On May 14, 2007 18:59 +0530, Amit K. Arora wrote: > asmlinkage long sys_fallocate(int fd, int mode, loff_t offset, loff_t len) > > fd: The descriptor of the open file. > > mode*: This specifies the behavior of the system call. Currently the > system call supports two modes - FA_ALLOCATE and FA_DEALLOCATE. > FA_ALLOCATE: Applications can use this mode to preallocate blocks to > a given file (specified by fd). This mode changes the file size if > the preallocation is done beyond the EOF. It also updates the > ctime/mtime in the inode of the corresponding file, marking a > successfull allocation. > FA_DEALLOCATE: This mode can be used by applications to deallocate the > previously preallocated blocks. This also may change the file size > and the ctime/mtime. > * New modes might get added in future. One such new mode which is > already under discussion is FA_PREALLOCATE, which when used will > preallocate space but will not change the filesize and [cm]time. > Since the semantics of this new mode is not clear and agreed upon yet, > this patchset does not implement it currently. > > offset: This is the offset in bytes, from where the preallocation should > start. > > len: This is the number of bytes requested for preallocation (from > offset). What is the return value? I'd hope it is the number of bytes preallocated, in case of interrupted preallocation for whatever reason (interrupt, out of space, etc) like a regular write(2) call. In this case the return type needs to also be an loff_t to match @len. Cheers, Andreas -- Andreas Dilger Principal Software Engineer Cluster File Systems, Inc. - To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
