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-rw-r--r--mm/shmem.c84
1 files changed, 20 insertions, 64 deletions
diff --git a/mm/shmem.c b/mm/shmem.c
index 96fa79fb6ad3..ad155c7745dc 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_FAULT, /* same as SGP_CACHE, return with page locked */
};
static int shmem_getpage(struct inode *inode, unsigned long idx,
@@ -1100,6 +1101,10 @@ static int shmem_getpage(struct inode *inode, unsigned long idx,
if (idx >= SHMEM_MAX_INDEX)
return -EFBIG;
+
+ if (type)
+ *type = 0;
+
/*
* Normally, filepage is NULL on entry, and either found
* uptodate immediately, or allocated and zeroed, or read
@@ -1133,9 +1138,9 @@ repeat:
if (!swappage) {
shmem_swp_unmap(entry);
/* here we actually do the io */
- if (type && *type == VM_FAULT_MINOR) {
+ if (type && !(*type & VM_FAULT_MAJOR)) {
__count_vm_event(PGMAJFAULT);
- *type = VM_FAULT_MAJOR;
+ *type |= VM_FAULT_MAJOR;
}
spin_unlock(&info->lock);
swappage = shmem_swapin(info, swap, idx);
@@ -1289,8 +1294,10 @@ repeat:
}
done:
if (*pagep != filepage) {
- unlock_page(filepage);
*pagep = filepage;
+ if (sgp != SGP_FAULT)
+ unlock_page(filepage);
+
}
return 0;
@@ -1302,72 +1309,21 @@ failed:
return error;
}
-static struct page *shmem_nopage(struct vm_area_struct *vma,
- unsigned long address, int *type)
+static int shmem_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
{
struct inode *inode = vma->vm_file->f_path.dentry->d_inode;
- struct page *page = NULL;
- unsigned long idx;
int error;
+ int ret;
- 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;
+ if (((loff_t)vmf->pgoff << PAGE_CACHE_SHIFT) >= i_size_read(inode))
+ return VM_FAULT_SIGBUS;
- error = shmem_getpage(inode, idx, &page, SGP_CACHE, type);
+ error = shmem_getpage(inode, vmf->pgoff, &vmf->page, SGP_FAULT, &ret);
if (error)
- return (error == -ENOMEM)? NOPAGE_OOM: NOPAGE_SIGBUS;
-
- mark_page_accessed(page);
- return page;
-}
-
-static int shmem_populate(struct vm_area_struct *vma,
- unsigned long addr, unsigned long len,
- pgprot_t prot, unsigned long pgoff, int nonblock)
-{
- struct inode *inode = vma->vm_file->f_path.dentry->d_inode;
- struct mm_struct *mm = vma->vm_mm;
- enum sgp_type sgp = nonblock? SGP_QUICK: SGP_CACHE;
- unsigned long size;
+ return ((error == -ENOMEM) ? VM_FAULT_OOM : VM_FAULT_SIGBUS);
- size = (i_size_read(inode) + PAGE_SIZE - 1) >> PAGE_SHIFT;
- if (pgoff >= size || pgoff + (len >> PAGE_SHIFT) > size)
- return -EINVAL;
-
- while ((long) len > 0) {
- struct page *page = NULL;
- int err;
- /*
- * Will need changing if PAGE_CACHE_SIZE != PAGE_SIZE
- */
- err = shmem_getpage(inode, pgoff, &page, sgp, NULL);
- if (err)
- return err;
- /* Page may still be null, but only if nonblock was set. */
- if (page) {
- mark_page_accessed(page);
- err = install_page(mm, vma, addr, page, prot);
- if (err) {
- page_cache_release(page);
- return err;
- }
- } else if (vma->vm_flags & VM_NONLINEAR) {
- /* No page was found just because we can't read it in
- * now (being here implies nonblock != 0), but the page
- * may exist, so set the PTE to fault it in later. */
- err = install_file_pte(mm, vma, addr, pgoff, prot);
- if (err)
- return err;
- }
-
- len -= PAGE_SIZE;
- addr += PAGE_SIZE;
- pgoff++;
- }
- return 0;
+ mark_page_accessed(vmf->page);
+ return ret | VM_FAULT_LOCKED;
}
#ifdef CONFIG_NUMA
@@ -1414,6 +1370,7 @@ 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_NONLINEAR;
return 0;
}
@@ -2459,8 +2416,7 @@ static const struct super_operations shmem_ops = {
};
static struct vm_operations_struct shmem_vm_ops = {
- .nopage = shmem_nopage,
- .populate = shmem_populate,
+ .fault = shmem_fault,
#ifdef CONFIG_NUMA
.set_policy = shmem_set_policy,
.get_policy = shmem_get_policy,