linux/fs/affs/affs.h
Al Viro 29333920a5 Fix remount races with symlink handling in affs
A couple of fields in affs_sb_info is used in follow_link() and
symlink() for handling AFFS "absolute" symlinks.  Need locking
against affs_remount() updates.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-01-26 22:22:24 -05:00

305 lines
10 KiB
C

#include <linux/types.h>
#include <linux/fs.h>
#include <linux/buffer_head.h>
#include <linux/amigaffs.h>
#include <linux/mutex.h>
/* AmigaOS allows file names with up to 30 characters length.
* Names longer than that will be silently truncated. If you
* want to disallow this, comment out the following #define.
* Creating filesystem objects with longer names will then
* result in an error (ENAMETOOLONG).
*/
/*#define AFFS_NO_TRUNCATE */
/* Ugly macros make the code more pretty. */
#define GET_END_PTR(st,p,sz) ((st *)((char *)(p)+((sz)-sizeof(st))))
#define AFFS_GET_HASHENTRY(data,hashkey) be32_to_cpu(((struct dir_front *)data)->hashtable[hashkey])
#define AFFS_BLOCK(sb, bh, blk) (AFFS_HEAD(bh)->table[AFFS_SB(sb)->s_hashsize-1-(blk)])
#ifdef __LITTLE_ENDIAN
#define BO_EXBITS 0x18UL
#elif defined(__BIG_ENDIAN)
#define BO_EXBITS 0x00UL
#else
#error Endianness must be known for affs to work.
#endif
#define AFFS_HEAD(bh) ((struct affs_head *)(bh)->b_data)
#define AFFS_TAIL(sb, bh) ((struct affs_tail *)((bh)->b_data+(sb)->s_blocksize-sizeof(struct affs_tail)))
#define AFFS_ROOT_HEAD(bh) ((struct affs_root_head *)(bh)->b_data)
#define AFFS_ROOT_TAIL(sb, bh) ((struct affs_root_tail *)((bh)->b_data+(sb)->s_blocksize-sizeof(struct affs_root_tail)))
#define AFFS_DATA_HEAD(bh) ((struct affs_data_head *)(bh)->b_data)
#define AFFS_DATA(bh) (((struct affs_data_head *)(bh)->b_data)->data)
#define AFFS_CACHE_SIZE PAGE_SIZE
#define AFFS_MAX_PREALLOC 32
#define AFFS_LC_SIZE (AFFS_CACHE_SIZE/sizeof(u32)/2)
#define AFFS_AC_SIZE (AFFS_CACHE_SIZE/sizeof(struct affs_ext_key)/2)
#define AFFS_AC_MASK (AFFS_AC_SIZE-1)
struct affs_ext_key {
u32 ext; /* idx of the extended block */
u32 key; /* block number */
};
/*
* affs fs inode data in memory
*/
struct affs_inode_info {
atomic_t i_opencnt;
struct semaphore i_link_lock; /* Protects internal inode access. */
struct semaphore i_ext_lock; /* Protects internal inode access. */
#define i_hash_lock i_ext_lock
u32 i_blkcnt; /* block count */
u32 i_extcnt; /* extended block count */
u32 *i_lc; /* linear cache of extended blocks */
u32 i_lc_size;
u32 i_lc_shift;
u32 i_lc_mask;
struct affs_ext_key *i_ac; /* associative cache of extended blocks */
u32 i_ext_last; /* last accessed extended block */
struct buffer_head *i_ext_bh; /* bh of last extended block */
loff_t mmu_private;
u32 i_protect; /* unused attribute bits */
u32 i_lastalloc; /* last allocated block */
int i_pa_cnt; /* number of preallocated blocks */
struct inode vfs_inode;
};
/* short cut to get to the affs specific inode data */
static inline struct affs_inode_info *AFFS_I(struct inode *inode)
{
return list_entry(inode, struct affs_inode_info, vfs_inode);
}
/*
* super-block data in memory
*
* Block numbers are adjusted for their actual size
*
*/
struct affs_bm_info {
u32 bm_key; /* Disk block number */
u32 bm_free; /* Free blocks in here */
};
struct affs_sb_info {
int s_partition_size; /* Partition size in blocks. */
int s_reserved; /* Number of reserved blocks. */
//u32 s_blksize; /* Initial device blksize */
u32 s_data_blksize; /* size of the data block w/o header */
u32 s_root_block; /* FFS root block number. */
int s_hashsize; /* Size of hash table. */
unsigned long s_flags; /* See below. */
uid_t s_uid; /* uid to override */
gid_t s_gid; /* gid to override */
umode_t s_mode; /* mode to override */
struct buffer_head *s_root_bh; /* Cached root block. */
struct mutex s_bmlock; /* Protects bitmap access. */
struct affs_bm_info *s_bitmap; /* Bitmap infos. */
u32 s_bmap_count; /* # of bitmap blocks. */
u32 s_bmap_bits; /* # of bits in one bitmap blocks */
u32 s_last_bmap;
struct buffer_head *s_bmap_bh;
char *s_prefix; /* Prefix for volumes and assigns. */
char s_volume[32]; /* Volume prefix for absolute symlinks. */
spinlock_t symlink_lock; /* protects the previous two */
};
#define SF_INTL 0x0001 /* International filesystem. */
#define SF_BM_VALID 0x0002 /* Bitmap is valid. */
#define SF_IMMUTABLE 0x0004 /* Protection bits cannot be changed */
#define SF_QUIET 0x0008 /* chmod errors will be not reported */
#define SF_SETUID 0x0010 /* Ignore Amiga uid */
#define SF_SETGID 0x0020 /* Ignore Amiga gid */
#define SF_SETMODE 0x0040 /* Ignore Amiga protection bits */
#define SF_MUFS 0x0100 /* Use MUFS uid/gid mapping */
#define SF_OFS 0x0200 /* Old filesystem */
#define SF_PREFIX 0x0400 /* Buffer for prefix is allocated */
#define SF_VERBOSE 0x0800 /* Talk about fs when mounting */
/* short cut to get to the affs specific sb data */
static inline struct affs_sb_info *AFFS_SB(struct super_block *sb)
{
return sb->s_fs_info;
}
/* amigaffs.c */
extern int affs_insert_hash(struct inode *inode, struct buffer_head *bh);
extern int affs_remove_hash(struct inode *dir, struct buffer_head *rem_bh);
extern int affs_remove_header(struct dentry *dentry);
extern u32 affs_checksum_block(struct super_block *sb, struct buffer_head *bh);
extern void affs_fix_checksum(struct super_block *sb, struct buffer_head *bh);
extern void secs_to_datestamp(time_t secs, struct affs_date *ds);
extern mode_t prot_to_mode(u32 prot);
extern void mode_to_prot(struct inode *inode);
extern void affs_error(struct super_block *sb, const char *function, const char *fmt, ...);
extern void affs_warning(struct super_block *sb, const char *function, const char *fmt, ...);
extern int affs_check_name(const unsigned char *name, int len);
extern int affs_copy_name(unsigned char *bstr, struct dentry *dentry);
/* bitmap. c */
extern u32 affs_count_free_blocks(struct super_block *s);
extern void affs_free_block(struct super_block *sb, u32 block);
extern u32 affs_alloc_block(struct inode *inode, u32 goal);
extern int affs_init_bitmap(struct super_block *sb, int *flags);
extern void affs_free_bitmap(struct super_block *sb);
/* namei.c */
extern int affs_hash_name(struct super_block *sb, const u8 *name, unsigned int len);
extern struct dentry *affs_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *);
extern int affs_unlink(struct inode *dir, struct dentry *dentry);
extern int affs_create(struct inode *dir, struct dentry *dentry, int mode, struct nameidata *);
extern int affs_mkdir(struct inode *dir, struct dentry *dentry, int mode);
extern int affs_rmdir(struct inode *dir, struct dentry *dentry);
extern int affs_link(struct dentry *olddentry, struct inode *dir,
struct dentry *dentry);
extern int affs_symlink(struct inode *dir, struct dentry *dentry,
const char *symname);
extern int affs_rename(struct inode *old_dir, struct dentry *old_dentry,
struct inode *new_dir, struct dentry *new_dentry);
/* inode.c */
extern unsigned long affs_parent_ino(struct inode *dir);
extern struct inode *affs_new_inode(struct inode *dir);
extern int affs_notify_change(struct dentry *dentry, struct iattr *attr);
extern void affs_delete_inode(struct inode *inode);
extern void affs_clear_inode(struct inode *inode);
extern struct inode *affs_iget(struct super_block *sb,
unsigned long ino);
extern int affs_write_inode(struct inode *inode, int);
extern int affs_add_entry(struct inode *dir, struct inode *inode, struct dentry *dentry, s32 type);
/* file.c */
void affs_free_prealloc(struct inode *inode);
extern void affs_truncate(struct inode *);
int affs_file_fsync(struct file *, struct dentry *, int);
/* dir.c */
extern void affs_dir_truncate(struct inode *);
/* jump tables */
extern const struct inode_operations affs_file_inode_operations;
extern const struct inode_operations affs_dir_inode_operations;
extern const struct inode_operations affs_symlink_inode_operations;
extern const struct file_operations affs_file_operations;
extern const struct file_operations affs_file_operations_ofs;
extern const struct file_operations affs_dir_operations;
extern const struct address_space_operations affs_symlink_aops;
extern const struct address_space_operations affs_aops;
extern const struct address_space_operations affs_aops_ofs;
extern const struct dentry_operations affs_dentry_operations;
static inline void
affs_set_blocksize(struct super_block *sb, int size)
{
sb_set_blocksize(sb, size);
}
static inline struct buffer_head *
affs_bread(struct super_block *sb, int block)
{
pr_debug("affs_bread: %d\n", block);
if (block >= AFFS_SB(sb)->s_reserved && block < AFFS_SB(sb)->s_partition_size)
return sb_bread(sb, block);
return NULL;
}
static inline struct buffer_head *
affs_getblk(struct super_block *sb, int block)
{
pr_debug("affs_getblk: %d\n", block);
if (block >= AFFS_SB(sb)->s_reserved && block < AFFS_SB(sb)->s_partition_size)
return sb_getblk(sb, block);
return NULL;
}
static inline struct buffer_head *
affs_getzeroblk(struct super_block *sb, int block)
{
struct buffer_head *bh;
pr_debug("affs_getzeroblk: %d\n", block);
if (block >= AFFS_SB(sb)->s_reserved && block < AFFS_SB(sb)->s_partition_size) {
bh = sb_getblk(sb, block);
lock_buffer(bh);
memset(bh->b_data, 0 , sb->s_blocksize);
set_buffer_uptodate(bh);
unlock_buffer(bh);
return bh;
}
return NULL;
}
static inline struct buffer_head *
affs_getemptyblk(struct super_block *sb, int block)
{
struct buffer_head *bh;
pr_debug("affs_getemptyblk: %d\n", block);
if (block >= AFFS_SB(sb)->s_reserved && block < AFFS_SB(sb)->s_partition_size) {
bh = sb_getblk(sb, block);
wait_on_buffer(bh);
set_buffer_uptodate(bh);
return bh;
}
return NULL;
}
static inline void
affs_brelse(struct buffer_head *bh)
{
if (bh)
pr_debug("affs_brelse: %lld\n", (long long) bh->b_blocknr);
brelse(bh);
}
static inline void
affs_adjust_checksum(struct buffer_head *bh, u32 val)
{
u32 tmp = be32_to_cpu(((__be32 *)bh->b_data)[5]);
((__be32 *)bh->b_data)[5] = cpu_to_be32(tmp - val);
}
static inline void
affs_adjust_bitmapchecksum(struct buffer_head *bh, u32 val)
{
u32 tmp = be32_to_cpu(((__be32 *)bh->b_data)[0]);
((__be32 *)bh->b_data)[0] = cpu_to_be32(tmp - val);
}
static inline void
affs_lock_link(struct inode *inode)
{
down(&AFFS_I(inode)->i_link_lock);
}
static inline void
affs_unlock_link(struct inode *inode)
{
up(&AFFS_I(inode)->i_link_lock);
}
static inline void
affs_lock_dir(struct inode *inode)
{
down(&AFFS_I(inode)->i_hash_lock);
}
static inline void
affs_unlock_dir(struct inode *inode)
{
up(&AFFS_I(inode)->i_hash_lock);
}
static inline void
affs_lock_ext(struct inode *inode)
{
down(&AFFS_I(inode)->i_ext_lock);
}
static inline void
affs_unlock_ext(struct inode *inode)
{
up(&AFFS_I(inode)->i_ext_lock);
}