On Thu, Jun 13, 2013 at 1:46 PM, Brian Foster <[email protected]> wrote: > On 06/13/2013 04:16 AM, Maxim Patlasov wrote: >> Changing size of a file on server and local update (fuse_write_update_size) >> should be always protected by inode->i_mutex. Otherwise a race like this is >> possible: >> >> 1. Process 'A' calls fallocate(2) to extend file (~FALLOC_FL_KEEP_SIZE). >> fuse_file_fallocate() sends FUSE_FALLOCATE request to the server. >> 2. Process 'B' calls ftruncate(2) shrinking the file. fuse_do_setattr() >> sends shrinking FUSE_SETATTR request to the server and updates local i_size >> by i_size_write(inode, outarg.attr.size). >> 3. Process 'A' resumes execution of fuse_file_fallocate() and calls >> fuse_write_update_size(inode, offset + length). But 'offset + length' was >> obsoleted by ftruncate from previous step. >> >> Changed in v2 (thanks Brian and Anand for suggestions): >> - made relation between mutex_lock() and fuse_set_nowrite(inode) more >> explicit and clear. >> - updated patch description to use ftruncate(2) in example >> >> Signed-off-by: Maxim V. Patlasov <[email protected]>
Thanks, applied. Miklos -- 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/
