Inode number changing

[Manish Katiyar]

On Fri, Mar 9, 2012 at 11:02 AM, Ganesh Patil <patil.ganesh170 at gmail.com> wrote:
>
>
> On Sat, Mar 10, 2012 at 12:18 AM, Manish Katiyar <mkatiyar at gmail.com> wrote:
>>
>> > 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