Hi Al, I think there is a race condition between iget_locked() and evict_inodes(). evict_inodes() checks i_count and if zero proceeds to take i_lock then set I_FREEING and eventually disposes of the inode. But a concurrent iget_locked() takes i_lock and then increments i_count. Thus if the events happen in this order: evict_inodes() iget_locked() in find_inode_fast() atomic_read(&inode->i_count) -> 0 take i_lock wait on i_lock __iget(inode); -> i_count now 1 set I_FREEING drop i_lock evict() return inode to caller The inode is now gone due to the evict() call whilst it is happily being used with an elevated i_count by the iget_locked() calling process. It seems to me like evict_inodes() should be checking i_count inside i_lock either as the only check or it should at least re-check it. Please tell me what I am missing here. I assume there must be something providing exclusion and I am just too blind to see it but I thought it worth bringing to your attention in case it really is simply broken. Best regards, Anton -- Anton Altaparmakov <anton at tuxera.com> (replace at with @) Lead in File System Development, Tuxera Inc., http://www.tuxera.com/ Linux NTFS maintainer -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
