On Fri, Sep 25, 2020 at 06:51:08PM -0700, Darrick J. Wong wrote: > On Thu, Sep 24, 2020 at 11:39:11AM -0500, Goldwyn Rodrigues wrote: > > From: Goldwyn Rodrigues <rgoldwyn@xxxxxxxx> > > > > iomap complete routine can deadlock with btrfs_fallocate because of the > > call to generic_write_sync(). > > > > P0 P1 > > inode_lock() fallocate(FALLOC_FL_ZERO_RANGE) > > __iomap_dio_rw() inode_lock() > > <block> > > <submits IO> > > <completes IO> > > inode_unlock() > > <gets inode_lock()> > > inode_dio_wait() > > iomap_dio_complete() > > generic_write_sync() > > btrfs_file_fsync() > > inode_lock() > > <deadlock> > > > > inode_dio_end() is used to notify the end of DIO data in order > > to synchronize with truncate. Call inode_dio_end() before calling > > generic_write_sync(), so filesystems can lock i_rwsem during a sync. > > > > This matches the way it is done in fs/direct-io.c:dio_complete(). > > > > Signed-off-by: Goldwyn Rodrigues <rgoldwyn@xxxxxxxx> > > Reviewed-by: Christoph Hellwig <hch@xxxxxx> > > Reviewed-by: Josef Bacik <josef@xxxxxxxxxxxxxx> > > Looks ok (at least with the fses that use either iomap or ye olde > directio) to me... > > Reviewed-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx> > > So, uh, do you want me to pull these two iomap patches in for 5.10? That would be great, thanks. Once they land in 5.10-rc we'll be able to base the rest on some master snapshot and target 5.11 for release.
