dirtying a lot of
             pages and this ensures we play nice with the VM and the system as a
             whole.
           - Implement file operations ->write, ->aio_write, ->writev for regular
             files.  This replaces the old use of generic_file_write(), et al and
             the address space operations ->prepare_write and ->commit_write.
             This means that both sparse and non-sparse (unencrypted and
             uncompressed) files can now be extended using the normal write(2)
             code path.  There are two limitations at present and these are that
             we never create sparse files and that we only have limited support
             for highly fragmented files, i.e. ones whose data attribute is split
             across multiple extents.   When such a case is encountered,
             EOPNOTSUPP is returned.
           - $EA attributes can be both resident and non-resident.
           - Use %z for size_t to fix compilation warnings.  (Andrew Morton)
           - Fix compilation warnings with gcc-4.0.2 on SUSE 10.0.
           - Document extended attribute ($EA) NEED_EA flag.  (Based on libntfs
             patch by Yura Pakhuchiy.)
   
   2.1.24 - Lots of bug fixes and support more clean journal states.
   
           - Support journals ($LogFile) which have been modified by chkdsk.  This
             means users can boot into Windows after we marked the volume dirty.
             The Windows boot will run chkdsk and then reboot.  The user can then
             immediately boot into Linux rather than having to do a full Windows
             boot first before rebooting into Linux and we will recognize such a
             journal and empty it as it is clean by definition.  Note, this only
             works if chkdsk left the journal in an obviously clean state.
           - Support journals ($LogFile) with only one restart page as well as
             journals with two different restart pages.  We sanity check both and
             either use the only sane one or the more recent one of the two in the
             case that both are valid.
           - Add fs/ntfs/malloc.h::ntfs_malloc_nofs_nofail() which is analogous to
             ntfs_malloc_nofs() but it performs allocations with __GFP_NOFAIL and
             hence cannot fail.
           - Use ntfs_malloc_nofs_nofail() in the two critical regions in
             fs/ntfs/runlist.c::ntfs_runlists_merge().  This means we no longer
             need to panic() if the allocation fails as it now cannot fail.
           - Fix two nasty runlist merging bugs that had gone unnoticed so far.
             Thanks to Stefano Picerno for the bug report.
           - Remove two bogus BUG_ON()s from fs/ntfs/mft.c.
           - Fix handling of valid but empty mapping pairs array in
             fs/ntfs/runlist.c::ntfs_mapping_pairs_decompress().
           - Report unrepresentable inodes during ntfs_readdir() as KERN_WARNING
             messages and include the inode number.  Thanks to Yura Pakhuchiy for
             pointing this out.
           - Change ntfs_rl_truncate_nolock() to throw away the runlist if the new
             length is zero.
           - Add runlist.[hc]::ntfs_rl_punch_nolock() which punches a caller
             specified hole into a runlist.
           - Fix a bug in fs/ntfs/index.c::ntfs_index_lookup().  When the returned
             index entry is in the index root, we forgot to set the @ir pointer in
             the index context.  Thanks to Yura Pakhuchiy for finding this bug.
           - Remove bogus setting of PageError in ntfs_read_compressed_block().
           - Add fs/ntfs/attrib.[hc]::ntfs_resident_attr_value_resize().
           - Fix a bug in ntfs_map_runlist_nolock() where we forgot to protect
             access to the allocated size in the ntfs inode with the size lock.
           - Fix ntfs_attr_vcn_to_lcn_nolock() and ntfs_attr_find_vcn_nolock() to
             return LCN_ENOENT when there is no runlist and the allocated size is
             zero.
           - Fix load_attribute_list() to handle the case of a NULL runlist.
           - Fix handling of sparse attributes in ntfs_attr_make_non_resident().
           - Add BUG() checks to ntfs_attr_make_non_resident() and ntfs_attr_set()
             to ensure that these functions are never called for compressed or
             encrypted attributes.
           - Fix cluster (de)allocators to work when the runlist is NULL and more
             importantly to take a locked runlist rather than them locking it
             which leads to lock reversal.
           - Truncate {a,c,m}time to the ntfs supported time granularity when
             updating the times in the inode in ntfs_setattr().
           - Fixup handling of sparse, compressed, and encrypted attributes in
             fs/ntfs/inode.c::ntfs_read_locked_{,attr_,index_}inode(),
             fs/ntfs/aops.c::ntfs_{read,write}page().
           - Make ntfs_write_block() not instantiate sparse blocks if they contain
             only zeroes.
           - Optimize fs/ntfs/aops.c::ntfs_write_block() by extending the page
             lock protection over the buffer submission for i/o which allows the
             removal of the get_bh()/put_bh() pairs for each buffer.
           - Fix fs/ntfs/aops.c::ntfs_{read,write}_block() to handle the case
             where a concurrent truncate has truncated the runlist under our feet.
           - Fix page_has_buffers()/page_buffers() handling in fs/ntfs/aops.c.
           - In fs/ntfs/aops.c::ntfs_end_buffer_async_read(), use a bit spin lock
             in the first buffer head instead of a driver global spin lock to
             improve scalability.
           - Minor fix to error handling and error message display in
             fs/ntfs/aops.c::ntfs_prepare_nonresident_write().
           - Change the mount options {u,f,d}mask to always parse the number as
             an octal number to conform to how chmod(1) works, too.  Thanks to
             Giuseppe Bilotta and Horst von Brand for pointing out the errors of
             my ways.
           - Fix various bugs in the runlist merging code.  (Based on libntfs
             changes by Richard Russon.)
           - Fix sparse warnings that have crept in over time.
           - Change ntfs_cluster_free() to require a write locked runlist on entry
             since we otherwise get into a lock reversal deadlock if a read locked
             runlist is passed in. In the process also change it to take an ntfs
             inode instead of a vfs inode as parameter.
           - Fix the definition of the CHKD ntfs record magic.  It had an off by
             two error causing it to be CHKB instead of CHKD.
           - Fix a stupid bug in __ntfs_bitmap_set_bits_in_run() which caused the
             count to become negative and hence we had a wild memset() scribbling
             all over the system's ram.
   
   2.1.23 - Implement extension of resident files and make writing safe as well as
            many bug fixes, cleanups, and enhancements...
   
           - Add printk rate limiting for ntfs_warning() and ntfs_error() when
             compiled without debug.  This avoids a possible denial of service
             attack.  Thanks to Carl-Daniel Hailfinger from SuSE for pointing this
             out.
           - Fix compilation warnings on ia64.  (Randy Dunlap)
           - Use i_size_{read,write}() instead of reading i_size by hand and cache
             the value where apropriate.
           - Add size_lock to the ntfs_inode structure.  This is an rw spinlock
             and it locks against access to the inode sizes.  Note, ->size_lock
             is also accessed from irq context so you must use the _irqsave and
             _irqrestore lock and unlock functions, respectively.  Protect all
             accesses to allocated_size, initialized_size, and compressed_size.
           - Minor optimization to fs/ntfs/super.c::ntfs_statfs() and its helpers.
           - Implement extension of resident files in the regular file write code
             paths (fs/ntfs/aops.c::ntfs_{prepare,commit}_write()).  At present
             this only works until the data attribute becomes too big for the mft
             record after which we abort the write returning -EOPNOTSUPP from
             ntfs_prepare_write().
           - Add disable_sparse mount option together with a per volume sparse
             enable bit which is set appropriately and a per inode sparse disable
             bit which is preset on some system file inodes as appropriate.
           - Enforce that sparse support is disabled on NTFS volumes pre 3.0.
           - Fix a bug in fs/ntfs/runlist.c::ntfs_mapping_pairs_decompress() in
             the creation of the unmapped runlist element for the base attribute
             extent.
           - Split ntfs_map_runlist() into ntfs_map_runlist() and a non-locking
             helper ntfs_map_runlist_nolock() which is used by ntfs_map_runlist().
             This allows us to map runlist fragments with the runlist lock already
             held without having to drop and reacquire it around the call.  Adapt
             all callers.
           - Change ntfs_find_vcn() to ntfs_find_vcn_nolock() which takes a locked
             runlist.  This allows us to find runlist elements with the runlist
             lock already held without having to drop and reacquire it around the
             call.  Adapt all callers.
           - Change time to u64 in time.h::ntfs2utc() as it otherwise generates a
             warning in the do_div() call on sparc32.  Thanks to Meelis Roos for
             the report and analysis of the warning.
           - Fix a nasty runlist merge bug when merging two holes.
           - Set the ntfs_inode->allocated_size to the real allocated size in the
             mft record for resident attributes (fs/ntfs/inode.c).
           - Small readability cleanup to use "a" instead of "ctx->attr"
             everywhere (fs/ntfs/inode.c).
           - Make fs/ntfs/namei.c::ntfs_get_{parent,dentry} static and move the
             definition of ntfs_export_ops from fs/ntfs/super.c to namei.c.  Also,
             declare ntfs_export_ops in fs/ntfs/ntfs.h.
           - Correct sparse file handling.  The compressed values need to be
             checked and set in the ntfs inode as done for compressed files and
             the compressed size needs to be used for vfs inode->i_blocks instead
             of the allocated size, again, as done for compressed files.
           - Add AT_EA in addition to AT_DATA to whitelist for being allowed to be
             non-resident in fs/ntfs/attrib.c::ntfs_attr_can_be_non_resident().
           - Add fs/ntfs/attrib.c::ntfs_attr_vcn_to_lcn_nolock() used by the new
             write code.
           - Fix bug in fs/ntfs/attrib.c::ntfs_find_vcn_nolock() where after
             dropping the read lock and taking the write lock we were not checking
             whether someone else did not already do the work we wanted to do.
           - Rename fs/ntfs/attrib.c::ntfs_find_vcn_nolock() to
             ntfs_attr_find_vcn_nolock() and update all callers.
           - Add fs/ntfs/attrib.[hc]::ntfs_attr_make_non_resident().
           - Fix sign of various error return values to be negative in
             fs/ntfs/lcnalloc.c.
           - Modify ->readpage and ->writepage (fs/ntfs/aops.c) so they detect and
             handle the case where an attribute is converted from resident to
             non-resident by a concurrent file write.
           - Remove checks for NULL before calling kfree() since kfree() does the
             checking itself.  (Jesper Juhl)
           - Some utilities modify the boot sector but do not update the checksum.
             Thus, relax the checking in fs/ntfs/super.c::is_boot_sector_ntfs() to
             only emit a warning when the checksum is incorrect rather than
             refusing the mount.  Thanks to Bernd Casimir for pointing this
             problem out.
           - Update attribute definition handling.
           - Add NTFS_MAX_CLUSTER_SIZE and NTFS_MAX_PAGES_PER_CLUSTER constants.
           - Use NTFS_MAX_CLUSTER_SIZE in super.c instead of hard coding 0x10000.
           - Use MAX_BUF_PER_PAGE instead of variable sized array allocation for
             better code generation and one less sparse warning in fs/ntfs/aops.c.
           - Remove spurious void pointer casts from fs/ntfs/.  (Pekka Enberg)
           - Use C99 style structure initialization after memory allocation where
             possible (fs/ntfs/{attrib.c,index.c,super.c}).  Thanks to Al Viro and
             Pekka Enberg.
           - Stamp the transaction log ($UsnJrnl), aka user space journal, if it
             is active on the volume and we are mounting read-write or remounting
             from read-only to read-write.
           - Fix a bug in address space operations error recovery code paths where
             if the runlist was not mapped at all and a mapping error occured we
             would leave the runlist locked on exit to the function so that the
             next access to the same file would try to take the lock and deadlock.
           - Detect the case when Windows has been suspended to disk on the volume
             to be mounted and if this is the case do not allow (re)mounting
             read-write.  This is done by parsing hiberfil.sys if present.
           - Fix several occurences of a bug where we would perform 'var & ~const'
             with a 64-bit variable and a int, i.e. 32-bit, constant.  This causes
             the higher order 32-bits of the 64-bit variable to be zeroed.  To fix
             this cast the 'const' to the same 64-bit type as 'var'.
           - Change the runlist terminator of the newly allocated cluster(s) to
             LCN_ENOENT in ntfs_attr_make_non_resident().  Otherwise the runlist
             code gets confused.
           - Add an extra parameter @last_vcn to ntfs_get_size_for_mapping_pairs()
             and ntfs_mapping_pairs_build() to allow the runlist encoding to be
             partial which is desirable when filling holes in sparse attributes.
             Update all callers.
           - Change ntfs_map_runlist_nolock() to only decompress the mapping pairs
             if the requested vcn is inside it.  Otherwise we get into problems
             when we try to map an out of bounds vcn because we then try to map
             the already mapped runlist fragment which causes
             ntfs_mapping_pairs_decompress() to fail and return error.  Update
             ntfs_attr_find_vcn_nolock() accordingly.
           - Fix a nasty deadlock that appeared in recent kernels.
             The situation: VFS inode X on a mounted ntfs volume is dirty.  For
             same inode X, the ntfs_inode is dirty and thus corresponding on-disk
             inode, i.e. mft record, which is in a dirty PAGE_CACHE_PAGE belonging
             to the table of inodes, i.e. $MFT, inode 0.
             What happens:
             Process 1: sys_sync()/umount()/whatever...  calls
             __sync_single_inode() for $MFT -> do_writepages() -> write_page for
             the dirty page containing the on-disk inode X, the page is now locked
             -> ntfs_write_mst_block() which clears PageUptodate() on the page to
             prevent anyone else getting hold of it whilst it does the write out.
             This is necessary as the on-disk inode needs "fixups" applied before
             the write to disk which are removed again after the write and
             PageUptodate is then set again.  It then analyses the page looking
             for dirty on-disk inodes and when it finds one it calls
             ntfs_may_write_mft_record() to see if it is safe to write this
             on-disk inode.  This then calls ilookup5() to check if the
             corresponding VFS inode is in icache().  This in turn calls ifind()
             which waits on the inode lock via wait_on_inode whilst holding the
             global inode_lock.
             Process 2: pdflush results in a call to __sync_single_inode for the
             same VFS inode X on the ntfs volume.  This locks the inode (I_LOCK)
             then calls write-inode -> ntfs_write_inode -> map_mft_record() ->
             read_cache_page() for the page (in page cache of table of inodes
             $MFT, inode 0) containing the on-disk inode.  This page has
             PageUptodate() clear because of Process 1 (see above) so
             read_cache_page() blocks when it tries to take the page lock for the
             page so it can call ntfs_read_page().
             Thus Process 1 is holding the page lock on the page containing the
             on-disk inode X and it is waiting on the inode X to be unlocked in
             ifind() so it can write the page out and then unlock the page.
             And Process 2 is holding the inode lock on inode X and is waiting for
             the page to be unlocked so it can call ntfs_readpage() or discover
             that Process 1 set PageUptodate() again and use the page.
             Thus we have a deadlock due to ifind() waiting on the inode lock.
             The solution: The fix is to use the newly introduced
             ilookup5_nowait() which does not wait on the inode's lock and hence
             avoids the deadlock.  This is safe as we do not care about the VFS
             inode and only use the fact that it is in the VFS inode cache and the
             fact that the vfs and ntfs inodes are one struct in memory to find
             the ntfs inode in memory if present.  Also, the ntfs inode has its
             own locking so it does not matter if the vfs inode is locked.
           - Fix bug in mft record writing where we forgot to set the device in
             the buffers when mapping them after the VM had discarded them.
             Thanks to Martin MOKREJÅ for the bug report.
   
   2.1.22 - Many bug and race fixes and error handling improvements.
   
           - Improve error handling in fs/ntfs/inode.c::ntfs_truncate().
           - Change fs/ntfs/inode.c::ntfs_truncate() to return an error code
             instead of void and provide a helper ntfs_truncate_vfs() for the
             vfs ->truncate method.
           - Add a new ntfs inode flag NInoTruncateFailed() and modify
             fs/ntfs/inode.c::ntfs_truncate() to set and clear it appropriately.
           - Fix min_size and max_size definitions in ATTR_DEF structure in
             fs/ntfs/layout.h to be signed.
           - Add attribute definition handling helpers to fs/ntfs/attrib.[hc]:
             ntfs_attr_size_bounds_check(), ntfs_attr_can_be_non_resident(), and
             ntfs_attr_can_be_resident(), which in turn use the new private helper
             ntfs_attr_find_in_attrdef().
           - In fs/ntfs/aops.c::mark_ntfs_record_dirty(), take the
             mapping->private_lock around the dirtying of the buffer heads
             analagous to the way it is done in __set_page_dirty_buffers().
           - Ensure the mft record size does not exceed the PAGE_CACHE_SIZE at
             mount time as this cannot work with the current implementation.
           - Check for location of attribute name and improve error handling in
             general in fs/ntfs/inode.c::ntfs_read_locked_inode() and friends.
           - In fs/ntfs/aops.c::ntfs_writepage(), if the page is fully outside
             i_size, i.e. race with truncate, invalidate the buffers on the page
             so that they become freeable and hence the page does not leak.
           - Remove unused function fs/ntfs/runlist.c::ntfs_rl_merge().  (Adrian
             Bunk)
           - Fix stupid bug in fs/ntfs/attrib.c::ntfs_attr_find() that resulted in
             a NULL pointer dereference in the error code path when a corrupt
             attribute was found.  (Thanks to Domen Puncer for the bug report.)
           - Add MODULE_VERSION() to fs/ntfs/super.c.
           - Make several functions and variables static.  (Adrian Bunk)
           - Modify fs/ntfs/aops.c::mark_ntfs_record_dirty() so it allocates
             buffers for the page if they are not present and then marks the
             buffers belonging to the ntfs record dirty.  This causes the buffers
             to become busy and hence they are safe from removal until the page
             has been written out.
           - Fix stupid bug in fs/ntfs/attrib.c::ntfs_external_attr_find() in the
             error handling code path that resulted in a BUG() due to trying to
             unmap an extent mft record when the mapping of it had failed and it
             thus was not mapped.  (Thanks to Ken MacFerrin for the bug report.)
           - Drop the runlist lock after the vcn has been read in
             fs/ntfs/lcnalloc.c::__ntfs_cluster_free().
           - Rewrite handling of multi sector transfer errors.  We now do not set
             PageError() when such errors are detected in the async i/o handler
             fs/ntfs/aops.c::ntfs_end_buffer_async_read().  All users of mst
             protected attributes now check the magic of each ntfs record as they
             use it and act appropriately.  This has the effect of making errors
             granular per ntfs record rather than per page which solves the case
             where we cannot access any of the ntfs records in a page when a
             single one of them had an mst error.  (Thanks to Ken MacFerrin for
             the bug report.)
           - Fix error handling in fs/ntfs/quota.c::ntfs_mark_quotas_out_of_date()
             where we failed to release i_mutex on the $Quota/$Q attribute inode.
           - Fix bug in handling of bad inodes in fs/ntfs/namei.c::ntfs_lookup().
           - Add mapping of unmapped buffers to all remaining code paths, i.e.
             fs/ntfs/aops.c::ntfs_write_mst_block(), mft.c::ntfs_sync_mft_mirror(),
             and write_mft_record_nolock().  From now on we require that the
             complete runlist for the mft mirror is always mapped into memory.
           - Add creation of buffers to fs/ntfs/mft.c::ntfs_sync_mft_mirror().
           - Improve error handling in fs/ntfs/aops.c::ntfs_{read,write}_block().
           - Cleanup fs/ntfs/aops.c::ntfs_{read,write}page() since we know that a
             resident attribute will be smaller than a page which makes the code
             simpler.  Also make the code more tolerant to concurrent ->truncate.
   
   2.1.21 - Fix some races and bugs, rewrite mft write code, add mft allocator.
   
           - Implement extent mft record deallocation
             fs/ntfs/mft.c::ntfs_extent_mft_record_free().
           - Splitt runlist related functions off from attrib.[hc] to runlist.[hc].
           - Add vol->mft_data_pos and initialize it at mount time.
           - Rename init_runlist() to ntfs_init_runlist(), ntfs_vcn_to_lcn() to
             ntfs_rl_vcn_to_lcn(), decompress_mapping_pairs() to
             ntfs_mapping_pairs_decompress(), ntfs_merge_runlists() to
             ntfs_runlists_merge() and adapt all callers.
           - Add fs/ntfs/runlist.[hc]::ntfs_get_nr_significant_bytes(),
             ntfs_get_size_for_mapping_pairs(), ntfs_write_significant_bytes(),
             and ntfs_mapping_pairs_build(), adapted from libntfs.
           - Make fs/ntfs/lcnalloc.c::ntfs_cluster_free_from_rl_nolock() not
             static and add a declaration for it to lcnalloc.h.
           - Add fs/ntfs/lcnalloc.h::ntfs_cluster_free_from_rl() which is a static
             inline wrapper for ntfs_cluster_free_from_rl_nolock() which takes the
             cluster bitmap lock for the duration of the call.
           - Add fs/ntfs/attrib.[hc]::ntfs_attr_record_resize().
           - Implement the equivalent of memset() for an ntfs attribute in
             fs/ntfs/attrib.[hc]::ntfs_attr_set() and switch
             fs/ntfs/logfile.c::ntfs_empty_logfile() to using it.
           - Remove unnecessary casts from LCN_* constants.
           - Implement fs/ntfs/runlist.c::ntfs_rl_truncate_nolock().
           - Add MFT_RECORD_OLD as a copy of MFT_RECORD in fs/ntfs/layout.h and
             change MFT_RECORD to contain the NTFS 3.1+ specific fields.
           - Add a helper function fs/ntfs/aops.c::mark_ntfs_record_dirty() which
             marks all buffers belonging to an ntfs record dirty, followed by
             marking the page the ntfs record is in dirty and also marking the vfs
             inode containing the ntfs record dirty (I_DIRTY_PAGES).
           - Switch fs/ntfs/index.h::ntfs_index_entry_mark_dirty() to using the
             new helper fs/ntfs/aops.c::mark_ntfs_record_dirty() and remove the no
             longer needed fs/ntfs/index.[hc]::__ntfs_index_entry_mark_dirty().
           - Move ntfs_{un,}map_page() from ntfs.h to aops.h and fix resulting
             include errors.
           - Move the typedefs for runlist_element and runlist from types.h to
             runlist.h and fix resulting include errors.
           - Remove unused {__,}format_mft_record() from fs/ntfs/mft.c.
           - Modify fs/ntfs/mft.c::__mark_mft_record_dirty() to use the helper
             mark_ntfs_record_dirty() which also changes the behaviour in that we
             now set the buffers belonging to the mft record dirty as well as the
             page itself.
           - Update fs/ntfs/mft.c::write_mft_record_nolock() and sync_mft_mirror()
             to cope with the fact that there now are dirty buffers in mft pages.
           - Update fs/ntfs/inode.c::ntfs_write_inode() to also use the helper
             mark_ntfs_record_dirty() and thus to set the buffers belonging to the
             mft record dirty as well as the page itself.
           - Fix compiler warnings on x86-64 in fs/ntfs/dir.c.  (Randy Dunlap,
             slightly modified by me)
           - Add fs/ntfs/mft.c::try_map_mft_record() which fails with -EALREADY if
             the mft record is already locked and otherwise behaves the same way
             as fs/ntfs/mft.c::map_mft_record().
           - Modify fs/ntfs/mft.c::write_mft_record_nolock() so that it only
             writes the mft record if the buffers belonging to it are dirty.
             Otherwise we assume that it was written out by other means already.
           - Attempting to write outside initialized size is _not_ a bug so remove
             the bug check from fs/ntfs/aops.c::ntfs_write_mst_block().  It is in
             fact required to write outside initialized size when preparing to
             extend the initialized size.
           - Map the page instead of using page_address() before writing to it in
             fs/ntfs/aops.c::ntfs_mft_writepage().
           - Provide exclusion between opening an inode / mapping an mft record
             and accessing the mft record in fs/ntfs/mft.c::ntfs_mft_writepage()
             by setting the page not uptodate throughout ntfs_mft_writepage().
           - Clear the page uptodate flag in fs/ntfs/aops.c::ntfs_write_mst_block()
             to ensure noone can see the page whilst the mst fixups are applied.
           - Add the helper fs/ntfs/mft.c::ntfs_may_write_mft_record() which
             checks if an mft record may be written out safely obtaining any
             necessary locks in the process.  This is used by
             fs/ntfs/aops.c::ntfs_write_mst_block().
           - Modify fs/ntfs/aops.c::ntfs_write_mst_block() to also work for
             writing mft records and improve its error handling in the process.
             Now if any of the records in the page fail to be written out, all
             other records will be written out instead of aborting completely.
           - Remove ntfs_mft_aops and update all users to use ntfs_mst_aops.
           - Modify fs/ntfs/inode.c::ntfs_read_locked_inode() to set the
             ntfs_mst_aops for all inodes which are NInoMstProtected() and
             ntfs_aops for all other inodes.
           - Rename fs/ntfs/mft.c::sync_mft_mirror{,_umount}() to
             ntfs_sync_mft_mirror{,_umount}() and change their parameters so they
             no longer require an ntfs inode to be present.  Update all callers.
           - Cleanup the error handling in fs/ntfs/mft.c::ntfs_sync_mft_mirror().
           - Clear the page uptodate flag in fs/ntfs/mft.c::ntfs_sync_mft_mirror()
             to ensure noone can see the page whilst the mst fixups are applied.
           - Remove the no longer needed fs/ntfs/mft.c::ntfs_mft_writepage() and
             fs/ntfs/mft.c::try_map_mft_record().
           - Fix callers of fs/ntfs/aops.c::mark_ntfs_record_dirty() to call it
             with the ntfs inode which contains the page rather than the ntfs
             inode the mft record of which is in the page.
           - Fix race condition in fs/ntfs/inode.c::ntfs_put_inode() by moving the
             index inode bitmap inode release code from there to
             fs/ntfs/inode.c::ntfs_clear_big_inode().  (Thanks to Christoph
             Hellwig for spotting this.)
           - Fix race condition in fs/ntfs/inode.c::ntfs_put_inode() by taking the
             inode semaphore around the code that sets ni->itype.index.bmp_ino to
             NULL and reorganize the code to optimize it a bit.  (Thanks to
             Christoph Hellwig for spotting this.)
           - Modify fs/ntfs/aops.c::mark_ntfs_record_dirty() to no longer take the
             ntfs inode as a parameter as this is confusing and misleading and the
             needed ntfs inode is available via NTFS_I(page->mapping->host).
             Adapt all callers to this change.
           - Modify fs/ntfs/mft.c::write_mft_record_nolock() and
             fs/ntfs/aops.c::ntfs_write_mst_block() to only check the dirty state
             of the first buffer in a record and to take this as the ntfs record
             dirty state.  We cannot look at the dirty state for subsequent
             buffers because we might be racing with
             fs/ntfs/aops.c::mark_ntfs_record_dirty().
           - Move the static inline ntfs_init_big_inode() from fs/ntfs/inode.c to
             inode.h and make fs/ntfs/inode.c::__ntfs_init_inode() non-static and
             add a declaration for it to inode.h.  Fix some compilation issues
             that resulted due to #includes and header file interdependencies.
           - Simplify setup of i_mode in fs/ntfs/inode.c::ntfs_read_locked_inode().
           - Add helpers fs/ntfs/layout.h::MK_MREF() and MK_LE_MREF().
           - Modify fs/ntfs/mft.c::map_extent_mft_record() to only verify the mft
             record sequence number if it is specified (i.e. not zero).
           - Add fs/ntfs/mft.[hc]::ntfs_mft_record_alloc() and various helper
             functions used by it.
           - Update Documentation/filesystems/ntfs.txt with instructions on how to
             use the Device-Mapper driver with NTFS ftdisk/LDM raid.  This removes
             the linear raid problem with the Software RAID / MD driver when one
             or more of the devices has an odd number of sectors.
   
   2.1.20 - Fix two stupid bugs introduced in 2.1.18 release.
   
           - Fix stupid bug in fs/ntfs/attrib.c::ntfs_attr_reinit_search_ctx()
             where we did not clear ctx->al_entry but it was still set due to
             changes in ntfs_attr_lookup() and ntfs_external_attr_find() in
             particular.
           - Fix another stupid bug in fs/ntfs/attrib.c::ntfs_external_attr_find()
             where we forgot to unmap the extent mft record when we had finished
             enumerating an attribute which caused a bug check to trigger when the
             VFS calls ->clear_inode.
   
   2.1.19 - Many cleanups, improvements, and a minor bug fix.
   
           - Update ->setattr (fs/ntfs/inode.c::ntfs_setattr()) to refuse to
             change the uid, gid, and mode of an inode as we do not support NTFS
             ACLs yet.
           - Remove BKL use from ntfs_setattr() syncing up with the rest of the
             kernel.
           - Get rid of the ugly transparent union in fs/ntfs/dir.c::ntfs_readdir()
             and ntfs_filldir() as per suggestion from Al Viro.
           - Change '\0' and L'\0' to simply 0 as per advice from Linus Torvalds.
           - Update ->truncate (fs/ntfs/inode.c::ntfs_truncate()) to check if the
             inode size has changed and to only output an error if so.
           - Rename fs/ntfs/attrib.h::attribute_value_length() to ntfs_attr_size().
           - Add le{16,32,64} as well as sle{16,32,64} data types to
             fs/ntfs/types.h.
           - Change ntfschar to be le16 instead of u16 in fs/ntfs/types.h.
           - Add le versions of VCN, LCN, and LSN called leVCN, leLCN, and leLSN,
             respectively, to fs/ntfs/types.h.
           - Update endianness conversion macros in fs/ntfs/endian.h to use the
             new types as appropriate.
           - Do proper type casting when using sle64_to_cpup() in fs/ntfs/dir.c
             and index.c.
           - Add leMFT_REF data type to fs/ntfs/layout.h.
           - Update all NTFS header files with the new little endian data types.
             Affected files are fs/ntfs/layout.h, logfile.h, and time.h.
           - Do proper type casting when using ntfs_is_*_recordp() in
             fs/ntfs/logfile.c, mft.c, and super.c. 
           - Fix all the sparse bitwise warnings.  Had to change all the typedef
             enums storing little endian values to simple enums plus a typedef for
             the datatype to make sparse happy.
           - Fix a bug found by the new sparse bitwise warnings where the default
             upcase table was defined as a pointer to wchar_t rather than ntfschar
             in fs/ntfs/ntfs.h and super.c.
           - Change {const_,}cpu_to_le{16,32}(0) to just 0 as suggested by Al Viro.
   
   2.1.18 - Fix scheduling latencies at mount time as well as an endianness bug.
   
           - Remove vol->nr_mft_records as it was pretty meaningless and optimize
             the calculation of total/free inodes as used by statfs().
           - Fix scheduling latencies in ntfs_fill_super() by dropping the BKL
             because the code itself is using the ntfs_lock semaphore which
             provides safe locking.  (Ingo Molnar)
           - Fix a potential bug in fs/ntfs/mft.c::map_extent_mft_record() that
             could occur in the future for when we start closing/freeing extent
             inodes if we don't set base_ni->ext.extent_ntfs_inos to NULL after
             we free it.
           - Rename {find,lookup}_attr() to ntfs_attr_{find,lookup}() as well as
             find_external_attr() to ntfs_external_attr_find() to cleanup the
             namespace a bit and to be more consistent with libntfs.
           - Rename {{re,}init,get,put}_attr_search_ctx() to
             ntfs_attr_{{re,}init,get,put}_search_ctx() as well as the type
             attr_search_context to ntfs_attr_search_ctx.
           - Force use of ntfs_attr_find() in ntfs_attr_lookup() when searching
             for the attribute list attribute itself.
           - Fix endianness bug in ntfs_external_attr_find().
           - Change ntfs_{external_,}attr_find() to return 0 on success, -ENOENT
             if the attribute is not found, and -EIO on real error.  In the case
             of -ENOENT, the search context is updated to describe the attribute
             before which the attribute being searched for would need to be
             inserted if such an action were to be desired and in the case of
             ntfs_external_attr_find() the search context is also updated to
             indicate the attribute list entry before which the attribute list
             entry of the attribute being searched for would need to be inserted
             if such an action were to be desired.  Also make ntfs_find_attr()
             static and remove its prototype from attrib.h as it is not used
             anywhere other than attrib.c.  Update ntfs_attr_lookup() and all
             callers of ntfs_{external,}attr_{find,lookup}() for the new return
             values.
           - Minor cleanup of fs/ntfs/inode.c::ntfs_init_locked_inode().
   
   2.1.17 - Fix bugs in mount time error code paths and other updates.
   
           - Implement bitmap modification code (fs/ntfs/bitmap.[hc]).  This
             includes functions to set/clear a single bit or a run of bits.
           - Add fs/ntfs/attrib.[hc]::ntfs_find_vcn() which returns the locked
             runlist element containing a particular vcn.  It also takes care of
             mapping any needed runlist fragments.
           - Implement cluster (de-)allocation code (fs/ntfs/lcnalloc.[hc]).
           - Load attribute definition table from $AttrDef at mount time.
           - Fix bugs in mount time error code paths involving (de)allocation of
             the default and volume upcase tables.
           - Remove ntfs_nr_mounts as it is no longer used.
   
   2.1.16 - Implement access time updates, file sync, async io, and read/writev.
   
           - Add support for readv/writev and aio_read/aio_write (fs/ntfs/file.c).
             This is done by setting the appropriate file operations pointers to
             the generic helper functions provided by mm/filemap.c.
           - Implement fsync, fdatasync, and msync both for files (fs/ntfs/file.c)
             and directories (fs/ntfs/dir.c).
           - Add support for {a,m,c}time updates to inode.c::ntfs_write_inode().
             Note, except for the root directory and any other system files opened
             by the user, the system files will not have their access times
             updated as they are only accessed at the inode level an hence the
             file level functions which cause the times to be updated are never
             invoked.
   
   2.1.15 - Invalidate quotas when (re)mounting read-write.
   
           - Add new element itype.index.collation_rule to the ntfs inode
             structure and set it appropriately in ntfs_read_locked_inode().
           - Implement a new inode type "index" to allow efficient access to the
             indices found in various system files and adapt inode handling
             accordingly (fs/ntfs/inode.[hc]).  An index inode is essentially an
             attribute inode (NInoAttr() is true) with an attribute type of
             AT_INDEX_ALLOCATION.  As such, it is no longer allowed to call
             ntfs_attr_iget() with an attribute type of AT_INDEX_ALLOCATION as
             there would be no way to distinguish between normal attribute inodes
             and index inodes.  The function to obtain an index inode is
             ntfs_index_iget() and it uses the helper function
             ntfs_read_locked_index_inode().  Note, we do not overload
             ntfs_attr_iget() as indices consist of multiple attributes so using
             ntfs_attr_iget() to obtain an index inode would be confusing.
           - Ensure that there is no overflow when doing page->index <<
             PAGE_CACHE_SHIFT by casting page->index to s64 in fs/ntfs/aops.c.
           - Use atomic kmap instead of kmap() in fs/ntfs/aops.c::ntfs_read_page()
             and ntfs_read_block().
           - Use case sensitive attribute lookups instead of case insensitive ones.
           - Lock all page cache pages belonging to mst protected attributes while
             accessing them to ensure we never see corrupt data while the page is
             under writeout.
           - Add framework for generic ntfs collation (fs/ntfs/collation.[hc]).
             We have ntfs_is_collation_rule_supported() to check if the collation
             rule you want to use is supported and ntfs_collation() which actually
             collates two data items.  We currently only support COLLATION_BINARY
             and COLLATION_NTOFS_ULONG but support for other collation rules will
             be added as the need arises.
           - Add a new type, ntfs_index_context, to allow retrieval of an index
             entry using the corresponding index key.  To get an index context,
             use ntfs_index_ctx_get() and to release it, use ntfs_index_ctx_put().
             This also adds a new slab cache for the index contexts.  To lookup a
             key in an index inode, use ntfs_index_lookup().  After modifying an
             index entry, call ntfs_index_entry_flush_dcache_page() followed by
             ntfs_index_entry_mark_dirty() to ensure the changes are written out
             to disk.  For details see fs/ntfs/index.[hc].  Note, at present, if
             an index entry is in the index allocation attribute rather than the
             index root attribute it will not be written out (you will get a
             warning message about discarded changes instead).
           - Load the quota file ($Quota) and check if quota tracking is enabled
             and if so, mark the quotas out of date.  This causes windows to
             rescan the volume on boot and update all quota entries.
           - Add a set_page_dirty address space operation for ntfs_m[fs]t_aops.
             It is simply set to __set_page_dirty_nobuffers() to make sure that
             running set_page_dirty() on a page containing mft/ntfs records will
             not affect the dirty state of the page buffers.
           - Add fs/ntfs/index.c::__ntfs_index_entry_mark_dirty() which sets all
             buffers that are inside the ntfs record in the page dirty after which
             it sets the page dirty.  This allows ->writepage to only write the
             dirty index records rather than having to write all the records in
             the page.  Modify fs/ntfs/index.h::ntfs_index_entry_mark_dirty() to
             use this rather than __set_page_dirty_nobuffers().
           - Implement fs/ntfs/aops.c::ntfs_write_mst_block() which enables the
             writing of page cache pages belonging to mst protected attributes
             like the index allocation attribute in directory indices and other
             indices like $Quota/$Q, etc.  This means that the quota is now marked
             out of date on all volumes rather than only on ones where the quota
             defaults entry is in the index root attribute of the $Quota/$Q index.
   
   2.1.14 - Fix an NFSd caused deadlock reported by several users.
   
           - Modify fs/ntfs/ntfs_readdir() to copy the index root attribute value
             to a buffer so that we can put the search context and unmap the mft
             record before calling the filldir() callback.  We need to do this
             because of NFSd which calls ->lookup() from its filldir callback()
             and this causes NTFS to deadlock as ntfs_lookup() maps the mft record
             of the directory and since ntfs_readdir() has got it mapped already
             ntfs_lookup() deadlocks.
   
   2.1.13 - Enable overwriting of resident files and housekeeping of system files.
   
           - Implement writing of mft records (fs/ntfs/mft.[hc]), which includes
             keeping the mft mirror in sync with the mft when mirrored mft records
             are written.  The functions are write_mft_record{,_nolock}().  The
             implementation is quite rudimentary for now with lots of things not
             implemented yet but I am not sure any of them can actually occur so
             I will wait for people to hit each one and only then implement it.
           - Commit open system inodes at umount time.  This should make it
             virtually impossible for sync_mft_mirror_umount() to ever be needed.
           - Implement ->write_inode (fs/ntfs/inode.c::ntfs_write_inode()) for the
             ntfs super operations.  This gives us inode writing via the VFS inode
             dirty code paths.  Note:  Access time updates are not implemented yet.
           - Implement fs/ntfs/mft.[hc]::{,__}mark_mft_record_dirty() and make
             fs/ntfs/aops.c::ntfs_writepage() and ntfs_commit_write() use it, thus
             finally enabling resident file overwrite!  (-8  This also includes a
             placeholder for ->writepage (ntfs_mft_writepage()), which for now
             just redirties the page and returns.  Also, at umount time, we for
             now throw away all mft data page cache pages after the last call to
             ntfs_commit_inode() in the hope that all inodes will have been
             written out by then and hence no dirty (meta)data will be lost.  We
             also check for this case and emit an error message telling the user
             to run chkdsk.
           - Use set_page_writeback() and end_page_writeback() in the resident
             attribute code path of fs/ntfs/aops.c::ntfs_writepage() otherwise
             the radix-tree tag PAGECACHE_TAG_DIRTY remains set even though the
             page is clean.
           - Implement ntfs_mft_writepage() so it now checks if any of the mft
             records in the page are dirty and if so redirties the page and
             returns.  Otherwise it just returns (after doing set_page_writeback(),
             unlock_page(), end_page_writeback() or the radix-tree tag
             PAGECACHE_TAG_DIRTY remains set even though the page is clean), thus
             alowing the VM to do with the page as it pleases.  Also, at umount
             time, now only throw away dirty mft (meta)data pages if dirty inodes
             are present and ask the user to email us if they see this happening.
           - Add functions ntfs_{clear,set}_volume_flags(), to modify the volume
             information flags (fs/ntfs/super.c).
           - Mark the volume dirty when (re)mounting read-write and mark it clean
             when unmounting or remounting read-only.  If any volume errors are
             found, the volume is left marked dirty to force chkdsk to run.
           - Add code to set the NT4 compatibility flag when (re)mounting
             read-write for newer NTFS versions but leave it commented out for now
             since we do not make any modifications that are NTFS 1.2 specific yet
             and since setting this flag breaks Captive-NTFS which is not nice.
             This code must be enabled once we start writing NTFS 1.2 specific
             changes otherwise Windows NTFS driver might crash / cause corruption.
   
   2.1.12 - Fix the second fix to the decompression engine and some cleanups.
   
           - Add a new address space operations struct, ntfs_mst_aops, for mst
             protected attributes.  This is because the default ntfs_aops do not
             make sense with mst protected data and were they to write anything to
             such an attribute they would cause data corruption so we provide
             ntfs_mst_aops which does not have any write related operations set.
           - Cleanup dirty ntfs inode handling (fs/ntfs/inode.[hc]) which also
             includes an adapted ntfs_commit_inode() and an implementation of
             ntfs_write_inode() which for now just cleans dirty inodes without
             writing them (it does emit a warning that this is happening).
           - Undo the second decompression engine fix (see 2.1.9 release ChangeLog
             entry) as it was only fixing a theoretical bug but at the same time
             it badly broke the handling of sparse and uncompressed compression
             blocks.
   
   2.1.11 - Driver internal cleanups.
   
           - Only build logfile.o if building the driver with read-write support.
           - Really final white space cleanups.
           - Use generic_ffs() instead of ffs() in logfile.c which allows the
             log_page_size variable to be optimized by gcc into a constant.
           - Rename uchar_t to ntfschar everywhere as uchar_t is unsigned 1-byte
             char as defined by POSIX and as found on some systems.
   
   2.1.10 - Force read-only (re)mounting of volumes with unsupported volume flags.
   
           - Finish off the white space cleanups (remove trailing spaces, etc).
           - Clean up ntfs_fill_super() and ntfs_read_inode_mount() by removing
             the kludges around the first iget().  Instead of (re)setting ->s_op
             we have the $MFT inode set up by explicit new_inode() / set ->i_ino /
             insert_inode_hash() / call ntfs_read_inode_mount() directly.  This
             kills the need for second super_operations and allows to return error
             from ntfs_read_inode_mount() without resorting to ugly "poisoning"
             tricks.  (Al Viro)
           - Force read-only (re)mounting if any of the following bits are set in
             the volume information flags:
                   VOLUME_IS_DIRTY, VOLUME_RESIZE_LOG_FILE,
                   VOLUME_UPGRADE_ON_MOUNT, VOLUME_DELETE_USN_UNDERWAY,
                   VOLUME_REPAIR_OBJECT_ID, VOLUME_MODIFIED_BY_CHKDSK
             To make this easier we define VOLUME_MUST_MOUNT_RO_MASK with all the
             above bits set so the test is made easy.
   
   2.1.9 - Fix two bugs in decompression engine.
   
           - Fix a bug where we would not always detect that we have reached the
             end of a compression block because we were ending at minus one byte
             which is effectively the same as being at the end.  The fix is to
             check whether the uncompressed buffer has been fully filled and if so
             we assume we have reached the end of the compression block.  A big
             thank you to Marcin Gibuła for the bug report, the assistance in
             tracking down the bug and testing the fix.
           - Fix a possible bug where when a compressed read is truncated to the
             end of the file, the offset inside the last page was not truncated.
   
   2.1.8 - Handle $MFT mirror and $LogFile, improve time handling, and cleanups.
   
           - Use get_bh() instead of manual atomic_inc() in fs/ntfs/compress.c.
           - Modify fs/ntfs/time.c::ntfs2utc(), get_current_ntfs_time(), and
             utc2ntfs() to work with struct timespec instead of time_t on the
             Linux UTC time side thus preserving the full precision of the NTFS
             time and only loosing up to 99 nano-seconds in the Linux UTC time.
           - Move fs/ntfs/time.c to fs/ntfs/time.h and make the time functions
             static inline.
           - Remove unused ntfs_dirty_inode().
           - Cleanup super operations declaration in fs/ntfs/super.c.
           - Wrap flush_dcache_mft_record_page() in #ifdef NTFS_RW.
           - Add NInoTestSetFoo() and NInoTestClearFoo() macro magic to
             fs/ntfs/inode.h and use it to declare NInoTest{Set,Clear}Dirty.
           - Move typedefs for ntfs_attr and test_t from fs/ntfs/inode.c to
             fs/ntfs/inode.h so they can be used elsewhere.
           - Determine the mft mirror size as the number of mirrored mft records
             and store it in ntfs_volume->mftmirr_size (fs/ntfs/super.c).
           - Load the mft mirror at mount time and compare the mft records stored
             in it to the ones in the mft.  Force a read-only mount if the two do
             not match (fs/ntfs/super.c).
           - Fix type casting related warnings on 64-bit architectures.  Thanks
             to Meelis Roos for reporting them.
           - Move %L to %ll as %L is floating point and %ll is integer which is
             what we want.
           - Read the journal ($LogFile) and determine if the volume has been
             shutdown cleanly and force a read-only mount if not (fs/ntfs/super.c
             and fs/ntfs/logfile.c).  This is a little bit of a crude check in
             that we only look at the restart areas and not at the actual log
             records so that there will be a very small number of cases where we
             think that a volume is dirty when in fact it is clean.  This should
             only affect volumes that have not been shutdown cleanly and did not
             have any pending, non-check-pointed i/o.
           - If the $LogFile indicates a clean shutdown and a read-write (re)mount
             is requested, empty $LogFile by overwriting it with 0xff bytes to
             ensure that Windows cannot cause data corruption by replaying a stale
             journal after Linux has written to the volume.
   
   2.1.7 - Enable NFS exporting of mounted NTFS volumes.
   
           - Set i_generation in the VFS inode from the seq_no of the NTFS inode.
           - Make ntfs_lookup() NFS export safe, i.e. use d_splice_alias(), etc.
           - Implement ->get_dentry() in fs/ntfs/namei.c::ntfs_get_dentry() as the
             default doesn't allow inode number 0 which is a valid inode on NTFS
             and even if it did allow that it uses iget() instead of ntfs_iget()
             which makes it useless for us.
           - Implement ->get_parent() in fs/ntfs/namei.c::ntfs_get_parent() as the
             default just returns -EACCES which is not very useful.
           - Define export operations (->s_export_op) for NTFS (ntfs_export_ops)
             and set them up in the super block at mount time (super.c) this
             allows mounted NTFS volumes to be exported via NFS.
           - Add missing return -EOPNOTSUPP; in
             fs/ntfs/aops.c::ntfs_commit_nonresident_write().
           - Enforce no atime and no dir atime updates at mount/remount time as
             they are not implemented yet anyway.
           - Move a few assignments in fs/ntfs/attrib.c::load_attribute_list() to
             after a NULL check.  Thanks to Dave Jones for pointing this out.
   
   2.1.6 - Fix minor bug in handling of compressed directories.
   
           - Fix bug in handling of compressed directories.  A compressed
             directory is not really compressed so when we set the ->i_blocks
             field of a compressed directory inode we were setting it from the
             non-existing field ni->itype.compressed.size which gave random
             results...  For directories we now always use ni->allocated_size.
   
   2.1.5 - Fix minor bug in attribute list attribute handling.
   
           - Fix bug in attribute list handling.  Actually it is not as much a bug
             as too much protection in that we were not allowing attribute lists
             which waste space on disk while Windows XP clearly allows it and in
             fact creates such attribute lists so our driver was failing.
           - Update NTFS documentation ready for 2.6 kernel release.
   
   2.1.4 - Reduce compiler requirements.
   
           - Remove all uses of unnamed structs and unions in the driver to make
             old and newer gcc versions happy. Makes it a bit uglier IMO but at
             least people will stop hassling me about it.
   
   2.1.3 - Important bug fixes in corner cases.
   
           - super.c::parse_ntfs_boot_sector(): Correct the check for 64-bit
             clusters. (Philipp Thomas)
           - attrib.c::load_attribute_list(): Fix bug when initialized_size is a
             multiple of the block_size but not the cluster size. (Szabolcs
             Szakacsits)
   
   2.1.2 - Important bug fixes aleviating the hangs in statfs.
   
           - Fix buggy free cluster and free inode determination logic.
   
   2.1.1 - Minor updates.
   
           - Add handling for initialized_size != data_size in compressed files.
           - Reduce function local stack usage from 0x3d4 bytes to just noise in
             fs/ntfs/upcase.c. (Randy Dunlap)
           - Remove compiler warnings for newer gcc.
           - Pages are no longer kmapped by mm/filemap.c::generic_file_write()
             around calls to ->{prepare,commit}_write.  Adapt NTFS appropriately
             in fs/ntfs/aops.c::ntfs_prepare_nonresident_write() by using
             kmap_atomic(KM_USER0).
   
   2.1.0 - First steps towards write support: implement file overwrite.
   
           - Add configuration option for developmental write support with an
             appropriately scary configuration help text.
           - Initial implementation of fs/ntfs/aops.c::ntfs_writepage() and its
             helper fs/ntfs/aops.c::ntfs_write_block(). This enables mmap(2) based
             overwriting of existing files on ntfs. Note: Resident files are
             only written into memory, and not written out to disk at present, so
             avoid writing to files smaller than about 1kiB.
           - Initial implementation of fs/ntfs/aops.c::ntfs_prepare_write(), its
             helper fs/ntfs/aops.c::ntfs_prepare_nonresident_write() and their
             counterparts, fs/ntfs/aops.c::ntfs_commit_write(), and
             fs/ntfs/aops.c::ntfs_commit_nonresident_write(), respectively. Also,
             add generic_file_write() to the ntfs file operations (fs/ntfs/file.c).
             This enables write(2) based overwriting of existing files on ntfs.
             Note: As with mmap(2) based overwriting, resident files are only
             written into memory, and not written out to disk at present, so avoid
             writing to files smaller than about 1kiB.
           - Implement ->truncate (fs/ntfs/inode.c::ntfs_truncate()) and
             ->setattr() (fs/ntfs/inode.c::ntfs_setattr()) inode operations for
             files with the purpose of intercepting and aborting all i_size
             changes which we do not support yet. ntfs_truncate() actually only
             emits a warning message but AFAICS our interception of i_size changes
             elsewhere means ntfs_truncate() never gets called for i_size changes.
             It is only called from generic_file_write() when we fail in
             ntfs_prepare_{,nonresident_}write() in order to discard any
             instantiated buffers beyond i_size. Thus i_size is not actually
             changed so our warning message is enough. Unfortunately it is not
             possible to easily determine if i_size is being changed or not hence
             we just emit an appropriately worded error message.
   
   2.0.25 - Small bug fixes and cleanups.
   
           - Unlock the page in an out of memory error code path in
             fs/ntfs/aops.c::ntfs_read_block().
           - If fs/ntfs/aops.c::ntfs_read_page() is called on an uptodate page,
             just unlock the page and return. (This can happen due to ->writepage
             clearing PageUptodate() during write out of MstProtected()
             attributes.
           - Remove leaked write code again.
   
   2.0.24 - Cleanups.
   
          - Treat BUG_ON() as ASSERT() not VERIFY(), i.e. do not use side effects
            inside BUG_ON(). (Adam J. Richter)
          - Split logical OR expressions inside BUG_ON() into individual BUG_ON()
            calls for improved debugging. (Adam J. Richter)
          - Add errors flag to the ntfs volume state, accessed via
            NVol{,Set,Clear}Errors(vol).
          - Do not allow read-write remounts of read-only volumes with errors.
          - Clarify comment for ntfs file operation sendfile which was added by
            Christoph Hellwig a while ago (just using generic_file_sendfile())
            to say that ntfs ->sendfile is only used for the case where the
            source data is on the ntfs partition and the destination is
            somewhere else, i.e. nothing we need to concern ourselves with.
          - Add generic_file_write() as our ntfs file write operation.
  
  2.0.23 - Major bug fixes (races, deadlocks, non-i386 architectures).
  
          - Massive internal locking changes to mft record locking. Fixes lock
            recursion and replaces the mrec_lock read/write semaphore with a
            mutex. Also removes the now superfluous mft_count. This fixes several
            race conditions and deadlocks, especially in the future write code.
          - Fix ntfs over loopback for compressed files by adding an
            optimization barrier. (gcc was screwing up otherwise ?)
          - Miscellaneous cleanups all over the code and a fix or two in error
            handling code paths.
          Thanks go to Christoph Hellwig for pointing out the following two:
          - Remove now unused function fs/ntfs/malloc.h::vmalloc_nofs().
          - Fix ntfs_free() for ia64 and parisc by checking for VMALLOC_END, too.
  
  2.0.22 - Cleanups, mainly to ntfs_readdir(), and use C99 initializers.
  
          - Change fs/ntfs/dir.c::ntfs_reddir() to only read/write ->f_pos once
            at entry/exit respectively.
          - Use C99 initializers for structures.
          - Remove unused variable blocks from fs/ntfs/aops.c::ntfs_read_block().
  
  2.0.21 - Check for, and refuse to work with too large files/directories/volumes.
  
          - Limit volume size at mount time to 2TiB on architectures where
            unsigned long is 32-bits (fs/ntfs/super.c::parse_ntfs_boot_sector()).
            This is the most we can do without overflowing the 32-bit limit of
            the block device size imposed on us by sb_bread() and sb_getblk()
            for the time being.
          - Limit file/directory size at open() time to 16TiB on architectures
            where unsigned long is 32-bits (fs/ntfs/file.c::ntfs_file_open() and
            fs/ntfs/dir.c::ntfs_dir_open()). This is the most we can do without
            overflowing the page cache page index.
  
  2.0.20 - Support non-resident directory index bitmaps, fix page leak in readdir.
  
          - Move the directory index bitmap to use an attribute inode instead of
            having special fields for it inside the ntfs inode structure. This
            means that the index bitmaps now use the page cache for i/o, too,
            and also as a side effect we get support for non-resident index
            bitmaps for free.
          - Simplify/cleanup error handling in fs/ntfs/dir.c::ntfs_readdir() and
            fix a page leak that manifested itself in some cases.
          - Add fs/ntfs/inode.c::ntfs_put_inode(), which we need to release the
            index bitmap inode on the final iput().
  
  2.0.19 - Fix race condition, improvements, and optimizations in i/o interface.
  
          - Apply block optimization added to fs/ntfs/aops.c::ntfs_read_block()
            to fs/ntfs/compress.c::ntfs_file_read_compressed_block() as well.
          - Drop the "file" from ntfs_file_read_compressed_block().
          - Rename fs/ntfs/aops.c::ntfs_enb_buffer_read_async() to
            ntfs_end_buffer_async_read() (more like the fs/buffer.c counterpart).
          - Update ntfs_end_buffer_async_read() with the improved logic from
            its updated counterpart fs/buffer.c::end_buffer_async_read(). Apply
            further logic improvements to better determine when we set PageError.
          - Update submission of buffers in fs/ntfs/aops.c::ntfs_read_block() to
            check for the buffers being uptodate first in line with the updated
            fs/buffer.c::block_read_full_page(). This plugs a small race
            condition.
  
  2.0.18 - Fix race condition in reading of compressed files.
  
          - There was a narrow window between checking a buffer head for being
            uptodate and locking it in ntfs_file_read_compressed_block(). We now
            lock the buffer and then check whether it is uptodate or not.
  
  2.0.17 - Cleanups and optimizations - shrinking the ToDo list.
  
          - Modify fs/ntfs/inode.c::ntfs_read_locked_inode() to return an error
            code and update callers, i.e. ntfs_iget(), to pass that error code
            up instead of just using -EIO.
          - Modifications to super.c to ensure that both mount and remount
            cannot set any write related options when the driver is compiled
            read-only.
          - Optimize block resolution in fs/ntfs/aops.c::ntfs_read_block() to
            cache the current runlist element. This should improve performance
            when reading very large and/or very fragmented data.
  
  2.0.16 - Convert access to $MFT/$BITMAP to attribute inode API.
  
          - Fix a stupid bug introduced in 2.0.15 where we were unmapping the
            wrong inode in fs/ntfs/inode.c::ntfs_attr_iget().
          - Fix debugging check in fs/ntfs/aops.c::ntfs_read_block().
          - Convert $MFT/$BITMAP access to attribute inode API and remove all
            remnants of the ugly mftbmp address space and operations hack. This
            means we finally have only one readpage function as well as only one
            async io completion handler. Yey! The mft bitmap is now just an
            attribute inode and is accessed from vol->mftbmp_ino just as if it
            were a normal file. Fake inodes rule. (-:
  
  2.0.15 - Fake inodes based attribute i/o via the pagecache, fixes and cleanups.
  
          - Fix silly bug in fs/ntfs/super.c::parse_options() which was causing
            remounts to fail when the partition had an entry in /etc/fstab and
            the entry specified the nls= option.
          - Apply same macro magic used in fs/ntfs/inode.h to fs/ntfs/volume.h to
            expand all the helper functions NVolFoo(), NVolSetFoo(), and
            NVolClearFoo().
          - Move copyright statement from driver initialisation message to
            module description (fs/super.c). This makes the initialisation
            message fit on one line and fits in better with rest of kernel.
          - Update fs/ntfs/attrib.c::map_run_list() to work on both real and
            attribute inodes, and both for files and directories.
          - Implement fake attribute inodes allowing all attribute i/o to go via
            the page cache and to use all the normal vfs/mm functionality:
            - Add ntfs_attr_iget() and its helper ntfs_read_locked_attr_inode()
              to fs/ntfs/inode.c.
            - Add needed cleanup code to ntfs_clear_big_inode().
          - Merge address space operations for files and directories (aops.c),
            now just have ntfs_aops:
            - Rename:
                  end_buffer_read_attr_async() -> ntfs_end_buffer_read_async(),
                  ntfs_attr_read_block()       -> ntfs_read_block(),
                  ntfs_file_read_page()        -> ntfs_readpage().
            - Rewrite fs/ntfs/aops.c::ntfs_readpage() to work on both real and
              attribute inodes, and both for files and directories.
            - Remove obsolete fs/ntfs/aops.c::ntfs_mst_readpage().
  
  2.0.14 - Run list merging code cleanup, minor locking changes, typo fixes.
  
          - Change fs/ntfs/super.c::ntfs_statfs() to not rely on BKL by moving
            the locking out of super.c::get_nr_free_mft_records() and taking and
            dropping the mftbmp_lock rw_semaphore in ntfs_statfs() itself.
          - Bring attribute runlist merging code (fs/ntfs/attrib.c) in sync with
            current userspace ntfs library code. This means that if a merge
            fails the original runlists are always left unmodified instead of
            being silently corrupted.
          - Misc typo fixes.
  
  2.0.13 - Use iget5_locked() in preparation for fake inodes and small cleanups.
  
          - Remove nr_mft_bits and the now superfluous union with nr_mft_records
            from ntfs_volume structure.
          - Remove nr_lcn_bits and the now superfluous union with nr_clusters
            from ntfs_volume structure.
          - Use iget5_locked() and friends instead of conventional iget(). Wrap
            the call in fs/ntfs/inode.c::ntfs_iget() and update callers of iget()
            to use ntfs_iget(). Leave only one iget() call at mount time so we
            don't need an ntfs_iget_mount().
          - Change fs/ntfs/inode.c::ntfs_new_extent_inode() to take mft_no as an
            additional argument.
  
  2.0.12 - Initial cleanup of address space operations following 2.0.11 changes.
  
          - Merge fs/ntfs/aops.c::end_buffer_read_mst_async() and
            fs/ntfs/aops.c::end_buffer_read_file_async() into one function
            fs/ntfs/aops.c::end_buffer_read_attr_async() using NInoMstProtected()
            to determine whether to apply mst fixups or not.
          - Above change allows merging fs/ntfs/aops.c::ntfs_file_read_block()
            and fs/ntfs/aops.c::ntfs_mst_readpage() into one function
            fs/ntfs/aops.c::ntfs_attr_read_block(). Also, create a tiny wrapper
            fs/ntfs/aops.c::ntfs_mst_readpage() to transform the parameters from
            the VFS readpage function prototype to the ntfs_attr_read_block()
            function prototype.
  
  2.0.11 - Initial preparations for fake inode based attribute i/o.
  
          - Move definition of ntfs_inode_state_bits to fs/ntfs/inode.h and
            do some macro magic (adapted from include/linux/buffer_head.h) to
            expand all the helper functions NInoFoo(), NInoSetFoo(), and
            NInoClearFoo().
          - Add new flag to ntfs_inode_state_bits: NI_Sparse.
          - Add new fields to ntfs_inode structure to allow use of fake inodes
            for attribute i/o: type, name, name_len. Also add new state bits:
            NI_Attr, which, if set, indicates the inode is a fake inode, and
            NI_MstProtected, which, if set, indicates the attribute uses multi
            sector transfer protection, i.e. fixups need to be applied after
            reads and before/after writes.
          - Rename fs/ntfs/inode.c::ntfs_{new,clear,destroy}_inode() to
            ntfs_{new,clear,destroy}_extent_inode() and update callers.
          - Use ntfs_clear_extent_inode() in fs/ntfs/inode.c::__ntfs_clear_inode()
            instead of ntfs_destroy_extent_inode().
          - Cleanup memory deallocations in {__,}ntfs_clear_{,big_}inode().
          - Make all operations on ntfs inode state bits use the NIno* functions.
          - Set up the new ntfs inode fields and state bits in
            fs/ntfs/inode.c::ntfs_read_inode() and add appropriate cleanup of
            allocated memory to __ntfs_clear_inode().
          - Cleanup ntfs_inode structure a bit for better ordering of elements
            w.r.t. their size to allow better packing of the structure in memory.
  
  2.0.10 - There can only be 2^32 - 1 inodes on an NTFS volume.
  
          - Add check at mount time to verify that the number of inodes on the
            volume does not exceed 2^32 - 1, which is the maximum allowed for
            NTFS according to Microsoft.
          - Change mft_no member of ntfs_inode structure to be unsigned long.
            Update all users. This makes ntfs_inode->mft_no just a copy of struct
            inode->i_ino. But we can't just always use struct inode->i_ino and
            remove mft_no because extent inodes do not have an attached struct
            inode.
  
  2.0.9 - Decompression engine now uses a single buffer and other cleanups.
  
          - Change decompression engine to use a single buffer protected by a
            spin lock instead of per-CPU buffers. (Rusty Russell)
          - Do not update cb_pos when handling a partial final page during
            decompression of a sparse compression block, as the value is later
            reset without being read/used. (Rusty Russell)
          - Switch to using the new KM_BIO_SRC_IRQ for atomic kmap()s. (Andrew
            Morton)
          - Change buffer size in ntfs_readdir()/ntfs_filldir() to use
            NLS_MAX_CHARSET_SIZE which makes the buffers almost 1kiB each but
            it also makes everything safer so it is a good thing.
          - Miscellaneous minor cleanups to comments.
  
  2.0.8 - Major updates for handling of case sensitivity and dcache aliasing.
  
          Big thanks go to Al Viro and other inhabitants of #kernel for investing
          their time to discuss the case sensitivity and dcache aliasing issues.
  
          - Remove unused source file fs/ntfs/attraops.c.
          - Remove show_inodes mount option(s), thus dropping support for
            displaying of short file names.
          - Remove deprecated mount option posix.
          - Restore show_sys_files mount option.
          - Add new mount option case_sensitive, to determine if the driver
            treats file names as case sensitive or not. If case sensitive, create
            file names in the POSIX namespace. Otherwise create file names in the
            LONG/WIN32 namespace. Note, files remain accessible via their short
            file name, if it exists.
          - Remove really dumb logic bug in boot sector recovery code.
          - Fix dcache aliasing issues wrt short/long file names via changes
            to fs/ntfs/dir.c::ntfs_lookup_inode_by_name() and
            fs/ntfs/namei.c::ntfs_lookup():
            - Add additional argument to ntfs_lookup_inode_by_name() in which we
              return information about the matching file name if the case is not
              matching or the match is a short file name. See comments above the
              function definition for details.
            - Change ntfs_lookup() to only create dcache entries for the correctly
              cased file name and only for the WIN32 namespace counterpart of DOS
              namespace file names. This ensures we have only one dentry per
              directory and also removes all dcache aliasing issues between short
              and long file names once we add write support. See comments above
              function for details.
          - Fix potential 1 byte overflow in fs/ntfs/unistr.c::ntfs_ucstonls().
  
  2.0.7 - Minor cleanups and updates for changes in core kernel code.
  
          - Remove much of the NULL struct element initializers.
          - Various updates to make compatible with recent kernels.
          - Remove defines of MAX_BUF_PER_PAGE and include linux/buffer_head.h
            in fs/ntfs/ntfs.h instead.
          - Remove no longer needed KERNEL_VERSION checks. We are now in the
            kernel proper so they are no longer needed.
  
  2.0.6 - Major bugfix to make compatible with other kernel changes.
  
          - Initialize the mftbmp address space properly now that there are more
            fields in the struct address_space. This was leading to hangs and
            oopses on umount since 2.5.12 because of changes to other parts of
            the kernel. We probably want a kernel generic init_address_space()
            function...
          - Drop BKL from ntfs_readdir() after consultation with Al Viro. The
            only caller of ->readdir() is vfs_readdir() which holds i_mutex
            during the call, and i_mutex is sufficient protection against changes
            in the directory inode (including ->i_size).
          - Use generic_file_llseek() for directories (as opposed to
            default_llseek()) as this downs i_mutex instead of the BKL which is
            what we now need for exclusion against ->f_pos changes considering we
            no longer take the BKL in ntfs_readdir().
  
  2.0.5 - Major bugfix. Buffer overflow in extent inode handling.
  
          - No need to set old blocksize in super.c::ntfs_fill_super() as the
            VFS does so via invocation of deactivate_super() calling
            fs->fill_super() calling block_kill_super() which does it.
          - BKL moved from VFS into dir.c::ntfs_readdir(). (Linus Torvalds)
            -> Do we really need it? I don't think so as we have exclusion on
            the directory ntfs_inode rw_semaphore mrec_lock. We mmight have to
            move the ->f_pos accesses under the mrec_lock though. Check this...
          - Fix really, really, really stupid buffer overflow in extent inode
            handling in mft.c::map_extent_mft_record().
  
  2.0.4 - Cleanups and updates for kernel 2.5.11.
  
          - Add documentation on how to use the MD driver to be able to use NTFS
            stripe and volume sets in Linux and generally cleanup documentation
            a bit.
          Remove all uses of kdev_t in favour of struct block_device *:
          - Change compress.c::ntfs_file_read_compressed_block() to use
            sb_getblk() instead of getblk().
          - Change super.c::ntfs_fill_super() to use bdev_hardsect_size() instead
            of get_hardsect_size().
          - No need to get old blocksize in super.c::ntfs_fill_super() as
            fs/super.c::get_sb_bdev() already does this.
          - Set bh->b_bdev instead of bh->b_dev throughout aops.c.
  
  2.0.3 - Small bug fixes, cleanups, and performance improvements.
  
          - Remove some dead code from mft.c.
          - Optimize readpage and read_block functions throughout aops.c so that
            only initialized blocks are read. Non-initialized ones have their
            buffer head mapped, zeroed, and set up to date, without scheduling
            any i/o. Thanks to Al Viro for advice on how to avoid the device i/o.
          Thanks go to Andrew Morton for spotting the below:
          - Fix buglet in allocate_compression_buffers() error code path.
          - Call flush_dcache_page() after modifying page cache page contents in
            ntfs_file_readpage().
          - Check for existence of page buffers throughout aops.c before calling
            create_empty_buffers(). This happens when an I/O error occurs and the
            read is retried. (It also happens once writing is implemented so that
            needed doing anyway but I had left it for later...)
          - Don't BUG_ON() uptodate and/or mapped buffers throughout aops.c in
            readpage and read_block functions. Reasoning same as above (i.e. I/O
            error retries and future write code paths.)
  
  2.0.2 - Minor updates and cleanups.
  
          - Cleanup: rename mst.c::__post_read_mst_fixup to post_write_mst_fixup
            and cleanup the code a bit, removing the unused size parameter.
          - Change default fmask to 0177 and update documentation.
          - Change attrib.c::get_attr_search_ctx() to return the search context
            directly instead of taking the address of a pointer. A return value
            of NULL means the allocation failed. Updated all callers
            appropriately.
          - Update to 2.5.9 kernel (preserving backwards compatibility) by
            replacing all occurences of page->buffers with page_buffers(page).
          - Fix minor bugs in runlist merging, also minor cleanup.
          - Updates to bootsector layout and mft mirror contents descriptions.
          - Small bug fix in error detection in unistr.c and some cleanups.
          - Grow name buffer allocations in unistr.c in aligned mutlipled of 64
            bytes.
  
  2.0.1 - Minor updates.
  
          - Make default umask correspond to documentation.
          - Improve documentation.
          - Set default mode to include execute bit. The {u,f,d}mask can be used
            to take it away if desired. This allows binaries to be executed from
            a mounted ntfs partition.
  
  2.0.0 - New version number. Remove TNG from the name. Now in the kernel.
  
          - Add kill_super, just keeping up with the vfs changes in the kernel.
          - Repeat some changes from tng-0.0.8 that somehow got lost on the way
            from the CVS import into BitKeeper.
          - Begin to implement proper handling of allocated_size vs
            initialized_size vs data_size (i.e. i_size). Done are
            mft.c::ntfs_mft_readpage(), aops.c::end_buffer_read_index_async(),
            and attrib.c::load_attribute_list().
          - Lock the runlist in attrib.c::load_attribute_list() while using it.
          - Fix memory leak in ntfs_file_read_compressed_block() and generally
            clean up compress.c a little, removing some uncommented/unused debug
            code.
          - Tidy up dir.c a little bit.
          - Don't bother getting the runlist in inode.c::ntfs_read_inode().
          - Merge mft.c::ntfs_mft_readpage() and aops.c::ntfs_index_readpage()
            creating aops.c::ntfs_mst_readpage(), improving the handling of
            holes and overflow in the process and implementing the correct
            equivalent of ntfs_file_get_block() in ntfs_mst_readpage() itself.
            I am aiming for correctness at the moment. Modularisation can come
            later.
          - Rename aops.c::end_buffer_read_index_async() to
            end_buffer_read_mst_async() and optimize the overflow checking and
            handling.
          - Use the host of the mftbmp address space mapping to hold the ntfs
            volume. This is needed so the async i/o completion handler can
            retrieve a pointer to the volume. Hopefully this will not cause
            problems elsewhere in the kernel... Otherwise will need to use a
            fake inode.
          - Complete implementation of proper handling of allocated_size vs
            initialized_size vs data_size (i.e. i_size) in whole driver.
            Basically aops.c is now completely rewritten.
          - Change NTFS driver name to just NTFS and set version number to 2.0.0
            to make a clear distinction from the old driver which is still on
            version 1.1.22.
  
  tng-0.0.8 - 08/03/2002 - Now using BitKeeper, http://linux-ntfs.bkbits.net/
  
          - Replace bdevname(sb->s_dev) with sb->s_id.
          - Remove now superfluous new-line characters in all callers of
            ntfs_debug().
          - Apply kludge in ntfs_read_inode(), setting i_nlink to 1 for
            directories. Without this the "find" utility gets very upset which is
            fair enough as Linux/Unix do not support directory hard links.
          - Further runlist merging work. (Richard Russon)
          - Backwards compatibility for gcc-2.95. (Richard Russon)
          - Update to kernel 2.5.5-pre1 and rediff the now tiny patch.
          - Convert to new filesystem declaration using ->ntfs_get_sb() and
            replacing ntfs_read_super() with ntfs_fill_super().
          - Set s_maxbytes to MAX_LFS_FILESIZE to avoid page cache page index
            overflow on 32-bit architectures.
          - Cleanup upcase loading code to use ntfs_(un)map_page().
          - Disable/reenable preemtion in critical sections of compession engine.
          - Replace device size determination in ntfs_fill_super() with
            sb->s_bdev->bd_inode->i_size (in bytes) and remove now superfluous
            function super.c::get_nr_blocks().
          - Implement a mount time option (show_inodes) allowing choice of which
            types of inode names readdir() returns and modify ntfs_filldir()
            accordingly. There are several parameters to show_inodes:
                  system: system files
                  win32:  long file names (including POSIX file names) [DEFAULT]
                  long:   same as win32
                  dos:    short file names only (excluding POSIX file names)
                  short:  same as dos
                  posix:  same as both win32 and dos
                  all:    all file names
            Note that the options are additive, i.e. specifying:
                  -o show_inodes=system,show_inodes=win32,show_inodes=dos
            is the same as specifying:
                  -o show_inodes=all
            Note that the "posix" and "all" options will show all directory
            names, BUT the link count on each directory inode entry is set to 1,
            due to Linux not supporting directory hard links. This may well
            confuse some userspace applications, since the directory names will
            have the same inode numbers. Thus it is NOT advisable to use the
            "posix" or "all" options. We provide them only for completeness sake.
          - Add copies of allocated_size, initialized_size, and compressed_size to
            the ntfs inode structure and set them up in
            inode.c::ntfs_read_inode(). These reflect the unnamed data attribute
            for files and the index allocation attribute for directories.
          - Add copies of allocated_size and initialized_size to ntfs inode for
            $BITMAP attribute of large directories and set them up in
            inode.c::ntfs_read_inode().
          - Add copies of allocated_size and initialized_size to ntfs volume for
            $BITMAP attribute of $MFT and set them up in
            super.c::load_system_files().
          - Parse deprecated ntfs driver options (iocharset, show_sys_files,
            posix, and utf8) and tell user what the new options to use are. Note
            we still do support them but they will be removed with kernel 2.7.x.
          - Change all occurences of integer long long printf formatting to hex
            as printk() will not support long long integer format if/when the
            div64 patch goes into the kernel.
          - Make slab caches have stable names and change the names to what they
            were intended to be. These changes are required/made possible by the
            new slab cache name handling which removes the length limitation by
            requiring the caller of kmem_cache_create() to supply a stable name
            which is then referenced but not copied.
          - Rename run_list structure to run_list_element and create a new
            run_list structure containing a pointer to a run_list_element
            structure and a read/write semaphore. Adapt all users of runlists
            to new scheme and take and release the lock as needed. This fixes a
            nasty race as the run_list changes even when inodes are locked for
            reading and even when the inode isn't locked at all, so we really
            needed the serialization. We use a semaphore rather than a spinlock
            as memory allocations can sleep and doing everything GFP_ATOMIC
            would be silly.
          - Cleanup read_inode() removing all code checking for lowest_vcn != 0.
            This can never happen due to the nature of lookup_attr() and how we
            support attribute lists. If it did happen it would imply the inode
            being corrupt.
          - Check for lowest_vcn != 0 in ntfs_read_inode() and mark the inode as
            bad if found.
          - Update to 2.5.6-pre2 changes in struct address_space.
          - Use parent_ino() when accessing d_parent inode number in dir.c.
          - Import Sourceforge CVS repository into BitKeeper repository:
                  http://linux-ntfs.bkbits.net/ntfs-tng-2.5
          - Update fs/Makefile, fs/Config.help, fs/Config.in, and
            Documentation/filesystems/ntfs.txt for NTFS TNG.
          - Create kernel configuration option controlling whether debugging
            is enabled or not.
          - Add the required export of end_buffer_io_sync() from the patches
            directory to the kernel code.
          - Update inode.c::ntfs_show_options() with show_inodes mount option.
          - Update errors mount option.
  
  tng-0.0.7 - 13/02/2002 - The driver is now feature complete for read-only!
  
          - Cleanup mft.c and it's debug/error output in particular. Fix a minor
            bug in mapping of extent inodes. Update all the comments to fit all
            the recent code changes.
          - Modify vcn_to_lcn() to cope with entirely unmapped runlists.
          - Cleanups in compress.c, mostly comments and folding help.
          - Implement attrib.c::map_run_list() as a generic helper.
          - Make compress.c::ntfs_file_read_compressed_block() use map_run_list()
            thus making code shorter and enabling attribute list support.
          - Cleanup incorrect use of [su]64 with %L printf format specifier in
            all source files. Type casts to [unsigned] long long added to correct
            the mismatches (important for architectures which have long long not
            being 64 bits).
          - Merge async io completion handlers for directory indexes and $MFT
            data into one by setting the index_block_size{_bits} of the ntfs
            inode for $MFT to the mft_record_size{_bits} of the ntfs_volume.
          - Cleanup aops.c, update comments.
          - Make ntfs_file_get_block() use map_run_list() so all files now
            support attribute lists.
          - Make ntfs_dir_readpage() almost verbatim copy of
            block_read_full_page() by using ntfs_file_get_block() with only real
            difference being the use of our own async io completion handler
            rather than the default one, thus reducing the amount of code and
            automatically enabling attribute list support for directory indices.
          - Fix bug in load_attribute_list() - forgot to call brelse in error
            code path.
          - Change parameters to find_attr() and lookup_attr(). We no longer
            pass in the upcase table and its length. These can be gotten from
            ctx->ntfs_ino->vol->upcase{_len}. Update all callers.
          - Cleanups in attrib.c.
          - Implement merging of runlists, attrib.c::merge_run_lists() and its
            helpers. (Richard Russon)
          - Attribute lists part 2, attribute extents and multi part runlists:
            enable proper support for LCN_RL_NOT_MAPPED and automatic mapping of
            further runlist parts via attrib.c::map_run_list().
          - Tiny endianness bug fix in decompress_mapping_pairs().
  
  tng-0.0.6 - Encrypted directories, bug fixes, cleanups, debugging enhancements.
  
          - Enable encrypted directories. (Their index root is marked encrypted
            to indicate that new files in that directory should be created
            encrypted.)
          - Fix bug in NInoBmpNonResident() macro. (Cut and paste error.)
          - Enable $Extend system directory. Most (if not all) extended system
            files do not have unnamed data attributes so ntfs_read_inode() had to
            special case them but that is ok, as the special casing recovery
            happens inside an error code path so there is zero slow down in the
            normal fast path. The special casing is done by introducing a new
            function inode.c::ntfs_is_extended_system_file() which checks if any
            of the hard links in the inode point to $Extend as being their parent
            directory and if they do we assume this is an extended system file.
          - Create a sysctl/proc interface to allow {dis,en}abling of debug output
            when compiled with -DDEBUG. Default is debug messages to be disabled.
            To enable them, one writes a non-zero value to /proc/sys/fs/ntfs-debug
            (if /proc is enabled) or uses sysctl(2) to effect the same (if sysctl
            interface is enabled). Inspired by old ntfs driver.
          - Add debug_msgs insmod/kernel boot parameter to set whether debug
            messages are {dis,en}abled. This is useful to enable debug messages
            during ntfs initialization and is the only way to activate debugging
            when the sysctl interface is not enabled.
          - Cleanup debug output in various places.
          - Remove all dollar signs ($) from the source (except comments) to
            enable compilation on architectures whose gcc compiler does not
            support dollar signs in the names of variables/constants. Attribute
            types now start with AT_ instead of $ and $I30 is now just I30.
          - Cleanup ntfs_lookup() and add consistency check of sequence numbers.
          - Load complete runlist for $MFT/$BITMAP during mount and cleanup
            access functions. This means we now cope with $MFT/$BITMAP being
            spread accross several mft records.
          - Disable modification of mft_zone_multiplier on remount. We can always
            reenable this later on if we really want to, but we will need to make
            sure we readjust the mft_zone size / layout accordingly.
  
  tng-0.0.5 - Modernize for 2.5.x and further in line-ing with Al Viro's comments.
  
          - Use sb_set_blocksize() instead of set_blocksize() and verify the
            return value.
          - Use sb_bread() instead of bread() throughout.
          - Add index_vcn_size{_bits} to ntfs_inode structure to store the size
            of a directory index block vcn. Apply resulting simplifications in
            dir.c everywhere.
          - Fix a small bug somewhere (but forgot what it was).
          - Change ntfs_{debug,error,warning} to enable gcc to do type checking
            on the printf-format parameter list and fix bugs reported by gcc
            as a result. (Richard Russon)
          - Move inode allocation strategy to Al's new stuff but maintain the
            divorce of ntfs_inode from struct inode. To achieve this we have two
            separate slab caches, one for big ntfs inodes containing a struct
            inode and pure ntfs inodes and at the same time fix some faulty
            error code paths in ntfs_read_inode().
          - Show mount options in proc (inode.c::ntfs_show_options()).
  
  tng-0.0.4 - Big changes, getting in line with Al Viro's comments.
  
          - Modified (un)map_mft_record functions to be common for read and write
            case. To specify which is which, added extra parameter at front of
            parameter list. Pass either READ or WRITE to this, each has the
            obvious meaning.
          - General cleanups to allow for easier folding in vi.
          - attrib.c::decompress_mapping_pairs() now accepts the old runlist
            argument, and invokes attrib.c::merge_run_lists() to merge the old
            and the new runlists.
          - Removed attrib.c::find_first_attr().
          - Implemented loading of attribute list and complete runlist for $MFT.
            This means we now cope with $MFT being spread across several mft
            records.
          - Adapt to 2.5.2-pre9 and the changed create_empty_buffers() syntax.
          - Adapt major/minor/kdev_t/[bk]devname stuff to new 2.5.x kernels.
          - Make ntfs_volume be allocated via kmalloc() instead of using a slab
            cache. There are too little ntfs_volume structures at any one time
            to justify a private slab cache.
          - Fix bogus kmap() use in async io completion. Now use kmap_atomic().
            Use KM_BIO_IRQ on advice from IRC/kernel...
          - Use ntfs_map_page() in map_mft_record() and create ->readpage method
            for reading $MFT (ntfs_mft_readpage). In the process create dedicated
            address space operations (ntfs_mft_aops) for $MFT inode mapping. Also
            removed the now superfluous exports from the kernel core patch.
          - Fix a bug where kfree() was used instead of ntfs_free().
          - Change map_mft_record() to take ntfs_inode as argument instead of
            vfs inode. Dito for unmap_mft_record(). Adapt all callers.
          - Add pointer to ntfs_volume to ntfs_inode.
          - Add mft record number and sequence number to ntfs_inode. Stop using
            i_ino and i_generation for in-driver purposes.
          - Implement attrib.c::merge_run_lists(). (Richard Russon)
          - Remove use of proper inodes by extent inodes. Move i_ino and
            i_generation to ntfs_inode to do this. Apply simplifications that
            result and remove iget_no_wait(), etc.
          - Pass ntfs_inode everywhere in the driver (used to be struct inode).
          - Add reference counting in ntfs_inode for the ntfs inode itself and
            for the mapped mft record.
          - Extend mft record mapping so we can (un)map extent mft records (new
            functions (un)map_extent_mft_record), and so mappings are reference
            counted and don't have to happen twice if already mapped - just ref
            count increases.
          - Add -o iocharset as alias to -o nls for backwards compatibility.
          - The latest core patch is now tiny. In fact just a single additional
            export is necessary over the base kernel.
  
  tng-0.0.3 - Cleanups, enhancements, bug fixes.
  
          - Work on attrib.c::decompress_mapping_pairs() to detect base extents
            and setup the runlist appropriately using knowledge provided by the
            sizes in the base attribute record.
          - Balance the get_/put_attr_search_ctx() calls so we don't leak memory
            any more.
          - Introduce ntfs_malloc_nofs() and ntfs_free() to allocate/free a single
            page or use vmalloc depending on the amount of memory requested.
          - Cleanup error output. The __FUNCTION__ "(): " is now added
            automatically. Introduced a new header file debug.h to support this
            and also moved ntfs_debug() function into it.
          - Make reading of compressed files more intelligent and especially get
            rid of the vmalloc_nofs() from readpage(). This now uses per CPU
            buffers (allocated at first mount with cluster size <= 4kiB and
            deallocated on last umount with cluster size <= 4kiB), and
            asynchronous io for the compressed data using a list of buffer heads.
            Er, we use synchronous io as async io only works on whole pages
            covered by buffers and not on individual buffer heads...
          - Bug fix for reading compressed files with sparse compression blocks.
  
  tng-0.0.2 - Now handles larger/fragmented/compressed volumes/files/dirs.
  
          - Fixed handling of directories when cluster size exceeds index block
            size.
          - Hide DOS only name space directory entries from readdir() but allow
            them in lookup(). This should fix the problem that Linux doesn't
            support directory hard links, while still allowing access to entries
            via their short file name. This also has the benefit of mimicking
            what Windows users are used to, so it is the ideal solution.
          - Implemented sync_page everywhere so no more hangs in D state when
            waiting for a page.
          - Stop using bforget() in favour of brelse().
          - Stop locking buffers unnecessarily.
          - Implemented compressed files (inode->mapping contains uncompressed
            data, raw compressed data is currently bread() into a vmalloc()ed
            memory buffer).
          - Enable compressed directories. (Their index root is marked compressed
            to indicate that new files in that directory should be created
            compressed.)
          - Use vsnprintf rather than vsprintf in the ntfs_error and ntfs_warning
            functions. (Thanks to Will Dyson for pointing this out.)
          - Moved the ntfs_inode and ntfs_volume (the former ntfs_inode_info and
            ntfs_sb_info) out of the common inode and super_block structures and
            started using the generic_ip and generic_sbp pointers instead. This
            makes ntfs entirely private with respect to the kernel tree.
          - Detect compiler version and abort with error message if gcc less than
            2.96 is used.
          - Fix bug in name comparison function in unistr.c.
          - Implement attribute lists part 1, the infrastructure: search contexts
            and operations, find_external_attr(), lookup_attr()) and make the
            code use the infrastructure.
          - Fix stupid buffer overflow bug that became apparent on larger run
            list containing attributes.
          - Fix bugs in readdir() that became apparent on larger directories.
  
          The driver is now really useful and survives the test
                  find . -type f -exec md5sum "{}" \;
          without any error messages on a over 1GiB sized partition with >16k
          files on it, including compressed files and directories and many files
          and directories with attribute lists.
  
  tng-0.0.1 - The first useful version.
  
          - Added ntfs_lookup().
          - Added default upcase generation and handling.
          - Added compile options to be shown on module init.
          - Many bug fixes that were "hidden" before.
          - Update to latest kernel.
          - Added ntfs_readdir().
          - Added file operations for mmap(), read(), open() and llseek(). We just
            use the generic ones. The whole point of going through implementing
            readpage() methods and where possible get_block() call backs is that
            this allows us to make use of the generic high level methods provided
            by the kernel.
  
          The driver is now actually useful! Yey. (-: It undoubtedly has got bugs
          though and it doesn't implement accesssing compressed files yet. Also,
          accessing files with attribute list attributes is not implemented yet
          either. But for small or simple filesystems it should work and allow
          you to list directories, use stat on directory entries and the file
          system, open, read, mmap and llseek around in files. A big mile stone
          has been reached!
  
  tng-0.0.0 - Initial version tag.
  
          Initial driver implementation. The driver can mount and umount simple
          NTFS filesystems (i.e. ones without attribute lists in the system
          files). If the mount fails there might be problems in the error handling
          code paths, so be warned. Otherwise it seems to be loading the system
          files nicely and the mft record read mapping/unmapping seems to be
          working nicely, too. Proof of inode metadata in the page cache and non-
          resident file unnamed stream data in the page cache concepts is thus
          complete.

Cache object: efb1e58c1f6c7a09c3907edc7321db97