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Subject[PATCH 02/25] staging: erofs: add erofs in-memory stuffs
Date
 - erofs_sb_info:
contains erofs-specific in-memory information.

- erofs_vnode:
contains vfs_inode and other fs-specific information.
same as super block, the only one in-memory definition exists.

- erofs_map_blocks
plays a role in the file L2P mapping

Signed-off-by: Miao Xie <miaoxie@huawei.com>
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Gao Xiang <gaoxiang25@huawei.com>
---
drivers/staging/erofs/internal.h | 281 +++++++++++++++++++++++++++++++++++++++
1 file changed, 281 insertions(+)
create mode 100644 drivers/staging/erofs/internal.h

diff --git a/drivers/staging/erofs/internal.h b/drivers/staging/erofs/internal.h
new file mode 100644
index 0000000..d0992d2
--- /dev/null
+++ b/drivers/staging/erofs/internal.h
@@ -0,0 +1,281 @@
+/* SPDX-License-Identifier: GPL-2.0
+ *
+ * linux/drivers/staging/erofs/internal.h
+ *
+ * Copyright (C) 2017-2018 HUAWEI, Inc.
+ * http://www.huawei.com/
+ * Created by Gao Xiang <gaoxiang25@huawei.com>
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License. See the file COPYING in the main directory of the Linux
+ * distribution for more details.
+ */
+#ifndef __INTERNAL_H
+#define __INTERNAL_H
+
+#include <linux/fs.h>
+#include <linux/dcache.h>
+#include <linux/mm.h>
+#include <linux/pagemap.h>
+#include <linux/bio.h>
+#include <linux/buffer_head.h>
+#include <linux/cleancache.h>
+#include <linux/slab.h>
+#include <linux/vmalloc.h>
+#include "erofs_fs.h"
+
+/* redefine pr_fmt "erofs: " */
+#undef pr_fmt
+#define pr_fmt(fmt) "erofs: " fmt
+
+#define errln(x, ...) pr_err(x "\n", ##__VA_ARGS__)
+#define infoln(x, ...) pr_info(x "\n", ##__VA_ARGS__)
+#ifdef CONFIG_EROFS_FS_DEBUG
+#define debugln(x, ...) pr_debug(x "\n", ##__VA_ARGS__)
+
+#define dbg_might_sleep might_sleep
+#define DBG_BUGON BUG_ON
+#else
+#define debugln(x, ...) ((void)0)
+
+#define dbg_might_sleep() ((void)0)
+#define DBG_BUGON(...) ((void)0)
+#endif
+
+/* EROFS_SUPER_MAGIC_V1 to represent the whole file system */
+#define EROFS_SUPER_MAGIC EROFS_SUPER_MAGIC_V1
+
+typedef u64 erofs_nid_t;
+
+struct erofs_sb_info {
+ u32 blocks;
+ u32 meta_blkaddr;
+
+ /* inode slot unit size in bit shift */
+ unsigned char islotbits;
+
+ u32 build_time_nsec;
+ u64 build_time;
+
+ /* what we really care is nid, rather than ino.. */
+ erofs_nid_t root_nid;
+ /* used for statfs, f_files - f_favail */
+ u64 inos;
+
+ u8 uuid[16]; /* 128-bit uuid for volume */
+ u8 volume_name[16]; /* volume name */
+ char *dev_name;
+
+ unsigned int mount_opt;
+};
+
+#define EROFS_SB(sb) ((struct erofs_sb_info *)(sb)->s_fs_info)
+#define EROFS_I_SB(inode) ((struct erofs_sb_info *)(inode)->i_sb->s_fs_info)
+
+#define clear_opt(sbi, option) ((sbi)->mount_opt &= ~EROFS_MOUNT_##option)
+#define set_opt(sbi, option) ((sbi)->mount_opt |= EROFS_MOUNT_##option)
+#define test_opt(sbi, option) ((sbi)->mount_opt & EROFS_MOUNT_##option)
+
+/* we strictly follow PAGE_SIZE and no buffer head yet */
+#define LOG_BLOCK_SIZE PAGE_SHIFT
+
+#undef LOG_SECTORS_PER_BLOCK
+#define LOG_SECTORS_PER_BLOCK (PAGE_SHIFT - 9)
+
+#undef SECTORS_PER_BLOCK
+#define SECTORS_PER_BLOCK (1 << SECTORS_PER_BLOCK)
+
+#define EROFS_BLKSIZ (1 << LOG_BLOCK_SIZE)
+
+#if (EROFS_BLKSIZ % 4096 || !EROFS_BLKSIZ)
+#error erofs cannot be used in this platform
+#endif
+
+#define ROOT_NID(sb) ((sb)->root_nid)
+
+typedef u64 erofs_off_t;
+
+/* data type for filesystem-wide blocks number */
+typedef u32 erofs_blk_t;
+
+#define erofs_blknr(addr) ((addr) / EROFS_BLKSIZ)
+#define erofs_blkoff(addr) ((addr) % EROFS_BLKSIZ)
+#define blknr_to_addr(nr) ((erofs_off_t)(nr) * EROFS_BLKSIZ)
+
+static inline erofs_off_t iloc(struct erofs_sb_info *sbi, erofs_nid_t nid)
+{
+ return blknr_to_addr(sbi->meta_blkaddr) + (nid << sbi->islotbits);
+}
+
+#define inode_set_inited_xattr(inode) (EROFS_V(inode)->flags |= 1)
+#define inode_has_inited_xattr(inode) (EROFS_V(inode)->flags & 1)
+
+struct erofs_vnode {
+ erofs_nid_t nid;
+ unsigned int flags;
+
+ unsigned char data_mapping_mode;
+ /* inline size in bytes */
+ unsigned char inode_isize;
+ unsigned short xattr_isize;
+
+ unsigned xattr_shared_count;
+ unsigned *xattr_shared_xattrs;
+
+ erofs_blk_t raw_blkaddr;
+
+ /* the corresponding vfs inode */
+ struct inode vfs_inode;
+};
+
+#define EROFS_V(ptr) \
+ container_of(ptr, struct erofs_vnode, vfs_inode)
+
+#define __inode_advise(x, bit, bits) \
+ (((x) >> (bit)) & ((1 << (bits)) - 1))
+
+#define __inode_version(advise) \
+ __inode_advise(advise, EROFS_I_VERSION_BIT, \
+ EROFS_I_VERSION_BITS)
+
+#define __inode_data_mapping(advise) \
+ __inode_advise(advise, EROFS_I_DATA_MAPPING_BIT,\
+ EROFS_I_DATA_MAPPING_BITS)
+
+static inline unsigned long inode_datablocks(struct inode *inode)
+{
+ /* since i_size cannot be changed */
+ return DIV_ROUND_UP(inode->i_size, EROFS_BLKSIZ);
+}
+
+static inline bool is_inode_layout_plain(struct inode *inode)
+{
+ return EROFS_V(inode)->data_mapping_mode == EROFS_INODE_LAYOUT_PLAIN;
+}
+
+static inline bool is_inode_layout_compression(struct inode *inode)
+{
+ return EROFS_V(inode)->data_mapping_mode ==
+ EROFS_INODE_LAYOUT_COMPRESSION;
+}
+
+static inline bool is_inode_layout_inline(struct inode *inode)
+{
+ return EROFS_V(inode)->data_mapping_mode == EROFS_INODE_LAYOUT_INLINE;
+}
+
+extern const struct super_operations erofs_sops;
+extern const struct inode_operations erofs_dir_iops;
+extern const struct file_operations erofs_dir_fops;
+
+extern const struct address_space_operations erofs_raw_access_aops;
+
+/*
+ * Logical to physical block mapping, used by erofs_map_blocks()
+ *
+ * Different with other file systems, it is used for 2 access modes:
+ *
+ * 1) RAW access mode:
+ *
+ * Users pass a valid (m_lblk, m_lofs -- usually 0) pair,
+ * and get the valid m_pblk, m_pofs and the longest m_len(in bytes).
+ *
+ * Note that m_lblk in the RAW access mode refers to the number of
+ * the compressed ondisk block rather than the uncompressed
+ * in-memory block for the compressed file.
+ *
+ * m_pofs equals to m_lofs except for the inline data page.
+ *
+ * 2) Normal access mode:
+ *
+ * If the inode is not compressed, it has no difference with
+ * the RAW access mode. However, if the inode is compressed,
+ * users should pass a valid (m_lblk, m_lofs) pair, and get
+ * the needed m_pblk, m_pofs, m_len to get the compressed data
+ * and the updated m_lblk, m_lofs which indicates the start
+ * of the corresponding uncompressed data in the file.
+ */
+enum {
+ BH_Zipped = BH_PrivateStart,
+};
+
+/* Has a disk mapping */
+#define EROFS_MAP_MAPPED (1 << BH_Mapped)
+/* Located in metadata (could be copied from bd_inode) */
+#define EROFS_MAP_META (1 << BH_Meta)
+/* The extent has been compressed */
+#define EROFS_MAP_ZIPPED (1 << BH_Zipped)
+
+struct erofs_map_blocks {
+ erofs_off_t m_pa, m_la;
+ u64 m_plen, m_llen;
+
+ unsigned int m_flags;
+};
+
+/* Flags used by erofs_map_blocks() */
+#define EROFS_GET_BLOCKS_RAW 0x0001
+
+/* data.c */
+extern struct page *erofs_get_meta_page(struct super_block *sb,
+ erofs_blk_t blkaddr, bool prio);
+extern int erofs_map_blocks(struct inode *, struct erofs_map_blocks *, int);
+
+static inline struct page *erofs_get_inline_page(struct inode *inode,
+ erofs_blk_t blkaddr)
+{
+ return erofs_get_meta_page(inode->i_sb,
+ blkaddr, S_ISDIR(inode->i_mode));
+}
+
+/* inode.c */
+extern struct inode *erofs_iget(struct super_block *sb,
+ erofs_nid_t nid, bool dir);
+
+/* dir.c */
+int erofs_namei(struct inode *dir, struct qstr *name,
+ erofs_nid_t *nid, unsigned *d_type);
+
+/* xattr.c */
+extern const struct xattr_handler *erofs_xattr_handlers[];
+
+/* symlink */
+static inline void set_inode_fast_symlink(struct inode *inode)
+{
+ inode->i_op = &simple_symlink_inode_operations;
+}
+
+static inline bool is_inode_fast_symlink(struct inode *inode)
+{
+ return inode->i_op == &simple_symlink_inode_operations;
+}
+
+static inline void *erofs_vmap(struct page **pages, unsigned int count)
+{
+#ifdef CONFIG_EROFS_FS_USE_VM_MAP_RAM
+ int i = 0;
+
+ while (1) {
+ void *addr = vm_map_ram(pages, count, -1, PAGE_KERNEL);
+ /* retry two more times (totally 3 times) */
+ if (addr != NULL || ++i >= 3)
+ return addr;
+ vm_unmap_aliases();
+ }
+ return NULL;
+#else
+ return vmap(pages, count, VM_MAP, PAGE_KERNEL);
+#endif
+}
+
+static inline void erofs_vunmap(const void *mem, unsigned int count)
+{
+#ifdef CONFIG_EROFS_FS_USE_VM_MAP_RAM
+ vm_unmap_ram(mem, count);
+#else
+ vunmap(mem);
+#endif
+}
+
+#endif
+
--
1.9.1
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