Commit fa073039 authored by Max Kellermann's avatar Max Kellermann Committed by Ilya Dryomov
Browse files

ceph: make ceph_start_io_*() killable 



This allows killing processes that wait for a lock when one process is
stuck waiting for the Ceph server.  This is similar to the NFS commit
38a125b3 ("fs/nfs/io: make nfs_start_io_*() killable").

[ idryomov: drop comment on include, formatting ]

Signed-off-by: default avatarMax Kellermann <max.kellermann@ionos.com>
Reviewed-by: default avatarIlya Dryomov <idryomov@gmail.com>
Signed-off-by: default avatarIlya Dryomov <idryomov@gmail.com>
parent 27c0a7b0

fs/ceph/file.c

+11 −9
Original line number Diff line number Diff line
@@ -2121,10 +2121,10 @@ static ssize_t ceph_read_iter(struct kiocb *iocb, struct iov_iter *to) 
	if (ceph_inode_is_shutdown(inode))

		return -ESTALE;



	if (direct_lock)

		ceph_start_io_direct(inode);

	else

	ret = direct_lock ? ceph_start_io_direct(inode) :

			    ceph_start_io_read(inode);

	if (ret)

		return ret;



	if (!(fi->flags & CEPH_F_SYNC) && !direct_lock)

		want |= CEPH_CAP_FILE_CACHE;
@@ -2277,7 +2277,9 @@ static ssize_t ceph_splice_read(struct file *in, loff_t *ppos, 
	    (fi->flags & CEPH_F_SYNC))

		return copy_splice_read(in, ppos, pipe, len, flags);



	ceph_start_io_read(inode);

	ret = ceph_start_io_read(inode);

	if (ret)

		return ret;



	want = CEPH_CAP_FILE_CACHE;

	if (fi->fmode & CEPH_FILE_MODE_LAZY)
@@ -2356,10 +2358,10 @@ static ssize_t ceph_write_iter(struct kiocb *iocb, struct iov_iter *from) 
		direct_lock = true;



retry_snap:

	if (direct_lock)

		ceph_start_io_direct(inode);

	else

	err = direct_lock ? ceph_start_io_direct(inode) :

			    ceph_start_io_write(inode);

	if (err)

		goto out_unlocked;



	if (iocb->ki_flags & IOCB_APPEND) {

		err = ceph_do_getattr(inode, CEPH_STAT_CAP_SIZE, false);

fs/ceph/io.c

+33 −14
Original line number Diff line number Diff line
@@ -47,20 +47,29 @@ static void ceph_block_o_direct(struct ceph_inode_info *ci, struct inode *inode) 
 * Note that buffered writes and truncates both take a write lock on

 * inode->i_rwsem, meaning that those are serialised w.r.t. the reads.

 */

void

ceph_start_io_read(struct inode *inode)

int ceph_start_io_read(struct inode *inode)

{

	struct ceph_inode_info *ci = ceph_inode(inode);

	int err;



	/* Be an optimist! */

	down_read(&inode->i_rwsem);

	err = down_read_killable(&inode->i_rwsem);

	if (err)

		return err;



	if (!(READ_ONCE(ci->i_ceph_flags) & CEPH_I_ODIRECT))

		return;

		return 0;

	up_read(&inode->i_rwsem);



	/* Slow path.... */

	down_write(&inode->i_rwsem);

	err = down_write_killable(&inode->i_rwsem);

	if (err)

		return err;



	ceph_block_o_direct(ci, inode);

	downgrade_write(&inode->i_rwsem);



	return 0;

}



/**
@@ -83,11 +92,12 @@ ceph_end_io_read(struct inode *inode) 
 * Declare that a buffered write operation is about to start, and ensure

 * that we block all direct I/O.

 */

void

ceph_start_io_write(struct inode *inode)

int ceph_start_io_write(struct inode *inode)

{

	down_write(&inode->i_rwsem);

	int err = down_write_killable(&inode->i_rwsem);

	if (!err)

		ceph_block_o_direct(ceph_inode(inode), inode);

	return err;

}



/**
@@ -133,20 +143,29 @@ static void ceph_block_buffered(struct ceph_inode_info *ci, struct inode *inode) 
 * Note that buffered writes and truncates both take a write lock on

 * inode->i_rwsem, meaning that those are serialised w.r.t. O_DIRECT.

 */

void

ceph_start_io_direct(struct inode *inode)

int ceph_start_io_direct(struct inode *inode)

{

	struct ceph_inode_info *ci = ceph_inode(inode);

	int err;



	/* Be an optimist! */

	down_read(&inode->i_rwsem);

	err = down_read_killable(&inode->i_rwsem);

	if (err)

		return err;



	if (READ_ONCE(ci->i_ceph_flags) & CEPH_I_ODIRECT)

		return;

		return 0;

	up_read(&inode->i_rwsem);



	/* Slow path.... */

	down_write(&inode->i_rwsem);

	err = down_write_killable(&inode->i_rwsem);

	if (err)

		return err;



	ceph_block_buffered(ci, inode);

	downgrade_write(&inode->i_rwsem);



	return 0;

}



/**

fs/ceph/io.h

+5 −3
Original line number Diff line number Diff line
@@ -2,11 +2,13 @@ 
#ifndef _FS_CEPH_IO_H

#define _FS_CEPH_IO_H



void ceph_start_io_read(struct inode *inode);

#include <linux/compiler_attributes.h>



int __must_check ceph_start_io_read(struct inode *inode);

void ceph_end_io_read(struct inode *inode);

void ceph_start_io_write(struct inode *inode);

int __must_check ceph_start_io_write(struct inode *inode);

void ceph_end_io_write(struct inode *inode);

void ceph_start_io_direct(struct inode *inode);

int __must_check ceph_start_io_direct(struct inode *inode);

void ceph_end_io_direct(struct inode *inode);



#endif /* FS_CEPH_IO_H */