On Thu, Dec 21, 2006 at 04:40:03PM +0800, colin wrote: > How do I know the file size limit on a unknown filesystem? > Our application can use CIFS and record data to the remote site. > We would like to know the file size limit before we start to record, but the > "fstat" doesn't tell us about this. AFAIK there is no system call to figure out though the information is in the (in-kernel) superblock. One way is to create a file and use a binary search with ftruncate() to figure out the largest possible size. That will only work fast on filesystems that support sparse files. Another way is to use a safe limit (i.e.: 1GB is usually safe). > And another question is how do I know if Direct I/O is usable on some > filesystem and storage? open() a file with O_DIRECT. If it fails, direct IO is not possible. Erik -- They're all fools. Don't worry. Darwin may be slow, but he'll eventually get them. -- Matthew Lammers in alt.sysadmin.recovery -- Kernelnewbies: Help each other learn about the Linux kernel. Archive: http://mail.nl.linux.org/kernelnewbies/ FAQ: http://kernelnewbies.org/faq/
