kernel/linux.git/drivers/md/md-linear.h, branch v6.6.133

md/raid1: Replace zero-length array with flexible-array

2020-05-13T19:02:23+00:00

The current codebase makes use of the zero-length array language extension to the C90 standard, but the preferred mechanism to declare variable-length types such as these ones is a flexible array member[1][2], introduced in C99: struct foo { int stuff; struct boo array[]; }; By making use of the mechanism above, we will get a compiler warning in case the flexible array does not occur last in the structure, which will help us prevent some kind of undefined behavior bugs from being inadvertently introduced[3] to the codebase from now on. Also, notice that, dynamic memory allocations won't be affected by this change: "Flexible array members have incomplete type, and so the sizeof operator may not be applied. As a quirk of the original implementation of zero-length arrays, sizeof evaluates to zero."[1] sizeof(flexible-array-member) triggers a warning because flexible array members have incomplete type[1]. There are some instances of code in which the sizeof operator is being incorrectly/erroneously applied to zero-length arrays and the result is zero. Such instances may be hiding some bugs. So, this work (flexible-array member conversions) will also help to get completely rid of those sorts of issues. This issue was found with the help of Coccinelle. [1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html [2] https://github.com/KSPP/linux/issues/21 [3] commit 76497732932f ("cxgb3/l2t: Fix undefined behaviour") Signed-off-by: Gustavo A. R. Silva Signed-off-by: Song Liu

Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/shli/md

2017-11-15T00:07:26+00:00

Pull MD update from Shaohua Li: "This update mostly includes bug fixes: - md-cluster now supports raid10 from Guoqing - raid5 PPL fixes from Artur - badblock regression fix from Bo - suspend hang related fixes from Neil - raid5 reshape fixes from Neil - raid1 freeze deadlock fix from Nate - memleak fixes from Zdenek - bitmap related fixes from Me and Tao - other fixes and cleanups" * 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/shli/md: (33 commits) md: free unused memory after bitmap resize md: release allocated bitset sync_set md/bitmap: clear BITMAP_WRITE_ERROR bit before writing it to sb md: be cautious about using ->curr_resync_completed for ->recovery_offset badblocks: fix wrong return value in badblocks_set if badblocks are disabled md: don't check MD_SB_CHANGE_CLEAN in md_allow_write md-cluster: update document for raid10 md: remove redundant variable q raid1: remove obsolete code in raid1_write_request md-cluster: Use a small window for raid10 resync md-cluster: Suspend writes in RAID10 if within range md-cluster/raid10: set "do_balance = 0" if area is resyncing md: use lockdep_assert_held raid1: prevent freeze_array/wait_all_barriers deadlock md: use TASK_IDLE instead of blocking signals md: remove special meaning of ->quiesce(.., 2) md: allow metadata update while suspending. md: use mddev_suspend/resume instead of ->quiesce() md: move suspend_hi/lo handling into core md code md: don't call bitmap_create() while array is quiesced. ...

md: rename some drivers/md/ files to have an "md-" prefix

2017-10-17T02:06:36+00:00

Motivated by the desire to illiminate the imprecise nature of DM-specific patches being unnecessarily sent to both the MD maintainer and mailing-list. Which is born out of the fact that DM files also reside in drivers/md/ Now all MD-specific files in drivers/md/ start with either "raid" or "md-" and the MAINTAINERS file has been updated accordingly. Shaohua: don't change module name Signed-off-by: Mike Snitzer Signed-off-by: Shaohua Li