linux/drivers/block/drbd, branch v4.14

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

2017-11-02T10:10:55Z

Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart Reviewed-by: Philippe Ombredanne Reviewed-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman

drbd: remove BIOSET_NEED_RESCUER flag from drbd_{md_,}io_bio_set

2017-08-30T14:10:02Z

Careful analysis shows that this flag is not needed. The RESCUER flag is only needed when a make_request_fn might: - allocate a bio from the bioset - submit it with generic_make_request() or similar - allocate another bio from the bioset The second allocation can block until the first bio is processed, so a rescuer is needed to ensure the first bio does get processed. With a rescuer it will only get processed when the make_request_fn completes. In drbd, allocations from drbd_io_bio_set happen from drbd_new_req() or w_restart_disk_io() which is only called to handle RESTART_FROZEN_DISK_IO. In former is called precisely once from the make_request_fn. The later is never called by within the make_request_fn. So there cannot be two allocations in the same call to the make_request_fn, so a rescuer is not needed. Allocations from drbd_md_io_bio_set are used for IO to the bitmap and the activity log. There are only accessed from worker threads and workqueues, never directly from make_request_fn. Again, the rescuer isn't needed. Signed-off-by: NeilBrown Signed-off-by: Philipp Reisner Signed-off-by: Jens Axboe

drbd: Fix allyesconfig build, fix recent commit

2017-08-30T14:09:29Z

Globals where prefixed with drbd_, that was missed in the in #ifdef'nd code when it is built-in. Signed-off-by: Philipp Reisner Fixes: 183ece30053f ("drbd: move global variables to drbd namespace and make some static") Signed-off-by: Jens Axboe

drbd: switch from kmalloc() to kmalloc_array()

2017-08-29T21:34:46Z

We had one call to kmalloc that actually allocates an array. Switch that one to the kmalloc_array() function. Signed-off-by: Philipp Reisner Signed-off-by: Lars Ellenberg Signed-off-by: Jens Axboe

drbd: abort drbd_start_resync if there is no connection

2017-08-29T21:34:46Z

This was found by a static analysis tool. While highly unlikely, be sure to return without dereferencing the NULL pointer. Reported-by: Shaobo Signed-off-by: Philipp Reisner Signed-off-by: Lars Ellenberg Signed-off-by: Jens Axboe

drbd: move global variables to drbd namespace and make some static

2017-08-29T21:34:46Z

This is a follow-up to Gregs complaints that drbd clutteres the global namespace. Some of DRBD's module parameters are only used within one compilation unit. Make these static. Signed-off-by: Roland Kammerer Signed-off-by: Philipp Reisner Signed-off-by: Lars Ellenberg Signed-off-by: Jens Axboe

drbd: rename "usermode_helper" to "drbd_usermode_helper"

2017-08-29T21:34:46Z

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 race between handshake and admin disconnect/down

2017-08-29T21:34:46Z

conn_try_disconnect() could potentialy hit the BUG_ON() in _conn_set_state() where it iterates over _drbd_set_state() and "asserts" via BUG_ON() that the latter was successful. If the STATE_SENT bit was not yet visible to conn_is_valid_transition() early in _conn_request_state(), but became visible before conn_set_state() later in that call path, we could hit the BUG_ON() after _drbd_set_state(), because it returned SS_IN_TRANSIENT_STATE. To avoid that race, we better protect set_bit(SENT_STATE) with the spinlock. 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

2017-08-29T21:34:45Z

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: A single dot should be put into a sequence.

2017-08-29T21:34:45Z

Thus use the corresponding function "seq_putc". This issue was detected by using the Coccinelle software. Signed-off-by: Markus Elfring Signed-off-by: Roland Kammerer Signed-off-by: Lars Ellenberg Signed-off-by: Jens Axboe