1 files changed, 81 insertions, 73 deletions

diff --git a/fs/nilfs2/dir.c b/fs/nilfs2/dir.c
index aee40db7a036..9b7f8e9655a2 100644
--- a/fs/nilfs2/dir.c
+++ b/fs/nilfs2/dir.c
@@ -70,7 +70,7 @@ static inline unsigned int nilfs_chunk_size(struct inode *inode)
  */
 static unsigned int nilfs_last_byte(struct inode *inode, unsigned long page_nr)
 {
-	unsigned int last_byte = inode->i_size;
+	u64 last_byte = inode->i_size;
 
 	last_byte -= page_nr << PAGE_SHIFT;
 	if (last_byte > PAGE_SIZE)
@@ -83,7 +83,7 @@ static int nilfs_prepare_chunk(struct folio *folio, unsigned int from,
 {
 	loff_t pos = folio_pos(folio) + from;
 
-	return __block_write_begin(&folio->page, pos, to - from, nilfs_get_block);
+	return __block_write_begin(folio, pos, to - from, nilfs_get_block);
 }
 
 static void nilfs_commit_chunk(struct folio *folio,
@@ -95,8 +95,8 @@ static void nilfs_commit_chunk(struct folio *folio,
 	unsigned int nr_dirty;
 	int err;
 
-	nr_dirty = nilfs_page_count_clean_buffers(&folio->page, from, to);
-	copied = block_write_end(NULL, mapping, pos, len, len, &folio->page, NULL);
+	nr_dirty = nilfs_page_count_clean_buffers(folio, from, to);
+	copied = block_write_end(NULL, mapping, pos, len, len, folio, NULL);
 	if (pos + copied > dir->i_size)
 		i_size_write(dir, pos + copied);
 	if (IS_DIRSYNC(dir))
@@ -135,6 +135,9 @@ static bool nilfs_check_folio(struct folio *folio, char *kaddr)
 			goto Enamelen;
 		if (((offs + rec_len - 1) ^ offs) & ~(chunk_size-1))
 			goto Espan;
+		if (unlikely(p->inode &&
+			     NILFS_PRIVATE_INODE(le64_to_cpu(p->inode))))
+			goto Einumber;
 	}
 	if (offs != limit)
 		goto Eend;
@@ -160,6 +163,9 @@ Enamelen:
 	goto bad_entry;
 Espan:
 	error = "directory entry across blocks";
+	goto bad_entry;
+Einumber:
+	error = "disallowed inode number";
 bad_entry:
 	nilfs_error(sb,
 		    "bad entry in directory #%lu: %s - offset=%lu, inode=%lu, rec_len=%zd, name_len=%d",
@@ -174,7 +180,6 @@ Eend:
 		    dir->i_ino, (folio->index << PAGE_SHIFT) + offs,
 		    (unsigned long)le64_to_cpu(p->inode));
 fail:
-	folio_set_error(folio);
 	return false;
 }
 
@@ -226,37 +231,6 @@ static struct nilfs_dir_entry *nilfs_next_entry(struct nilfs_dir_entry *p)
 					  nilfs_rec_len_from_disk(p->rec_len));
 }
 
-static unsigned char
-nilfs_filetype_table[NILFS_FT_MAX] = {
-	[NILFS_FT_UNKNOWN]	= DT_UNKNOWN,
-	[NILFS_FT_REG_FILE]	= DT_REG,
-	[NILFS_FT_DIR]		= DT_DIR,
-	[NILFS_FT_CHRDEV]	= DT_CHR,
-	[NILFS_FT_BLKDEV]	= DT_BLK,
-	[NILFS_FT_FIFO]		= DT_FIFO,
-	[NILFS_FT_SOCK]		= DT_SOCK,
-	[NILFS_FT_SYMLINK]	= DT_LNK,
-};
-
-#define S_SHIFT 12
-static unsigned char
-nilfs_type_by_mode[(S_IFMT >> S_SHIFT) + 1] = {
-	[S_IFREG >> S_SHIFT]	= NILFS_FT_REG_FILE,
-	[S_IFDIR >> S_SHIFT]	= NILFS_FT_DIR,
-	[S_IFCHR >> S_SHIFT]	= NILFS_FT_CHRDEV,
-	[S_IFBLK >> S_SHIFT]	= NILFS_FT_BLKDEV,
-	[S_IFIFO >> S_SHIFT]	= NILFS_FT_FIFO,
-	[S_IFSOCK >> S_SHIFT]	= NILFS_FT_SOCK,
-	[S_IFLNK >> S_SHIFT]	= NILFS_FT_SYMLINK,
-};
-
-static void nilfs_set_de_type(struct nilfs_dir_entry *de, struct inode *inode)
-{
-	umode_t mode = inode->i_mode;
-
-	de->file_type = nilfs_type_by_mode[(mode & S_IFMT)>>S_SHIFT];
-}
-
 static int nilfs_readdir(struct file *file, struct dir_context *ctx)
 {
 	loff_t pos = ctx->pos;
@@ -292,10 +266,7 @@ static int nilfs_readdir(struct file *file, struct dir_context *ctx)
 			if (de->inode) {
 				unsigned char t;
 
-				if (de->file_type < NILFS_FT_MAX)
-					t = nilfs_filetype_table[de->file_type];
-				else
-					t = DT_UNKNOWN;
+				t = fs_ftype_to_dtype(de->file_type);
 
 				if (!dir_emit(ctx, de->name, de->name_len,
 						le64_to_cpu(de->inode), t)) {
@@ -318,7 +289,7 @@ static int nilfs_readdir(struct file *file, struct dir_context *ctx)
  * The folio is mapped and unlocked.  When the caller is finished with
  * the entry, it should call folio_release_kmap().
  *
- * On failure, returns NULL and the caller should ignore foliop.
+ * On failure, returns an error pointer and the caller should ignore foliop.
  */
 struct nilfs_dir_entry *nilfs_find_entry(struct inode *dir,
 		const struct qstr *qstr, struct folio **foliop)
@@ -341,22 +312,24 @@ struct nilfs_dir_entry *nilfs_find_entry(struct inode *dir,
 	do {
 		char *kaddr = nilfs_get_folio(dir, n, foliop);
 
-		if (!IS_ERR(kaddr)) {
-			de = (struct nilfs_dir_entry *)kaddr;
-			kaddr += nilfs_last_byte(dir, n) - reclen;
-			while ((char *) de <= kaddr) {
-				if (de->rec_len == 0) {
-					nilfs_error(dir->i_sb,
-						"zero-length directory entry");
-					folio_release_kmap(*foliop, kaddr);
-					goto out;
-				}
-				if (nilfs_match(namelen, name, de))
-					goto found;
-				de = nilfs_next_entry(de);
+		if (IS_ERR(kaddr))
+			return ERR_CAST(kaddr);
+
+		de = (struct nilfs_dir_entry *)kaddr;
+		kaddr += nilfs_last_byte(dir, n) - reclen;
+		while ((char *)de <= kaddr) {
+			if (de->rec_len == 0) {
+				nilfs_error(dir->i_sb,
+					    "zero-length directory entry");
+				folio_release_kmap(*foliop, kaddr);
+				goto out;
 			}
-			folio_release_kmap(*foliop, kaddr);
+			if (nilfs_match(namelen, name, de))
+				goto found;
+			de = nilfs_next_entry(de);
 		}
+		folio_release_kmap(*foliop, kaddr);
+
 		if (++n >= npages)
 			n = 0;
 		/* next folio is past the blocks we've got */
@@ -369,7 +342,7 @@ struct nilfs_dir_entry *nilfs_find_entry(struct inode *dir,
 		}
 	} while (n != start);
 out:
-	return NULL;
+	return ERR_PTR(-ENOENT);
 
 found:
 	ei->i_dir_start_lookup = n;
@@ -378,28 +351,56 @@ found:
 
 struct nilfs_dir_entry *nilfs_dotdot(struct inode *dir, struct folio **foliop)
 {
-	struct nilfs_dir_entry *de = nilfs_get_folio(dir, 0, foliop);
+	struct folio *folio;
+	struct nilfs_dir_entry *de, *next_de;
+	size_t limit;
+	char *msg;
 
+	de = nilfs_get_folio(dir, 0, &folio);
 	if (IS_ERR(de))
 		return NULL;
-	return nilfs_next_entry(de);
+
+	limit = nilfs_last_byte(dir, 0);  /* is a multiple of chunk size */
+	if (unlikely(!limit || le64_to_cpu(de->inode) != dir->i_ino ||
+		     !nilfs_match(1, ".", de))) {
+		msg = "missing '.'";
+		goto fail;
+	}
+
+	next_de = nilfs_next_entry(de);
+	/*
+	 * If "next_de" has not reached the end of the chunk, there is
+	 * at least one more record.  Check whether it matches "..".
+	 */
+	if (unlikely((char *)next_de == (char *)de + nilfs_chunk_size(dir) ||
+		     !nilfs_match(2, "..", next_de))) {
+		msg = "missing '..'";
+		goto fail;
+	}
+	*foliop = folio;
+	return next_de;
+
+fail:
+	nilfs_error(dir->i_sb, "directory #%lu %s", dir->i_ino, msg);
+	folio_release_kmap(folio, de);
+	return NULL;
 }
 
-ino_t nilfs_inode_by_name(struct inode *dir, const struct qstr *qstr)
+int nilfs_inode_by_name(struct inode *dir, const struct qstr *qstr, ino_t *ino)
 {
-	ino_t res = 0;
 	struct nilfs_dir_entry *de;
 	struct folio *folio;
 
 	de = nilfs_find_entry(dir, qstr, &folio);
-	if (de) {
-		res = le64_to_cpu(de->inode);
-		folio_release_kmap(folio, de);
-	}
-	return res;
+	if (IS_ERR(de))
+		return PTR_ERR(de);
+
+	*ino = le64_to_cpu(de->inode);
+	folio_release_kmap(folio, de);
+	return 0;
 }
 
-void nilfs_set_link(struct inode *dir, struct nilfs_dir_entry *de,
+int nilfs_set_link(struct inode *dir, struct nilfs_dir_entry *de,
 		    struct folio *folio, struct inode *inode)
 {
 	size_t from = offset_in_folio(folio, de);
@@ -409,11 +410,15 @@ void nilfs_set_link(struct inode *dir, struct nilfs_dir_entry *de,
 
 	folio_lock(folio);
 	err = nilfs_prepare_chunk(folio, from, to);
-	BUG_ON(err);
+	if (unlikely(err)) {
+		folio_unlock(folio);
+		return err;
+	}
 	de->inode = cpu_to_le64(inode->i_ino);
-	nilfs_set_de_type(de, inode);
+	de->file_type = fs_umode_to_ftype(inode->i_mode);
 	nilfs_commit_chunk(folio, mapping, from, to);
 	inode_set_mtime_to_ts(dir, inode_set_ctime_current(dir));
+	return 0;
 }
 
 /*
@@ -498,7 +503,7 @@ got_it:
 	de->name_len = namelen;
 	memcpy(de->name, name, namelen);
 	de->inode = cpu_to_le64(inode->i_ino);
-	nilfs_set_de_type(de, inode);
+	de->file_type = fs_umode_to_ftype(inode->i_mode);
 	nilfs_commit_chunk(folio, folio->mapping, from, to);
 	inode_set_mtime_to_ts(dir, inode_set_ctime_current(dir));
 	nilfs_mark_inode_dirty(dir);
@@ -542,7 +547,10 @@ int nilfs_delete_entry(struct nilfs_dir_entry *dir, struct folio *folio)
 		from = (char *)pde - kaddr;
 	folio_lock(folio);
 	err = nilfs_prepare_chunk(folio, from, to);
-	BUG_ON(err);
+	if (unlikely(err)) {
+		folio_unlock(folio);
+		goto out;
+	}
 	if (pde)
 		pde->rec_len = nilfs_rec_len_to_disk(to - from);
 	dir->inode = 0;
@@ -579,14 +587,14 @@ int nilfs_make_empty(struct inode *inode, struct inode *parent)
 	de->rec_len = nilfs_rec_len_to_disk(NILFS_DIR_REC_LEN(1));
 	memcpy(de->name, ".\0\0", 4);
 	de->inode = cpu_to_le64(inode->i_ino);
-	nilfs_set_de_type(de, inode);
+	de->file_type = fs_umode_to_ftype(inode->i_mode);
 
 	de = (struct nilfs_dir_entry *)(kaddr + NILFS_DIR_REC_LEN(1));
 	de->name_len = 2;
 	de->rec_len = nilfs_rec_len_to_disk(chunk_size - NILFS_DIR_REC_LEN(1));
 	de->inode = cpu_to_le64(parent->i_ino);
 	memcpy(de->name, "..\0", 4);
-	nilfs_set_de_type(de, inode);
+	de->file_type = fs_umode_to_ftype(inode->i_mode);
 	kunmap_local(kaddr);
 	nilfs_commit_chunk(folio, mapping, 0, chunk_size);
 fail:
@@ -608,7 +616,7 @@ int nilfs_empty_dir(struct inode *inode)
 
 		kaddr = nilfs_get_folio(inode, i, &folio);
 		if (IS_ERR(kaddr))
-			continue;
+			return 0;
 
 		de = (struct nilfs_dir_entry *)kaddr;
 		kaddr += nilfs_last_byte(inode, i) - NILFS_DIR_REC_LEN(1);