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Commit 72432ffc authored by Pavel Shilovsky's avatar Pavel Shilovsky Committed by Steve French
Browse files

CIFS: Implement cifs_strict_writev (try #4) 



If we don't have Exclusive oplock we write a data to the server.
Also set invalidate_mapping flag on the inode if we wrote something
to the server. Add cifs_iovec_write to let the client write iovec
buffers through CIFSSMBWrite2.

Signed-off-by: default avatarPavel Shilovsky <piastryyy@gmail.com>
Reviewed-by: default avatarJeff Layton <jlayton@redhat.com>
Signed-off-by: default avatarSteve French <sfrench@us.ibm.com>
parent 93c100c0

fs/cifs/cifsfs.c

+11 −4
Original line number Diff line number Diff line
@@ -600,10 +600,17 @@ static ssize_t cifs_file_aio_write(struct kiocb *iocb, const struct iovec *iov, 
{

	struct inode *inode = iocb->ki_filp->f_path.dentry->d_inode;

	ssize_t written;

	int rc;



	written = generic_file_aio_write(iocb, iov, nr_segs, pos);

	if (!CIFS_I(inode)->clientCanCacheAll)

		filemap_fdatawrite(inode->i_mapping);



	if (CIFS_I(inode)->clientCanCacheAll)

		return written;



	rc = filemap_fdatawrite(inode->i_mapping);

	if (rc)

		cFYI(1, "cifs_file_aio_write: %d rc on %p inode", rc, inode);



	return written;

}
@@ -737,7 +744,7 @@ const struct file_operations cifs_file_strict_ops = { 
	.read = do_sync_read,

	.write = do_sync_write,

	.aio_read = cifs_strict_readv,

	.aio_write = cifs_file_aio_write,

	.aio_write = cifs_strict_writev,

	.open = cifs_open,

	.release = cifs_close,

	.lock = cifs_lock,
@@ -793,7 +800,7 @@ const struct file_operations cifs_file_strict_nobrl_ops = { 
	.read = do_sync_read,

	.write = do_sync_write,

	.aio_read = cifs_strict_readv,

	.aio_write = cifs_file_aio_write,

	.aio_write = cifs_strict_writev,

	.open = cifs_open,

	.release = cifs_close,

	.fsync = cifs_strict_fsync,

fs/cifs/cifsfs.h

+3 −1
Original line number Diff line number Diff line
@@ -86,6 +86,8 @@ extern ssize_t cifs_strict_readv(struct kiocb *iocb, const struct iovec *iov, 
				 unsigned long nr_segs, loff_t pos);

extern ssize_t cifs_user_write(struct file *file, const char __user *write_data,

			       size_t write_size, loff_t *poffset);

extern ssize_t cifs_strict_writev(struct kiocb *iocb, const struct iovec *iov,

				  unsigned long nr_segs, loff_t pos);

extern int cifs_lock(struct file *, int, struct file_lock *);

extern int cifs_fsync(struct file *, int);

extern int cifs_strict_fsync(struct file *, int);

fs/cifs/cifsproto.h

+2 −0
Original line number Diff line number Diff line
@@ -85,6 +85,8 @@ extern int checkSMB(struct smb_hdr *smb, __u16 mid, unsigned int length); 
extern bool is_valid_oplock_break(struct smb_hdr *smb,

				  struct TCP_Server_Info *);

extern bool is_size_safe_to_change(struct cifsInodeInfo *, __u64 eof);

extern void cifs_update_eof(struct cifsInodeInfo *cifsi, loff_t offset,

			    unsigned int bytes_written);

extern struct cifsFileInfo *find_writable_file(struct cifsInodeInfo *, bool);

extern struct cifsFileInfo *find_readable_file(struct cifsInodeInfo *, bool);

extern unsigned int smbCalcSize(struct smb_hdr *ptr);

fs/cifs/file.c

+201 −1
Original line number Diff line number Diff line
@@ -848,7 +848,7 @@ int cifs_lock(struct file *file, int cmd, struct file_lock *pfLock) 
}



/* update the file size (if needed) after a write */

static void

void

cifs_update_eof(struct cifsInodeInfo *cifsi, loff_t offset,

		      unsigned int bytes_written)

{
@@ -1619,6 +1619,206 @@ int cifs_flush(struct file *file, fl_owner_t id) 
	return rc;

}



static int

cifs_write_allocate_pages(struct page **pages, unsigned long num_pages)

{

	int rc = 0;

	unsigned long i;



	for (i = 0; i < num_pages; i++) {

		pages[i] = alloc_page(__GFP_HIGHMEM);

		if (!pages[i]) {

			/*

			 * save number of pages we have already allocated and

			 * return with ENOMEM error

			 */

			num_pages = i;

			rc = -ENOMEM;

			goto error;

		}

	}



	return rc;



error:

	for (i = 0; i < num_pages; i++)

		put_page(pages[i]);

	return rc;

}



static inline

size_t get_numpages(const size_t wsize, const size_t len, size_t *cur_len)

{

	size_t num_pages;

	size_t clen;



	clen = min_t(const size_t, len, wsize);

	num_pages = clen / PAGE_CACHE_SIZE;

	if (clen % PAGE_CACHE_SIZE)

		num_pages++;



	if (cur_len)

		*cur_len = clen;



	return num_pages;

}



static ssize_t

cifs_iovec_write(struct file *file, const struct iovec *iov,

		 unsigned long nr_segs, loff_t *poffset)

{

	size_t total_written = 0, written = 0;

	unsigned long num_pages, npages;

	size_t copied, len, cur_len, i;

	struct kvec *to_send;

	struct page **pages;

	struct iov_iter it;

	struct inode *inode;

	struct cifsFileInfo *open_file;

	struct cifsTconInfo *pTcon;

	struct cifs_sb_info *cifs_sb;

	int xid, rc;



	len = iov_length(iov, nr_segs);

	if (!len)

		return 0;



	rc = generic_write_checks(file, poffset, &len, 0);

	if (rc)

		return rc;



	cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);

	num_pages = get_numpages(cifs_sb->wsize, len, &cur_len);



	pages = kmalloc(sizeof(struct pages *)*num_pages, GFP_KERNEL);

	if (!pages)

		return -ENOMEM;



	to_send = kmalloc(sizeof(struct kvec)*(num_pages + 1), GFP_KERNEL);

	if (!to_send) {

		kfree(pages);

		return -ENOMEM;

	}



	rc = cifs_write_allocate_pages(pages, num_pages);

	if (rc) {

		kfree(pages);

		kfree(to_send);

		return rc;

	}



	xid = GetXid();

	open_file = file->private_data;

	pTcon = tlink_tcon(open_file->tlink);

	inode = file->f_path.dentry->d_inode;



	iov_iter_init(&it, iov, nr_segs, len, 0);

	npages = num_pages;



	do {

		size_t save_len = cur_len;

		for (i = 0; i < npages; i++) {

			copied = min_t(const size_t, cur_len, PAGE_CACHE_SIZE);

			copied = iov_iter_copy_from_user(pages[i], &it, 0,

							 copied);

			cur_len -= copied;

			iov_iter_advance(&it, copied);

			to_send[i+1].iov_base = kmap(pages[i]);

			to_send[i+1].iov_len = copied;

		}



		cur_len = save_len - cur_len;



		do {

			if (open_file->invalidHandle) {

				rc = cifs_reopen_file(open_file, false);

				if (rc != 0)

					break;

			}

			rc = CIFSSMBWrite2(xid, pTcon, open_file->netfid,

					   cur_len, *poffset, &written,

					   to_send, npages, 0);

		} while (rc == -EAGAIN);



		for (i = 0; i < npages; i++)

			kunmap(pages[i]);



		if (written) {

			len -= written;

			total_written += written;

			cifs_update_eof(CIFS_I(inode), *poffset, written);

			*poffset += written;

		} else if (rc < 0) {

			if (!total_written)

				total_written = rc;

			break;

		}



		/* get length and number of kvecs of the next write */

		npages = get_numpages(cifs_sb->wsize, len, &cur_len);

	} while (len > 0);



	if (total_written > 0) {

		spin_lock(&inode->i_lock);

		if (*poffset > inode->i_size)

			i_size_write(inode, *poffset);

		spin_unlock(&inode->i_lock);

	}



	cifs_stats_bytes_written(pTcon, total_written);

	mark_inode_dirty_sync(inode);



	for (i = 0; i < num_pages; i++)

		put_page(pages[i]);

	kfree(to_send);

	kfree(pages);

	FreeXid(xid);

	return total_written;

}



static ssize_t cifs_user_writev(struct kiocb *iocb, const struct iovec *iov,

				unsigned long nr_segs, loff_t pos)

{

	ssize_t written;

	struct inode *inode;



	inode = iocb->ki_filp->f_path.dentry->d_inode;



	/*

	 * BB - optimize the way when signing is disabled. We can drop this

	 * extra memory-to-memory copying and use iovec buffers for constructing

	 * write request.

	 */



	written = cifs_iovec_write(iocb->ki_filp, iov, nr_segs, &pos);

	if (written > 0) {

		CIFS_I(inode)->invalid_mapping = true;

		iocb->ki_pos = pos;

	}



	return written;

}



ssize_t cifs_strict_writev(struct kiocb *iocb, const struct iovec *iov,

			   unsigned long nr_segs, loff_t pos)

{

	struct inode *inode;



	inode = iocb->ki_filp->f_path.dentry->d_inode;



	if (CIFS_I(inode)->clientCanCacheAll)

		return generic_file_aio_write(iocb, iov, nr_segs, pos);



	/*

	 * In strict cache mode we need to write the data to the server exactly

	 * from the pos to pos+len-1 rather than flush all affected pages

	 * because it may cause a error with mandatory locks on these pages but

	 * not on the region from pos to ppos+len-1.

	 */



	return cifs_user_writev(iocb, iov, nr_segs, pos);

}



static ssize_t

cifs_iovec_read(struct file *file, const struct iovec *iov,

		 unsigned long nr_segs, loff_t *poffset)