If we don't have Exclusive oplock we write a data to the server through
CISSMBWrite2. Also set invalidate_mapping flag on the inode if we wrote
something to the server.
Signed-off-by: Pavel Shilovsky <piastryyy@xxxxxxxxx>
---
fs/cifs/cifsfs.c | 228 ++++++++++++++++++++++++++++++++++++++++++++++++++-
fs/cifs/cifsproto.h | 2 +
fs/cifs/file.c | 2 +-
3 files changed, 227 insertions(+), 5 deletions(-)
diff --git a/fs/cifs/cifsfs.c b/fs/cifs/cifsfs.c
index bcb4d2c..fb50883 100644
--- a/fs/cifs/cifsfs.c
+++ b/fs/cifs/cifsfs.c
@@ -606,15 +606,235 @@ static ssize_t cifs_strict_read(struct kiocb *iocb, const struct iovec *iov,
return read;
}
+/* Assume that dest points to memory area that is enough for source data */
+static int cifs_copy_iovs(struct kvec *dst, const struct iovec **source,
+ unsigned long *lastlen, unsigned long len)
+{
+ const struct iovec *src = *source;
+ unsigned long dst_lastlen, src_lastlen;
+ unsigned long cur_len;
+
+ dst_lastlen = dst->iov_len;
+ src_lastlen = *lastlen;
+
+ while (len > 0) {
+ cur_len = min_t(unsigned long, dst_lastlen, src_lastlen);
+ cur_len = min_t(unsigned long, cur_len, len);
+
+ if (copy_from_user(dst->iov_base + dst->iov_len - dst_lastlen,
+ src->iov_base + src->iov_len - src_lastlen,
+ cur_len))
+ return -EFAULT;
+
+ dst_lastlen -= cur_len;
+ if (!dst_lastlen) {
+ dst++;
+ dst_lastlen = dst->iov_len;
+ }
+
+ src_lastlen -= cur_len;
+ if (!src_lastlen) {
+ src++;
+ src_lastlen = src->iov_len;
+ }
+
+ len -= cur_len;
+ }
+
+ /* update length of the last element in dest */
+ if (dst_lastlen)
+ dst->iov_len -= dst_lastlen;
+
+ /* save offset and length of the last element in source */
+ *lastlen = src_lastlen;
+ *source = src;
+
+ return 0;
+}
+
+static int
+cifs_strict_write_helper(struct page ***ppages, struct kvec **pto_send,
+ unsigned long num_pages)
+{
+ int rc = 0;
+ unsigned long i;
+ struct page **pages;
+ struct kvec *to_send;
+
+ *ppages = kmalloc(sizeof(struct pages *)*num_pages, GFP_KERNEL);
+ if (!ppages)
+ return -ENOMEM;
+
+ *pto_send = kmalloc(sizeof(struct kvec)*(num_pages + 1),
+ GFP_KERNEL);
+ if (!pto_send) {
+ kfree(ppages);
+ return -ENOMEM;
+ }
+
+ pages = *ppages;
+ to_send = *pto_send;
+
+ 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;
+ }
+ to_send[i+1].iov_base = kmap(pages[i]);
+ to_send[i+1].iov_len = PAGE_CACHE_SIZE;
+ }
+
+ return rc;
+
+error:
+ for (i = 0; i < num_pages; i++) {
+ kunmap(pages[i]);
+ put_page(pages[i]);
+ }
+ kfree(to_send);
+ kfree(pages);
+ return rc;
+}
+
+static ssize_t cifs_strict_write(struct kiocb *iocb, const struct iovec *iov,
+ unsigned long nr_segs, loff_t pos)
+{
+ struct inode *inode;
+ struct cifs_sb_info *cifs_sb;
+ ssize_t written = 0, total_written = 0;
+ unsigned long i, num_pages, cur_numpages;
+ unsigned long len, cur_len, last_len;
+ struct kvec *to_send;
+ const struct iovec *offset;
+ struct page **pages;
+ struct cifsFileInfo *open_file;
+ struct cifsTconInfo *pTcon;
+ int xid, rc;
+
+ inode = iocb->ki_filp->f_path.dentry->d_inode;
+
+ if (CIFS_I(inode)->clientCanCacheAll)
+ return generic_file_aio_write(iocb, iov, nr_segs, pos);
+
+ cifs_sb = CIFS_SB(iocb->ki_filp->f_path.dentry->d_sb);
+
+ /*
+ * 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.
+ */
+
+ len = 0;
+ for (i = 0; i < nr_segs; i++)
+ len += iov[i].iov_len;
+
+ if (!len)
+ return 0;
+
+ /*
+ * 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.
+ */
+
+ xid = GetXid();
+ open_file = iocb->ki_filp->private_data;
+ pTcon = tlink_tcon(open_file->tlink);
+
+ /* calculate number of pages we need for process this write */
+ cur_len = min_t(unsigned long, len, cifs_sb->wsize);
+ num_pages = cur_len / PAGE_CACHE_SIZE;
+ if (cur_len % PAGE_CACHE_SIZE)
+ num_pages++;
+
+ rc = cifs_strict_write_helper(&pages, &to_send, num_pages);
+ if (rc) {
+ total_written = rc;
+ goto error;
+ }
+
+ last_len = iov->iov_len;
+ offset = iov;
+ cur_numpages = num_pages;
+
+ do {
+ rc = cifs_copy_iovs(to_send+1, &offset, &last_len, cur_len);
+ if (rc) {
+ total_written = -EFAULT;
+ goto exit;
+ }
+
+ do {
+ rc = CIFSSMBWrite2(xid, pTcon, open_file->netfid,
+ cur_len, pos, &written, to_send,
+ cur_numpages, 0);
+ } while (rc == -EAGAIN);
+
+ if (written) {
+ len -= written;
+ total_written += written;
+ cifs_update_eof(CIFS_I(inode), pos, written);
+ pos += written;
+ } else if (rc < 0) {
+ if (!total_written)
+ total_written = rc;
+ goto exit;
+ }
+
+ /* get length and number of kvecs of the next write */
+ cur_len = min_t(unsigned long, len, cifs_sb->wsize);
+ cur_numpages = cur_len / PAGE_CACHE_SIZE;
+ if (cur_len % PAGE_CACHE_SIZE)
+ cur_numpages++;
+ } while (len > 0);
+
+exit:
+ if (total_written > 0) {
+ CIFS_I(inode)->invalid_mapping = true;
+ iocb->ki_pos += total_written;
+ spin_lock(&inode->i_lock);
+ if (pos > inode->i_size)
+ i_size_write(inode, pos);
+ spin_unlock(&inode->i_lock);
+ }
+
+ cifs_stats_bytes_written(pTcon, total_written);
+ mark_inode_dirty_sync(inode);
+
+ for (i = 0; i < num_pages; i++) {
+ kunmap(pages[i]);
+ put_page(pages[i]);
+ }
+ kfree(to_send);
+ kfree(pages);
+error:
+ FreeXid(xid);
+ return total_written;
+}
+
static ssize_t cifs_file_aio_write(struct kiocb *iocb, const struct iovec *iov,
unsigned long nr_segs, loff_t pos)
{
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;
}
@@ -748,7 +968,7 @@ const struct file_operations cifs_file_strict_ops = {
.read = do_sync_read,
.write = do_sync_write,
.aio_read = cifs_strict_read,
- .aio_write = cifs_file_aio_write,
+ .aio_write = cifs_strict_write,
.open = cifs_open,
.release = cifs_close,
.lock = cifs_lock,
@@ -804,7 +1024,7 @@ const struct file_operations cifs_file_strict_nobrl_ops = {
.read = do_sync_read,
.write = do_sync_write,
.aio_read = cifs_strict_read,
- .aio_write = cifs_file_aio_write,
+ .aio_write = cifs_strict_write,
.open = cifs_open,
.release = cifs_close,
.fsync = cifs_strict_fsync,
diff --git a/fs/cifs/cifsproto.h b/fs/cifs/cifsproto.h
index e6d1481..e7d6c24 100644
--- a/fs/cifs/cifsproto.h
+++ b/fs/cifs/cifsproto.h
@@ -79,6 +79,8 @@ 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);
diff --git a/fs/cifs/file.c b/fs/cifs/file.c
index bc53e9e..8260f53 100644
--- a/fs/cifs/file.c
+++ b/fs/cifs/file.c
@@ -924,7 +924,7 @@ cifs_write_timeout(struct cifsInodeInfo *cifsi, loff_t offset)
}
/* 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)
{
--
1.7.3.2
--
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