diff options
| -rw-r--r-- | fs/gfs2/file.c | 64 |
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 = { |