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-rw-r--r--fs/btrfs/inode.c15
-rw-r--r--fs/buffer.c16
-rw-r--r--fs/ceph/addr.c2
-rw-r--r--fs/ext4/inode.c15
-rw-r--r--fs/iomap/buffered-io.c18
-rw-r--r--fs/ubifs/file.c3
-rw-r--r--include/linux/pagemap.h28
7 files changed, 46 insertions, 51 deletions
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index e3c76645cad7..e2bac1c8f478 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -9014,13 +9014,11 @@ vm_fault_t btrfs_page_mkwrite(struct vm_fault *vmf)
ret = VM_FAULT_NOPAGE; /* make the VM retry the fault */
again:
lock_page(page);
- size = i_size_read(inode);
- if ((page->mapping != inode->i_mapping) ||
- (page_start >= size)) {
- /* page got truncated out from underneath us */
+ ret2 = page_mkwrite_check_truncate(page, inode);
+ if (ret2 < 0)
goto out_unlock;
- }
+ zero_start = ret2;
wait_on_page_writeback(page);
lock_extent_bits(io_tree, page_start, page_end, &cached_state);
@@ -9041,6 +9039,7 @@ again:
goto again;
}
+ size = i_size_read(inode);
if (page->index == ((size - 1) >> PAGE_SHIFT)) {
reserved_space = round_up(size - page_start,
fs_info->sectorsize);
@@ -9073,12 +9072,6 @@ again:
}
ret2 = 0;
- /* page is wholly or partially inside EOF */
- if (page_start + PAGE_SIZE > size)
- zero_start = offset_in_page(size);
- else
- zero_start = PAGE_SIZE;
-
if (zero_start != PAGE_SIZE) {
kaddr = kmap(page);
memset(kaddr + zero_start, 0, PAGE_SIZE - zero_start);
diff --git a/fs/buffer.c b/fs/buffer.c
index d8c7242426bb..53aabde57ca7 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -2499,23 +2499,13 @@ int block_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf,
struct page *page = vmf->page;
struct inode *inode = file_inode(vma->vm_file);
unsigned long end;
- loff_t size;
int ret;
lock_page(page);
- size = i_size_read(inode);
- if ((page->mapping != inode->i_mapping) ||
- (page_offset(page) > size)) {
- /* We overload EFAULT to mean page got truncated */
- ret = -EFAULT;
+ ret = page_mkwrite_check_truncate(page, inode);
+ if (ret < 0)
goto out_unlock;
- }
-
- /* page is wholly or partially inside EOF */
- if (((page->index + 1) << PAGE_SHIFT) > size)
- end = size & ~PAGE_MASK;
- else
- end = PAGE_SIZE;
+ end = ret;
ret = __block_write_begin(page, 0, end, get_block);
if (!ret)
diff --git a/fs/ceph/addr.c b/fs/ceph/addr.c
index 7ab616601141..ef958aa4adb4 100644
--- a/fs/ceph/addr.c
+++ b/fs/ceph/addr.c
@@ -1575,7 +1575,7 @@ static vm_fault_t ceph_page_mkwrite(struct vm_fault *vmf)
do {
lock_page(page);
- if ((off > size) || (page->mapping != inode->i_mapping)) {
+ if (page_mkwrite_check_truncate(page, inode) < 0) {
unlock_page(page);
ret = VM_FAULT_NOPAGE;
break;
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 629a25d999f0..3244803df30a 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -5871,13 +5871,11 @@ vm_fault_t ext4_page_mkwrite(struct vm_fault *vmf)
{
struct vm_area_struct *vma = vmf->vma;
struct page *page = vmf->page;
- loff_t size;
unsigned long len;
int err;
vm_fault_t ret;
struct file *file = vma->vm_file;
struct inode *inode = file_inode(file);
- struct address_space *mapping = inode->i_mapping;
handle_t *handle;
get_block_t *get_block;
int retries = 0;
@@ -5907,18 +5905,13 @@ vm_fault_t ext4_page_mkwrite(struct vm_fault *vmf)
}
lock_page(page);
- size = i_size_read(inode);
- /* Page got truncated from under us? */
- if (page->mapping != mapping || page_offset(page) > size) {
+ err = page_mkwrite_check_truncate(page, inode);
+ if (err < 0) {
unlock_page(page);
- ret = VM_FAULT_NOPAGE;
- goto out;
+ goto out_ret;
}
+ len = err;
- if (page->index == size >> PAGE_SHIFT)
- len = size & ~PAGE_MASK;
- else
- len = PAGE_SIZE;
/*
* Return if we have all the buffers mapped. This avoids the need to do
* journal_start/journal_stop which can block and take a long time
diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c
index 828444e14d09..7c84c4c027c4 100644
--- a/fs/iomap/buffered-io.c
+++ b/fs/iomap/buffered-io.c
@@ -1077,24 +1077,16 @@ vm_fault_t iomap_page_mkwrite(struct vm_fault *vmf, const struct iomap_ops *ops)
struct page *page = vmf->page;
struct inode *inode = file_inode(vmf->vma->vm_file);
unsigned long length;
- loff_t offset, size;
+ loff_t offset;
ssize_t ret;
lock_page(page);
- size = i_size_read(inode);
- offset = page_offset(page);
- if (page->mapping != inode->i_mapping || offset > size) {
- /* We overload EFAULT to mean page got truncated */
- ret = -EFAULT;
+ ret = page_mkwrite_check_truncate(page, inode);
+ if (ret < 0)
goto out_unlock;
- }
-
- /* page is wholly or partially inside EOF */
- if (offset > size - PAGE_SIZE)
- length = offset_in_page(size);
- else
- length = PAGE_SIZE;
+ length = ret;
+ offset = page_offset(page);
while (length > 0) {
ret = iomap_apply(inode, offset, length,
IOMAP_WRITE | IOMAP_FAULT, ops, page,
diff --git a/fs/ubifs/file.c b/fs/ubifs/file.c
index cd52585c8f4f..91f7a1f2db0d 100644
--- a/fs/ubifs/file.c
+++ b/fs/ubifs/file.c
@@ -1563,8 +1563,7 @@ static vm_fault_t ubifs_vm_page_mkwrite(struct vm_fault *vmf)
}
lock_page(page);
- if (unlikely(page->mapping != inode->i_mapping ||
- page_offset(page) > i_size_read(inode))) {
+ if (unlikely(page_mkwrite_check_truncate(page, inode) < 0)) {
/* Page got truncated out from underneath us */
goto sigbus;
}
diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h
index 37a4d9e32cd3..ccb14b6a16b5 100644
--- a/include/linux/pagemap.h
+++ b/include/linux/pagemap.h
@@ -636,4 +636,32 @@ static inline unsigned long dir_pages(struct inode *inode)
PAGE_SHIFT;
}
+/**
+ * page_mkwrite_check_truncate - check if page was truncated
+ * @page: the page to check
+ * @inode: the inode to check the page against
+ *
+ * Returns the number of bytes in the page up to EOF,
+ * or -EFAULT if the page was truncated.
+ */
+static inline int page_mkwrite_check_truncate(struct page *page,
+ struct inode *inode)
+{
+ loff_t size = i_size_read(inode);
+ pgoff_t index = size >> PAGE_SHIFT;
+ int offset = offset_in_page(size);
+
+ if (page->mapping != inode->i_mapping)
+ return -EFAULT;
+
+ /* page is wholly inside EOF */
+ if (page->index < index)
+ return PAGE_SIZE;
+ /* page is wholly past EOF */
+ if (page->index > index || !offset)
+ return -EFAULT;
+ /* page is partially inside EOF */
+ return offset;
+}
+
#endif /* _LINUX_PAGEMAP_H */