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-rw-r--r--fs/gfs2/file.c64
1 files changed, 46 insertions, 18 deletions
diff --git a/fs/gfs2/file.c b/fs/gfs2/file.c
index 3b65f67bb38..aa3a4ddb834 100644
--- a/fs/gfs2/file.c
+++ b/fs/gfs2/file.c
@@ -366,8 +366,15 @@ static int gfs2_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
unsigned int data_blocks, ind_blocks, rblocks;
struct gfs2_holder gh;
struct gfs2_alloc *al;
+ loff_t size;
int ret;
+ /* Wait if fs is frozen. This is racy so we check again later on
+ * and retry if the fs has been frozen after the page lock has
+ * been acquired
+ */
+ vfs_check_frozen(inode->i_sb, SB_FREEZE_WRITE);
+
gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &gh);
ret = gfs2_glock_nq(&gh);
if (ret)
@@ -376,8 +383,15 @@ static int gfs2_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
set_bit(GLF_DIRTY, &ip->i_gl->gl_flags);
set_bit(GIF_SW_PAGED, &ip->i_flags);
- if (!gfs2_write_alloc_required(ip, pos, PAGE_CACHE_SIZE))
+ if (!gfs2_write_alloc_required(ip, pos, PAGE_CACHE_SIZE)) {
+ lock_page(page);
+ if (!PageUptodate(page) || page->mapping != inode->i_mapping) {
+ ret = -EAGAIN;
+ unlock_page(page);
+ }
goto out_unlock;
+ }
+
ret = -ENOMEM;
al = gfs2_alloc_get(ip);
if (al == NULL)
@@ -405,21 +419,29 @@ static int gfs2_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
lock_page(page);
ret = -EINVAL;
- last_index = ip->i_inode.i_size >> PAGE_CACHE_SHIFT;
- if (page->index > last_index)
- goto out_unlock_page;
+ size = i_size_read(inode);
+ last_index = (size - 1) >> PAGE_CACHE_SHIFT;
+ /* Check page index against inode size */
+ if (size == 0 || (page->index > last_index))
+ goto out_trans_end;
+
+ ret = -EAGAIN;
+ /* If truncated, we must retry the operation, we may have raced
+ * with the glock demotion code.
+ */
+ if (!PageUptodate(page) || page->mapping != inode->i_mapping)
+ goto out_trans_end;
+
+ /* Unstuff, if required, and allocate backing blocks for page */
ret = 0;
- if (!PageUptodate(page) || page->mapping != ip->i_inode.i_mapping)
- goto out_unlock_page;
- if (gfs2_is_stuffed(ip)) {
+ if (gfs2_is_stuffed(ip))
ret = gfs2_unstuff_dinode(ip, page);
- if (ret)
- goto out_unlock_page;
- }
- ret = gfs2_allocate_page_backing(page);
+ if (ret == 0)
+ ret = gfs2_allocate_page_backing(page);
-out_unlock_page:
- unlock_page(page);
+out_trans_end:
+ if (ret)
+ unlock_page(page);
gfs2_trans_end(sdp);
out_trans_fail:
gfs2_inplace_release(ip);
@@ -431,11 +453,17 @@ out_unlock:
gfs2_glock_dq(&gh);
out:
gfs2_holder_uninit(&gh);
- if (ret == -ENOMEM)
- ret = VM_FAULT_OOM;
- else if (ret)
- ret = VM_FAULT_SIGBUS;
- return ret;
+ if (ret == 0) {
+ set_page_dirty(page);
+ /* This check must be post dropping of transaction lock */
+ if (inode->i_sb->s_frozen == SB_UNFROZEN) {
+ wait_on_page_writeback(page);
+ } else {
+ ret = -EAGAIN;
+ unlock_page(page);
+ }
+ }
+ return block_page_mkwrite_return(ret);
}
static const struct vm_operations_struct gfs2_vm_ops = {