- Enable the code for setting the NT4 compatibility flag when we start
making NTFS 1.2 specific modifications.
-2.1.23-WIP
+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() in fs/ntfs/attrib.c::ntfs_attr_set().
- - Use i_size_read() in fs/ntfs/logfile.c::ntfs_{check,empty}_logfile().
- - Use i_size_read() once and then use the cached value in
- fs/ntfs/lcnalloc.c::ntfs_cluster_alloc().
- - Use i_size_read() in fs/ntfs/file.c::ntfs_file_open().
+ - 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.
- - Use i_size_read() in fs/ntfs/compress.c at the start of the read and
- use the cached value afterwards. Cache the initialized_size in the
- same way and protect access to the two sizes using the size_lock.
- - Use i_size_read() in fs/ntfs/dir.c once and then use the cached
- value afterwards.
- - Use i_size_read() in fs/ntfs/super.c once and then use the cached
- value afterwards. Cache the initialized_size in the same way and
- protect access to the two sizes using the size_lock.
+ _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.
- - Use i_size_read() in fs/ntfs/inode.c once and then use the cached
- value afterwards when reading the size of the bitmap inode.
- - Use i_size_{read,write}() in fs/ntfs/{aops.c,mft.c} and protect
- access to the i_size and other size fields using the size_lock.
- 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
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 MOKREJŠ for the bug report.
2.1.22 - Many bug and race fixes and error handling improvements.
projects / linux-2.6 / blobdiff