+/*
+ * 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:
+ */