/*
* Read a new inode into a file structure.
*/
static int
read_inode(ino32_t inumber, struct open_file *f)
{
struct file *fp = (struct file *)f->f_fsdata;
struct fs *fs = fp->f_fs;
char *buf;
size_t rsize;
int rc;
daddr_t inode_sector = 0; /* XXX: gcc */
#ifdef LIBSA_LFS
struct ufs_dinode *dip;
int cnt;
#endif
#ifdef LIBSA_LFS
if (inumber == fs->lfs_ifile)
inode_sector = FSBTODB(fs, fs->lfs_idaddr);
else if ((rc = find_inode_sector(inumber, f, &inode_sector)) != 0)
return rc;
#else
inode_sector = FSBTODB(fs, ino_to_fsba(fs, inumber));
#endif
/*
* Read inode and save it.
*/
buf = fp->f_buf;
twiddle();
rc = DEV_STRATEGY(f->f_dev)(f->f_devdata, F_READ,
inode_sector, fs->fs_bsize, buf, &rsize);
if (rc)
return rc;
if (rsize != fs->fs_bsize)
return EIO;
#ifdef LIBSA_LFS
cnt = INOPBx(fs);
dip = (struct ufs_dinode *)buf + (cnt - 1);
for (; dip->di_inumber != inumber; --dip) {
/* kernel code panics, but boot blocks which panic are Bad. */
if (--cnt == 0)
return EINVAL;
}
fp->f_di = *dip;
#else
fp->f_di = ((struct ufs_dinode *)buf)[ino_to_fsbo(fs, inumber)];
#endif
/*
* Clear out the old buffers
*/
fp->f_ind_cache_block = ~0;
fp->f_buf_blkno = -1;
return rc;
}
int
read_gdblock(struct open_file *f, struct m_ext2fs *fs)
{
struct file *fp = (struct file *)f->f_fsdata;
size_t rsize;
uint gdpb;
int i, rc;
gdpb = fs->e2fs_bsize / sizeof(struct ext2_gd);
for (i = 0; i < fs->e2fs_ngdb; i++) {
rc = DEV_STRATEGY(f->f_dev)(f->f_devdata, F_READ,
FSBTODB(fs, fs->e2fs.e2fs_first_dblock +
1 /* superblock */ + i),
fs->e2fs_bsize, fp->f_buf, &rsize);
if (rc)
return rc;
if (rsize != fs->e2fs_bsize)
return EIO;
e2fs_cgload((struct ext2_gd *)fp->f_buf,
&fs->e2fs_gd[i * gdpb],
(i == (fs->e2fs_ngdb - 1)) ?
(fs->e2fs_ncg - gdpb * i) * sizeof(struct ext2_gd):
fs->e2fs_bsize);
}
return 0;
}
/*
* Find an inode's block. Look it up in the ifile. Whee!
*/
static int
find_inode_sector(ino32_t inumber, struct open_file *f, daddr_t *isp)
{
struct file *fp = (struct file *)f->f_fsdata;
struct fs *fs = fp->f_fs;
daddr_t ifileent_blkno;
char *ent_in_buf;
size_t buf_after_ent;
int rc;
rc = read_inode(fs->lfs_ifile, f);
if (rc)
return rc;
ifileent_blkno =
(inumber / fs->lfs_ifpb) + fs->lfs_cleansz + fs->lfs_segtabsz;
fp->f_seekp = (off_t)ifileent_blkno * fs->fs_bsize +
(inumber % fs->lfs_ifpb) * sizeof (IFILE_Vx);
rc = buf_read_file(f, &ent_in_buf, &buf_after_ent);
if (rc)
return rc;
/* make sure something's not badly wrong, but don't panic. */
if (buf_after_ent < sizeof (IFILE_Vx))
return EINVAL;
*isp = FSBTODB(fs, ((IFILE_Vx *)ent_in_buf)->if_daddr);
if (*isp == LFS_UNUSED_DADDR) /* again, something badly wrong */
return EINVAL;
return 0;
}
/*
* Read a portion of a file into an internal buffer.
* Return the location in the buffer and the amount in the buffer.
*/
static int
buf_read_file(struct open_file *f, char **buf_p, size_t *size_p)
{
struct file *fp = (struct file *)f->f_fsdata;
struct fs *fs = fp->f_fs;
long off;
indp_t file_block;
size_t block_size;
int rc;
off = ufs_blkoff(fs, fp->f_seekp);
file_block = ufs_lblkno(fs, fp->f_seekp);
#ifdef LIBSA_LFS
block_size = dblksize(fs, &fp->f_di, file_block);
#else
block_size = ffs_sblksize(fs, (int64_t)fp->f_di.di_size, file_block);
#endif
if (file_block != fp->f_buf_blkno) {
indp_t disk_block = 0; /* XXX: gcc */
rc = block_map(f, file_block, &disk_block);
if (rc)
return rc;
if (disk_block == 0) {
memset(fp->f_buf, 0, block_size);
fp->f_buf_size = block_size;
} else {
twiddle();
rc = DEV_STRATEGY(f->f_dev)(f->f_devdata, F_READ,
FSBTODB(fs, disk_block),
block_size, fp->f_buf, &fp->f_buf_size);
if (rc)
return rc;
}
fp->f_buf_blkno = file_block;
}
/*
* Return address of byte in buffer corresponding to
* offset, and size of remainder of buffer after that
* byte.
*/
*buf_p = fp->f_buf + off;
*size_p = block_size - off;
/*
* But truncate buffer at end of file.
*/
if (*size_p > fp->f_di.di_size - fp->f_seekp)
*size_p = fp->f_di.di_size - fp->f_seekp;
return 0;
}
/*
* Read a portion of a file into an internal buffer.
* Return the location in the buffer and the amount in the buffer.
*/
static int
buf_read_file(struct open_file *f, char **buf_p, size_t *size_p)
{
struct file *fp = (struct file *)f->f_fsdata;
struct m_ext2fs *fs = fp->f_fs;
long off;
indp_t file_block;
indp_t disk_block = 0; /* XXX: gcc */
size_t block_size;
int rc;
off = ext2_blkoff(fs, fp->f_seekp);
file_block = ext2_lblkno(fs, fp->f_seekp);
block_size = fs->e2fs_bsize; /* no fragment */
if (file_block != fp->f_buf_blkno) {
rc = block_map(f, file_block, &disk_block);
if (rc)
return rc;
if (disk_block == 0) {
memset(fp->f_buf, 0, block_size);
fp->f_buf_size = block_size;
} else {
twiddle();
rc = DEV_STRATEGY(f->f_dev)(f->f_devdata, F_READ,
FSBTODB(fs, disk_block),
block_size, fp->f_buf, &fp->f_buf_size);
if (rc)
return rc;
}
fp->f_buf_blkno = file_block;
}
/*
* Return address of byte in buffer corresponding to
* offset, and size of remainder of buffer after that
* byte.
*/
*buf_p = fp->f_buf + off;
*size_p = block_size - off;
/*
* But truncate buffer at end of file.
*/
/* XXX should handle LARGEFILE */
if (*size_p > fp->f_di.e2di_size - fp->f_seekp)
*size_p = fp->f_di.e2di_size - fp->f_seekp;
return 0;
}
/*
* Read a portion of a file into an internal buffer.
* Return the location in the buffer and the amount in the buffer.
*/
static int
buf_read_file(struct open_file *f, void *v, size_t *size_p)
{
char **buf_p = v;
struct file *fp = (struct file *)f->f_fsdata;
struct mfs_sblock *fs = fp->f_fs;
long off;
block_t file_block;
block_t disk_block;
size_t block_size;
int rc;
off = mfs_blkoff(fs, fp->f_seekp);
file_block = mfs_lblkno(fs, fp->f_seekp);
block_size = fs->mfs_block_size;
if (file_block != fp->f_buf_blkno) {
rc = block_map(f, file_block, &disk_block);
if (rc)
return rc;
if (disk_block == 0) {
memset(fp->f_buf, 0, block_size);
fp->f_buf_size = block_size;
} else {
twiddle();
rc = DEV_STRATEGY(f->f_dev)(f->f_devdata, F_READ,
FSBTODB(fs, disk_block),
block_size, fp->f_buf, &fp->f_buf_size);
if (rc)
return rc;
}
fp->f_buf_blkno = file_block;
}
/*
* Return address of byte in buffer corresponding to
* offset, and size of remainder of buffer after that
* byte.
*/
*buf_p = fp->f_buf + off;
*size_p = block_size - off;
/*
* But truncate buffer at end of file.
*/
if (*size_p > fp->f_di.mdi_size - fp->f_seekp)
*size_p = fp->f_di.mdi_size - fp->f_seekp;
return 0;
}
/*
* Read a new inode into a file structure.
*/
static int
read_inode(ino32_t inumber, struct open_file *f)
{
struct file *fp = (struct file *)f->f_fsdata;
struct m_ext2fs *fs = fp->f_fs;
char *buf;
size_t rsize;
int rc;
daddr_t inode_sector;
struct ext2fs_dinode *dip;
inode_sector = FSBTODB(fs, ino_to_fsba(fs, inumber));
/*
* Read inode and save it.
*/
buf = fp->f_buf;
twiddle();
rc = DEV_STRATEGY(f->f_dev)(f->f_devdata, F_READ,
inode_sector, fs->e2fs_bsize, buf, &rsize);
if (rc)
return rc;
if (rsize != fs->e2fs_bsize)
return EIO;
dip = (struct ext2fs_dinode *)(buf +
EXT2_DINODE_SIZE(fs) * ino_to_fsbo(fs, inumber));
e2fs_iload(dip, &fp->f_di, EXT2_DINODE_SIZE(fs));
/*
* Clear out the old buffers
*/
fp->f_ind_cache_block = ~0;
fp->f_buf_blkno = -1;
return rc;
}
/*
* Open a file.
*/
__compactcall int
ufs_open(const char *path, struct open_file *f)
{
#ifndef LIBSA_FS_SINGLECOMPONENT
const char *cp, *ncp;
int c;
#endif
ino32_t inumber;
struct file *fp;
struct fs *fs;
int rc;
#ifndef LIBSA_NO_FS_SYMLINK
ino32_t parent_inumber;
int nlinks = 0;
char namebuf[MAXPATHLEN+1];
char *buf;
#endif
/* allocate file system specific data structure */
fp = alloc(sizeof(struct file));
memset(fp, 0, sizeof(struct file));
f->f_fsdata = (void *)fp;
/* allocate space and read super block */
fs = alloc(SBLOCKSIZE);
fp->f_fs = fs;
twiddle();
#ifdef LIBSA_FFSv2
rc = ffs_find_superblock(f, fs);
if (rc)
goto out;
#else
{
size_t buf_size;
rc = DEV_STRATEGY(f->f_dev)(f->f_devdata, F_READ,
SBLOCKOFFSET / DEV_BSIZE, SBLOCKSIZE, fs, &buf_size);
if (rc)
goto out;
if (buf_size != SBLOCKSIZE ||
#ifdef LIBSA_FFS
fs->lfs_version != REQUIRED_LFS_VERSION ||
#endif
fs->fs_magic != FS_MAGIC) {
rc = EINVAL;
goto out;
}
}
#if defined(LIBSA_LFS) && REQUIRED_LFS_VERSION == 2
/*
* XXX We should check the second superblock and use the eldest
* of the two. See comments near the top of lfs_mountfs()
* in sys/ufs/lfs/lfs_vfsops.c.
* This may need a LIBSA_LFS_SMALL check as well.
*/
#endif
#endif
#ifdef LIBSA_FFSv1
ffs_oldfscompat(fs);
#endif
if (fs->fs_bsize > MAXBSIZE ||
(size_t)fs->fs_bsize < sizeof(struct fs)) {
rc = EINVAL;
goto out;
}
/*
* Calculate indirect block levels.
*/
{
indp_t mult;
int ln2;
/*
* We note that the number of indirect blocks is always
* a power of 2. This lets us use shifts and masks instead
* of divide and remainder and avoinds pulling in the
* 64bit division routine into the boot code.
*/
mult = UFS_NINDIR(fs);
#ifdef DEBUG
if (mult & (mult - 1)) {
/* Hummm was't a power of 2 */
rc = EINVAL;
goto out;
}
#endif
for (ln2 = 0; mult != 1; ln2++)
mult >>= 1;
fp->f_nishift = ln2;
}
/* alloc a block sized buffer used for all fs transfers */
fp->f_buf = alloc(fs->fs_bsize);
inumber = UFS_ROOTINO;
if ((rc = read_inode(inumber, f)) != 0)
goto out;
#ifndef LIBSA_FS_SINGLECOMPONENT
cp = path;
while (*cp) {
/*
* Remove extra separators
*/
while (*cp == '/')
cp++;
if (*cp == '\0')
break;
/*
* Check that current node is a directory.
*/
if ((fp->f_di.di_mode & IFMT) != IFDIR) {
rc = ENOTDIR;
goto out;
}
/*
* Get next component of path name.
*/
ncp = cp;
while ((c = *cp) != '\0' && c != '/')
cp++;
/*
* Look up component in current directory.
* Save directory inumber in case we find a
* symbolic link.
*/
#ifndef LIBSA_NO_FS_SYMLINK
parent_inumber = inumber;
#endif
rc = search_directory(ncp, cp - ncp, f, &inumber);
if (rc)
goto out;
/*
* Open next component.
*/
if ((rc = read_inode(inumber, f)) != 0)
goto out;
#ifndef LIBSA_NO_FS_SYMLINK
/*
* Check for symbolic link.
*/
if ((fp->f_di.di_mode & IFMT) == IFLNK) {
int link_len = fp->f_di.di_size;
int len;
len = strlen(cp);
if (link_len + len > MAXPATHLEN ||
++nlinks > MAXSYMLINKS) {
rc = ENOENT;
goto out;
}
memmove(&namebuf[link_len], cp, len + 1);
if (link_len < fs->fs_maxsymlinklen) {
memcpy(namebuf, fp->f_di.di_db, link_len);
} else {
/*
* Read file for symbolic link
*/
size_t buf_size;
indp_t disk_block;
buf = fp->f_buf;
rc = block_map(f, (indp_t)0, &disk_block);
if (rc)
goto out;
twiddle();
rc = DEV_STRATEGY(f->f_dev)(f->f_devdata,
F_READ, FSBTODB(fs, disk_block),
fs->fs_bsize, buf, &buf_size);
if (rc)
goto out;
memcpy(namebuf, buf, link_len);
}
/*
* If relative pathname, restart at parent directory.
* If absolute pathname, restart at root.
*/
cp = namebuf;
if (*cp != '/')
inumber = parent_inumber;
else
inumber = (ino32_t)UFS_ROOTINO;
if ((rc = read_inode(inumber, f)) != 0)
goto out;
}
#endif /* !LIBSA_NO_FS_SYMLINK */
}
/*
* Found terminal component.
*/
rc = 0;
#else /* !LIBSA_FS_SINGLECOMPONENT */
/* look up component in the current (root) directory */
rc = search_directory(path, strlen(path), f, &inumber);
if (rc)
goto out;
/* open it */
rc = read_inode(inumber, f);
#endif /* !LIBSA_FS_SINGLECOMPONENT */
fp->f_seekp = 0; /* reset seek pointer */
out:
if (rc)
ufs_close(f);
#ifdef FSMOD /* Only defined for lfs */
else
fsmod = FSMOD;
#endif
return rc;
}
/*
* Given an offset in a file, find the disk block number that
* contains that block.
*/
static int
block_map(struct open_file *f, indp_t file_block, indp_t *disk_block_p)
{
struct file *fp = (struct file *)f->f_fsdata;
struct fs *fs = fp->f_fs;
uint level;
indp_t ind_cache;
indp_t ind_block_num;
size_t rsize;
int rc;
indp_t *buf = (void *)fp->f_buf;
/*
* Index structure of an inode:
*
* di_db[0..UFS_NDADDR-1] hold block numbers for blocks
* 0..UFS_NDADDR-1
*
* di_ib[0] index block 0 is the single indirect block
* holds block numbers for blocks
* UFS_NDADDR .. UFS_NDADDR + UFS_NINDIR(fs)-1
*
* di_ib[1] index block 1 is the double indirect block
* holds block numbers for INDEX blocks for blocks
* UFS_NDADDR + UFS_NINDIR(fs) ..
* UFS_NDADDR + UFS_NINDIR(fs) + UFS_NINDIR(fs)**2 - 1
*
* di_ib[2] index block 2 is the triple indirect block
* holds block numbers for double-indirect
* blocks for blocks
* UFS_NDADDR + UFS_NINDIR(fs) + UFS_NINDIR(fs)**2 ..
* UFS_NDADDR + UFS_NINDIR(fs) + UFS_NINDIR(fs)**2
* + UFS_NINDIR(fs)**3 - 1
*/
if (file_block < UFS_NDADDR) {
/* Direct block. */
*disk_block_p = fp->f_di.di_db[file_block];
return 0;
}
file_block -= UFS_NDADDR;
ind_cache = file_block >> LN2_IND_CACHE_SZ;
if (ind_cache == fp->f_ind_cache_block) {
*disk_block_p = fp->f_ind_cache[file_block & IND_CACHE_MASK];
return 0;
}
for (level = 0;;) {
level += fp->f_nishift;
if (file_block < (indp_t)1 << level)
break;
if (level > UFS_NIADDR * fp->f_nishift)
/* Block number too high */
return EFBIG;
file_block -= (indp_t)1 << level;
}
ind_block_num = fp->f_di.di_ib[level / fp->f_nishift - 1];
for (;;) {
level -= fp->f_nishift;
if (ind_block_num == 0) {
*disk_block_p = 0; /* missing */
return 0;
}
twiddle();
/*
* If we were feeling brave, we could work out the number
* of the disk sector and read a single disk sector instead
* of a filesystem block.
* However we don't do this very often anyway...
*/
rc = DEV_STRATEGY(f->f_dev)(f->f_devdata, F_READ,
FSBTODB(fp->f_fs, ind_block_num), fs->fs_bsize,
buf, &rsize);
if (rc)
return rc;
if (rsize != fs->fs_bsize)
return EIO;
ind_block_num = buf[file_block >> level];
if (level == 0)
break;
file_block &= (1 << level) - 1;
}
/* Save the part of the block that contains this sector */
memcpy(fp->f_ind_cache, &buf[file_block & ~IND_CACHE_MASK],
IND_CACHE_SZ * sizeof fp->f_ind_cache[0]);
fp->f_ind_cache_block = ind_cache;
*disk_block_p = ind_block_num;
return 0;
}
/*
* Open a file.
*/
__compactcall int
ext2fs_open(const char *path, struct open_file *f)
{
#ifndef LIBSA_FS_SINGLECOMPONENT
const char *cp, *ncp;
int c;
#endif
ino32_t inumber;
struct file *fp;
struct m_ext2fs *fs;
int rc;
#ifndef LIBSA_NO_FS_SYMLINK
ino32_t parent_inumber;
int nlinks = 0;
char namebuf[MAXPATHLEN+1];
char *buf;
#endif
/* allocate file system specific data structure */
fp = alloc(sizeof(struct file));
memset(fp, 0, sizeof(struct file));
f->f_fsdata = (void *)fp;
/* allocate space and read super block */
fs = alloc(sizeof(*fs));
memset(fs, 0, sizeof(*fs));
fp->f_fs = fs;
twiddle();
rc = read_sblock(f, fs);
if (rc)
goto out;
#ifdef EXT2FS_DEBUG
dump_sblock(fs);
#endif
/* alloc a block sized buffer used for all fs transfers */
fp->f_buf = alloc(fs->e2fs_bsize);
/* read group descriptor blocks */
fs->e2fs_gd = alloc(sizeof(struct ext2_gd) * fs->e2fs_ncg);
rc = read_gdblock(f, fs);
if (rc)
goto out;
/*
* Calculate indirect block levels.
*/
{
indp_t mult;
int ln2;
/*
* We note that the number of indirect blocks is always
* a power of 2. This lets us use shifts and masks instead
* of divide and remainder and avoinds pulling in the
* 64bit division routine into the boot code.
*/
mult = EXT2_NINDIR(fs);
#ifdef DEBUG
if (!powerof2(mult)) {
/* Hummm was't a power of 2 */
rc = EINVAL;
goto out;
}
#endif
for (ln2 = 0; mult != 1; ln2++)
mult >>= 1;
fp->f_nishift = ln2;
}
inumber = EXT2_ROOTINO;
if ((rc = read_inode(inumber, f)) != 0)
goto out;
#ifndef LIBSA_FS_SINGLECOMPONENT
cp = path;
while (*cp) {
/*
* Remove extra separators
*/
while (*cp == '/')
cp++;
if (*cp == '\0')
break;
/*
* Check that current node is a directory.
*/
if ((fp->f_di.e2di_mode & EXT2_IFMT) != EXT2_IFDIR) {
rc = ENOTDIR;
goto out;
}
/*
* Get next component of path name.
*/
ncp = cp;
while ((c = *cp) != '\0' && c != '/')
cp++;
/*
* Look up component in current directory.
* Save directory inumber in case we find a
* symbolic link.
*/
#ifndef LIBSA_NO_FS_SYMLINK
parent_inumber = inumber;
#endif
rc = search_directory(ncp, cp - ncp, f, &inumber);
if (rc)
goto out;
/*
* Open next component.
*/
if ((rc = read_inode(inumber, f)) != 0)
goto out;
#ifndef LIBSA_NO_FS_SYMLINK
/*
* Check for symbolic link.
*/
if ((fp->f_di.e2di_mode & EXT2_IFMT) == EXT2_IFLNK) {
/* XXX should handle LARGEFILE */
int link_len = fp->f_di.e2di_size;
int len;
len = strlen(cp);
if (link_len + len > MAXPATHLEN ||
++nlinks > MAXSYMLINKS) {
rc = ENOENT;
goto out;
}
memmove(&namebuf[link_len], cp, len + 1);
if (link_len < EXT2_MAXSYMLINKLEN) {
memcpy(namebuf, fp->f_di.e2di_blocks, link_len);
} else {
/*
* Read file for symbolic link
*/
size_t buf_size;
indp_t disk_block;
buf = fp->f_buf;
rc = block_map(f, (indp_t)0, &disk_block);
if (rc)
goto out;
twiddle();
rc = DEV_STRATEGY(f->f_dev)(f->f_devdata,
F_READ, FSBTODB(fs, disk_block),
fs->e2fs_bsize, buf, &buf_size);
if (rc)
goto out;
memcpy(namebuf, buf, link_len);
}
/*
* If relative pathname, restart at parent directory.
* If absolute pathname, restart at root.
*/
cp = namebuf;
if (*cp != '/')
inumber = parent_inumber;
else
inumber = (ino32_t)EXT2_ROOTINO;
if ((rc = read_inode(inumber, f)) != 0)
goto out;
}
#endif /* !LIBSA_NO_FS_SYMLINK */
}
/*
* Found terminal component.
*/
rc = 0;
#else /* !LIBSA_FS_SINGLECOMPONENT */
/* look up component in the current (root) directory */
rc = search_directory(path, strlen(path), f, &inumber);
if (rc)
goto out;
/* open it */
rc = read_inode(inumber, f);
#endif /* !LIBSA_FS_SINGLECOMPONENT */
fp->f_seekp = 0; /* reset seek pointer */
out:
if (rc)
ext2fs_close(f);
else
fsmod = "ext2fs";
return rc;
}
/*
* Given an offset in a file, find the disk block number (not zone!)
* that contains that block.
*/
static int
block_map(struct open_file *f, block_t file_block, block_t *disk_block_p)
{
struct file *fp = (struct file *)f->f_fsdata;
struct mfs_sblock *fs = fp->f_fs;
uint level;
block_t ind_cache;
block_t ind_block_num;
zone_t zone;
size_t rsize;
int rc;
int boff;
int scale = fs->mfs_log_zone_size; /* for block-zone conversion */
block_t *buf = (void *)fp->f_buf;
/*
* Index structure of an inode:
*
* mdi_blocks[0..NR_DZONES-1]
* hold zone numbers for zones
* 0..NR_DZONES-1
*
* mdi_blocks[NR_DZONES+0]
* block NDADDR+0 is the single indirect block
* holds zone numbers for zones
* NR_DZONES .. NR_DZONES + MFS_NINDIR(fs)-1
*
* mdi_blocks[NR_DZONES+1]
* block NDADDR+1 is the double indirect block
* holds zone numbers for INDEX blocks for zones
* NR_DZONES + MFS_NINDIR(fs) ..
* NR_TZONES + MFS_NINDIR(fs) + MFS_NINDIR(fs)**2 - 1
*/
zone = file_block >> scale;
boff = (int) (file_block - (zone << scale) ); /* relative blk in zone */
if (zone < NR_DZONES) {
/* Direct zone */
zone_t z = fs2h32(fp->f_di.mdi_zone[zone]);
if (z == NO_ZONE) {
*disk_block_p = NO_BLOCK;
return 0;
}
*disk_block_p = (block_t) ((z << scale) + boff);
return 0;
}
zone -= NR_DZONES;
ind_cache = zone >> LN2_IND_CACHE_SZ;
if (ind_cache == fp->f_ind_cache_block) {
*disk_block_p =
fs2h32(fp->f_ind_cache[zone & IND_CACHE_MASK]);
return 0;
}
for (level = 0;;) {
level += fp->f_nishift;
if (zone < (block_t)1 << level)
break;
if (level > NIADDR * fp->f_nishift)
/* Zone number too high */
return EFBIG;
zone -= (block_t)1 << level;
}
ind_block_num =
fs2h32(fp->f_di.mdi_zone[NR_DZONES + (level / fp->f_nishift - 1)]);
for (;;) {
level -= fp->f_nishift;
if (ind_block_num == 0) {
*disk_block_p = NO_BLOCK; /* missing */
return 0;
}
twiddle();
/*
* If we were feeling brave, we could work out the number
* of the disk sector and read a single disk sector instead
* of a filesystem block.
* However we don't do this very often anyway...
*/
rc = DEV_STRATEGY(f->f_dev)(f->f_devdata, F_READ,
FSBTODB(fs, ind_block_num), fs->mfs_block_size,
buf, &rsize);
if (rc)
return rc;
if (rsize != fs->mfs_block_size)
return EIO;
ind_block_num = fs2h32(buf[zone >> level]);
if (level == 0)
break;
zone &= (1 << level) - 1;
}
/* Save the part of the block that contains this sector */
memcpy(fp->f_ind_cache, &buf[zone & ~IND_CACHE_MASK],
IND_CACHE_SZ * sizeof fp->f_ind_cache[0]);
fp->f_ind_cache_block = ind_cache;
zone = (zone_t)ind_block_num;
*disk_block_p = (block_t)((zone << scale) + boff);
return 0;
}
