diff options
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/mmap_lock.h | 30 |
1 files changed, 28 insertions, 2 deletions
diff --git a/include/linux/mmap_lock.h b/include/linux/mmap_lock.h index e05da70dc0cb..d53f72dba7fe 100644 --- a/include/linux/mmap_lock.h +++ b/include/linux/mmap_lock.h @@ -195,7 +195,8 @@ static inline bool __is_vma_write_locked(struct vm_area_struct *vma, unsigned in return (vma->vm_lock_seq == *mm_lock_seq); } -void __vma_start_write(struct vm_area_struct *vma, unsigned int mm_lock_seq); +int __vma_start_write(struct vm_area_struct *vma, unsigned int mm_lock_seq, + int state); /* * Begin writing to a VMA. @@ -209,7 +210,30 @@ static inline void vma_start_write(struct vm_area_struct *vma) if (__is_vma_write_locked(vma, &mm_lock_seq)) return; - __vma_start_write(vma, mm_lock_seq); + __vma_start_write(vma, mm_lock_seq, TASK_UNINTERRUPTIBLE); +} + +/** + * vma_start_write_killable - Begin writing to a VMA. + * @vma: The VMA we are going to modify. + * + * Exclude concurrent readers under the per-VMA lock until the currently + * write-locked mmap_lock is dropped or downgraded. + * + * Context: May sleep while waiting for readers to drop the vma read lock. + * Caller must already hold the mmap_lock for write. + * + * Return: 0 for a successful acquisition. -EINTR if a fatal signal was + * received. + */ +static inline __must_check +int vma_start_write_killable(struct vm_area_struct *vma) +{ + unsigned int mm_lock_seq; + + if (__is_vma_write_locked(vma, &mm_lock_seq)) + return 0; + return __vma_start_write(vma, mm_lock_seq, TASK_KILLABLE); } static inline void vma_assert_write_locked(struct vm_area_struct *vma) @@ -283,6 +307,8 @@ static inline bool mmap_lock_speculate_retry(struct mm_struct *mm, unsigned int static inline void vma_lock_init(struct vm_area_struct *vma, bool reset_refcnt) {} static inline void vma_end_read(struct vm_area_struct *vma) {} static inline void vma_start_write(struct vm_area_struct *vma) {} +static inline __must_check +int vma_start_write_killable(struct vm_area_struct *vma) { return 0; } static inline void vma_assert_write_locked(struct vm_area_struct *vma) { mmap_assert_write_locked(vma->vm_mm); } static inline void vma_assert_attached(struct vm_area_struct *vma) {} |