]> git.ozlabs.org Git - yaboot.git/blobdiff - second/fs_xfs.c
Commit yaboot 1.3.4-pre1
[yaboot.git] / second / fs_xfs.c
diff --git a/second/fs_xfs.c b/second/fs_xfs.c
new file mode 100644 (file)
index 0000000..866ceac
--- /dev/null
@@ -0,0 +1,800 @@
+/*
+ *  fsys_xfs.c - an implementation for the SGI XFS file system
+ *
+ *  Copyright (C) 2001  Ethan Benson
+ *
+ *  Adapted from Grub
+ *
+ *  Copyright (C) 2001  Serguei Tzukanov
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to the Free Software
+ *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include "types.h"
+#include "ctype.h"
+#include "string.h"
+#include "stdlib.h"
+#include "fs.h"
+#include "xfs/xfs.h"
+#include "errors.h"
+
+#define SECTOR_BITS 9
+
+int xfs_mount (void);
+int xfs_read_data (char *buf, int len);
+int xfs_dir (char *dirname);
+
+/* Exported in struct fs_t */
+static int xfs_open(struct boot_file_t *file, const char *dev_name,
+                   struct partition_t *part, const char *file_name);
+static int xfs_read(struct boot_file_t *file, unsigned int size, void *buffer);
+static int xfs_seek(struct boot_file_t *file, unsigned int newpos);
+static int xfs_close(struct boot_file_t *file);
+
+struct fs_t xfs_filesystem = {
+       name:"xfs",
+       open:xfs_open,
+       read:xfs_read,
+       seek:xfs_seek,
+       close:xfs_close
+};
+
+struct boot_file_t *xfs_file;
+static char FSYS_BUF[32768];
+__u64 partition_offset;
+int errnum;
+
+static int
+xfs_open(struct boot_file_t *file, const char *dev_name,
+        struct partition_t *part, const char *file_name)
+{
+       static char buffer[1024];
+
+       DEBUG_ENTER;
+       DEBUG_OPEN;
+
+       if (part)
+       {
+               DEBUG_F("Determining offset for partition %d\n", part->part_number);
+               partition_offset = ((__u64)(part->part_start)) * ((__u64)part->blocksize);
+               DEBUG_F("%Lu = %lu * %hu\n", partition_offset,
+                       part->part_start,
+                       part->blocksize);
+       }
+       else
+               partition_offset = 0;
+
+       sprintf(buffer, "%s:%d", dev_name, 0); /* 0 is full disk in OF */
+       DEBUG_F("Trying to open dev_name=%s; filename=%s; partition offset=%Lu\n",
+               buffer, file_name, partition_offset);
+       file->of_device = prom_open(buffer);
+
+       if (file->of_device == PROM_INVALID_HANDLE || file->of_device == NULL)
+       {
+               DEBUG_F("Can't open device %p\n", file->of_device);
+               DEBUG_LEAVE(FILE_ERR_BADDEV);
+               return FILE_ERR_BADDEV;
+       }
+
+       DEBUG_F("%p was successfully opened\n", file->of_device);
+
+       xfs_file = file;
+    
+       if (xfs_mount() != 1)
+       {
+               DEBUG_F("Couldn't open XFS @ %s/%Lu\n", buffer, partition_offset);
+               prom_close(file->of_device);
+               DEBUG_LEAVE(FILE_ERR_BAD_FSYS);
+               DEBUG_SLEEP;
+               return FILE_ERR_BAD_FSYS;
+       }
+
+       DEBUG_F("Attempting to open %s\n", file_name);
+       strcpy(buffer, file_name); /* xfs_dir modifies argument */
+       if(!xfs_dir(buffer))
+       {
+               DEBUG_F("xfs_dir() failed. errnum = %d\n", errnum);
+               prom_close( file->of_device );
+               DEBUG_LEAVE_F(errnum);
+               DEBUG_SLEEP;
+               return errnum;
+       }
+
+       DEBUG_F("Successfully opened %s\n", file_name);
+
+       DEBUG_LEAVE(FILE_ERR_OK);
+       return FILE_ERR_OK;
+}
+
+static int
+xfs_read(struct boot_file_t *file, unsigned int size, void *buffer)
+{
+       return xfs_read_data(buffer, size);
+}
+
+static int
+xfs_seek(struct boot_file_t *file, unsigned int newpos)
+{
+       file->pos = newpos;
+       return FILE_ERR_OK;
+}
+
+static int
+xfs_close(struct boot_file_t *file)
+{
+       if(file->of_device)
+       {
+               prom_close(file->of_device);
+               file->of_device = 0;
+               DEBUG_F("xfs_close called\n");
+       }
+       return FILE_ERR_OK;
+}
+
+static int
+read_disk_block(struct boot_file_t *file, __u32 block, __u32 start,
+               __u32 length, void *buf)
+{
+       unsigned long long pos = block * 512;
+       pos += partition_offset + start;
+       DEBUG_F("Reading %u bytes, starting at block %u, disk offset %Lu\n",
+               length, block, pos);
+       if (!prom_lseek(file->of_device, pos)) {
+               DEBUG_F("prom_lseek failed\n");
+               return 0;
+       }
+       return prom_read(file->of_device, buf, length);
+}
+
+#define MAX_LINK_COUNT 8
+
+typedef struct xad {
+       xfs_fileoff_t offset;
+       xfs_fsblock_t start;
+       xfs_filblks_t len;
+} xad_t;
+
+struct xfs_info {
+       int bsize;
+       int dirbsize;
+       int isize;
+       unsigned int agblocks;
+       int bdlog;
+       int blklog;
+       int inopblog;
+       int agblklog;
+       int agnolog;
+       int dirblklog;
+       unsigned int nextents;
+       xfs_daddr_t next;
+       xfs_daddr_t daddr;
+       xfs_dablk_t forw;
+       xfs_dablk_t dablk;
+       xfs_bmbt_rec_32_t *xt;
+       xfs_bmbt_ptr_t ptr0;
+       int btnode_ptr0_off;
+       int i8param;
+       int dirpos;
+       int dirmax;
+       int blkoff;
+       int fpos;
+       xfs_ino_t rootino;
+};
+
+static struct xfs_info xfs;
+
+#define dirbuf         ((char *)FSYS_BUF)
+#define filebuf                ((char *)FSYS_BUF + 4096)
+#define inode          ((xfs_dinode_t *)((char *)FSYS_BUF + 8192))
+#define icore          (inode->di_core)
+
+#define        mask32lo(n)     (((__uint32_t)1 << (n)) - 1)
+
+#define        XFS_INO_MASK(k)         ((__uint32_t)((1ULL << (k)) - 1))
+#define        XFS_INO_OFFSET_BITS     xfs.inopblog
+#define        XFS_INO_AGBNO_BITS      xfs.agblklog
+#define        XFS_INO_AGINO_BITS      (xfs.agblklog + xfs.inopblog)
+#define        XFS_INO_AGNO_BITS       xfs.agnolog
+
+static inline xfs_agblock_t
+agino2agbno (xfs_agino_t agino)
+{
+       return agino >> XFS_INO_OFFSET_BITS;
+}
+
+static inline xfs_agnumber_t
+ino2agno (xfs_ino_t ino)
+{
+       return ino >> XFS_INO_AGINO_BITS;
+}
+
+static inline xfs_agino_t
+ino2agino (xfs_ino_t ino)
+{
+       return ino & XFS_INO_MASK(XFS_INO_AGINO_BITS);
+}
+
+static inline int
+ino2offset (xfs_ino_t ino)
+{
+       return ino & XFS_INO_MASK(XFS_INO_OFFSET_BITS);
+}
+
+/* XFS is big endian, powerpc is big endian */
+
+static inline __const__ __uint16_t
+le16 (__uint16_t x)
+{
+       return x;
+}
+
+static inline __const__ __uint32_t
+le32 (__uint32_t x)
+{
+       return x;
+}
+
+static inline __const__ __uint64_t
+le64 (__uint64_t x)
+{
+       return x;
+}
+
+static xfs_fsblock_t
+xt_start (xfs_bmbt_rec_32_t *r)
+{
+       return (((xfs_fsblock_t)(le32 (r->l1) & mask32lo(9))) << 43) | 
+              (((xfs_fsblock_t)le32 (r->l2)) << 11) |
+              (((xfs_fsblock_t)le32 (r->l3)) >> 21);
+}
+
+static xfs_fileoff_t
+xt_offset (xfs_bmbt_rec_32_t *r)
+{
+       return (((xfs_fileoff_t)le32 (r->l0) &
+               mask32lo(31)) << 23) |
+               (((xfs_fileoff_t)le32 (r->l1)) >> 9);
+}
+
+static xfs_filblks_t
+xt_len (xfs_bmbt_rec_32_t *r)
+{
+       return le32(r->l3) & mask32lo(21);
+}
+
+static const char xfs_highbit[256] = {
+       -1, 0, 1, 1, 2, 2, 2, 2,                        /* 00 .. 07 */
+       3, 3, 3, 3, 3, 3, 3, 3,                 /* 08 .. 0f */
+       4, 4, 4, 4, 4, 4, 4, 4,                 /* 10 .. 17 */
+       4, 4, 4, 4, 4, 4, 4, 4,                 /* 18 .. 1f */
+       5, 5, 5, 5, 5, 5, 5, 5,                 /* 20 .. 27 */
+       5, 5, 5, 5, 5, 5, 5, 5,                 /* 28 .. 2f */
+       5, 5, 5, 5, 5, 5, 5, 5,                 /* 30 .. 37 */
+       5, 5, 5, 5, 5, 5, 5, 5,                 /* 38 .. 3f */
+       6, 6, 6, 6, 6, 6, 6, 6,                 /* 40 .. 47 */
+       6, 6, 6, 6, 6, 6, 6, 6,                 /* 48 .. 4f */
+       6, 6, 6, 6, 6, 6, 6, 6,                 /* 50 .. 57 */
+       6, 6, 6, 6, 6, 6, 6, 6,                 /* 58 .. 5f */
+       6, 6, 6, 6, 6, 6, 6, 6,                 /* 60 .. 67 */
+       6, 6, 6, 6, 6, 6, 6, 6,                 /* 68 .. 6f */
+       6, 6, 6, 6, 6, 6, 6, 6,                 /* 70 .. 77 */
+       6, 6, 6, 6, 6, 6, 6, 6,                 /* 78 .. 7f */
+       7, 7, 7, 7, 7, 7, 7, 7,                 /* 80 .. 87 */
+       7, 7, 7, 7, 7, 7, 7, 7,                 /* 88 .. 8f */
+       7, 7, 7, 7, 7, 7, 7, 7,                 /* 90 .. 97 */
+       7, 7, 7, 7, 7, 7, 7, 7,                 /* 98 .. 9f */
+       7, 7, 7, 7, 7, 7, 7, 7,                 /* a0 .. a7 */
+       7, 7, 7, 7, 7, 7, 7, 7,                 /* a8 .. af */
+       7, 7, 7, 7, 7, 7, 7, 7,                 /* b0 .. b7 */
+       7, 7, 7, 7, 7, 7, 7, 7,                 /* b8 .. bf */
+       7, 7, 7, 7, 7, 7, 7, 7,                 /* c0 .. c7 */
+       7, 7, 7, 7, 7, 7, 7, 7,                 /* c8 .. cf */
+       7, 7, 7, 7, 7, 7, 7, 7,                 /* d0 .. d7 */
+       7, 7, 7, 7, 7, 7, 7, 7,                 /* d8 .. df */
+       7, 7, 7, 7, 7, 7, 7, 7,                 /* e0 .. e7 */
+       7, 7, 7, 7, 7, 7, 7, 7,                 /* e8 .. ef */
+       7, 7, 7, 7, 7, 7, 7, 7,                 /* f0 .. f7 */
+       7, 7, 7, 7, 7, 7, 7, 7,                 /* f8 .. ff */
+};
+
+static int
+xfs_highbit32(__uint32_t v)
+{
+       int             i;
+
+       if (v & 0xffff0000)
+               if (v & 0xff000000)
+                       i = 24;
+               else
+                       i = 16;
+       else if (v & 0x0000ffff)
+               if (v & 0x0000ff00)
+                       i = 8;
+               else
+                       i = 0;
+       else
+               return -1;
+       return i + xfs_highbit[(v >> i) & 0xff];
+}
+
+static int
+isinxt (xfs_fileoff_t key, xfs_fileoff_t offset, xfs_filblks_t len)
+{
+       return (key >= offset) ? (key < offset + len ? 1 : 0) : 0;
+}
+
+static xfs_daddr_t
+agb2daddr (xfs_agnumber_t agno, xfs_agblock_t agbno)
+{
+       return ((xfs_fsblock_t)agno*xfs.agblocks + agbno) << xfs.bdlog;
+}
+
+static xfs_daddr_t
+fsb2daddr (xfs_fsblock_t fsbno)
+{
+       return agb2daddr ((xfs_agnumber_t)(fsbno >> xfs.agblklog),
+                        (xfs_agblock_t)(fsbno & mask32lo(xfs.agblklog)));
+}
+
+static inline int
+btroot_maxrecs (void)
+{
+       int tmp = icore.di_forkoff ? (icore.di_forkoff << 3) : xfs.isize;
+
+       return (tmp - sizeof(xfs_bmdr_block_t) -
+               (int)((char *)&inode->di_u - (char*)inode)) /
+               (sizeof (xfs_bmbt_key_t) + sizeof (xfs_bmbt_ptr_t));
+}
+
+static int
+di_read (xfs_ino_t ino)
+{
+       xfs_agino_t agino;
+       xfs_agnumber_t agno;
+       xfs_agblock_t agbno;
+       xfs_daddr_t daddr;
+       int offset;
+
+       agno = ino2agno (ino);
+       agino = ino2agino (ino);
+       agbno = agino2agbno (agino);
+       offset = ino2offset (ino);
+       daddr = agb2daddr (agno, agbno);
+
+       read_disk_block(xfs_file, daddr, offset*xfs.isize, xfs.isize, (char *)inode);
+
+       xfs.ptr0 = *(xfs_bmbt_ptr_t *)
+                   (inode->di_u.di_c + sizeof(xfs_bmdr_block_t)
+                   + btroot_maxrecs ()*sizeof(xfs_bmbt_key_t));
+
+       return 1;
+}
+
+static void
+init_extents (void)
+{
+       xfs_bmbt_ptr_t ptr0;
+       xfs_btree_lblock_t h;
+
+       switch (icore.di_format) {
+       case XFS_DINODE_FMT_EXTENTS:
+               xfs.xt = inode->di_u.di_bmx;
+               xfs.nextents = le32 (icore.di_nextents);
+               break;
+       case XFS_DINODE_FMT_BTREE:
+               ptr0 = xfs.ptr0;
+               for (;;) {
+                       xfs.daddr = fsb2daddr (le64(ptr0));
+                       read_disk_block(xfs_file, xfs.daddr, 0,
+                                       sizeof(xfs_btree_lblock_t), (char *)&h);
+                       if (!h.bb_level) {
+                               xfs.nextents = le16(h.bb_numrecs);
+                               xfs.next = fsb2daddr (le64(h.bb_leftsib));
+                               xfs.fpos = sizeof(xfs_btree_block_t);
+                               return;
+                       }
+                       read_disk_block(xfs_file, xfs.daddr, xfs.btnode_ptr0_off,
+                                sizeof(xfs_bmbt_ptr_t), (char *)&ptr0);
+               }
+       }
+}
+
+static xad_t *
+next_extent (void)
+{
+       static xad_t xad;
+
+       switch (icore.di_format) {
+       case XFS_DINODE_FMT_EXTENTS:
+               if (xfs.nextents == 0)
+                       return NULL;
+               break;
+       case XFS_DINODE_FMT_BTREE:
+               if (xfs.nextents == 0) {
+                       xfs_btree_lblock_t h;
+                       if (xfs.next == 0)
+                               return NULL;
+                       xfs.daddr = xfs.next;
+                       read_disk_block(xfs_file, xfs.daddr, 0,
+                                       sizeof(xfs_btree_lblock_t), (char *)&h);
+                       xfs.nextents = le16(h.bb_numrecs);
+                       xfs.next = fsb2daddr (le64(h.bb_leftsib));
+                       xfs.fpos = sizeof(xfs_btree_block_t);
+               }
+               /* Yeah, I know that's slow, but I really don't care */
+               read_disk_block(xfs_file, xfs.daddr, xfs.fpos,
+                               sizeof(xfs_bmbt_rec_t), filebuf);
+               xfs.xt = (xfs_bmbt_rec_32_t *)filebuf;
+               xfs.fpos += sizeof(xfs_bmbt_rec_32_t);
+               break;
+       default:
+               return NULL;
+       }
+       xad.offset = xt_offset (xfs.xt);
+       xad.start = xt_start (xfs.xt);
+       xad.len = xt_len (xfs.xt);
+       ++xfs.xt;
+       --xfs.nextents;
+
+       return &xad;
+}
+
+/*
+ * Name lies - the function reads only first 100 bytes
+ */
+static void
+xfs_dabread (void)
+{
+       xad_t *xad;
+       xfs_fileoff_t offset;;
+
+       init_extents ();
+       while ((xad = next_extent ())) {
+               offset = xad->offset;
+               if (isinxt (xfs.dablk, offset, xad->len)) {
+                       read_disk_block(xfs_file, fsb2daddr (xad->start + xfs.dablk - offset),
+                                       0, 100, dirbuf);
+                       break;
+               }
+       }
+}
+
+static inline xfs_ino_t
+sf_ino (char *sfe, int namelen)
+{
+       void *p = sfe + namelen + 3;
+
+       return (xfs.i8param == 0)
+               ? le64(*(xfs_ino_t *)p) : le32(*(__uint32_t *)p);
+}
+
+static inline xfs_ino_t
+sf_parent_ino (void)
+{
+       return (xfs.i8param == 0)
+               ? le64(*(xfs_ino_t *)(&inode->di_u.di_dir2sf.hdr.parent))
+               : le32(*(__uint32_t *)(&inode->di_u.di_dir2sf.hdr.parent));
+}
+
+static inline int
+roundup8 (int n)
+{
+       return ((n+7)&~7);
+}
+
+static char *
+next_dentry (xfs_ino_t *ino)
+{
+       int namelen = 1;
+       int toread;
+       static char *usual[2] = {".", ".."};
+       static xfs_dir2_sf_entry_t *sfe;
+       char *name = usual[0];
+
+       if (xfs.dirpos >= xfs.dirmax) {
+               if (xfs.forw == 0)
+                       return NULL;
+               xfs.dablk = xfs.forw;
+               xfs_dabread ();
+#define h      ((xfs_dir2_leaf_hdr_t *)dirbuf)
+               xfs.dirmax = le16 (h->count) - le16 (h->stale);
+               xfs.forw = le32 (h->info.forw);
+#undef h
+               xfs.dirpos = 0;
+       }
+
+       switch (icore.di_format) {
+       case XFS_DINODE_FMT_LOCAL:
+               switch (xfs.dirpos) {
+               case -2:
+                       *ino = 0;
+                       break;
+               case -1:
+                       *ino = sf_parent_ino ();
+                       ++name;
+                       ++namelen;
+                       sfe = (xfs_dir2_sf_entry_t *)
+                               (inode->di_u.di_c 
+                                + sizeof(xfs_dir2_sf_hdr_t)
+                                - xfs.i8param);
+                       break;
+               default:
+                       namelen = sfe->namelen;
+                       *ino = sf_ino ((char *)sfe, namelen);
+                       name = sfe->name;
+                       sfe = (xfs_dir2_sf_entry_t *)
+                                 ((char *)sfe + namelen + 11 - xfs.i8param);
+               }
+               break;
+       case XFS_DINODE_FMT_BTREE:
+       case XFS_DINODE_FMT_EXTENTS:
+#define dau    ((xfs_dir2_data_union_t *)dirbuf)
+               for (;;) {
+                       if (xfs.blkoff >= xfs.dirbsize) {
+                               xfs.blkoff = sizeof(xfs_dir2_data_hdr_t);
+                               xfs_file->pos &= ~(xfs.dirbsize - 1);
+                               xfs_file->pos |= xfs.blkoff;
+                       }
+                       xfs_read_data (dirbuf, 4);
+                       xfs.blkoff += 4;
+                       if (dau->unused.freetag == XFS_DIR2_DATA_FREE_TAG) {
+                               toread = roundup8 (le16(dau->unused.length)) - 4;
+                               xfs.blkoff += toread;
+                               xfs_file->pos += toread;
+                               continue;
+                       }
+                       break;
+               }
+               xfs_read_data ((char *)dirbuf + 4, 5);
+               *ino = le64 (dau->entry.inumber);
+               namelen = dau->entry.namelen;
+#undef dau
+               toread = roundup8 (namelen + 11) - 9;
+               xfs_read_data (dirbuf, toread);
+               name = (char *)dirbuf;
+               xfs.blkoff += toread + 5;
+               break;
+       }
+       ++xfs.dirpos;
+       name[namelen] = 0;
+
+       return name;
+}
+
+static char *
+first_dentry (xfs_ino_t *ino)
+{
+       xfs.forw = 0;
+       switch (icore.di_format) {
+       case XFS_DINODE_FMT_LOCAL:
+               xfs.dirmax = inode->di_u.di_dir2sf.hdr.count;
+               xfs.i8param = inode->di_u.di_dir2sf.hdr.i8count ? 0 : 4;
+               xfs.dirpos = -2;
+               break;
+       case XFS_DINODE_FMT_EXTENTS:
+       case XFS_DINODE_FMT_BTREE:
+               xfs_file->pos = 0;
+               xfs_file->len = le64 (icore.di_size);
+               xfs_read_data (dirbuf, sizeof(xfs_dir2_data_hdr_t));
+               if (((xfs_dir2_data_hdr_t *)dirbuf)->magic == le32(XFS_DIR2_BLOCK_MAGIC)) {
+#define tail           ((xfs_dir2_block_tail_t *)dirbuf)
+                       xfs_file->pos = xfs.dirbsize - sizeof(*tail);
+                       xfs_read_data (dirbuf, sizeof(*tail));
+                       xfs.dirmax = le32 (tail->count) - le32 (tail->stale);
+#undef tail
+               } else {
+                       xfs.dablk = (1ULL << 35) >> xfs.blklog;
+#define h              ((xfs_dir2_leaf_hdr_t *)dirbuf)
+#define n              ((xfs_da_intnode_t *)dirbuf)
+                       for (;;) {
+                               xfs_dabread ();
+                               if ((n->hdr.info.magic == le16(XFS_DIR2_LEAFN_MAGIC))
+                                   || (n->hdr.info.magic == le16(XFS_DIR2_LEAF1_MAGIC))) {
+                                       xfs.dirmax = le16 (h->count) - le16 (h->stale);
+                                       xfs.forw = le32 (h->info.forw);
+                                       break;
+                               }
+                               xfs.dablk = le32 (n->btree[0].before);
+                       }
+#undef n
+#undef h
+               }
+               xfs.blkoff = sizeof(xfs_dir2_data_hdr_t);
+               xfs_file->pos = xfs.blkoff;
+               xfs.dirpos = 0;
+               break;
+       }
+       return next_dentry (ino);
+}
+
+int
+xfs_mount (void)
+{
+       xfs_sb_t super;
+
+       if (read_disk_block(xfs_file, 0, 0, sizeof(super), &super) != sizeof(super)) {
+               DEBUG_F("read_disk_block failed!\n");
+               return 0;
+       } else if (super.sb_magicnum != XFS_SB_MAGIC) {
+               DEBUG_F("xfs_mount: Bad magic: %x\n", super.sb_magicnum);
+               return 0;
+       } else if ((super.sb_versionnum & XFS_SB_VERSION_NUMBITS) != XFS_SB_VERSION_4) {
+               DEBUG_F("xfs_mount: Bad version: %x\n", super.sb_versionnum);
+               return 0;
+       }
+
+       xfs.bsize = le32 (super.sb_blocksize);
+       xfs.blklog = super.sb_blocklog;
+       xfs.bdlog = xfs.blklog - SECTOR_BITS;
+       xfs.rootino = le64 (super.sb_rootino);
+       xfs.isize = le16 (super.sb_inodesize);
+       xfs.agblocks = le32 (super.sb_agblocks);
+       xfs.dirblklog = super.sb_dirblklog;
+       xfs.dirbsize = xfs.bsize << super.sb_dirblklog;
+
+       xfs.inopblog = super.sb_inopblog;
+       xfs.agblklog = super.sb_agblklog;
+       xfs.agnolog = xfs_highbit32 (le32 (super.sb_agcount) - 1) + 1;
+
+       xfs.btnode_ptr0_off =
+               ((xfs.bsize - sizeof(xfs_btree_block_t)) /
+               (sizeof (xfs_bmbt_key_t) + sizeof (xfs_bmbt_ptr_t)))
+                * sizeof(xfs_bmbt_key_t) + sizeof(xfs_btree_block_t);
+
+       return 1;
+}
+
+int
+xfs_read_data (char *buf, int len)
+{
+       xad_t *xad;
+       xfs_fileoff_t endofprev, endofcur, offset;
+       xfs_filblks_t xadlen;
+       int toread, startpos, endpos;
+
+       if (icore.di_format == XFS_DINODE_FMT_LOCAL) {
+               memmove(buf, inode->di_u.di_c + xfs_file->pos, len);
+               xfs_file->pos += len;
+               return len;
+       }
+
+       startpos = xfs_file->pos;
+       endpos = xfs_file->pos + len;
+       if (endpos > xfs_file->len)
+               endpos = xfs_file->len;
+       endofprev = (xfs_fileoff_t)-1;
+       init_extents ();
+       while (len > 0 && (xad = next_extent ())) {
+               offset = xad->offset;
+               xadlen = xad->len;
+               if (isinxt (xfs_file->pos >> xfs.blklog, offset, xadlen)) {
+                       endofcur = (offset + xadlen) << xfs.blklog; 
+                       toread = (endofcur >= endpos)
+                                 ? len : (endofcur - xfs_file->pos);
+                       read_disk_block(xfs_file, fsb2daddr (xad->start),
+                                       xfs_file->pos - (offset << xfs.blklog), toread, buf);
+                       buf += toread;
+                       len -= toread;
+                       xfs_file->pos += toread;
+               } else if (offset > endofprev) {
+                       toread = ((offset << xfs.blklog) >= endpos)
+                                 ? len : ((offset - endofprev) << xfs.blklog);
+                       len -= toread;
+                       xfs_file->pos += toread;
+                       for (; toread; toread--) {
+                               *buf++ = 0;
+                       }
+                       continue;
+               }
+               endofprev = offset + xadlen; 
+       }
+
+       return xfs_file->pos - startpos;
+}
+
+int
+xfs_dir (char *dirname)
+{
+       xfs_ino_t ino, parent_ino, new_ino;
+       xfs_fsize_t di_size;
+       int di_mode;
+       int cmp, n, link_count;
+       char linkbuf[xfs.bsize];
+       char *rest, *name, ch;
+
+       DEBUG_ENTER;
+
+       parent_ino = ino = xfs.rootino;
+       link_count = 0;
+       for (;;) {
+               di_read (ino);
+               di_size = le64 (icore.di_size);
+               di_mode = le16 (icore.di_mode);
+
+               DEBUG_F("di_mode: %o\n", di_mode);
+               if ((di_mode & IFMT) == IFLNK) {
+                       if (++link_count > MAX_LINK_COUNT) {
+                               errnum = FILE_ERR_SYMLINK_LOOP;
+                               DEBUG_LEAVE(FILE_ERR_SYMLINK_LOOP);
+                               return 0;
+                       }
+                       if (di_size < xfs.bsize - 1) {
+                               xfs_file->pos = 0;
+                               xfs_file->len = di_size;
+                               n = xfs_read_data (linkbuf, xfs_file->len);
+                       } else {
+                               errnum = FILE_ERR_LENGTH;
+                               DEBUG_LEAVE(FILE_ERR_LENGTH);
+                               return 0;
+                       }
+
+                       ino = (linkbuf[0] == '/') ? xfs.rootino : parent_ino;
+                       while (n < (xfs.bsize - 1) && (linkbuf[n++] = *dirname++));
+                       linkbuf[n] = 0;
+                       dirname = linkbuf;
+                       continue;
+               }
+
+               DEBUG_F("*dirname: %s\n", dirname);
+               if (!*dirname || isspace (*dirname)) {
+                       if ((di_mode & IFMT) != IFREG) {
+                               errnum = FILE_ERR_BAD_TYPE;
+                               DEBUG_LEAVE(FILE_ERR_BAD_TYPE);
+                               return 0;
+                       }
+                       xfs_file->pos = 0;
+                       xfs_file->len = di_size;
+                       DEBUG_LEAVE(1);
+                       return 1;
+               }
+
+               if ((di_mode & IFMT) != IFDIR) {
+                       errnum = FILE_ERR_NOTDIR;
+                       DEBUG_LEAVE(FILE_ERR_NOTDIR);
+                       return 0;
+               }
+
+               for (; *dirname == '/'; dirname++);
+
+               for (rest = dirname; (ch = *rest) && !isspace (ch) && ch != '/'; rest++);
+               *rest = 0;
+
+               name = first_dentry (&new_ino);
+               for (;;) {
+                       cmp = (!*dirname) ? -1 : strcmp(dirname, name);
+                       if (cmp == 0) {
+                               parent_ino = ino;
+                               if (new_ino)
+                                       ino = new_ino;
+                               *(dirname = rest) = ch;
+                               break;
+                       }
+                       name = next_dentry (&new_ino);
+                       if (name == NULL) {
+                               errnum = FILE_ERR_NOTFOUND;
+                               DEBUG_LEAVE(FILE_ERR_NOTFOUND);
+                               *rest = ch;
+                               return 0;
+                       }
+               }
+       }
+}
+
+/* 
+ * Local variables:
+ * c-file-style: "K&R"
+ * c-basic-offset: 8
+ * End:
+ */