2012/8/21, J. Bruce Fields <[email protected]>: > On Mon, Aug 20, 2012 at 01:19:51PM +0900, Namjae Jeon wrote: >> 2012/8/18, OGAWA Hirofumi <[email protected]>: >> > Al Viro <[email protected]> writes: >> > >> >> On Sat, Aug 18, 2012 at 05:41:39AM -0400, Namjae Jeon wrote: >> >>> From: Namjae Jeon <[email protected]> >> >>> >> >>> This patch-set eliminates the client side ESTALE errors when >> >>> a FAT partition exported over NFS has its dentries evicted >> >>> from the cache. >> >>> >> >>> One of the reasons for this error is lack of permanent inode >> >>> numbers on FAT which makes it difficult to construct persistent >> >>> file handles.This can be overcome by using the on-disk location >> >>> of the directory entries (i_pos) as the inode number. >> >> >> >> The hell it can. You've just made them unstable on rename(2). >> > >> > As more hint. We can't use i_pos as the inode number. >> > >> > E.g. inode is unlinked but is still opened (orphaned inode), the dir >> > entry is free and you can create the inode on same i_pos. After that, >> > both inodes have same i_pos (so inode number). >> > >> > Thanks. >> Hi. Ogawa. >> Thanks for specific explanation. I will check it. > Hi Bruce. > Fo somebody that knows more about fat than me--is there really any hope > of making it play well with nfs?
I think that this patch is only solution to fix estale issue from inode cache eviction. In case FAT - it makes use of iunique() to get unique inode number -which is just based upon getting an incremented value from unique counter variable. So, there is no way to reconstruct the inode based upon inode numbers - like in case of other filesystems We can check it easily like this. 1. ls -al /directory on nfs client. 2. echo 3 > /proc/sys/vm/drop_caches 3. ls -al /directory on nfs client again. estale error will be occurred. There is no estale issue from reclaim with this patch. And.. Hi Ogawa. I checked other filesystem about unlink - inode issue. but I found Ext4 have same issue. Although other filesysm is having this issue, Can we think It could be only FAT issue ? > > --b. > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
