From: Patrick Farrell <p...@cray.com> The lli_trunc_sem is taken in 'read' mode in both ll_page_mkwrite and vvp_io_fault_start. This can lead to a deadlock with another thread which asks for the semaphore in write mode between thse two read calls.
Since all users of lli_trunc_sem are in the vvp layer, we can satisfy the requirement to exclude truncate by taking the semaphore only in vvp_io_fault_start. Signed-off-by: Patrick Farrell <p...@cray.com> Reviewed-on: http://review.whamcloud.com/19315 Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-7981 Reviewed-by: Jinshan Xiong <jinshan.xi...@intel.com> Reviewed-by: Andriy Skulysh <andriy.skul...@seagate.com> Signed-off-by: Oleg Drokin <gr...@linuxhacker.ru> --- drivers/staging/lustre/lustre/llite/llite_mmap.c | 7 ------- 1 file changed, 7 deletions(-) diff --git a/drivers/staging/lustre/lustre/llite/llite_mmap.c b/drivers/staging/lustre/lustre/llite/llite_mmap.c index fb1c3b6..66ee5db 100644 --- a/drivers/staging/lustre/lustre/llite/llite_mmap.c +++ b/drivers/staging/lustre/lustre/llite/llite_mmap.c @@ -196,18 +196,11 @@ static int ll_page_mkwrite0(struct vm_area_struct *vma, struct page *vmpage, set = cfs_block_sigsinv(sigmask(SIGKILL) | sigmask(SIGTERM)); - /* we grab lli_trunc_sem to exclude truncate case. - * Otherwise, we could add dirty pages into osc cache - * while truncate is on-going. - */ inode = vvp_object_inode(io->ci_obj); lli = ll_i2info(inode); - down_read(&lli->lli_trunc_sem); result = cl_io_loop(env, io); - up_read(&lli->lli_trunc_sem); - cfs_restore_sigs(set); if (result == 0) { -- 2.7.4
