109c434b8SThomas Gleixner // SPDX-License-Identifier: GPL-2.0-only
21da177e4SLinus Torvalds /*
31da177e4SLinus Torvalds * inode.c
41da177e4SLinus Torvalds *
51da177e4SLinus Torvalds * Copyright (c) 1999 Al Smith
61da177e4SLinus Torvalds *
71da177e4SLinus Torvalds * Portions derived from work (c) 1995,1996 Christian Vogelgsang,
81da177e4SLinus Torvalds * and from work (c) 1998 Mike Shaver.
91da177e4SLinus Torvalds */
101da177e4SLinus Torvalds
111da177e4SLinus Torvalds #include <linux/buffer_head.h>
121da177e4SLinus Torvalds #include <linux/module.h>
131da177e4SLinus Torvalds #include <linux/fs.h>
1445254b4fSChristoph Hellwig #include "efs.h"
1545254b4fSChristoph Hellwig #include <linux/efs_fs_sb.h>
161da177e4SLinus Torvalds
efs_read_folio(struct file * file,struct folio * folio)172c69e205SMatthew Wilcox (Oracle) static int efs_read_folio(struct file *file, struct folio *folio)
181da177e4SLinus Torvalds {
192c69e205SMatthew Wilcox (Oracle) return block_read_full_folio(folio, efs_get_block);
201da177e4SLinus Torvalds }
212c69e205SMatthew Wilcox (Oracle)
_efs_bmap(struct address_space * mapping,sector_t block)221da177e4SLinus Torvalds static sector_t _efs_bmap(struct address_space *mapping, sector_t block)
231da177e4SLinus Torvalds {
241da177e4SLinus Torvalds return generic_block_bmap(mapping,block,efs_get_block);
251da177e4SLinus Torvalds }
262c69e205SMatthew Wilcox (Oracle)
27f5e54d6eSChristoph Hellwig static const struct address_space_operations efs_aops = {
282c69e205SMatthew Wilcox (Oracle) .read_folio = efs_read_folio,
291da177e4SLinus Torvalds .bmap = _efs_bmap
301da177e4SLinus Torvalds };
311da177e4SLinus Torvalds
extent_copy(efs_extent * src,efs_extent * dst)321da177e4SLinus Torvalds static inline void extent_copy(efs_extent *src, efs_extent *dst) {
331da177e4SLinus Torvalds /*
341da177e4SLinus Torvalds * this is slightly evil. it doesn't just copy
351da177e4SLinus Torvalds * efs_extent from src to dst, it also mangles
361da177e4SLinus Torvalds * the bits so that dst ends up in cpu byte-order.
371da177e4SLinus Torvalds */
381da177e4SLinus Torvalds
391da177e4SLinus Torvalds dst->cooked.ex_magic = (unsigned int) src->raw[0];
401da177e4SLinus Torvalds dst->cooked.ex_bn = ((unsigned int) src->raw[1] << 16) |
411da177e4SLinus Torvalds ((unsigned int) src->raw[2] << 8) |
421da177e4SLinus Torvalds ((unsigned int) src->raw[3] << 0);
431da177e4SLinus Torvalds dst->cooked.ex_length = (unsigned int) src->raw[4];
441da177e4SLinus Torvalds dst->cooked.ex_offset = ((unsigned int) src->raw[5] << 16) |
451da177e4SLinus Torvalds ((unsigned int) src->raw[6] << 8) |
461da177e4SLinus Torvalds ((unsigned int) src->raw[7] << 0);
471da177e4SLinus Torvalds return;
481da177e4SLinus Torvalds }
491da177e4SLinus Torvalds
efs_iget(struct super_block * super,unsigned long ino)50298384cdSDavid Howells struct inode *efs_iget(struct super_block *super, unsigned long ino)
511da177e4SLinus Torvalds {
521da177e4SLinus Torvalds int i, inode_index;
531da177e4SLinus Torvalds dev_t device;
541da177e4SLinus Torvalds u32 rdev;
551da177e4SLinus Torvalds struct buffer_head *bh;
56298384cdSDavid Howells struct efs_sb_info *sb = SUPER_INFO(super);
57298384cdSDavid Howells struct efs_inode_info *in;
581da177e4SLinus Torvalds efs_block_t block, offset;
591da177e4SLinus Torvalds struct efs_dinode *efs_inode;
60298384cdSDavid Howells struct inode *inode;
61298384cdSDavid Howells
62298384cdSDavid Howells inode = iget_locked(super, ino);
63136eefa4SDan Carpenter if (!inode)
64298384cdSDavid Howells return ERR_PTR(-ENOMEM);
65298384cdSDavid Howells if (!(inode->i_state & I_NEW))
66298384cdSDavid Howells return inode;
67298384cdSDavid Howells
68298384cdSDavid Howells in = INODE_INFO(inode);
691da177e4SLinus Torvalds
701da177e4SLinus Torvalds /*
711da177e4SLinus Torvalds ** EFS layout:
721da177e4SLinus Torvalds **
731da177e4SLinus Torvalds ** | cylinder group | cylinder group | cylinder group ..etc
741da177e4SLinus Torvalds ** |inodes|data |inodes|data |inodes|data ..etc
751da177e4SLinus Torvalds **
761da177e4SLinus Torvalds ** work out the inode block index, (considering initially that the
771da177e4SLinus Torvalds ** inodes are stored as consecutive blocks). then work out the block
781da177e4SLinus Torvalds ** number of that inode given the above layout, and finally the
791da177e4SLinus Torvalds ** offset of the inode within that block.
801da177e4SLinus Torvalds */
811da177e4SLinus Torvalds
821da177e4SLinus Torvalds inode_index = inode->i_ino /
831da177e4SLinus Torvalds (EFS_BLOCKSIZE / sizeof(struct efs_dinode));
841da177e4SLinus Torvalds
851da177e4SLinus Torvalds block = sb->fs_start + sb->first_block +
861da177e4SLinus Torvalds (sb->group_size * (inode_index / sb->inode_blocks)) +
871da177e4SLinus Torvalds (inode_index % sb->inode_blocks);
881da177e4SLinus Torvalds
891da177e4SLinus Torvalds offset = (inode->i_ino %
901da177e4SLinus Torvalds (EFS_BLOCKSIZE / sizeof(struct efs_dinode))) *
911da177e4SLinus Torvalds sizeof(struct efs_dinode);
921da177e4SLinus Torvalds
931da177e4SLinus Torvalds bh = sb_bread(inode->i_sb, block);
941da177e4SLinus Torvalds if (!bh) {
95f403d1dbSFabian Frederick pr_warn("%s() failed at block %d\n", __func__, block);
961da177e4SLinus Torvalds goto read_inode_error;
971da177e4SLinus Torvalds }
981da177e4SLinus Torvalds
991da177e4SLinus Torvalds efs_inode = (struct efs_dinode *) (bh->b_data + offset);
1001da177e4SLinus Torvalds
1011da177e4SLinus Torvalds inode->i_mode = be16_to_cpu(efs_inode->di_mode);
102bfe86848SMiklos Szeredi set_nlink(inode, be16_to_cpu(efs_inode->di_nlink));
1035d4ea4daSEric W. Biederman i_uid_write(inode, (uid_t)be16_to_cpu(efs_inode->di_uid));
1045d4ea4daSEric W. Biederman i_gid_write(inode, (gid_t)be16_to_cpu(efs_inode->di_gid));
1051da177e4SLinus Torvalds inode->i_size = be32_to_cpu(efs_inode->di_size);
1061da177e4SLinus Torvalds inode->i_atime.tv_sec = be32_to_cpu(efs_inode->di_atime);
1071da177e4SLinus Torvalds inode->i_mtime.tv_sec = be32_to_cpu(efs_inode->di_mtime);
108*a68d1f51SJeff Layton inode_set_ctime(inode, be32_to_cpu(efs_inode->di_ctime), 0);
109*a68d1f51SJeff Layton inode->i_atime.tv_nsec = inode->i_mtime.tv_nsec = 0;
1101da177e4SLinus Torvalds
1111da177e4SLinus Torvalds /* this is the number of blocks in the file */
1121da177e4SLinus Torvalds if (inode->i_size == 0) {
1131da177e4SLinus Torvalds inode->i_blocks = 0;
1141da177e4SLinus Torvalds } else {
1151da177e4SLinus Torvalds inode->i_blocks = ((inode->i_size - 1) >> EFS_BLOCKSIZE_BITS) + 1;
1161da177e4SLinus Torvalds }
1171da177e4SLinus Torvalds
1181da177e4SLinus Torvalds rdev = be16_to_cpu(efs_inode->di_u.di_dev.odev);
1191da177e4SLinus Torvalds if (rdev == 0xffff) {
1201da177e4SLinus Torvalds rdev = be32_to_cpu(efs_inode->di_u.di_dev.ndev);
1211da177e4SLinus Torvalds if (sysv_major(rdev) > 0xfff)
1221da177e4SLinus Torvalds device = 0;
1231da177e4SLinus Torvalds else
1241da177e4SLinus Torvalds device = MKDEV(sysv_major(rdev), sysv_minor(rdev));
1251da177e4SLinus Torvalds } else
1261da177e4SLinus Torvalds device = old_decode_dev(rdev);
1271da177e4SLinus Torvalds
1281da177e4SLinus Torvalds /* get the number of extents for this object */
1291da177e4SLinus Torvalds in->numextents = be16_to_cpu(efs_inode->di_numextents);
1301da177e4SLinus Torvalds in->lastextent = 0;
1311da177e4SLinus Torvalds
1321da177e4SLinus Torvalds /* copy the extents contained within the inode to memory */
1331da177e4SLinus Torvalds for(i = 0; i < EFS_DIRECTEXTENTS; i++) {
1341da177e4SLinus Torvalds extent_copy(&(efs_inode->di_u.di_extents[i]), &(in->extents[i]));
1351da177e4SLinus Torvalds if (i < in->numextents && in->extents[i].cooked.ex_magic != 0) {
136f403d1dbSFabian Frederick pr_warn("extent %d has bad magic number in inode %lu\n",
137f403d1dbSFabian Frederick i, inode->i_ino);
1381da177e4SLinus Torvalds brelse(bh);
1391da177e4SLinus Torvalds goto read_inode_error;
1401da177e4SLinus Torvalds }
1411da177e4SLinus Torvalds }
1421da177e4SLinus Torvalds
1431da177e4SLinus Torvalds brelse(bh);
144d1826f2aSFabian Frederick pr_debug("efs_iget(): inode %lu, extents %d, mode %o\n",
1451da177e4SLinus Torvalds inode->i_ino, in->numextents, inode->i_mode);
1461da177e4SLinus Torvalds switch (inode->i_mode & S_IFMT) {
1471da177e4SLinus Torvalds case S_IFDIR:
1481da177e4SLinus Torvalds inode->i_op = &efs_dir_inode_operations;
1491da177e4SLinus Torvalds inode->i_fop = &efs_dir_operations;
1501da177e4SLinus Torvalds break;
1511da177e4SLinus Torvalds case S_IFREG:
1521da177e4SLinus Torvalds inode->i_fop = &generic_ro_fops;
1531da177e4SLinus Torvalds inode->i_data.a_ops = &efs_aops;
1541da177e4SLinus Torvalds break;
1551da177e4SLinus Torvalds case S_IFLNK:
1561da177e4SLinus Torvalds inode->i_op = &page_symlink_inode_operations;
15721fc61c7SAl Viro inode_nohighmem(inode);
1581da177e4SLinus Torvalds inode->i_data.a_ops = &efs_symlink_aops;
1591da177e4SLinus Torvalds break;
1601da177e4SLinus Torvalds case S_IFCHR:
1611da177e4SLinus Torvalds case S_IFBLK:
1621da177e4SLinus Torvalds case S_IFIFO:
1631da177e4SLinus Torvalds init_special_inode(inode, inode->i_mode, device);
1641da177e4SLinus Torvalds break;
1651da177e4SLinus Torvalds default:
166f403d1dbSFabian Frederick pr_warn("unsupported inode mode %o\n", inode->i_mode);
1671da177e4SLinus Torvalds goto read_inode_error;
1681da177e4SLinus Torvalds break;
1691da177e4SLinus Torvalds }
1701da177e4SLinus Torvalds
171298384cdSDavid Howells unlock_new_inode(inode);
172298384cdSDavid Howells return inode;
1731da177e4SLinus Torvalds
1741da177e4SLinus Torvalds read_inode_error:
175f403d1dbSFabian Frederick pr_warn("failed to read inode %lu\n", inode->i_ino);
176298384cdSDavid Howells iget_failed(inode);
177298384cdSDavid Howells return ERR_PTR(-EIO);
1781da177e4SLinus Torvalds }
1791da177e4SLinus Torvalds
1801da177e4SLinus Torvalds static inline efs_block_t
efs_extent_check(efs_extent * ptr,efs_block_t block,struct efs_sb_info * sb)1811da177e4SLinus Torvalds efs_extent_check(efs_extent *ptr, efs_block_t block, struct efs_sb_info *sb) {
1821da177e4SLinus Torvalds efs_block_t start;
1831da177e4SLinus Torvalds efs_block_t length;
1841da177e4SLinus Torvalds efs_block_t offset;
1851da177e4SLinus Torvalds
1861da177e4SLinus Torvalds /*
1871da177e4SLinus Torvalds * given an extent and a logical block within a file,
1881da177e4SLinus Torvalds * can this block be found within this extent ?
1891da177e4SLinus Torvalds */
1901da177e4SLinus Torvalds start = ptr->cooked.ex_bn;
1911da177e4SLinus Torvalds length = ptr->cooked.ex_length;
1921da177e4SLinus Torvalds offset = ptr->cooked.ex_offset;
1931da177e4SLinus Torvalds
1941da177e4SLinus Torvalds if ((block >= offset) && (block < offset+length)) {
1951da177e4SLinus Torvalds return(sb->fs_start + start + block - offset);
1961da177e4SLinus Torvalds } else {
1971da177e4SLinus Torvalds return 0;
1981da177e4SLinus Torvalds }
1991da177e4SLinus Torvalds }
2001da177e4SLinus Torvalds
efs_map_block(struct inode * inode,efs_block_t block)2011da177e4SLinus Torvalds efs_block_t efs_map_block(struct inode *inode, efs_block_t block) {
2021da177e4SLinus Torvalds struct efs_sb_info *sb = SUPER_INFO(inode->i_sb);
2031da177e4SLinus Torvalds struct efs_inode_info *in = INODE_INFO(inode);
2041da177e4SLinus Torvalds struct buffer_head *bh = NULL;
2051da177e4SLinus Torvalds
2061da177e4SLinus Torvalds int cur, last, first = 1;
2071da177e4SLinus Torvalds int ibase, ioffset, dirext, direxts, indext, indexts;
2081da177e4SLinus Torvalds efs_block_t iblock, result = 0, lastblock = 0;
2091da177e4SLinus Torvalds efs_extent ext, *exts;
2101da177e4SLinus Torvalds
2111da177e4SLinus Torvalds last = in->lastextent;
2121da177e4SLinus Torvalds
2131da177e4SLinus Torvalds if (in->numextents <= EFS_DIRECTEXTENTS) {
2141da177e4SLinus Torvalds /* first check the last extent we returned */
2151da177e4SLinus Torvalds if ((result = efs_extent_check(&in->extents[last], block, sb)))
2161da177e4SLinus Torvalds return result;
2171da177e4SLinus Torvalds
2181da177e4SLinus Torvalds /* if we only have one extent then nothing can be found */
2191da177e4SLinus Torvalds if (in->numextents == 1) {
220f403d1dbSFabian Frederick pr_err("%s() failed to map (1 extent)\n", __func__);
2211da177e4SLinus Torvalds return 0;
2221da177e4SLinus Torvalds }
2231da177e4SLinus Torvalds
2241da177e4SLinus Torvalds direxts = in->numextents;
2251da177e4SLinus Torvalds
2261da177e4SLinus Torvalds /*
2271da177e4SLinus Torvalds * check the stored extents in the inode
2281da177e4SLinus Torvalds * start with next extent and check forwards
2291da177e4SLinus Torvalds */
2301da177e4SLinus Torvalds for(dirext = 1; dirext < direxts; dirext++) {
2311da177e4SLinus Torvalds cur = (last + dirext) % in->numextents;
2321da177e4SLinus Torvalds if ((result = efs_extent_check(&in->extents[cur], block, sb))) {
2331da177e4SLinus Torvalds in->lastextent = cur;
2341da177e4SLinus Torvalds return result;
2351da177e4SLinus Torvalds }
2361da177e4SLinus Torvalds }
2371da177e4SLinus Torvalds
238f403d1dbSFabian Frederick pr_err("%s() failed to map block %u (dir)\n", __func__, block);
2391da177e4SLinus Torvalds return 0;
2401da177e4SLinus Torvalds }
2411da177e4SLinus Torvalds
242d1826f2aSFabian Frederick pr_debug("%s(): indirect search for logical block %u\n",
243d1826f2aSFabian Frederick __func__, block);
2441da177e4SLinus Torvalds direxts = in->extents[0].cooked.ex_offset;
2451da177e4SLinus Torvalds indexts = in->numextents;
2461da177e4SLinus Torvalds
2471da177e4SLinus Torvalds for(indext = 0; indext < indexts; indext++) {
2481da177e4SLinus Torvalds cur = (last + indext) % indexts;
2491da177e4SLinus Torvalds
2501da177e4SLinus Torvalds /*
2511da177e4SLinus Torvalds * work out which direct extent contains `cur'.
2521da177e4SLinus Torvalds *
2531da177e4SLinus Torvalds * also compute ibase: i.e. the number of the first
2541da177e4SLinus Torvalds * indirect extent contained within direct extent `cur'.
2551da177e4SLinus Torvalds *
2561da177e4SLinus Torvalds */
2571da177e4SLinus Torvalds ibase = 0;
2581da177e4SLinus Torvalds for(dirext = 0; cur < ibase && dirext < direxts; dirext++) {
2591da177e4SLinus Torvalds ibase += in->extents[dirext].cooked.ex_length *
2601da177e4SLinus Torvalds (EFS_BLOCKSIZE / sizeof(efs_extent));
2611da177e4SLinus Torvalds }
2621da177e4SLinus Torvalds
2631da177e4SLinus Torvalds if (dirext == direxts) {
2641da177e4SLinus Torvalds /* should never happen */
265f403d1dbSFabian Frederick pr_err("couldn't find direct extent for indirect extent %d (block %u)\n",
266f403d1dbSFabian Frederick cur, block);
2671da177e4SLinus Torvalds if (bh) brelse(bh);
2681da177e4SLinus Torvalds return 0;
2691da177e4SLinus Torvalds }
2701da177e4SLinus Torvalds
2711da177e4SLinus Torvalds /* work out block number and offset of this indirect extent */
2721da177e4SLinus Torvalds iblock = sb->fs_start + in->extents[dirext].cooked.ex_bn +
2731da177e4SLinus Torvalds (cur - ibase) /
2741da177e4SLinus Torvalds (EFS_BLOCKSIZE / sizeof(efs_extent));
2751da177e4SLinus Torvalds ioffset = (cur - ibase) %
2761da177e4SLinus Torvalds (EFS_BLOCKSIZE / sizeof(efs_extent));
2771da177e4SLinus Torvalds
2781da177e4SLinus Torvalds if (first || lastblock != iblock) {
2791da177e4SLinus Torvalds if (bh) brelse(bh);
2801da177e4SLinus Torvalds
2811da177e4SLinus Torvalds bh = sb_bread(inode->i_sb, iblock);
2821da177e4SLinus Torvalds if (!bh) {
283f403d1dbSFabian Frederick pr_err("%s() failed at block %d\n",
284f403d1dbSFabian Frederick __func__, iblock);
2851da177e4SLinus Torvalds return 0;
2861da177e4SLinus Torvalds }
287d1826f2aSFabian Frederick pr_debug("%s(): read indirect extent block %d\n",
288d1826f2aSFabian Frederick __func__, iblock);
2891da177e4SLinus Torvalds first = 0;
2901da177e4SLinus Torvalds lastblock = iblock;
2911da177e4SLinus Torvalds }
2921da177e4SLinus Torvalds
2931da177e4SLinus Torvalds exts = (efs_extent *) bh->b_data;
2941da177e4SLinus Torvalds
2951da177e4SLinus Torvalds extent_copy(&(exts[ioffset]), &ext);
2961da177e4SLinus Torvalds
2971da177e4SLinus Torvalds if (ext.cooked.ex_magic != 0) {
298f403d1dbSFabian Frederick pr_err("extent %d has bad magic number in block %d\n",
299f403d1dbSFabian Frederick cur, iblock);
3001da177e4SLinus Torvalds if (bh) brelse(bh);
3011da177e4SLinus Torvalds return 0;
3021da177e4SLinus Torvalds }
3031da177e4SLinus Torvalds
3041da177e4SLinus Torvalds if ((result = efs_extent_check(&ext, block, sb))) {
3051da177e4SLinus Torvalds if (bh) brelse(bh);
3061da177e4SLinus Torvalds in->lastextent = cur;
3071da177e4SLinus Torvalds return result;
3081da177e4SLinus Torvalds }
3091da177e4SLinus Torvalds }
3101da177e4SLinus Torvalds if (bh) brelse(bh);
311f403d1dbSFabian Frederick pr_err("%s() failed to map block %u (indir)\n", __func__, block);
3121da177e4SLinus Torvalds return 0;
3131da177e4SLinus Torvalds }
3141da177e4SLinus Torvalds
3151da177e4SLinus Torvalds MODULE_LICENSE("GPL");
316