1 // SPDX-License-Identifier: GPL-2.0
13  * inode_dio_wait_interruptible - wait for outstanding DIO requests to finish
14  * @inode: inode to wait for
20  * to i_dio_count, usually by inode->i_mutex.
28 	return !inode_dio_finished(inode) ? -ERESTARTSYS : 0;  in netfs_inode_dio_wait_interruptible()
31 /* Call with exclusively locked inode->i_rwsem */
34 	if (!test_bit(NETFS_ICTX_ODIRECT, &ictx->flags))  in netfs_block_o_direct()
36 	clear_bit(NETFS_ICTX_ODIRECT, &ictx->flags);  in netfs_block_o_direct()
37 	return netfs_inode_dio_wait_interruptible(&ictx->inode);  in netfs_block_o_direct()
41  * netfs_start_io_read - declare the file is being used for buffered reads
44  * Declare that a buffered read operation is about to start, and ensure
46  * On exit, the function ensures that the NETFS_ICTX_ODIRECT flag is unset,
47  * and holds a shared lock on inode->i_rwsem to ensure that the flag
49  * In practice, this means that buffered read operations are allowed to
51  * operations need to wait to grab an exclusive lock in order to set
53  * Note that buffered writes and truncates both take a write lock on
54  * inode->i_rwsem, meaning that those are serialised w.r.t. the reads.
57 	__acquires(inode->i_rwsem)  in netfs_start_io_read()
62 	if (down_read_interruptible(&inode->i_rwsem) < 0)  in netfs_start_io_read()
63 		return -ERESTARTSYS;  in netfs_start_io_read()
64 	if (test_bit(NETFS_ICTX_ODIRECT, &ictx->flags) == 0)  in netfs_start_io_read()
66 	up_read(&inode->i_rwsem);  in netfs_start_io_read()
69 	if (down_write_killable(&inode->i_rwsem) < 0)  in netfs_start_io_read()
70 		return -ERESTARTSYS;  in netfs_start_io_read()
72 		up_write(&inode->i_rwsem);  in netfs_start_io_read()
73 		return -ERESTARTSYS;  in netfs_start_io_read()
75 	downgrade_write(&inode->i_rwsem);  in netfs_start_io_read()
81  * netfs_end_io_read - declare that the buffered read operation is done
84  * Declare that a buffered read operation is done, and release the shared
85  * lock on inode->i_rwsem.
88 	__releases(inode->i_rwsem)  in netfs_end_io_read()
90 	up_read(&inode->i_rwsem);  in netfs_end_io_read()
95  * netfs_start_io_write - declare the file is being used for buffered writes
98  * Declare that a buffered read operation is about to start, and ensure
102 	__acquires(inode->i_rwsem)  in netfs_start_io_write()
106 	if (down_write_killable(&inode->i_rwsem) < 0)  in netfs_start_io_write()
107 		return -ERESTARTSYS;  in netfs_start_io_write()
109 		up_write(&inode->i_rwsem);  in netfs_start_io_write()
110 		return -ERESTARTSYS;  in netfs_start_io_write()
112 	downgrade_write(&inode->i_rwsem);  in netfs_start_io_write()
118  * netfs_end_io_write - declare that the buffered write operation is done
122  * lock on inode->i_rwsem.
125 	__releases(inode->i_rwsem)  in netfs_end_io_write()
127 	up_read(&inode->i_rwsem);  in netfs_end_io_write()
131 /* Call with exclusively locked inode->i_rwsem */
137 	if (!test_bit(NETFS_ICTX_ODIRECT, &ictx->flags)) {  in netfs_block_buffered()
138 		set_bit(NETFS_ICTX_ODIRECT, &ictx->flags);  in netfs_block_buffered()
139 		if (inode->i_mapping->nrpages != 0) {  in netfs_block_buffered()
140 			unmap_mapping_range(inode->i_mapping, 0, 0, 0);  in netfs_block_buffered()
141 			ret = filemap_fdatawait(inode->i_mapping);  in netfs_block_buffered()
143 				clear_bit(NETFS_ICTX_ODIRECT, &ictx->flags);  in netfs_block_buffered()
152  * netfs_start_io_direct - declare the file is being used for direct i/o
157  * On exit, the function ensures that the NETFS_ICTX_ODIRECT flag is set,
158  * and holds a shared lock on inode->i_rwsem to ensure that the flag
162  * operations need to wait to grab an exclusive lock in order to clear
164  * Note that buffered writes and truncates both take a write lock on
165  * inode->i_rwsem, meaning that those are serialised w.r.t. O_DIRECT.
168 	__acquires(inode->i_rwsem)  in netfs_start_io_direct()
174 	if (down_read_interruptible(&inode->i_rwsem) < 0)  in netfs_start_io_direct()
175 		return -ERESTARTSYS;  in netfs_start_io_direct()
176 	if (test_bit(NETFS_ICTX_ODIRECT, &ictx->flags) != 0)  in netfs_start_io_direct()
178 	up_read(&inode->i_rwsem);  in netfs_start_io_direct()
181 	if (down_write_killable(&inode->i_rwsem) < 0)  in netfs_start_io_direct()
182 		return -ERESTARTSYS;  in netfs_start_io_direct()
185 		up_write(&inode->i_rwsem);  in netfs_start_io_direct()
188 	downgrade_write(&inode->i_rwsem);  in netfs_start_io_direct()
194  * netfs_end_io_direct - declare that the direct i/o operation is done
198  * lock on inode->i_rwsem.
201 	__releases(inode->i_rwsem)  in netfs_end_io_direct()
203 	up_read(&inode->i_rwsem);  in netfs_end_io_direct()