From: Gao Xiang <gaoxiang25@huawei.com>
To: Alexander Viro <viro@zeniv.linux.org.uk>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Andrew Morton <akpm@linux-foundation.org>,
Stephen Rothwell <sfr@canb.auug.org.au>,
Theodore Ts'o <tytso@mit.edu>,
"Linus Torvalds" <torvalds@linux-foundation.org>
Cc: <linux-fsdevel@vger.kernel.org>, <devel@driverdev.osuosl.org>,
LKML <linux-kernel@vger.kernel.org>,
<linux-erofs@lists.ozlabs.org>, Chao Yu <yuchao0@huawei.com>,
Miao Xie <miaoxie@huawei.com>,
Li Guifu <bluce.liguifu@huawei.com>,
Fang Wei <fangwei1@huawei.com>, Gao Xiang <gaoxiang25@huawei.com>
Subject: [PATCH v3 07/24] erofs: add directory operations
Date: Mon, 22 Jul 2019 10:50:26 +0800 [thread overview]
Message-ID: <20190722025043.166344-8-gaoxiang25@huawei.com> (raw)
In-Reply-To: <20190722025043.166344-1-gaoxiang25@huawei.com>
This adds functions for directory, mainly readdir.
Signed-off-by: Gao Xiang <gaoxiang25@huawei.com>
---
fs/erofs/dir.c | 147 +++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 147 insertions(+)
create mode 100644 fs/erofs/dir.c
diff --git a/fs/erofs/dir.c b/fs/erofs/dir.c
new file mode 100644
index 000000000000..f5bedf4e142f
--- /dev/null
+++ b/fs/erofs/dir.c
@@ -0,0 +1,147 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * linux/fs/erofs/dir.c
+ *
+ * Copyright (C) 2017-2018 HUAWEI, Inc.
+ * http://www.huawei.com/
+ * Created by Gao Xiang <gaoxiang25@huawei.com>
+ */
+#include "internal.h"
+
+static const unsigned char erofs_filetype_table[EROFS_FT_MAX] = {
+ [EROFS_FT_UNKNOWN] = DT_UNKNOWN,
+ [EROFS_FT_REG_FILE] = DT_REG,
+ [EROFS_FT_DIR] = DT_DIR,
+ [EROFS_FT_CHRDEV] = DT_CHR,
+ [EROFS_FT_BLKDEV] = DT_BLK,
+ [EROFS_FT_FIFO] = DT_FIFO,
+ [EROFS_FT_SOCK] = DT_SOCK,
+ [EROFS_FT_SYMLINK] = DT_LNK,
+};
+
+static void debug_one_dentry(unsigned char d_type, const char *de_name,
+ unsigned int de_namelen)
+{
+#ifdef CONFIG_EROFS_FS_DEBUG
+ /* since the on-disk name could not have the trailing '\0' */
+ unsigned char dbg_namebuf[EROFS_NAME_LEN + 1];
+
+ memcpy(dbg_namebuf, de_name, de_namelen);
+ dbg_namebuf[de_namelen] = '\0';
+
+ debugln("found dirent %s de_len %u d_type %d", dbg_namebuf,
+ de_namelen, d_type);
+#endif
+}
+
+static int erofs_fill_dentries(struct dir_context *ctx,
+ void *dentry_blk, unsigned int *ofs,
+ unsigned int nameoff, unsigned int maxsize)
+{
+ struct erofs_dirent *de = dentry_blk + *ofs;
+ const struct erofs_dirent *end = dentry_blk + nameoff;
+
+ while (de < end) {
+ const char *de_name;
+ unsigned int de_namelen;
+ unsigned char d_type;
+
+ if (de->file_type < EROFS_FT_MAX)
+ d_type = erofs_filetype_table[de->file_type];
+ else
+ d_type = DT_UNKNOWN;
+
+ nameoff = le16_to_cpu(de->nameoff);
+ de_name = (char *)dentry_blk + nameoff;
+
+ /* the last dirent in the block? */
+ if (de + 1 >= end)
+ de_namelen = strnlen(de_name, maxsize - nameoff);
+ else
+ de_namelen = le16_to_cpu(de[1].nameoff) - nameoff;
+
+ /* a corrupted entry is found */
+ if (unlikely(nameoff + de_namelen > maxsize ||
+ de_namelen > EROFS_NAME_LEN)) {
+ DBG_BUGON(1);
+ return -EIO;
+ }
+
+ debug_one_dentry(d_type, de_name, de_namelen);
+ if (!dir_emit(ctx, de_name, de_namelen,
+ le64_to_cpu(de->nid), d_type))
+ /* stopped by some reason */
+ return 1;
+ ++de;
+ *ofs += sizeof(struct erofs_dirent);
+ }
+ *ofs = maxsize;
+ return 0;
+}
+
+static int erofs_readdir(struct file *f, struct dir_context *ctx)
+{
+ struct inode *dir = file_inode(f);
+ struct address_space *mapping = dir->i_mapping;
+ const size_t dirsize = i_size_read(dir);
+ unsigned int i = ctx->pos / EROFS_BLKSIZ;
+ unsigned int ofs = ctx->pos % EROFS_BLKSIZ;
+ int err = 0;
+ bool initial = true;
+
+ while (ctx->pos < dirsize) {
+ struct page *dentry_page;
+ struct erofs_dirent *de;
+ unsigned int nameoff, maxsize;
+
+ dentry_page = read_mapping_page(mapping, i, NULL);
+ if (IS_ERR(dentry_page))
+ continue;
+
+ de = (struct erofs_dirent *)kmap(dentry_page);
+
+ nameoff = le16_to_cpu(de->nameoff);
+
+ if (unlikely(nameoff < sizeof(struct erofs_dirent) ||
+ nameoff >= PAGE_SIZE)) {
+ errln("%s, invalid de[0].nameoff %u",
+ __func__, nameoff);
+
+ err = -EIO;
+ goto skip_this;
+ }
+
+ maxsize = min_t(unsigned int,
+ dirsize - ctx->pos + ofs, PAGE_SIZE);
+
+ /* search dirents at the arbitrary position */
+ if (unlikely(initial)) {
+ initial = false;
+
+ ofs = roundup(ofs, sizeof(struct erofs_dirent));
+ if (unlikely(ofs >= nameoff))
+ goto skip_this;
+ }
+
+ err = erofs_fill_dentries(ctx, de, &ofs, nameoff, maxsize);
+skip_this:
+ kunmap(dentry_page);
+
+ put_page(dentry_page);
+
+ ctx->pos = blknr_to_addr(i) + ofs;
+
+ if (unlikely(err))
+ break;
+ ++i;
+ ofs = 0;
+ }
+ return err < 0 ? err : 0;
+}
+
+const struct file_operations erofs_dir_fops = {
+ .llseek = generic_file_llseek,
+ .read = generic_read_dir,
+ .iterate_shared = erofs_readdir,
+};
+
--
2.17.1
next prev parent reply other threads:[~2019-07-22 2:51 UTC|newest]
Thread overview: 45+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-07-22 2:50 [PATCH v3 00/24] erofs: promote erofs from staging Gao Xiang
2019-07-22 2:50 ` [PATCH v3 01/24] erofs: add on-disk layout Gao Xiang
2019-07-22 3:26 ` Stephen Rothwell
2019-07-22 3:29 ` Gao Xiang
2019-07-22 5:05 ` Greg Kroah-Hartman
2019-07-22 5:24 ` Gao Xiang
2019-07-22 2:50 ` [PATCH v3 02/24] erofs: add erofs in-memory stuffs Gao Xiang
2019-07-22 2:50 ` [PATCH v3 03/24] erofs: add super block operations Gao Xiang
2019-07-22 2:50 ` [PATCH v3 04/24] erofs: add raw address_space operations Gao Xiang
2019-07-22 2:50 ` [PATCH v3 05/24] erofs: add inode operations Gao Xiang
2019-07-22 2:50 ` [PATCH v3 06/24] erofs: support special inode Gao Xiang
2019-07-22 2:50 ` Gao Xiang [this message]
2019-07-22 2:50 ` [PATCH v3 08/24] erofs: add namei functions Gao Xiang
2019-07-22 2:50 ` [PATCH v3 09/24] erofs: support tracepoint Gao Xiang
2019-07-22 2:50 ` [PATCH v3 10/24] erofs: update Kconfig and Makefile Gao Xiang
2019-07-22 2:50 ` [PATCH v3 11/24] erofs: introduce xattr & posixacl support Gao Xiang
2019-07-22 2:50 ` [PATCH v3 12/24] erofs: introduce tagged pointer Gao Xiang
2019-07-22 4:39 ` Amir Goldstein
2019-07-22 5:01 ` Gao Xiang
2019-07-22 6:16 ` Amir Goldstein
2019-07-22 6:31 ` Gao Xiang
2019-07-22 14:40 ` Steven Rostedt
2019-07-22 15:33 ` Gao Xiang
2019-07-22 16:35 ` Steven Rostedt
2019-07-22 16:52 ` Gao Xiang
2019-07-22 2:50 ` [PATCH v3 13/24] erofs: add compression indexes support Gao Xiang
2019-07-22 2:50 ` [PATCH v3 14/24] erofs: introduce superblock registration Gao Xiang
2019-07-22 2:50 ` [PATCH v3 15/24] erofs: introduce erofs shrinker Gao Xiang
2019-07-22 2:50 ` [PATCH v3 16/24] erofs: introduce workstation for decompression Gao Xiang
2019-07-22 2:50 ` [PATCH v3 17/24] erofs: introduce per-CPU buffers implementation Gao Xiang
2019-07-22 2:50 ` [PATCH v3 18/24] erofs: introduce pagevec for decompression subsystem Gao Xiang
2019-07-22 2:50 ` [PATCH v3 19/24] erofs: add erofs_allocpage() Gao Xiang
2019-07-22 2:50 ` [PATCH v3 20/24] erofs: introduce generic decompression backend Gao Xiang
2019-07-22 2:50 ` [PATCH v3 21/24] erofs: introduce LZ4 decompression inplace Gao Xiang
2019-07-22 2:50 ` [PATCH v3 22/24] erofs: introduce the decompression frontend Gao Xiang
2019-07-22 2:50 ` [PATCH v3 23/24] erofs: introduce cached decompression Gao Xiang
2019-07-22 10:18 ` David Sterba
2019-07-22 10:58 ` Gao Xiang
2019-07-22 13:25 ` Theodore Y. Ts'o
2019-07-22 14:16 ` Gao Xiang
2019-07-22 15:12 ` Theodore Y. Ts'o
2019-07-22 16:27 ` Gao Xiang
2019-07-23 12:31 ` David Sterba
2019-07-23 13:30 ` Gao Xiang
2019-07-22 2:50 ` [PATCH v3 24/24] erofs: add document Gao Xiang
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