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mkfs creates a welcome file. readdir(ls) tries to list this file

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Sankar சங்கர் 2013-04-22 23:53:59 +05:30
parent fec3cb7f9b
commit f5cf481557
2 changed files with 85 additions and 7 deletions
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82
mkfs-simplefs.c
View File

@ -4,15 +4,27 @@
#include <sys/stat.h>
#include <fcntl.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include "simple.h"
int main(int argc, char *argv[])
{
int fd;
int fd, nbytes;
ssize_t ret;
struct simplefs_super_block sb;
struct simplefs_inode root_inode;
struct simplefs_inode welcomefile_inode;
char welcomefile_name[] = "vanakkam";
char welcomefile_body[] = "Love is God. God is Love. Anbe Murugan.";
const uint64_t WELCOMEFILE_INODE_NUMBER = 2;
const uint64_t WELCOMEFILE_DATABLOCK_NUMBER = 3;
char *block_padding;
struct simplefs_dir_record record;
if (argc != 2) {
printf("Usage: mkfs-simplefs <device>\n");
@ -29,8 +41,10 @@ int main(int argc, char *argv[])
sb.magic = SIMPLEFS_MAGIC;
sb.block_size = SIMPLEFS_DEFAULT_BLOCK_SIZE;
/* Only the root dir will have an inode now */
sb.inodes_count = 1;
/* One inode for rootdirectory and another for a welcome file that we are going to create */
sb.inodes_count = 2;
/* FIXME: Free blocks management is not implemented yet */
sb.free_blocks = ~0;
ret = write(fd, (char *)&sb, sizeof(sb));
@ -48,7 +62,7 @@ int main(int argc, char *argv[])
root_inode.mode = S_IFDIR;
root_inode.inode_no = SIMPLEFS_ROOTDIR_INODE_NUMBER;
root_inode.data_block_number = SIMPLEFS_ROOTDIR_DATABLOCK_NUMBER;
root_inode.dir_children_count = 0;
root_inode.dir_children_count = 1;
ret = write(fd, (char *)&root_inode, sizeof(root_inode));
@ -57,7 +71,65 @@ int main(int argc, char *argv[])
ret = -1;
goto exit;
}
printf("inode store written succesfully\n");
printf("root directory inode written succesfully\n");
welcomefile_inode.mode = S_IFREG;
welcomefile_inode.inode_no = WELCOMEFILE_INODE_NUMBER;
welcomefile_inode.data_block_number = WELCOMEFILE_DATABLOCK_NUMBER;
welcomefile_inode.file_size = sizeof(welcomefile_body);
ret = write(fd, (char *)&welcomefile_inode, sizeof(root_inode));
if (ret != sizeof(root_inode)) {
printf("The welcomefile inode was not written properly. Retry your mkfs\n");
ret = -1;
goto exit;
}
printf("welcomefile inode written succesfully\n");
nbytes = SIMPLEFS_DEFAULT_BLOCK_SIZE - sizeof(root_inode) - sizeof(welcomefile_inode);
block_padding = malloc(nbytes);
ret = write(fd, block_padding, nbytes);
if (ret != nbytes) {
printf("The padding bytes are not written properly. Retry your mkfs\n");
ret = -1;
goto exit;
}
printf("inode store padding bytes (after the two inodes) written sucessfully\n");
strcpy(record.filename, welcomefile_name);
record.inode_no = WELCOMEFILE_INODE_NUMBER;
nbytes = sizeof(record);
ret = write(fd, (char *)&record, nbytes);
if (ret != nbytes) {
printf("Writing the rootdirectory datablock (name+inode_no pair for welcomefile) has failed\n");
ret = -1;
goto exit;
}
printf("root directory datablocks (name+inode_no pair for welcomefile) written succesfully\n");
nbytes = SIMPLEFS_DEFAULT_BLOCK_SIZE - sizeof(record);
block_padding = realloc(block_padding, nbytes);
ret = write(fd, block_padding, nbytes);
if (ret != nbytes) {
printf("Writing the padding for rootdirectory children datablock has failed\n");
ret = -1;
goto exit;
}
printf("padding after the rootdirectory children written succesfully\n");
nbytes = sizeof(welcomefile_body);
ret = write(fd, welcomefile_body, nbytes);
if (ret != nbytes) {
printf("Writing welcomefile body has failed\n");
ret = -1;
goto exit;
}
printf("welcomefilebody has been written succesfully\n");
ret = 0;
exit:

10
simple.c
View File

@ -23,7 +23,12 @@ static int simplefs_readdir(struct file *filp, void *dirent, filldir_t filldir)
struct simplefs_dir_record *record;
int i;
printk(KERN_INFO "We are inside readdir. The pos[%lld], inode number[%lu], superblock magic [%lu]\n", pos, inode->i_ino, sb->s_magic);
printk(KERN_INFO "We are inside readdir. The pos[%lld], inode number[%lu], superblock magic [%lu] inodesize [%lld]\n", pos, inode->i_ino, sb->s_magic, inode->i_size);
if (pos) {
printk(KERN_INFO "pos seem to be non-zero which means we have already filled in all the details\n");
return 0;
}
sfs_inode = SIMPLEFS_INODE(inode);
@ -38,11 +43,12 @@ static int simplefs_readdir(struct file *filp, void *dirent, filldir_t filldir)
for (i=0; i < sfs_inode->dir_children_count; i++) {
printk(KERN_INFO "Got filename: %s\n", record->filename);
filldir(dirent, record->filename, SIMPLEFS_FILENAME_MAXLEN, pos, record->inode_no, DT_UNKNOWN);
filp->f_pos += sizeof(struct simplefs_dir_record);
pos += sizeof(struct simplefs_dir_record);
record ++;
}
return 1;
return 0;
}
const struct file_operations simplefs_dir_operations = {