From 6552321831dce87ff5c466a55b58d472732caadc Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Wed, 30 Nov 2016 14:33:25 +1100 Subject: xfs: remove i_iolock and use i_rwsem in the VFS inode instead This patch drops the XFS-own i_iolock and uses the VFS i_rwsem which recently replaced i_mutex instead. This means we only have to take one lock instead of two in many fast path operations, and we can also shrink the xfs_inode structure. Thanks to the xfs_ilock family there is very little churn, the only thing of note is that we need to switch to use the lock_two_directory helper for taking the i_rwsem on two inodes in a few places to make sure our lock order matches the one used in the VFS. Signed-off-by: Christoph Hellwig Tested-by: Jens Axboe Reviewed-by: Darrick J. Wong Signed-off-by: Dave Chinner --- fs/xfs/xfs_file.c | 79 ++++++++++++++++--------------------------------------- 1 file changed, 23 insertions(+), 56 deletions(-) (limited to 'fs/xfs/xfs_file.c') diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c index d818c160451f..d054b73b56fb 100644 --- a/fs/xfs/xfs_file.c +++ b/fs/xfs/xfs_file.c @@ -47,40 +47,6 @@ static const struct vm_operations_struct xfs_file_vm_ops; -/* - * Locking primitives for read and write IO paths to ensure we consistently use - * and order the inode->i_mutex, ip->i_lock and ip->i_iolock. - */ -static inline void -xfs_rw_ilock( - struct xfs_inode *ip, - int type) -{ - if (type & XFS_IOLOCK_EXCL) - inode_lock(VFS_I(ip)); - xfs_ilock(ip, type); -} - -static inline void -xfs_rw_iunlock( - struct xfs_inode *ip, - int type) -{ - xfs_iunlock(ip, type); - if (type & XFS_IOLOCK_EXCL) - inode_unlock(VFS_I(ip)); -} - -static inline void -xfs_rw_ilock_demote( - struct xfs_inode *ip, - int type) -{ - xfs_ilock_demote(ip, type); - if (type & XFS_IOLOCK_EXCL) - inode_unlock(VFS_I(ip)); -} - /* * Clear the specified ranges to zero through either the pagecache or DAX. * Holes and unwritten extents will be left as-is as they already are zeroed. @@ -273,7 +239,7 @@ xfs_file_dio_aio_read( file_accessed(iocb->ki_filp); - xfs_rw_ilock(ip, XFS_IOLOCK_SHARED); + xfs_ilock(ip, XFS_IOLOCK_SHARED); if (mapping->nrpages) { ret = filemap_write_and_wait_range(mapping, iocb->ki_pos, end); if (ret) @@ -299,7 +265,7 @@ xfs_file_dio_aio_read( } out_unlock: - xfs_rw_iunlock(ip, XFS_IOLOCK_SHARED); + xfs_iunlock(ip, XFS_IOLOCK_SHARED); return ret; } @@ -317,9 +283,9 @@ xfs_file_dax_read( if (!count) return 0; /* skip atime */ - xfs_rw_ilock(ip, XFS_IOLOCK_SHARED); + xfs_ilock(ip, XFS_IOLOCK_SHARED); ret = dax_iomap_rw(iocb, to, &xfs_iomap_ops); - xfs_rw_iunlock(ip, XFS_IOLOCK_SHARED); + xfs_iunlock(ip, XFS_IOLOCK_SHARED); file_accessed(iocb->ki_filp); return ret; @@ -335,9 +301,9 @@ xfs_file_buffered_aio_read( trace_xfs_file_buffered_read(ip, iov_iter_count(to), iocb->ki_pos); - xfs_rw_ilock(ip, XFS_IOLOCK_SHARED); + xfs_ilock(ip, XFS_IOLOCK_SHARED); ret = generic_file_read_iter(iocb, to); - xfs_rw_iunlock(ip, XFS_IOLOCK_SHARED); + xfs_iunlock(ip, XFS_IOLOCK_SHARED); return ret; } @@ -418,15 +384,18 @@ restart: if (error <= 0) return error; - error = xfs_break_layouts(inode, iolock, true); + error = xfs_break_layouts(inode, iolock); if (error) return error; - /* For changing security info in file_remove_privs() we need i_mutex */ + /* + * For changing security info in file_remove_privs() we need i_rwsem + * exclusively. + */ if (*iolock == XFS_IOLOCK_SHARED && !IS_NOSEC(inode)) { - xfs_rw_iunlock(ip, *iolock); + xfs_iunlock(ip, *iolock); *iolock = XFS_IOLOCK_EXCL; - xfs_rw_ilock(ip, *iolock); + xfs_ilock(ip, *iolock); goto restart; } /* @@ -451,9 +420,9 @@ restart: spin_unlock(&ip->i_flags_lock); if (!drained_dio) { if (*iolock == XFS_IOLOCK_SHARED) { - xfs_rw_iunlock(ip, *iolock); + xfs_iunlock(ip, *iolock); *iolock = XFS_IOLOCK_EXCL; - xfs_rw_ilock(ip, *iolock); + xfs_ilock(ip, *iolock); iov_iter_reexpand(from, count); } /* @@ -559,7 +528,7 @@ xfs_file_dio_aio_write( iolock = XFS_IOLOCK_SHARED; } - xfs_rw_ilock(ip, iolock); + xfs_ilock(ip, iolock); ret = xfs_file_aio_write_checks(iocb, from, &iolock); if (ret) @@ -591,7 +560,7 @@ xfs_file_dio_aio_write( if (unaligned_io) inode_dio_wait(inode); else if (iolock == XFS_IOLOCK_EXCL) { - xfs_rw_ilock_demote(ip, XFS_IOLOCK_EXCL); + xfs_ilock_demote(ip, XFS_IOLOCK_EXCL); iolock = XFS_IOLOCK_SHARED; } @@ -621,7 +590,7 @@ xfs_file_dio_aio_write( iov_iter_advance(from, ret); } out: - xfs_rw_iunlock(ip, iolock); + xfs_iunlock(ip, iolock); /* * No fallback to buffered IO on errors for XFS, direct IO will either @@ -643,7 +612,7 @@ xfs_file_dax_write( size_t count; loff_t pos; - xfs_rw_ilock(ip, iolock); + xfs_ilock(ip, iolock); ret = xfs_file_aio_write_checks(iocb, from, &iolock); if (ret) goto out; @@ -652,15 +621,13 @@ xfs_file_dax_write( count = iov_iter_count(from); trace_xfs_file_dax_write(ip, count, pos); - ret = dax_iomap_rw(iocb, from, &xfs_iomap_ops); if (ret > 0 && iocb->ki_pos > i_size_read(inode)) { i_size_write(inode, iocb->ki_pos); error = xfs_setfilesize(ip, pos, ret); } - out: - xfs_rw_iunlock(ip, iolock); + xfs_iunlock(ip, iolock); return error ? error : ret; } @@ -677,7 +644,7 @@ xfs_file_buffered_aio_write( int enospc = 0; int iolock = XFS_IOLOCK_EXCL; - xfs_rw_ilock(ip, iolock); + xfs_ilock(ip, iolock); ret = xfs_file_aio_write_checks(iocb, from, &iolock); if (ret) @@ -721,7 +688,7 @@ write_retry: current->backing_dev_info = NULL; out: - xfs_rw_iunlock(ip, iolock); + xfs_iunlock(ip, iolock); return ret; } @@ -797,7 +764,7 @@ xfs_file_fallocate( return -EOPNOTSUPP; xfs_ilock(ip, iolock); - error = xfs_break_layouts(inode, &iolock, false); + error = xfs_break_layouts(inode, &iolock); if (error) goto out_unlock; -- cgit v1.2.3-70-g09d2