Hi Rohit, On Mon, Jan 12, 2009 at 11:48 AM, Rohit Sharma <imreckless@xxxxxxxxx> wrote: > Hi, > > I am having some issues in locking inode while copying data blocks. > We are trying to keep file system live during this operation, so > both read and write operations should work. > In this case what type of lock on inode should be used, semaphore, > mutex or spinlock? > Now here you need to do some homework first. Each of the locks have its own meaning and particular uses cases. The current inode struct has the following locks: 1. i_lock 2. i_alloc_sem 3. i_mutex 4. i_flock 646 spinlock_t i_lock; /* i_blocks, i_bytes, maybe i_size */ 647 struct mutex i_mutex; 648 struct rw_semaphore i_alloc_sem; 649 const struct inode_operations *i_op; 650 const struct file_operations *i_fop; /* former ->i_op->default_file_ops */ 651 struct super_block *i_sb; 652 struct file_lock *i_flock; Read the difference between spinlock, mutex, and semaphore. You will be able to understand the semantics of each of these. > > On Sun, Jan 11, 2009 at 8:45 PM, Peter Teoh <htmldeveloper@xxxxxxxxx> wrote: >> Sorry.....some mistakes...a resent: >> >> Here are some tips on the blockdevice API: >> >> http://lkml.org/lkml/2006/1/24/287 >> http://linux.derkeiler.com/Mailing-Lists/Kernel/2006-01/msg09388.html >> >> as indicated, documentation is rather sparse in this area. >> >> not sure if anyone else have a summary list of blockdevice API and its >> explanation? >> >> not wrt the following "cleanup patch", i am not sure how the API will change: >> >> http://lwn.net/Articles/304485/ >> >> thanks. >> >> On Tue, Jan 6, 2009 at 6:36 PM, Rohit Sharma <imreckless@xxxxxxxxx> wrote: >>> >>> I want to read data blocks from one inode >>> and copy it to other inode. >>> >>> I mean to copy data from data blocks associated with one inode >>> to the data blocks associated with other inode. >>> >>> Is that possible in kernel space.? >>> -- >> >> >> >> -- >> Regards, >> Peter Teoh >> > > -- > To unsubscribe from this list: send an email with > "unsubscribe kernelnewbies" to ecartis@xxxxxxxxxxxx > Please read the FAQ at http://kernelnewbies.org/FAQ > > -- Regards, Sandeep. "To learn is to change. Education is a process that changes the learner." -- To unsubscribe from this list: send an email with "unsubscribe kernelnewbies" to ecartis@xxxxxxxxxxxx Please read the FAQ at http://kernelnewbies.org/FAQ
