On Fri, Mar 9, 2012 at 11:02 AM, Ganesh Patil [off-list ref] wrote:

On Sat, Mar 10, 2012 at 12:18 AM, Manish Katiyar [off-list ref] wrote:

quoted

quoted

Sir, every time when I modify file content then file's inode get change.
Why this is happening?
Below I have pasted the output please check inode numbers.

Without looking at the code and knowing what you are doing, its close
to impossible to say what inode you are accessing or what you are
doing. On my wildest guess, I can think of that you are probably
trying to modify something in editor, and the inode number that is
getting printed is one of the temp files that the editor may be
creating underneath( similar to .swp files of vi).


--
Thanks -
Manish

Yes sir, I am trying to modify my file in vim editor.
below I have pasted my code :
#include <linux/kernel.h>
#include<linux/module.h>
#include<linux/fs.h>
#include<linux/namei.h>
#include<linux/path.h>
#include<linux/mount.h>
#include<linux/myheader.h>
struct ext4_inode1 {
??????? __le16? i_mode;???????? /* File mode */
??????? __le16? i_uid;????????? /* Low 16 bits of Owner Uid */
??????? __le32? i_size_lo;????? /* Size in bytes */
??????? __le32? i_atime;??????? /* Access time */
??????? __le32? i_ctime;??????? /* Inode Change time */
??????? __le32? i_mtime;??????? /* Modification time */
??????? __le32? i_dtime;??????? /* Deletion Time */
??????? __le16? i_gid;????????? /* Low 16 bits of Group Id */
??????? __le16? i_links_count;? /* Links count */
??????? __le32? i_blocks_lo;??? /* Blocks count */
??????? __le32? i_flags;??????? /* File flags */
??????? union {
??????????????? struct {
??????????????????????? __le32? l_i_version;
??????????????? } linux1;
??????????????? struct {
??????????????????????? __u32? h_i_translator;
??????????????? } hurd1;
??????????????? struct {
??????????????????????? __u32? m_i_reserved1;
??????????????? } masix1;
??????? } osd1;???????????????????????? /* OS dependent 1 */
??????? __le32? i_block[EXT4_N_BLOCKS];/* Pointers to blocks */
??????? __le32? i_generation;?? /* File version (for NFS) */
??????? __le32? i_file_acl_lo;? /* File ACL */
??????? __le32? i_size_high;
??????? __le32? i_obso_faddr;?? /* Obsoleted fragment address */
union {
??????????????? struct {
??????????????????????? __le16? l_i_blocks_high; /* were l_i_reserved1 */
??????????????????????? __le16? l_i_file_acl_high;
??????????????????????? __le16? l_i_uid_high;?? /* these 2 fields */
??????????????????????? __le16? l_i_gid_high;?? /* were reserved2[0] */
??????????????????????? __u32?? l_i_reserved2;
??????????????? } linux2;
??????????????? struct {
??????????????????????? __le16? h_i_reserved1;? /* Obsoleted fragment
number/size which are removed in ext4 */
??????????????????????? __u16?? h_i_mode_high;
??????????????????????? __u16?? h_i_uid_high;
??????????????????????? __u16?? h_i_gid_high;
??????????????????????? __u32?? h_i_author;
??????????????? } hurd2;
??????????????? struct {
??????????????????????? __le16? h_i_reserved1;? /* Obsoleted fragment
number/size which are removed in ext4 */
??????????????????????? __le16? m_i_file_acl_high;
??????????????????????? __u32?? m_i_reserved2[2];
??????????????? } masix2;
??????? } osd2;???????????????????????? /* OS dependent 2 */
??????? __le16? i_extra_isize;
??????? __le16? i_pad1;
??????? __le32? i_ctime_extra;? /* extra Change time????? (nsec << 2 |
epoch) */
??????? __le32? i_mtime_extra;? /* extra Modification time(nsec << 2 |
epoch) */
??????? __le32? i_atime_extra;? /* extra Access time????? (nsec << 2 |
epoch) */
??????? __le32? i_crtime;?????? /* File Creation time */
??????? __le32? i_crtime_extra; /* extra FileCreationtime (nsec << 2 |
epoch) */
??????? __le32? i_version_hi;?? /* high 32 bits for 64-bit version */
};
typedef struct ext4_inode ext4_inode1;
extern int ext4_get_inode_loc(struct inode *, struct ext4_iloc *);

int init_module(void)
{
?char buf[200]="/mnt/one/a.txt";

???????? struct nameidata nd;
???????? struct path path1;
????????? struct dentry *dentry1;
????????? struct inode *d_inode1;
????????? struct ext4_iloc iloc;
????????? int ret,i;
???????? struct ext4_inode *e4_inode=NULL;
????????? ext4_inode1? *m1;
?path_lookup(buf, LOOKUP_CONTINUE, &nd);
?????? path1=nd.path;
?????? dentry1=path1.dentry;
?????? d_inode1=dentry1->d_inode;
?????? m1 = (ext4_inode1 *) kmalloc (sizeof (ext4_inode1), GFP_KERNEL);
?????? //m1->i_ino=d_inode1->i_ino;
?????? printk(KERN_INFO "inode no of file=%ld",d_inode1->i_ino);
ret= ext4_get_inode_loc(d_inode1, &iloc);
?????? e4_inode= ext4_raw_inode(&iloc);
?????? m1->i_size_lo=e4_inode->i_size_lo;
?????? printk(KERN_INFO "size of file =%d",e4_inode->i_size_lo);
?????? printk(KERN_INFO "size of file copied =%d",m1->i_size_lo);
?????? printk(KERN_INFO "data blocks=");
?????? for(i=0;i<5;i++)
?????? {
??????????? printk(KERN_INFO "%d",e4_inode->i_block[i]);
????? }
return 0;
}
void cleanup_module(void)
{
printk(KERN_INFO "Goodbye world 1.\n");
}

Did you get an answer for this ? Did you try writing through 'dd'.
Also what were your original inode numbers ?


-- 
Thanks -
Manish