Mohit,

From your mails it looks to me you are coming very early to post questions on this list. I would suggest to be little patient and go through some text books (preferably Understanding Linux Kernel 3rd Ed.) and try to cover all I/O subsystem related chapters. I am sure most of your answers you will find reading text only.

well by something i mean , that some process needs to access the offset of file for next read or dup that file discriptor  so why  each time to go for inode . (check me if i am wrong)

are you saying that process refers to inode for getting next read location? If this is the case, then you are wrong. next read/write location is kept in file object not in inode. file object is like a session between process opening the file and inode of the file. A process (or multiple process) can open a file multiple times creating multiple file objects against a single inode, with each file object reading/writing different portions of same file. Rajat On Wed, Jan 12, 2011 at 5:38 PM, mohit verma <mohit89mlnc@gmail.com> wrote:

On Wed, Jan 12, 2011 at 5:08 PM, prabhu <prabhum@msys-tech.com> wrote:

...

mohit verma wrote:

hi folks,

i am confused with the functions starting from vfs_ . i  think they show the significance of VFS model  i  mean if something could be done without touching the  disk stuff then why not to do that but i am not quite sure. so please help me understand what does these actually mean??

thanks in advance guysss

 well by something i mean , that some process needs to access the offset of file for next read or dup that file discriptor  so why  each time to go for inode . (check me if i am wrong)

 m sorry for not being clear in textual work.

...

 but i got it now . thank  u  for  noticing this query.

I am not sure that I understand the above question correctly, you mean "what is the use of VFS file system if doing operation without touching the disk . That means doing operation on cd rom, keyboard,mouse ?"

VFS is a upper layer of all the filesystem and all the module register its file operation into this layer. So Whenever you doing operation on any file, VFS layer receive the request and redirect into corresponding registered module operation.

I don't think we can do the operation without vfs.

Please correct me if i am wrong.

Thanks , Skm prabhu

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