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![Christian Brauner](/assets/img/avatar_default.png)
Extend some inode methods with an additional user namespace argument. A filesystem that is aware of idmapped mounts will receive the user namespace the mount has been marked with. This can be used for additional permission checking and also to enable filesystems to translate between uids and gids if they need to. We have implemented all relevant helpers in earlier patches. As requested we simply extend the exisiting inode method instead of introducing new ones. This is a little more code churn but it's mostly mechanical and doesnt't leave us with additional inode methods. Link: https://lore.kernel.org/r/20210121131959.646623-25-christian.brauner@ubuntu.com Cc: Christoph Hellwig <hch@lst.de> Cc: David Howells <dhowells@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: linux-fsdevel@vger.kernel.org Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
230 lines
6.5 KiB
C
230 lines
6.5 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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#include <linux/buffer_head.h>
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#include <linux/fs.h>
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#include <linux/adfs_fs.h>
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/* Internal data structures for ADFS */
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#define ADFS_FREE_FRAG 0
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#define ADFS_BAD_FRAG 1
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#define ADFS_ROOT_FRAG 2
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#define ADFS_FILETYPE_NONE ((u16)~0)
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/* RISC OS 12-bit filetype is stored in load_address[19:8] */
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static inline u16 adfs_filetype(u32 loadaddr)
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{
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return (loadaddr & 0xfff00000) == 0xfff00000 ?
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(loadaddr >> 8) & 0xfff : ADFS_FILETYPE_NONE;
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}
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#define ADFS_NDA_OWNER_READ (1 << 0)
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#define ADFS_NDA_OWNER_WRITE (1 << 1)
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#define ADFS_NDA_LOCKED (1 << 2)
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#define ADFS_NDA_DIRECTORY (1 << 3)
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#define ADFS_NDA_EXECUTE (1 << 4)
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#define ADFS_NDA_PUBLIC_READ (1 << 5)
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#define ADFS_NDA_PUBLIC_WRITE (1 << 6)
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/*
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* adfs file system inode data in memory
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*/
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struct adfs_inode_info {
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loff_t mmu_private;
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__u32 parent_id; /* parent indirect disc address */
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__u32 indaddr; /* object indirect disc address */
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__u32 loadaddr; /* RISC OS load address */
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__u32 execaddr; /* RISC OS exec address */
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unsigned int attr; /* RISC OS permissions */
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struct inode vfs_inode;
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};
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static inline struct adfs_inode_info *ADFS_I(struct inode *inode)
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{
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return container_of(inode, struct adfs_inode_info, vfs_inode);
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}
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static inline bool adfs_inode_is_stamped(struct inode *inode)
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{
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return (ADFS_I(inode)->loadaddr & 0xfff00000) == 0xfff00000;
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}
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/*
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* Forward-declare this
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*/
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struct adfs_discmap;
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struct adfs_dir_ops;
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/*
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* ADFS file system superblock data in memory
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*/
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struct adfs_sb_info {
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union { struct {
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struct adfs_discmap *s_map; /* bh list containing map */
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const struct adfs_dir_ops *s_dir; /* directory operations */
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};
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struct rcu_head rcu; /* used only at shutdown time */
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};
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kuid_t s_uid; /* owner uid */
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kgid_t s_gid; /* owner gid */
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umode_t s_owner_mask; /* ADFS owner perm -> unix perm */
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umode_t s_other_mask; /* ADFS other perm -> unix perm */
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int s_ftsuffix; /* ,xyz hex filetype suffix option */
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__u32 s_ids_per_zone; /* max. no ids in one zone */
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__u32 s_idlen; /* length of ID in map */
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__u32 s_map_size; /* sector size of a map */
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signed int s_map2blk; /* shift left by this for map->sector*/
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unsigned int s_log2sharesize;/* log2 share size */
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unsigned int s_namelen; /* maximum number of characters in name */
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};
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static inline struct adfs_sb_info *ADFS_SB(struct super_block *sb)
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{
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return sb->s_fs_info;
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}
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/*
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* Directory handling
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*/
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struct adfs_dir {
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struct super_block *sb;
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int nr_buffers;
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struct buffer_head *bh[4];
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struct buffer_head **bhs;
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unsigned int pos;
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__u32 parent_id;
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union {
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struct adfs_dirheader *dirhead;
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struct adfs_bigdirheader *bighead;
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};
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union {
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struct adfs_newdirtail *newtail;
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struct adfs_bigdirtail *bigtail;
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};
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};
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/*
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* This is the overall maximum name length
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*/
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#define ADFS_MAX_NAME_LEN (256 + 4) /* +4 for ,xyz hex filetype suffix */
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struct object_info {
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__u32 parent_id; /* parent object id */
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__u32 indaddr; /* indirect disc addr */
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__u32 loadaddr; /* load address */
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__u32 execaddr; /* execution address */
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__u32 size; /* size */
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__u8 attr; /* RISC OS attributes */
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unsigned int name_len; /* name length */
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char name[ADFS_MAX_NAME_LEN];/* file name */
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};
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struct adfs_dir_ops {
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int (*read)(struct super_block *sb, unsigned int indaddr,
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unsigned int size, struct adfs_dir *dir);
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int (*iterate)(struct adfs_dir *dir, struct dir_context *ctx);
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int (*setpos)(struct adfs_dir *dir, unsigned int fpos);
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int (*getnext)(struct adfs_dir *dir, struct object_info *obj);
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int (*update)(struct adfs_dir *dir, struct object_info *obj);
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int (*create)(struct adfs_dir *dir, struct object_info *obj);
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int (*remove)(struct adfs_dir *dir, struct object_info *obj);
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int (*commit)(struct adfs_dir *dir);
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};
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struct adfs_discmap {
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struct buffer_head *dm_bh;
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__u32 dm_startblk;
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unsigned int dm_startbit;
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unsigned int dm_endbit;
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};
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/* Inode stuff */
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struct inode *adfs_iget(struct super_block *sb, struct object_info *obj);
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int adfs_write_inode(struct inode *inode, struct writeback_control *wbc);
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int adfs_notify_change(struct user_namespace *mnt_userns, struct dentry *dentry,
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struct iattr *attr);
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/* map.c */
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int adfs_map_lookup(struct super_block *sb, u32 frag_id, unsigned int offset);
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void adfs_map_statfs(struct super_block *sb, struct kstatfs *buf);
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struct adfs_discmap *adfs_read_map(struct super_block *sb, struct adfs_discrecord *dr);
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void adfs_free_map(struct super_block *sb);
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/* Misc */
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__printf(3, 4)
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void __adfs_error(struct super_block *sb, const char *function,
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const char *fmt, ...);
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#define adfs_error(sb, fmt...) __adfs_error(sb, __func__, fmt)
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void adfs_msg(struct super_block *sb, const char *pfx, const char *fmt, ...);
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/* super.c */
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/*
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* Inodes and file operations
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*/
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/* dir_*.c */
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extern const struct inode_operations adfs_dir_inode_operations;
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extern const struct file_operations adfs_dir_operations;
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extern const struct dentry_operations adfs_dentry_operations;
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extern const struct adfs_dir_ops adfs_f_dir_ops;
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extern const struct adfs_dir_ops adfs_fplus_dir_ops;
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int adfs_dir_copyfrom(void *dst, struct adfs_dir *dir, unsigned int offset,
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size_t len);
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int adfs_dir_copyto(struct adfs_dir *dir, unsigned int offset, const void *src,
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size_t len);
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void adfs_dir_relse(struct adfs_dir *dir);
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int adfs_dir_read_buffers(struct super_block *sb, u32 indaddr,
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unsigned int size, struct adfs_dir *dir);
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void adfs_object_fixup(struct adfs_dir *dir, struct object_info *obj);
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extern int adfs_dir_update(struct super_block *sb, struct object_info *obj,
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int wait);
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/* file.c */
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extern const struct inode_operations adfs_file_inode_operations;
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extern const struct file_operations adfs_file_operations;
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static inline __u32 signed_asl(__u32 val, signed int shift)
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{
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if (shift >= 0)
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val <<= shift;
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else
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val >>= -shift;
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return val;
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}
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/*
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* Calculate the address of a block in an object given the block offset
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* and the object identity.
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*
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* The root directory ID should always be looked up in the map [3.4]
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*/
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static inline int __adfs_block_map(struct super_block *sb, u32 indaddr,
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unsigned int block)
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{
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if (indaddr & 255) {
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unsigned int off;
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off = (indaddr & 255) - 1;
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block += off << ADFS_SB(sb)->s_log2sharesize;
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}
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return adfs_map_lookup(sb, indaddr >> 8, block);
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}
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/* Return the disc record from the map */
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static inline
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struct adfs_discrecord *adfs_map_discrecord(struct adfs_discmap *dm)
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{
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return (void *)(dm[0].dm_bh->b_data + 4);
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}
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static inline u64 adfs_disc_size(const struct adfs_discrecord *dr)
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{
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return (u64)le32_to_cpu(dr->disc_size_high) << 32 |
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le32_to_cpu(dr->disc_size);
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}
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