+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.)
+