On Tue, Mar 27, 2012 at 10:34:47AM -0400, Christoph Hellwig wrote: > We do not need the ilock for generic_write_checks and the i_size read, > which are protected by i_mutex and/or iolock, so reduce the ilock > critical section to just the call to xfs_zero_eof. So.. I agree that it looks like the only thing we need to protect in generic_write_checks is the i_size_read. For buffered io i_size_write is done in generic_write_end, and protected XFS_IOLOCK_EXCL in xfs_file_buffered_write. For direct io i_size_write is done in generic_file_direct_write and also protected by the iolock in xfs_file_dio_aio_write. It's not as clear here whether that lock is taken exclusive at that time. However, this is handled in xfs_file_aio_write_checks, where we go io exclusive for xfs_zero_eof. Maybe it would be best for this to be done more explicitly with respect to the inode size in xfs_file_dio_aio_write. Just wanting to show why generic_write_checks is ok protected with just the iolock... Reviewed-by: Ben Myers <bpm@xxxxxxx> _______________________________________________ xfs mailing list xfs@xxxxxxxxxxx http://oss.sgi.com/mailman/listinfo/xfs
