kernel.git/fs/gfs2, branch linux-2.6.37.y

mm: prevent concurrent unmap_mapping_range() on the same inode

2011-03-07T23:05:08Z

commit 2aa15890f3c191326678f1bd68af61ec6b8753ec upstream. Michael Leun reported that running parallel opens on a fuse filesystem can trigger a "kernel BUG at mm/truncate.c:475" Gurudas Pai reported the same bug on NFS. The reason is, unmap_mapping_range() is not prepared for more than one concurrent invocation per inode. For example: thread1: going through a big range, stops in the middle of a vma and stores the restart address in vm_truncate_count. thread2: comes in with a small (e.g. single page) unmap request on the same vma, somewhere before restart_address, finds that the vma was already unmapped up to the restart address and happily returns without doing anything. Another scenario would be two big unmap requests, both having to restart the unmapping and each one setting vm_truncate_count to its own value. This could go on forever without any of them being able to finish. Truncate and hole punching already serialize with i_mutex. Other callers of unmap_mapping_range() do not, and it's difficult to get i_mutex protection for all callers. In particular ->d_revalidate(), which calls invalidate_inode_pages2_range() in fuse, may be called with or without i_mutex. This patch adds a new mutex to 'struct address_space' to prevent running multiple concurrent unmap_mapping_range() on the same mapping. [ We'll hopefully get rid of all this with the upcoming mm preemptibility series by Peter Zijlstra, the "mm: Remove i_mmap_mutex lockbreak" patch in particular. But that is for 2.6.39 ] Signed-off-by: Miklos Szeredi Reported-by: Michael Leun Reported-by: Gurudas Pai Tested-by: Gurudas Pai Acked-by: Hugh Dickins Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

GFS2: Userland expects quota limit/warn/usage in 512b blocks

2010-11-19T11:20:29Z

Userland programs using the quotactl() syscall assume limit/warn/usage block counts in 512b basic blocks which were instead being read/written in fs blocksize in gfs2. With this patch, gfs2 correctly interacts with the syscall using 512b blocks. Signed-off-by: Abhi Das Reviewed-by: Christoph Hellwig Signed-off-by: Steven Whitehouse

GFS2: Fix inode deallocation race

2010-11-15T12:44:42Z

This area of the code has always been a bit delicate due to the subtleties of lock ordering. The problem is that for "normal" alloc/dealloc, we always grab the inode locks first and the rgrp lock later. In order to ensure no races in looking up the unlinked, but still allocated inodes, we need to hold the rgrp lock when we do the lookup, which means that we can't take the inode glock. The solution is to borrow the technique already used by NFS to solve what is essentially the same problem (given an inode number, look up the inode carefully, checking that it really is in the expected state). We cannot do that directly from the allocation code (lock ordering again) so we give the job to the pre-existing delete workqueue and carry on with the allocation as normal. If we find there is no space, we do a journal flush (required anyway if space from a deallocation is to be released) which should block against the pending deallocations, so we should always get the space back. Signed-off-by: Steven Whitehouse

locks: let the caller free file_lock on ->setlease failure

2010-10-31T13:35:15Z

The caller allocated it, the caller should free it. The only issue so far is that we could change the flp pointer even on an error return if the fl_change callback failed. But we can simply move the flp assignment after the fl_change invocation, as the callers don't care about the flp return value if the setlease call failed. Signed-off-by: Christoph Hellwig Signed-off-by: Linus Torvalds

locks: fix setlease methods to free passed-in lock

2010-10-31T01:08:15Z

We modified setlease to require the caller to allocate the new lease in the case of creating a new lease, but forgot to fix up the filesystem methods. Cc: Steven Whitehouse Cc: Steve French Cc: Trond Myklebust Signed-off-by: J. Bruce Fields Acked-by: Arnd Bergmann Signed-off-by: Linus Torvalds

convert gfs2

2010-10-29T08:17:16Z

Signed-off-by: Al Viro

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6

2010-10-27T00:58:44Z

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6: (52 commits) split invalidate_inodes() fs: skip I_FREEING inodes in writeback_sb_inodes fs: fold invalidate_list into invalidate_inodes fs: do not drop inode_lock in dispose_list fs: inode split IO and LRU lists fs: switch bdev inode bdi's correctly fs: fix buffer invalidation in invalidate_list fsnotify: use dget_parent smbfs: use dget_parent exportfs: use dget_parent fs: use RCU read side protection in d_validate fs: clean up dentry lru modification fs: split __shrink_dcache_sb fs: improve DCACHE_REFERENCED usage fs: use percpu counter for nr_dentry and nr_dentry_unused fs: simplify __d_free fs: take dcache_lock inside __d_path fs: do not assign default i_ino in new_inode fs: introduce a per-cpu last_ino allocator new helper: ihold() ...

writeback: remove nonblocking/encountered_congestion references

2010-10-26T23:52:05Z

This removes more dead code that was somehow missed by commit 0d99519efef (writeback: remove unused nonblocking and congestion checks). There are no behavior change except for the removal of two entries from one of the ext4 tracing interface. The nonblocking checks in ->writepages are no longer used because the flusher now prefer to block on get_request_wait() than to skip inodes on IO congestion. The latter will lead to more seeky IO. The nonblocking checks in ->writepage are no longer used because it's redundant with the WB_SYNC_NONE check. We no long set ->nonblocking in VM page out and page migration, because a) it's effectively redundant with WB_SYNC_NONE in current code b) it's old semantic of "Don't get stuck on request queues" is mis-behavior: that would skip some dirty inodes on congestion and page out others, which is unfair in terms of LRU age. Inspired by Christoph Hellwig. Thanks! Signed-off-by: Wu Fengguang Cc: Theodore Ts'o Cc: David Howells Cc: Sage Weil Cc: Steve French Cc: Chris Mason Cc: Jens Axboe Cc: Christoph Hellwig Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

new helper: ihold()

2010-10-26T01:26:11Z

Clones an existing reference to inode; caller must already hold one. Signed-off-by: Al Viro

gfs2: invalidate_inodes() is no-op there

2010-10-26T01:23:01Z

In fill_super() we hadn't MS_ACTIVE set yet, so there won't be any inodes with zero i_count sitting around. In put_super() we already have MS_ACTIVE removed *and* we had called invalidate_inodes() since then. So again there won't be any inodes with zero i_count... Signed-off-by: Al Viro