^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1) // SPDX-License-Identifier: GPL-2.0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3) * QNX4 file system, Linux implementation.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5) * Version : 0.2.1
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7) * Using parts of the xiafs filesystem.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9) * History :
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) * 28-05-1998 by Richard Frowijn : first release.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) * 20-06-1998 by Frank Denis : Linux 2.1.99+ & dcache support.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) #include <linux/buffer_head.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) #include "qnx4.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) * A qnx4 directory entry is an inode entry or link info
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) * depending on the status field in the last byte. The
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) * first byte is where the name start either way, and a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) * zero means it's empty.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) * Also, due to a bug in gcc, we don't want to use the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) * real (differently sized) name arrays in the inode and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) * link entries, but always the 'de_name[]' one in the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) * fake struct entry.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) * See
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) * https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99578#c6
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) * for details, but basically gcc will take the size of the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) * 'name' array from one of the used union entries randomly.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) * This use of 'de_name[]' (48 bytes) avoids the false positive
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) * warnings that would happen if gcc decides to use 'inode.di_name'
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) * (16 bytes) even when the pointer and size were to come from
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) * 'link.dl_name' (48 bytes).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) * In all cases the actual name pointer itself is the same, it's
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) * only the gcc internal 'what is the size of this field' logic
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) * that can get confused.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) union qnx4_directory_entry {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) struct {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) const char de_name[48];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) u8 de_pad[15];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) u8 de_status;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) struct qnx4_inode_entry inode;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) struct qnx4_link_info link;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) static int qnx4_readdir(struct file *file, struct dir_context *ctx)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) struct inode *inode = file_inode(file);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) unsigned int offset;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) struct buffer_head *bh;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) unsigned long blknum;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) int ix, ino;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) int size;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64) QNX4DEBUG((KERN_INFO "qnx4_readdir:i_size = %ld\n", (long) inode->i_size));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) QNX4DEBUG((KERN_INFO "pos = %ld\n", (long) ctx->pos));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) while (ctx->pos < inode->i_size) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) blknum = qnx4_block_map(inode, ctx->pos >> QNX4_BLOCK_SIZE_BITS);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69) bh = sb_bread(inode->i_sb, blknum);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) if (bh == NULL) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71) printk(KERN_ERR "qnx4_readdir: bread failed (%ld)\n", blknum);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74) ix = (ctx->pos >> QNX4_DIR_ENTRY_SIZE_BITS) % QNX4_INODES_PER_BLOCK;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75) for (; ix < QNX4_INODES_PER_BLOCK; ix++, ctx->pos += QNX4_DIR_ENTRY_SIZE) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76) union qnx4_directory_entry *de;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78) offset = ix * QNX4_DIR_ENTRY_SIZE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79) de = (union qnx4_directory_entry *) (bh->b_data + offset);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81) if (!de->de_name[0])
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82) continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83) if (!(de->de_status & (QNX4_FILE_USED|QNX4_FILE_LINK)))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84) continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85) if (!(de->de_status & QNX4_FILE_LINK)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86) size = sizeof(de->inode.di_fname);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87) ino = blknum * QNX4_INODES_PER_BLOCK + ix - 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89) size = sizeof(de->link.dl_fname);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90) ino = ( le32_to_cpu(de->link.dl_inode_blk) - 1 ) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91) QNX4_INODES_PER_BLOCK +
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92) de->link.dl_inode_ndx;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 94) size = strnlen(de->de_name, size);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 95) QNX4DEBUG((KERN_INFO "qnx4_readdir:%.*s\n", size, name));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 96) if (!dir_emit(ctx, de->de_name, size, ino, DT_UNKNOWN)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 97) brelse(bh);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 98) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 99) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) brelse(bh);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) const struct file_operations qnx4_dir_operations =
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) .llseek = generic_file_llseek,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) .read = generic_read_dir,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) .iterate_shared = qnx4_readdir,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) .fsync = generic_file_fsync,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) const struct inode_operations qnx4_dir_inode_operations =
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) .lookup = qnx4_lookup,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) };
Orange Pi5 kernel
Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
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