kernel/linux.git/drivers/block/drbd/drbd_nl.c, branch linux-4.16.y

drbd: rename "usermode_helper" to "drbd_usermode_helper"

2017-08-29T21:34:46+00:00

Nothing like having a very generic global variable in a tiny driver subsystem to make a mess of the global namespace... Note, there are many other "generic" named global variables in the drbd subsystem, someone should fix those up one day before they hit a linking error. Signed-off-by: Philipp Reisner Signed-off-by: Lars Ellenberg Signed-off-by: Jens Axboe

drbd: fix potential deadlock when trying to detach during handshake

2017-08-29T21:34:45+00:00

When requesting a detach, we first suspend IO, and also inhibit meta-data IO by means of drbd_md_get_buffer(), because we don't want to "fail" the disk while there is IO in-flight: the transition into D_FAILED for detach purposes may get misinterpreted as actual IO error in a confused endio function. We wrap it all into wait_event(), to retry in case the drbd_req_state() returns SS_IN_TRANSIENT_STATE, as it does for example during an ongoing connection handshake. In that example, the receiver thread may need to grab drbd_md_get_buffer() during the handshake to make progress. To avoid potential deadlock with detach, detach needs to grab and release the meta data buffer inside of that wait_event retry loop. To avoid lock inversion between mutex_lock(&device->state_mutex) and drbd_md_get_buffer(device), introduce a new enum chg_state_flag CS_INHIBIT_MD_IO, and move the call to drbd_md_get_buffer() inside the state_mutex grabbed in drbd_req_state(). Signed-off-by: Philipp Reisner Signed-off-by: Lars Ellenberg Signed-off-by: Jens Axboe

drbd: new disk-option disable-write-same

2017-08-29T21:34:44+00:00

Some backend devices claim to support write-same, but would fail actual write-same requests. Allow to set (or toggle) whether or not DRBD tries to support write-same. Signed-off-by: Philipp Reisner Signed-off-by: Lars Ellenberg Signed-off-by: Jens Axboe

drbd: Drop unnecessary static

2017-06-27T23:56:50+00:00

Drop static on a local variable, when the variable is initialized before any use, on every possible execution path through the function. The static has no benefit, and dropping it reduces the code size. The semantic patch that fixes this problem is as follows: (http://coccinelle.lip6.fr/) // @bad exists@ position p; identifier x; type T; @@ static T x@p; ... x = <+...x...+> @@ identifier x; expression e; type T; position p != bad.p; @@ -static T x@p; ... when != x when strict ?x = e; // The change in code size is indicates by the following output from the size command. before: text data bss dec hex filename 67299 2291 1056 70646 113f6 drivers/block/drbd/drbd_nl.o after: text data bss dec hex filename 67283 2291 1056 70630 113e6 drivers/block/drbd/drbd_nl.o Signed-off-by: Julia Lawall Signed-off-by: Roland Kammerer Signed-off-by: Jens Axboe

block: remove the discard_zeroes_data flag

2017-04-08T17:25:38+00:00

Now that we use the proper REQ_OP_WRITE_ZEROES operation everywhere we can kill this hack. Signed-off-by: Christoph Hellwig Reviewed-by: Martin K. Petersen Reviewed-by: Hannes Reinecke Signed-off-by: Jens Axboe

drbd: implement REQ_OP_WRITE_ZEROES

2017-04-08T17:25:38+00:00

It seems like DRBD assumes its on the wire TRIM request always zeroes data. Use that fact to implement REQ_OP_WRITE_ZEROES. Signed-off-by: Christoph Hellwig Reviewed-by: Hannes Reinecke Signed-off-by: Jens Axboe

block: Use pointer to backing_dev_info from request_queue

2017-02-02T15:20:48+00:00

We will want to have struct backing_dev_info allocated separately from struct request_queue. As the first step add pointer to backing_dev_info to request_queue and convert all users touching it. No functional changes in this patch. Reviewed-by: Christoph Hellwig Signed-off-by: Jan Kara Signed-off-by: Jens Axboe

drbd: code cleanups without semantic changes

2016-06-14T03:43:07+00:00

This contains various cosmetic fixes ranging from simple typos to const-ifying, and using booleans properly. Original commit messages from Fabian's patch set: drbd: debugfs: constify drbd_version_fops drbd: use seq_put instead of seq_print where possible drbd: include linux/uaccess.h instead of asm/uaccess.h drbd: use const char * const for drbd strings drbd: kerneldoc warning fix in w_e_end_data_req() drbd: use unsigned for one bit fields drbd: use bool for peer is_ states drbd: fix typo drbd: use | for bitmask combination drbd: use true/false for bool drbd: fix drbd_bm_init() comments drbd: introduce peer state union drbd: fix maybe_pull_ahead() locking comments drbd: use bool for growing drbd: remove redundant declarations drbd: replace if/BUG by BUG_ON Signed-off-by: Fabian Frederick Signed-off-by: Roland Kammerer Signed-off-by: Jens Axboe

drbd: introduce WRITE_SAME support

2016-06-14T03:43:07+00:00

We will support WRITE_SAME, if * all peers support WRITE_SAME (both in kernel and DRBD version), * all peer devices support WRITE_SAME * logical_block_size is identical on all peers. We may at some point introduce a fallback on the receiving side for devices/kernels that do not support WRITE_SAME, by open-coding a submit loop. But not yet. Signed-off-by: Philipp Reisner Signed-off-by: Lars Ellenberg Signed-off-by: Jens Axboe

drbd: discard_zeroes_if_aligned allows "thin" resync for discard_zeroes_data=0

2016-06-14T03:43:06+00:00

Even if discard_zeroes_data != 0, if discard_zeroes_if_aligned is set, we assume we can reliably zero-out/discard using the drbd_issue_peer_discard() helper. Signed-off-by: Philipp Reisner Signed-off-by: Lars Ellenberg Signed-off-by: Jens Axboe