af01bda509
The "bdev" library provides basic primitives for file systems to talk to block device drivers, hiding the details of the underlying protocol and interaction model. This version of libbdev is rather basic. It is planned to support the following features in the long run: - asynchronous requests and replies; - recovery support for underlying block drivers; - retrying of failed I/O requests. The commit also changes our block-based file systems (mfs, ext2, isofs) to make use of libbdev.
119 lines
4.2 KiB
C
119 lines
4.2 KiB
C
/* Functions to manage the superblock of the filesystem. These functions are
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* are called at the beginning and at the end of the server. */
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#include "inc.h"
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#include <string.h>
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#include <minix/com.h>
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#include <minix/u64.h>
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#include <minix/bdev.h>
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/* This function is called when the filesystem is umounted. It releases the
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* super block. */
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PUBLIC int release_v_pri(v_pri)
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register struct iso9660_vd_pri *v_pri;
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{
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/* Release the root dir record */
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release_dir_record(v_pri->dir_rec_root);
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v_pri->count = 0;
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return OK;
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}
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/* This function fullfill the super block data structure using the information
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* contained in the stream buf. Such stream is physically read from the device
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* . */
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PUBLIC int create_v_pri(v_pri,buf,address)
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register struct iso9660_vd_pri *v_pri;
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register char* buf;
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register unsigned long address;
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{
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struct dir_record *dir;
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v_pri->vd_type = buf[0];
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memcpy(v_pri->standard_id,buf + 1,sizeof(v_pri->standard_id));
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v_pri->vd_version = buf[6];
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memcpy(v_pri->system_id,buf + 8,sizeof(v_pri->system_id));
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memcpy(v_pri->volume_id,buf + 40,sizeof(v_pri->volume_id));
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memcpy(&v_pri->volume_space_size_l,buf + 80,
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sizeof(v_pri->volume_space_size_l));
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memcpy(&v_pri->volume_space_size_m,buf + 84,
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sizeof(v_pri->volume_space_size_m));
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memcpy(&v_pri->volume_set_size,buf + 120,sizeof(v_pri->volume_set_size));
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memcpy(&v_pri->volume_sequence_number,buf + 124,
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sizeof(v_pri->volume_sequence_number));
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memcpy(&v_pri->logical_block_size_l,buf + 128,
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sizeof(v_pri->logical_block_size_l));
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memcpy(&v_pri->logical_block_size_m,buf + 130,
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sizeof(v_pri->logical_block_size_m));
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memcpy(&v_pri->path_table_size_l,buf + 132,
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sizeof(v_pri->path_table_size_l));
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memcpy(&v_pri->path_table_size_m,buf + 136,
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sizeof(v_pri->path_table_size_m));
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memcpy(&v_pri->loc_l_occ_path_table,buf + 140,
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sizeof(v_pri->loc_l_occ_path_table));
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memcpy(&v_pri->loc_opt_l_occ_path_table,buf + 144,
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sizeof(v_pri->loc_opt_l_occ_path_table));
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memcpy(&v_pri->loc_m_occ_path_table, buf + 148,
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sizeof(v_pri->loc_m_occ_path_table));
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memcpy(&v_pri->loc_opt_m_occ_path_table,buf + 152,
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sizeof(v_pri->loc_opt_m_occ_path_table));
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dir = get_free_dir_record();
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if (dir == NULL) return EINVAL;
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create_dir_record(dir,buf + 156,(u32_t)(address + 156));
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v_pri->dir_rec_root = dir;
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dir->d_ino_nr = ROOT_INO_NR;
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memcpy(v_pri->volume_set_id,buf + 190,sizeof(v_pri->volume_set_id));
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memcpy(v_pri->publisher_id,buf + 318,sizeof(v_pri->publisher_id));
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memcpy(v_pri->data_preparer_id,buf + 446,sizeof(v_pri->data_preparer_id));
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memcpy(v_pri->application_id,buf + 574,sizeof(v_pri->application_id));
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memcpy(v_pri->copyright_file_id,buf + 702,sizeof(v_pri->copyright_file_id));
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memcpy(v_pri->abstract_file_id,buf + 739,sizeof(v_pri->abstract_file_id));
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memcpy(v_pri->bibl_file_id,buf + 776,sizeof(v_pri->bibl_file_id));
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memcpy(v_pri->volume_cre_date,buf + 813,sizeof(v_pri->volume_cre_date));
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memcpy(v_pri->volume_mod_date,buf + 830,sizeof(v_pri->volume_mod_date));
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memcpy(v_pri->volume_exp_date,buf + 847,sizeof(v_pri->volume_exp_date));
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memcpy(v_pri->volume_eff_date,buf + 864,sizeof(v_pri->volume_eff_date));
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v_pri->file_struct_ver = buf[881];
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return OK;
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}
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/* This function reads from a ISO9660 filesystem (in the device dev) the
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* super block and saves it in v_pri. */
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PUBLIC int read_vds(
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register struct iso9660_vd_pri *v_pri,
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register dev_t dev
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)
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{
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u64_t offset;
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int vol_ok = FALSE;
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int r;
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static char sbbuf[ISO9660_MIN_BLOCK_SIZE];
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int i = 0;
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offset = cvul64(ISO9660_SUPER_BLOCK_POSITION);
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while (!vol_ok && i++<MAX_ATTEMPTS) {
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/* Read the sector of the super block. */
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r = bdev_read(dev, offset, sbbuf, ISO9660_MIN_BLOCK_SIZE, BDEV_NOFLAGS);
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if (r != ISO9660_MIN_BLOCK_SIZE) /* Damaged sector or what? */
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continue;
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if ((sbbuf[0] & BYTE) == VD_PRIMARY) {
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create_v_pri(v_pri,sbbuf,cv64ul(offset)); /* copy the buffer in the data structure. */
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}
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if ((sbbuf[0] & BYTE) == VD_SET_TERM)
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/* I dont need to save anything about it */
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vol_ok = TRUE;
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offset = add64u(offset,ISO9660_MIN_BLOCK_SIZE);
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}
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if (vol_ok == FALSE)
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return EINVAL; /* If no superblock was found... */
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else
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return OK; /* otherwise. */
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}
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