FROMLIST: f2fs: don't put dentry page in pagecache into highmem

Cherry-pick from origin/upstream-f2fs-stable-linux-4.4.y:
39ed8376d611 ("f2fs: don't put dentry page in pagecache into highmem")

Previous dentry page uses highmem, which will cause panic in platforms
using highmem (such as arm), since the address space of dentry pages
from highmem directly goes into the decryption path via the function
fscrypt_fname_disk_to_usr. But sg_init_one assumes the address is not
from highmem, and then cause panic since it doesn't call kmap_high but
kunmap_high is triggered at the end. To fix this problem in a simple
way, this patch avoids to put dentry page in pagecache into highmem.

Change-Id: I0c87dafb92fce72bf70403a15d28c73992c03203
Signed-off-by: Yunlong Song <yunlong.song@huawei.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
[Jaegeuk Kim: fix coding style]
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

7 files changed, 20 insertions, 58 deletions

diff --git a/fs/f2fs/dir.c b/fs/f2fs/dir.c
index bde445e4e690..560b707050ca 100644
--- a/fs/f2fs/dir.c
+++ b/fs/f2fs/dir.c
@@ -94,14 +94,12 @@ static struct f2fs_dir_entry *find_in_block(struct page *dentry_page,
 	struct f2fs_dir_entry *de;
 	struct f2fs_dentry_ptr d;
 
-	dentry_blk = (struct f2fs_dentry_block *)kmap(dentry_page);
+	dentry_blk = (struct f2fs_dentry_block *)page_address(dentry_page);
 
 	make_dentry_ptr_block(NULL, &d, dentry_blk);
 	de = find_target_dentry(fname, namehash, max_slots, &d);
 	if (de)
 		*res_page = dentry_page;
-	else
-		kunmap(dentry_page);
 
 	return de;
 }
@@ -287,7 +285,6 @@ ino_t f2fs_inode_by_name(struct inode *dir, const struct qstr *qstr,
 	de = f2fs_find_entry(dir, qstr, page);
 	if (de) {
 		res = le32_to_cpu(de->ino);
-		f2fs_dentry_kunmap(dir, *page);
 		f2fs_put_page(*page, 0);
 	}
 
@@ -302,7 +299,6 @@ void f2fs_set_link(struct inode *dir, struct f2fs_dir_entry *de,
 	f2fs_wait_on_page_writeback(page, type, true);
 	de->ino = cpu_to_le32(inode->i_ino);
 	set_de_type(de, inode->i_mode);
-	f2fs_dentry_kunmap(dir, page);
 	set_page_dirty(page);
 
 	dir->i_mtime = dir->i_ctime = current_time(dir);
@@ -350,13 +346,11 @@ static int make_empty_dir(struct inode *inode,
 	if (IS_ERR(dentry_page))
 		return PTR_ERR(dentry_page);
 
-	dentry_blk = kmap_atomic(dentry_page);
+	dentry_blk = page_address(dentry_page);
 
 	make_dentry_ptr_block(NULL, &d, dentry_blk);
 	do_make_empty_dir(inode, parent, &d);
 
-	kunmap_atomic(dentry_blk);
-
 	set_page_dirty(dentry_page);
 	f2fs_put_page(dentry_page, 1);
 	return 0;
@@ -547,13 +541,12 @@ start:
 		if (IS_ERR(dentry_page))
 			return PTR_ERR(dentry_page);
 
-		dentry_blk = kmap(dentry_page);
+		dentry_blk = page_address(dentry_page);
 		bit_pos = room_for_filename(&dentry_blk->dentry_bitmap,
 						slots, NR_DENTRY_IN_BLOCK);
 		if (bit_pos < NR_DENTRY_IN_BLOCK)
 			goto add_dentry;
 
-		kunmap(dentry_page);
 		f2fs_put_page(dentry_page, 1);
 	}
 
@@ -588,7 +581,6 @@ fail:
 	if (inode)
 		up_write(&F2FS_I(inode)->i_sem);
 
-	kunmap(dentry_page);
 	f2fs_put_page(dentry_page, 1);
 
 	return err;
@@ -642,7 +634,6 @@ int __f2fs_add_link(struct inode *dir, const struct qstr *name,
 		F2FS_I(dir)->task = NULL;
 	}
 	if (de) {
-		f2fs_dentry_kunmap(dir, page);
 		f2fs_put_page(page, 0);
 		err = -EEXIST;
 	} else if (IS_ERR(page)) {
@@ -730,7 +721,6 @@ void f2fs_delete_entry(struct f2fs_dir_entry *dentry, struct page *page,
 	bit_pos = find_next_bit_le(&dentry_blk->dentry_bitmap,
 			NR_DENTRY_IN_BLOCK,
 			0);
-	kunmap(page); /* kunmap - pair of f2fs_find_entry */
 	set_page_dirty(page);
 
 	dir->i_ctime = dir->i_mtime = current_time(dir);
@@ -775,7 +765,7 @@ bool f2fs_empty_dir(struct inode *dir)
 				return false;
 		}
 
-		dentry_blk = kmap_atomic(dentry_page);
+		dentry_blk = page_address(dentry_page);
 		if (bidx == 0)
 			bit_pos = 2;
 		else
@@ -783,7 +773,6 @@ bool f2fs_empty_dir(struct inode *dir)
 		bit_pos = find_next_bit_le(&dentry_blk->dentry_bitmap,
 						NR_DENTRY_IN_BLOCK,
 						bit_pos);
-		kunmap_atomic(dentry_blk);
 
 		f2fs_put_page(dentry_page, 1);
 
@@ -901,19 +890,17 @@ static int f2fs_readdir(struct file *file, struct dir_context *ctx)
 			}
 		}
 
-		dentry_blk = kmap(dentry_page);
+		dentry_blk = page_address(dentry_page);
 
 		make_dentry_ptr_block(inode, &d, dentry_blk);
 
 		err = f2fs_fill_dentries(ctx, &d,
 				n * NR_DENTRY_IN_BLOCK, &fstr);
 		if (err) {
-			kunmap(dentry_page);
 			f2fs_put_page(dentry_page, 1);
 			break;
 		}
 
-		kunmap(dentry_page);
 		f2fs_put_page(dentry_page, 1);
 	}
 out_free:
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index d2a6b688a622..34595ca42f68 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -2458,12 +2458,6 @@ static inline int f2fs_has_inline_dentry(struct inode *inode)
 	return is_inode_flag_set(inode, FI_INLINE_DENTRY);
 }
 
-static inline void f2fs_dentry_kunmap(struct inode *dir, struct page *page)
-{
-	if (!f2fs_has_inline_dentry(dir))
-		kunmap(page);
-}
-
 static inline int is_file(struct inode *inode, int type)
 {
 	return F2FS_I(inode)->i_advise & type;
diff --git a/fs/f2fs/inline.c b/fs/f2fs/inline.c
index 91d5d831be72..37ab2159506a 100644
--- a/fs/f2fs/inline.c
+++ b/fs/f2fs/inline.c
@@ -387,7 +387,7 @@ static int f2fs_move_inline_dirents(struct inode *dir, struct page *ipage,
 	f2fs_wait_on_page_writeback(page, DATA, true);
 	zero_user_segment(page, MAX_INLINE_DATA(dir), PAGE_SIZE);
 
-	dentry_blk = kmap_atomic(page);
+	dentry_blk = page_address(page);
 
 	make_dentry_ptr_inline(dir, &src, inline_dentry);
 	make_dentry_ptr_block(dir, &dst, dentry_blk);
@@ -404,7 +404,6 @@ static int f2fs_move_inline_dirents(struct inode *dir, struct page *ipage,
 	memcpy(dst.dentry, src.dentry, SIZE_OF_DIR_ENTRY * src.max);
 	memcpy(dst.filename, src.filename, src.max * F2FS_SLOT_LEN);
 
-	kunmap_atomic(dentry_blk);
 	if (!PageUptodate(page))
 		SetPageUptodate(page);
 	set_page_dirty(page);
diff --git a/fs/f2fs/inode.c b/fs/f2fs/inode.c
index 89c838bfb067..10be247ca421 100644
--- a/fs/f2fs/inode.c
+++ b/fs/f2fs/inode.c
@@ -328,7 +328,7 @@ make_now:
 		inode->i_op = &f2fs_dir_inode_operations;
 		inode->i_fop = &f2fs_dir_operations;
 		inode->i_mapping->a_ops = &f2fs_dblock_aops;
-		mapping_set_gfp_mask(inode->i_mapping, GFP_F2FS_HIGH_ZERO);
+		inode_nohighmem(inode);
 	} else if (S_ISLNK(inode->i_mode)) {
 		if (f2fs_encrypted_inode(inode))
 			inode->i_op = &f2fs_encrypted_symlink_inode_operations;
diff --git a/fs/f2fs/namei.c b/fs/f2fs/namei.c
index da7f709e3926..6bb1adb84324 100644
--- a/fs/f2fs/namei.c
+++ b/fs/f2fs/namei.c
@@ -317,7 +317,6 @@ static int __recover_dot_dentries(struct inode *dir, nid_t pino)
 
 	de = f2fs_find_entry(dir, &dot, &page);
 	if (de) {
-		f2fs_dentry_kunmap(dir, page);
 		f2fs_put_page(page, 0);
 	} else if (IS_ERR(page)) {
 		err = PTR_ERR(page);
@@ -329,14 +328,12 @@ static int __recover_dot_dentries(struct inode *dir, nid_t pino)
 	}
 
 	de = f2fs_find_entry(dir, &dotdot, &page);
-	if (de) {
-		f2fs_dentry_kunmap(dir, page);
+	if (de)
 		f2fs_put_page(page, 0);
-	} else if (IS_ERR(page)) {
+	else if (IS_ERR(page))
 		err = PTR_ERR(page);
-	} else {
+	else
 		err = __f2fs_add_link(dir, &dotdot, NULL, pino, S_IFDIR);
-	}
 out:
 	if (!err)
 		clear_inode_flag(dir, FI_INLINE_DOTS);
@@ -377,7 +374,6 @@ static struct dentry *f2fs_lookup(struct inode *dir, struct dentry *dentry,
 	}
 
 	ino = le32_to_cpu(de->ino);
-	f2fs_dentry_kunmap(dir, page);
 	f2fs_put_page(page, 0);
 
 	inode = f2fs_iget(dir->i_sb, ino);
@@ -452,7 +448,6 @@ static int f2fs_unlink(struct inode *dir, struct dentry *dentry)
 	err = acquire_orphan_inode(sbi);
 	if (err) {
 		f2fs_unlock_op(sbi);
-		f2fs_dentry_kunmap(dir, page);
 		f2fs_put_page(page, 0);
 		goto fail;
 	}
@@ -610,7 +605,7 @@ static int f2fs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
 	inode->i_op = &f2fs_dir_inode_operations;
 	inode->i_fop = &f2fs_dir_operations;
 	inode->i_mapping->a_ops = &f2fs_dblock_aops;
-	mapping_set_gfp_mask(inode->i_mapping, GFP_F2FS_HIGH_ZERO);
+	inode_nohighmem(inode);
 
 	set_inode_flag(inode, FI_INC_LINK);
 	f2fs_lock_op(sbi);
@@ -924,13 +919,11 @@ static int f2fs_rename(struct inode *old_dir, struct dentry *old_dentry,
 	}
 
 	if (old_dir_entry) {
-		if (old_dir != new_dir && !whiteout) {
+		if (old_dir != new_dir && !whiteout)
 			f2fs_set_link(old_inode, old_dir_entry,
 						old_dir_page, new_dir);
-		} else {
-			f2fs_dentry_kunmap(old_inode, old_dir_page);
+		else
 			f2fs_put_page(old_dir_page, 0);
-		}
 		f2fs_i_links_write(old_dir, false);
 	}
 	add_ino_entry(sbi, new_dir->i_ino, TRANS_DIR_INO);
@@ -943,20 +936,15 @@ static int f2fs_rename(struct inode *old_dir, struct dentry *old_dentry,
 
 put_out_dir:
 	f2fs_unlock_op(sbi);
-	if (new_page) {
-		f2fs_dentry_kunmap(new_dir, new_page);
+	if (new_page)
 		f2fs_put_page(new_page, 0);
-	}
 out_whiteout:
 	if (whiteout)
 		iput(whiteout);
 out_dir:
-	if (old_dir_entry) {
-		f2fs_dentry_kunmap(old_inode, old_dir_page);
+	if (old_dir_entry)
 		f2fs_put_page(old_dir_page, 0);
-	}
 out_old:
-	f2fs_dentry_kunmap(old_dir, old_page);
 	f2fs_put_page(old_page, 0);
 out:
 	return err;
@@ -1098,19 +1086,15 @@ static int f2fs_cross_rename(struct inode *old_dir, struct dentry *old_dentry,
 	return 0;
 out_new_dir:
 	if (new_dir_entry) {
-		f2fs_dentry_kunmap(new_inode, new_dir_page);
 		f2fs_put_page(new_dir_page, 0);
 	}
 out_old_dir:
 	if (old_dir_entry) {
-		f2fs_dentry_kunmap(old_inode, old_dir_page);
 		f2fs_put_page(old_dir_page, 0);
 	}
 out_new:
-	f2fs_dentry_kunmap(new_dir, new_page);
 	f2fs_put_page(new_page, 0);
 out_old:
-	f2fs_dentry_kunmap(old_dir, old_page);
 	f2fs_put_page(old_page, 0);
 out:
 	return err;
diff --git a/fs/f2fs/recovery.c b/fs/f2fs/recovery.c
index b6d1ec620a8c..210de28c9cd2 100644
--- a/fs/f2fs/recovery.c
+++ b/fs/f2fs/recovery.c
@@ -144,7 +144,7 @@ static int recover_dentry(struct inode *inode, struct page *ipage,
 retry:
 	de = __f2fs_find_entry(dir, &fname, &page);
 	if (de && inode->i_ino == le32_to_cpu(de->ino))
-		goto out_unmap_put;
+		goto out_put;
 
 	if (de) {
 		einode = f2fs_iget_retry(inode->i_sb, le32_to_cpu(de->ino));
@@ -153,19 +153,19 @@ retry:
 			err = PTR_ERR(einode);
 			if (err == -ENOENT)
 				err = -EEXIST;
-			goto out_unmap_put;
+			goto out_put;
 		}
 
 		err = dquot_initialize(einode);
 		if (err) {
 			iput(einode);
-			goto out_unmap_put;
+			goto out_put;
 		}
 
 		err = acquire_orphan_inode(F2FS_I_SB(inode));
 		if (err) {
 			iput(einode);
-			goto out_unmap_put;
+			goto out_put;
 		}
 		f2fs_delete_entry(de, page, dir, einode);
 		iput(einode);
@@ -180,8 +180,7 @@ retry:
 		goto retry;
 	goto out;
 
-out_unmap_put:
-	f2fs_dentry_kunmap(dir, page);
+out_put:
 	f2fs_put_page(page, 0);
 out:
 	if (file_enc_name(inode))
diff --git a/include/linux/f2fs_fs.h b/include/linux/f2fs_fs.h
index c82ae65b5330..073365c9808a 100644
--- a/include/linux/f2fs_fs.h
+++ b/include/linux/f2fs_fs.h
@@ -46,7 +46,6 @@
 
 /* This flag is used by node and meta inodes, and by recovery */
 #define GFP_F2FS_ZERO		(GFP_NOFS | __GFP_ZERO)
-#define GFP_F2FS_HIGH_ZERO	(GFP_NOFS | __GFP_ZERO | __GFP_HIGHMEM)
 
 /*
  * For further optimization on multi-head logs, on-disk layout supports maximum