diff options
Diffstat (limited to 'mm/shmem.c')
| -rw-r--r-- | mm/shmem.c | 11 |
1 files changed, 9 insertions, 2 deletions
diff --git a/mm/shmem.c b/mm/shmem.c index 96fa79fb6ad3..5808fadd3944 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -83,6 +83,7 @@ enum sgp_type { SGP_READ, /* don't exceed i_size, don't allocate page */ SGP_CACHE, /* don't exceed i_size, may allocate page */ SGP_WRITE, /* may exceed i_size, may allocate page */ + SGP_NOPAGE, /* same as SGP_CACHE, return with page locked */ }; static int shmem_getpage(struct inode *inode, unsigned long idx, @@ -1289,8 +1290,10 @@ repeat: } done: if (*pagep != filepage) { - unlock_page(filepage); *pagep = filepage; + if (sgp != SGP_NOPAGE) + unlock_page(filepage); + } return 0; @@ -1310,13 +1313,15 @@ static struct page *shmem_nopage(struct vm_area_struct *vma, unsigned long idx; int error; + BUG_ON(!(vma->vm_flags & VM_CAN_INVALIDATE)); + idx = (address - vma->vm_start) >> PAGE_SHIFT; idx += vma->vm_pgoff; idx >>= PAGE_CACHE_SHIFT - PAGE_SHIFT; if (((loff_t) idx << PAGE_CACHE_SHIFT) >= i_size_read(inode)) return NOPAGE_SIGBUS; - error = shmem_getpage(inode, idx, &page, SGP_CACHE, type); + error = shmem_getpage(inode, idx, &page, SGP_NOPAGE, type); if (error) return (error == -ENOMEM)? NOPAGE_OOM: NOPAGE_SIGBUS; @@ -1414,6 +1419,7 @@ static int shmem_mmap(struct file *file, struct vm_area_struct *vma) { file_accessed(file); vma->vm_ops = &shmem_vm_ops; + vma->vm_flags |= VM_CAN_INVALIDATE; return 0; } @@ -2596,5 +2602,6 @@ int shmem_zero_setup(struct vm_area_struct *vma) fput(vma->vm_file); vma->vm_file = file; vma->vm_ops = &shmem_vm_ops; + vma->vm_flags |= VM_CAN_INVALIDATE; return 0; } |