Currently we do write coalescing in a very inefficient manner: one pass in
generic_writepages() in order to lock the pages for writing, then one pass
in nfs_flush_mapping() and/or nfs_sync_mapping_wait() in order to gather
the locked pages for coalescing into RPC requests of size "wsize".
In fact, it turns out there is actually a deadlock possible here since we
only start I/O on the second pass. If the user signals the process while
we're in nfs_sync_mapping_wait(), for instance, then we may exit before
starting I/O on all the requests that have been queued up.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Do the coalescing of read requests into block sized requests at start of
I/O as we scan through the pages instead of going through a second pass.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Get rid of the inlined #ifdefs.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
If the writebacks are cancelled via nfs_cancel_dirty_list, or due to the
memory allocation failing in nfs_flush_one/nfs_flush_multi, then we must
ensure that the PG_writeback flag is cleared.
Also ensure that we actually own the PG_writeback flag whenever we
schedule a new writeback by making nfs_set_page_writeback() return the
value of test_set_page_writeback().
The PG_writeback page flag ends up replacing the functionality of the
PG_FLUSHING nfs_page flag, so we rip that out too.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This will ensure that we can call set_page_writeback() from within
nfs_writepage(), which is always called with the page lock set.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
We will want to allow nfs_writepage() to distinguish between pages that
have been marked as dirty by the VM, and those that have been marked as
dirty by nfs_updatepage().
In the former case, the entire page will want to be written out, and so any
requests that were pending need to be flushed out first.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
This should enable us to detect if we are crossing a mountpoint in the
case where the server is exporting "nohide" mounts.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
In the case of a call to truncate_inode_pages(), we should really try to
cancel any pending writes on the page.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Minor cleanup: inlined bit ops in nfs_page.h can be simpler.
Test plan:
Write-intensive workload against a server that requires COMMITs.
Signed-off-by: Chuck Lever <cel@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Basically copies the VFS's method for tracking writebacks and applies
it to the struct nfs_page.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
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!
Trond Myklebust