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2005-10-11NTFS: The big ntfs write(2) rewrite has arrived. We now implement our ownAnton Altaparmakov
file operations ->write(), ->aio_write(), and ->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. Signed-off-by: Anton Altaparmakov <aia21@cantab.net>
2005-09-08NTFS: 2.1.24 release and some minor final fixes.Anton Altaparmakov
Signed-off-by: Anton Altaparmakov <aia21@cantab.net>
2005-06-26NTFS: Fix a nasty deadlock that appeared in recent kernels.Anton Altaparmakov
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. Signed-off-by: Anton Altaparmakov <aia21@cantab.net>
2005-06-25NTFS: Prepare for 2.1.23 release: Update documentation and bump version.Anton Altaparmakov
Signed-off-by: Anton Altaparmakov <aia21@cantab.net>
2005-05-05NTFS: - Add disable_sparse mount option together with a per volume sparseAnton Altaparmakov
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. Signed-off-by: Anton Altaparmakov <aia21@cantab.net>
2005-04-16Linux-2.6.12-rc2Linus Torvalds
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!