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.
24 	if (!atomic_read(&inode->i_dio_count))  in inode_dio_wait_interruptible()
27 	wait_queue_head_t *wq = bit_waitqueue(&inode->i_state, __I_DIO_WAKEUP);  in inode_dio_wait_interruptible()
28 	DEFINE_WAIT_BIT(q, &inode->i_state, __I_DIO_WAKEUP);  in inode_dio_wait_interruptible()
32 		if (!atomic_read(&inode->i_dio_count))  in inode_dio_wait_interruptible()
40 	return atomic_read(&inode->i_dio_count) ? -ERESTARTSYS : 0;  in inode_dio_wait_interruptible()
43 /* Call with exclusively locked inode->i_rwsem */
46 	if (!test_bit(NETFS_ICTX_ODIRECT, &ictx->flags))  in netfs_block_o_direct()
48 	clear_bit(NETFS_ICTX_ODIRECT, &ictx->flags);  in netfs_block_o_direct()
49 	return inode_dio_wait_interruptible(&ictx->inode);  in netfs_block_o_direct()
53  * netfs_start_io_read - declare the file is being used for buffered reads
58  * On exit, the function ensures that the NETFS_ICTX_ODIRECT flag is unset,
59  * and holds a shared lock on inode->i_rwsem to ensure that the flag
63  * operations need to wait to grab an exclusive lock in order to set
65  * Note that buffered writes and truncates both take a write lock on
66  * inode->i_rwsem, meaning that those are serialised w.r.t. the reads.
69 	__acquires(inode->i_rwsem)  in netfs_start_io_read()
74 	if (down_read_interruptible(&inode->i_rwsem) < 0)  in netfs_start_io_read()
75 		return -ERESTARTSYS;  in netfs_start_io_read()
76 	if (test_bit(NETFS_ICTX_ODIRECT, &ictx->flags) == 0)  in netfs_start_io_read()
78 	up_read(&inode->i_rwsem);  in netfs_start_io_read()
81 	if (down_write_killable(&inode->i_rwsem) < 0)  in netfs_start_io_read()
82 		return -ERESTARTSYS;  in netfs_start_io_read()
84 		up_write(&inode->i_rwsem);  in netfs_start_io_read()
85 		return -ERESTARTSYS;  in netfs_start_io_read()
87 	downgrade_write(&inode->i_rwsem);  in netfs_start_io_read()
93  * netfs_end_io_read - declare that the buffered read operation is done
97  * lock on inode->i_rwsem.
100 	__releases(inode->i_rwsem)  in netfs_end_io_read()
102 	up_read(&inode->i_rwsem);  in netfs_end_io_read()
107  * netfs_start_io_write - declare the file is being used for buffered writes
114 	__acquires(inode->i_rwsem)  in netfs_start_io_write()
118 	if (down_write_killable(&inode->i_rwsem) < 0)  in netfs_start_io_write()
119 		return -ERESTARTSYS;  in netfs_start_io_write()
121 		up_write(&inode->i_rwsem);  in netfs_start_io_write()
122 		return -ERESTARTSYS;  in netfs_start_io_write()
129  * netfs_end_io_write - declare that the buffered write operation is done
132  * Declare that a buffered write operation is done, and release the
133  * lock on inode->i_rwsem.
136 	__releases(inode->i_rwsem)  in netfs_end_io_write()
138 	up_write(&inode->i_rwsem);  in netfs_end_io_write()
142 /* Call with exclusively locked inode->i_rwsem */
148 	if (!test_bit(NETFS_ICTX_ODIRECT, &ictx->flags)) {  in netfs_block_buffered()
149 		set_bit(NETFS_ICTX_ODIRECT, &ictx->flags);  in netfs_block_buffered()
150 		if (inode->i_mapping->nrpages != 0) {  in netfs_block_buffered()
151 			unmap_mapping_range(inode->i_mapping, 0, 0, 0);  in netfs_block_buffered()
152 			ret = filemap_fdatawait(inode->i_mapping);  in netfs_block_buffered()
154 				clear_bit(NETFS_ICTX_ODIRECT, &ictx->flags);  in netfs_block_buffered()
163  * netfs_start_io_direct - declare the file is being used for direct i/o
168  * On exit, the function ensures that the NETFS_ICTX_ODIRECT flag is set,
169  * and holds a shared lock on inode->i_rwsem to ensure that the flag
173  * operations need to wait to grab an exclusive lock in order to clear
175  * Note that buffered writes and truncates both take a write lock on
176  * inode->i_rwsem, meaning that those are serialised w.r.t. O_DIRECT.
179 	__acquires(inode->i_rwsem)  in netfs_start_io_direct()
185 	if (down_read_interruptible(&inode->i_rwsem) < 0)  in netfs_start_io_direct()
186 		return -ERESTARTSYS;  in netfs_start_io_direct()
187 	if (test_bit(NETFS_ICTX_ODIRECT, &ictx->flags) != 0)  in netfs_start_io_direct()
189 	up_read(&inode->i_rwsem);  in netfs_start_io_direct()
192 	if (down_write_killable(&inode->i_rwsem) < 0)  in netfs_start_io_direct()
193 		return -ERESTARTSYS;  in netfs_start_io_direct()
196 		up_write(&inode->i_rwsem);  in netfs_start_io_direct()
199 	downgrade_write(&inode->i_rwsem);  in netfs_start_io_direct()
205  * netfs_end_io_direct - declare that the direct i/o operation is done
209  * lock on inode->i_rwsem.
212 	__releases(inode->i_rwsem)  in netfs_end_io_direct()
214 	up_read(&inode->i_rwsem);  in netfs_end_io_direct()