use lock guards for scope based resource management of mutex. This would make the code simpler and easier to maintain.
More details on lock guards can be found at https://lore.kernel.org/all/20230612093537.614161...@infradead.org/T/#u This shows the use of both guard and scoped_guard Signed-off-by: Shrikanth Hegde <sshe...@linux.ibm.com> --- arch/powerpc/platforms/book3s/vas-api.c | 32 ++++++++++--------------- 1 file changed, 13 insertions(+), 19 deletions(-) diff --git a/arch/powerpc/platforms/book3s/vas-api.c b/arch/powerpc/platforms/book3s/vas-api.c index 0b6365d85d11..d7462c16d828 100644 --- a/arch/powerpc/platforms/book3s/vas-api.c +++ b/arch/powerpc/platforms/book3s/vas-api.c @@ -425,23 +425,22 @@ static vm_fault_t vas_mmap_fault(struct vm_fault *vmf) return VM_FAULT_SIGBUS; } - mutex_lock(&txwin->task_ref.mmap_mutex); /* * The window may be inactive due to lost credit (Ex: core * removal with DLPAR). If the window is active again when * the credit is available, map the new paste address at the * window virtual address. */ - if (txwin->status == VAS_WIN_ACTIVE) { - paste_addr = cp_inst->coproc->vops->paste_addr(txwin); - if (paste_addr) { - fault = vmf_insert_pfn(vma, vma->vm_start, - (paste_addr >> PAGE_SHIFT)); - mutex_unlock(&txwin->task_ref.mmap_mutex); - return fault; + scoped_guard(mutex, &txwin->task_ref.mmap_mutex) { + if (txwin->status == VAS_WIN_ACTIVE) { + paste_addr = cp_inst->coproc->vops->paste_addr(txwin); + if (paste_addr) { + fault = vmf_insert_pfn(vma, vma->vm_start, + (paste_addr >> PAGE_SHIFT)); + return fault; + } } } - mutex_unlock(&txwin->task_ref.mmap_mutex); /* * Received this fault due to closing the actual window. @@ -494,9 +493,8 @@ static void vas_mmap_close(struct vm_area_struct *vma) return; } - mutex_lock(&txwin->task_ref.mmap_mutex); - txwin->task_ref.vma = NULL; - mutex_unlock(&txwin->task_ref.mmap_mutex); + scoped_guard(mutex, &txwin->task_ref.mmap_mutex) + txwin->task_ref.vma = NULL; } static const struct vm_operations_struct vas_vm_ops = { @@ -543,18 +541,16 @@ static int coproc_mmap(struct file *fp, struct vm_area_struct *vma) * close/open event and allows mmap() only when the window is * active. */ - mutex_lock(&txwin->task_ref.mmap_mutex); + guard(mutex)(&txwin->task_ref.mmap_mutex); if (txwin->status != VAS_WIN_ACTIVE) { pr_err("Window is not active\n"); - rc = -EACCES; - goto out; + return -EACCES; } paste_addr = cp_inst->coproc->vops->paste_addr(txwin); if (!paste_addr) { pr_err("Window paste address failed\n"); - rc = -EINVAL; - goto out; + return -EINVAL; } pfn = paste_addr >> PAGE_SHIFT; @@ -574,8 +570,6 @@ static int coproc_mmap(struct file *fp, struct vm_area_struct *vma) txwin->task_ref.vma = vma; vma->vm_ops = &vas_vm_ops; -out: - mutex_unlock(&txwin->task_ref.mmap_mutex); return rc; } -- 2.39.3
