search for: write_locks

This version fixes three bugs in the 2nd patch of this series that caused kernel BUG when the system was under race. We weren't accounting with t_oustanding_credits correctly, and there were race conditions caused by the fact the I had overlooked the fact that __jbd2_log_wait_for_space() and jbd2_get_transaction() requires j_state_lock to be write locked. Theodore Ts'o (3): jbd2: Use

In preparation for parallel processing, we need to be sure that two threads belonging to the same connection cannot interleave their I/O except at message boundaries. Add a mutex around all reads and writes that must occur as a group (for now, there is no contention for either mutex). Signed-off-by: Eric Blake <eblake@redhat.com> --- src/connections.c | 27 +++++++++++++++++++++++++-- 1

Dave Sterba pointed out a sleeping while atomic bug while doing fsync. This is because I''m an idiot and didn''t realize that rwlock''s were spin locks, so we''ve been holding this thing while doing allocations and such which is not good. This patch fixes this by dropping the write lock before we do anything heavy and re-acquire it when it is done. We also need

I want to make my nbd forwarding plugin fully parallel - but to do that, I first need to make nbdkit itself fully parallel ;) With this series, I was finally able to demonstrate out-of-order responses when using qemu-io (which is great at sending back-to-back requests prior to waiting for responses) coupled with the nbd file plugin (which has a great feature of rdelay and wdelay, to make it

On Thu, Nov 16, 2017 at 09:26:54PM -0600, Eric Blake wrote: > In preparation for parallel processing, we need to be sure that > two threads belonging to the same connection cannot interleave > their I/O except at message boundaries. Add a mutex around > all reads and writes that must occur as a group (for now, there > is no contention for either mutex). > > Signed-off-by:

Hi to group! I am new to ROR! I am facing problems on sessions. First I created the one session variable. after that I created the other one. after moving to three pages the session was destroyed automatically. What is the reason please help me! Thnaks and Regards, -Kumar Varma -- Posted via http://www.ruby-forum.com/.

With this, I am finally able to get the nbd plugin to do out-of-order responses to the client. Once this series goes in, we should be ready for Rich to cut a release. Eric Blake (4): nbd: Split reading into separate thread nbd: Protect writes with mutex nbd: Enable parallel handling tests: Test parallel nbd behavior plugins/nbd/nbd.c | 217

This is about the simplest implementation of NBD Structured Replies (SR) that we can do right now. It accepts NBD_OPT_STRUCTURED_REPLIES when negotiated by the client, but only sends back the simplest possible SR when required to by NBD_CMD_READ. The rest of the time it will send back simple replies as before. We do not modify the plugin API so plugins are unable to send complex SRs. Also we

Diff against libnbd’s copy of this file, and change this one until it matches. --- common/protocol/nbd-protocol.h | 76 +++++++++++++++++----------- server/protocol-handshake-newstyle.c | 26 +++++----- server/protocol-handshake-oldstyle.c | 4 +- server/protocol.c | 25 ++++----- tests/test-layers.c | 14 ++--- 5 files changed, 81 insertions(+), 64

Clang warns: kernel/resource.c:1281:53: warning: operator '?:' has lower precedence than '|'; '|' will be evaluated first [-Wbitwise-conditional-parentheses] new_res = alloc_resource(GFP_KERNEL | alloc_nofail ? __GFP_NOFAIL : 0); ~~~~~~~~~~~~~~~~~~~~~~~~~ ^ kernel/resource.c:1281:53: note: place parentheses around the '|'

Now that cleanup.h is in common code, we can use it in our plugins where it makes sense. Many uses of pthread_mutex_unlock() are not function-wide, and over small enough snippets of code as to be easier to read when left as-is; but when the scope is indeed function-wide or across multiple exit paths, it is nicer to use the macro for automatic unlock. Signed-off-by: Eric Blake

On 3/8/19 4:04 AM, Richard W.M. Jones wrote: > This is about the simplest implementation of NBD Structured Replies > (SR) that we can do right now. > > It accepts NBD_OPT_STRUCTURED_REPLIES when negotiated by the client, > but only sends back the simplest possible SR when required to by > NBD_CMD_READ. The rest of the time it will send back simple replies > as before. We do

As part of migrating the FLUSH/FUA knob to the block layer, remove the journal flags and various conditionals in jbd2 that surround flush issue calls in favor of always issuing the flush. The block layer will handle gracefully the situation where a FLUSH or FUA request is issued to a device that doesn't support it. Signed-off-by: Darrick J. Wong <djwong at us.ibm.com> ---

To make Btrfs code more robust, several return value checks where memory allocation can fail are introduced. I use BUG_ON where I don''t know how to handle the error properly, which increases the number of using the notorious BUG_ON, though. Signed-off-by: Yoshinori Sano <yoshinori.sano@gmail.com> --- fs/btrfs/compression.c | 6 ++++++ fs/btrfs/extent-tree.c | 2 ++

Hi, I''m currently trying to set up a solution involving multiple servers using the same index over nfs. The problem is that from what I have seen, ferret doesn''t support multiple processes writing to the same index. Using a DRb service is not an option since this would create a single point of failure. I tried using Ferret::Store::FSDirectory to create a write lock on the the

Two weeks ago we switched all our IMAP users (around 25,000) from the Washington IMAP server to Dovecot, and since then there have been several occasions when reading new email just hangs, and duplicate emails appear. We are using the 'snarf' plugin to copy new email to the inbox, and it looks as though the problems are caused by file locking. We have been using the Washington IMAP server

ThreadSanitizer [1] pointed out that in the nbd plugin, nbd_close() can attempt close() in the main thread while the worker thread is still attempting to start a read(). Normally, if the read() loses the race, it will get a harmless EBADF that exits the worker thread (which is what we want, as we are closing the connection anyway); but if another connection happens to start in that window, we

I've posted some of these patches or ideas before; but now I'm confident enough with the series that it should be ready to push; at any rate, I can now run test-socket-activation in a tight loop without triggering any crashes or hangs. With this in place, I'm going back to work on making the nbd forwarder wort with the parallel thread model. Eric Blake (8): sockets: Use

qemu-nbd defaults to permitting only a single NBD client. Of course, you can run qemu-nbd -t to work around it, but other servers may have similar restrictions, at which point nbdkit's nbd plugin can provide the automatic fanout to multiple clients via a single server link. Note that the shared=true parameter makes the previously-added retry=N parameter more useful, as it is much easier to

This conversion should be feature compatible with the standalone nbd code. Note that the use of libnbd makes the binary for this particular plugin fall under an LGPLv2+ license rather than BSD; but the source code in nbd.c remains BSD. A lot of code simply disappears, now that I'm no longer directly utilizing the NBD protocol files but relying on libnbd. Coordination between threads from