CIFS: Use pid saved from cifsFileInfo in writepages and set_file_size

We need it to make them work with mandatory locking style because
we can fail in a situation like when kernel need to flush dirty pages
and there is a lock held by a process who opened file.

Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Steve French <sfrench@us.ibm.com>

7 files changed, 96 insertions, 43 deletions

diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h
index fd877c110e4c..30699d9378e9 100644
--- a/fs/cifs/cifsglob.h
+++ b/fs/cifs/cifsglob.h
@@ -455,6 +455,14 @@ struct cifsFileInfo {
         struct work_struct oplock_break; /* work for oplock breaks */
 };
 
+struct cifs_io_parms {
+        __u16 netfid;
+        __u32 pid;
+        __u64 offset;
+        unsigned int length;
+        struct cifsTconInfo *tcon;
+};
+
 /*
  * Take a reference on the file private data. Must be called with
  * cifs_file_list_lock held.
diff --git a/fs/cifs/cifsproto.h b/fs/cifs/cifsproto.h
index 8aea8850ffee..eb3b58d9668f 100644
--- a/fs/cifs/cifsproto.h
+++ b/fs/cifs/cifsproto.h
@@ -348,15 +348,12 @@ extern int CIFSSMBRead(const int xid, struct cifsTconInfo *tcon,
                         const int netfid, unsigned int count,
                         const __u64 lseek, unsigned int *nbytes, char **buf,
                         int *return_buf_type);
-extern int CIFSSMBWrite(const int xid, struct cifsTconInfo *tcon,
-                        const int netfid, const unsigned int count,
-                        const __u64 lseek, unsigned int *nbytes,
-                        const char *buf, const char __user *ubuf,
+extern int CIFSSMBWrite(const int xid, struct cifs_io_parms *io_parms,
+                        unsigned int *nbytes, const char *buf,
+                        const char __user *ubuf, const int long_op);
+extern int CIFSSMBWrite2(const int xid, struct cifs_io_parms *io_parms,
+                        unsigned int *nbytes, struct kvec *iov, const int nvec,
                         const int long_op);
-extern int CIFSSMBWrite2(const int xid, struct cifsTconInfo *tcon,
-                        const int netfid, const unsigned int count,
-                        const __u64 offset, unsigned int *nbytes,
-                        struct kvec *iov, const int nvec, const int long_op);
 extern int CIFSGetSrvInodeNumber(const int xid, struct cifsTconInfo *tcon,
                         const unsigned char *searchName, __u64 *inode_number,
                         const struct nls_table *nls_codepage,
diff --git a/fs/cifs/cifssmb.c b/fs/cifs/cifssmb.c
index 136df013b0aa..f39fa08b9b0e 100644
--- a/fs/cifs/cifssmb.c
+++ b/fs/cifs/cifssmb.c
@@ -1487,9 +1487,8 @@ CIFSSMBRead(const int xid, struct cifsTconInfo *tcon, const int netfid,
 
 
 int
-CIFSSMBWrite(const int xid, struct cifsTconInfo *tcon,
-             const int netfid, const unsigned int count,
-             const __u64 offset, unsigned int *nbytes, const char *buf,
+CIFSSMBWrite(const int xid, struct cifs_io_parms *io_parms,
+             unsigned int *nbytes, const char *buf,
              const char __user *ubuf, const int long_op)
 {
         int rc = -EACCES;
@@ -1498,6 +1497,11 @@ CIFSSMBWrite(const int xid, struct cifsTconInfo *tcon,
         int bytes_returned, wct;
         __u32 bytes_sent;
         __u16 byte_count;
+        __u32 pid = io_parms->pid;
+        __u16 netfid = io_parms->netfid;
+        __u64 offset = io_parms->offset;
+        struct cifsTconInfo *tcon = io_parms->tcon;
+        unsigned int count = io_parms->length;
 
         *nbytes = 0;
 
@@ -1519,6 +1523,10 @@ CIFSSMBWrite(const int xid, struct cifsTconInfo *tcon,
                       (void **) &pSMBr);
         if (rc)
                 return rc;
+
+        pSMB->hdr.Pid = cpu_to_le16((__u16)pid);
+        pSMB->hdr.PidHigh = cpu_to_le16((__u16)(pid >> 16));
+
         /* tcon and ses pointer are checked in smb_init */
         if (tcon->ses->server == NULL)
                 return -ECONNABORTED;
@@ -1778,6 +1786,9 @@ cifs_async_writev(struct cifs_writedata *wdata)
                 goto async_writev_out;
         }
 
+        smb->hdr.Pid = cpu_to_le16((__u16)wdata->cfile->pid);
+        smb->hdr.PidHigh = cpu_to_le16((__u16)(wdata->cfile->pid >> 16));
+
         smb->AndXCommand = 0xFF;        /* none */
         smb->Fid = wdata->cfile->netfid;
         smb->OffsetLow = cpu_to_le32(wdata->offset & 0xFFFFFFFF);
@@ -1841,16 +1852,20 @@ async_writev_out:
 }
 
 int
-CIFSSMBWrite2(const int xid, struct cifsTconInfo *tcon,
-             const int netfid, const unsigned int count,
-             const __u64 offset, unsigned int *nbytes, struct kvec *iov,
-             int n_vec, const int long_op)
+CIFSSMBWrite2(const int xid, struct cifs_io_parms *io_parms,
+              unsigned int *nbytes, struct kvec *iov, int n_vec,
+              const int long_op)
 {
         int rc = -EACCES;
         WRITE_REQ *pSMB = NULL;
         int wct;
         int smb_hdr_len;
         int resp_buf_type = 0;
+        __u32 pid = io_parms->pid;
+        __u16 netfid = io_parms->netfid;
+        __u64 offset = io_parms->offset;
+        struct cifsTconInfo *tcon = io_parms->tcon;
+        unsigned int count = io_parms->length;
 
         *nbytes = 0;
 
@@ -1868,6 +1883,10 @@ CIFSSMBWrite2(const int xid, struct cifsTconInfo *tcon,
         rc = small_smb_init(SMB_COM_WRITE_ANDX, wct, tcon, (void **) &pSMB);
         if (rc)
                 return rc;
+
+        pSMB->hdr.Pid = cpu_to_le16((__u16)pid);
+        pSMB->hdr.PidHigh = cpu_to_le16((__u16)(pid >> 16));
+
         /* tcon and ses pointer are checked in smb_init */
         if (tcon->ses->server == NULL)
                 return -ECONNABORTED;
diff --git a/fs/cifs/dir.c b/fs/cifs/dir.c
index 9ea65cf36714..0521492f5b3b 100644
--- a/fs/cifs/dir.c
+++ b/fs/cifs/dir.c
@@ -357,6 +357,7 @@ int cifs_mknod(struct inode *inode, struct dentry *direntry, int mode,
         struct cifs_sb_info *cifs_sb;
         struct tcon_link *tlink;
         struct cifsTconInfo *pTcon;
+        struct cifs_io_parms io_parms;
         char *full_path = NULL;
         struct inode *newinode = NULL;
         int oplock = 0;
@@ -439,16 +440,19 @@ int cifs_mknod(struct inode *inode, struct dentry *direntry, int mode,
          * timestamps in, but we can reuse it safely */
 
         pdev = (struct win_dev *)buf;
+        io_parms.netfid = fileHandle;
+        io_parms.pid = current->tgid;
+        io_parms.tcon = pTcon;
+        io_parms.offset = 0;
+        io_parms.length = sizeof(struct win_dev);
         if (S_ISCHR(mode)) {
                 memcpy(pdev->type, "IntxCHR", 8);
                 pdev->major =
                       cpu_to_le64(MAJOR(device_number));
                 pdev->minor =
                       cpu_to_le64(MINOR(device_number));
-                rc = CIFSSMBWrite(xid, pTcon,
-                        fileHandle,
-                        sizeof(struct win_dev),
-                        0, &bytes_written, (char *)pdev,
+                rc = CIFSSMBWrite(xid, &io_parms,
+                        &bytes_written, (char *)pdev,
                         NULL, 0);
         } else if (S_ISBLK(mode)) {
                 memcpy(pdev->type, "IntxBLK", 8);
@@ -456,10 +460,8 @@ int cifs_mknod(struct inode *inode, struct dentry *direntry, int mode,
                       cpu_to_le64(MAJOR(device_number));
                 pdev->minor =
                       cpu_to_le64(MINOR(device_number));
-                rc = CIFSSMBWrite(xid, pTcon,
-                        fileHandle,
-                        sizeof(struct win_dev),
-                        0, &bytes_written, (char *)pdev,
+                rc = CIFSSMBWrite(xid, &io_parms,
+                        &bytes_written, (char *)pdev,
                         NULL, 0);
         } /* else if (S_ISFIFO) */
         CIFSSMBClose(xid, pTcon, fileHandle);
diff --git a/fs/cifs/file.c b/fs/cifs/file.c
index 00b926ce7935..dfc0d35b1470 100644
--- a/fs/cifs/file.c
+++ b/fs/cifs/file.c
@@ -857,7 +857,7 @@ cifs_update_eof(struct cifsInodeInfo *cifsi, loff_t offset,
                 cifsi->server_eof = end_of_write;
 }
 
-static ssize_t cifs_write(struct cifsFileInfo *open_file,
+static ssize_t cifs_write(struct cifsFileInfo *open_file, __u32 pid,
                           const char *write_data, size_t write_size,
                           loff_t *poffset)
 {
@@ -869,6 +869,7 @@ static ssize_t cifs_write(struct cifsFileInfo *open_file,
         int xid;
         struct dentry *dentry = open_file->dentry;
         struct cifsInodeInfo *cifsi = CIFS_I(dentry->d_inode);
+        struct cifs_io_parms io_parms;
 
         cifs_sb = CIFS_SB(dentry->d_sb);
 
@@ -901,8 +902,13 @@ static ssize_t cifs_write(struct cifsFileInfo *open_file,
                         /* iov[0] is reserved for smb header */
                         iov[1].iov_base = (char *)write_data + total_written;
                         iov[1].iov_len = len;
-                        rc = CIFSSMBWrite2(xid, pTcon, open_file->netfid, len,
-                                           *poffset, &bytes_written, iov, 1, 0);
+                        io_parms.netfid = open_file->netfid;
+                        io_parms.pid = pid;
+                        io_parms.tcon = pTcon;
+                        io_parms.offset = *poffset;
+                        io_parms.length = len;
+                        rc = CIFSSMBWrite2(xid, &io_parms, &bytes_written, iov,
+                                           1, 0);
                 }
                 if (rc || (bytes_written == 0)) {
                         if (total_written)
@@ -1071,8 +1077,8 @@ static int cifs_partialpagewrite(struct page *page, unsigned from, unsigned to)
 
         open_file = find_writable_file(CIFS_I(mapping->host), false);
         if (open_file) {
-                bytes_written = cifs_write(open_file, write_data,
-                                           to - from, &offset);
+                bytes_written = cifs_write(open_file, open_file->pid,
+                                           write_data, to - from, &offset);
                 cifsFileInfo_put(open_file);
                 /* Does mm or vfs already set times? */
                 inode->i_atime = inode->i_mtime = current_fs_time(inode->i_sb);
@@ -1363,8 +1369,8 @@ static int cifs_write_end(struct file *file, struct address_space *mapping,
                 /* BB check if anything else missing out of ppw
                    such as updating last write time */
                 page_data = kmap(page);
-                rc = cifs_write(file->private_data, page_data + offset,
-                                copied, &pos);
+                rc = cifs_write(file->private_data, current->tgid,
+                                page_data + offset, copied, &pos);
                 /* if (rc < 0) should we set writebehind rc? */
                 kunmap(page);
 
@@ -1515,6 +1521,7 @@ cifs_iovec_write(struct file *file, const struct iovec *iov,
         struct cifsFileInfo *open_file;
         struct cifsTconInfo *pTcon;
         struct cifs_sb_info *cifs_sb;
+        struct cifs_io_parms io_parms;
         int xid, rc;
 
         len = iov_length(iov, nr_segs);
@@ -1573,9 +1580,13 @@ cifs_iovec_write(struct file *file, const struct iovec *iov,
                                 if (rc != 0)
                                         break;
                         }
-                        rc = CIFSSMBWrite2(xid, pTcon, open_file->netfid,
-                                           cur_len, *poffset, &written,
-                                           to_send, npages, 0);
+                        io_parms.netfid = open_file->netfid;
+                        io_parms.pid = current->tgid;
+                        io_parms.tcon = pTcon;
+                        io_parms.offset = *poffset;
+                        io_parms.length = cur_len;
+                        rc = CIFSSMBWrite2(xid, &io_parms, &written, to_send,
+                                           npages, 0);
                 } while (rc == -EAGAIN);
 
                 for (i = 0; i < npages; i++)
diff --git a/fs/cifs/inode.c b/fs/cifs/inode.c
index de02ed5e25c2..5e278d37912b 100644
--- a/fs/cifs/inode.c
+++ b/fs/cifs/inode.c
@@ -1873,6 +1873,7 @@ cifs_set_file_size(struct inode *inode, struct iattr *attrs,
         struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
         struct tcon_link *tlink = NULL;
         struct cifsTconInfo *pTcon = NULL;
+        struct cifs_io_parms io_parms;
 
         /*
          * To avoid spurious oplock breaks from server, in the case of
@@ -1894,8 +1895,14 @@ cifs_set_file_size(struct inode *inode, struct iattr *attrs,
                 cFYI(1, "SetFSize for attrs rc = %d", rc);
                 if ((rc == -EINVAL) || (rc == -EOPNOTSUPP)) {
                         unsigned int bytes_written;
-                        rc = CIFSSMBWrite(xid, pTcon, nfid, 0, attrs->ia_size,
-                                          &bytes_written, NULL, NULL, 1);
+
+                        io_parms.netfid = nfid;
+                        io_parms.pid = npid;
+                        io_parms.tcon = pTcon;
+                        io_parms.offset = 0;
+                        io_parms.length = attrs->ia_size;
+                        rc = CIFSSMBWrite(xid, &io_parms, &bytes_written,
+                                          NULL, NULL, 1);
                         cFYI(1, "Wrt seteof rc %d", rc);
                 }
         } else
@@ -1930,10 +1937,15 @@ cifs_set_file_size(struct inode *inode, struct iattr *attrs,
                                         CIFS_MOUNT_MAP_SPECIAL_CHR);
                         if (rc == 0) {
                                 unsigned int bytes_written;
-                                rc = CIFSSMBWrite(xid, pTcon, netfid, 0,
-                                                  attrs->ia_size,
-                                                  &bytes_written, NULL,
-                                                  NULL, 1);
+
+                                io_parms.netfid = netfid;
+                                io_parms.pid = current->tgid;
+                                io_parms.tcon = pTcon;
+                                io_parms.offset = 0;
+                                io_parms.length = attrs->ia_size;
+                                rc = CIFSSMBWrite(xid, &io_parms,
+                                                  &bytes_written,
+                                                  NULL, NULL,  1);
                                 cFYI(1, "wrt seteof rc %d", rc);
                                 CIFSSMBClose(xid, pTcon, netfid);
                         }
diff --git a/fs/cifs/link.c b/fs/cifs/link.c
index ce417a9764a3..1a6a388cf5d8 100644
--- a/fs/cifs/link.c
+++ b/fs/cifs/link.c
@@ -184,6 +184,7 @@ CIFSCreateMFSymLink(const int xid, struct cifsTconInfo *tcon,
         __u16 netfid = 0;
         u8 *buf;
         unsigned int bytes_written = 0;
+        struct cifs_io_parms io_parms;
 
         buf = kmalloc(CIFS_MF_SYMLINK_FILE_SIZE, GFP_KERNEL);
         if (!buf)
@@ -203,10 +204,13 @@ CIFSCreateMFSymLink(const int xid, struct cifsTconInfo *tcon,
                 return rc;
         }
 
-        rc = CIFSSMBWrite(xid, tcon, netfid,
-                          CIFS_MF_SYMLINK_FILE_SIZE /* length */,
-                          0 /* offset */,
-                          &bytes_written, buf, NULL, 0);
+        io_parms.netfid = netfid;
+        io_parms.pid = current->tgid;
+        io_parms.tcon = tcon;
+        io_parms.offset = 0;
+        io_parms.length = CIFS_MF_SYMLINK_FILE_SIZE;
+
+        rc = CIFSSMBWrite(xid, &io_parms, &bytes_written, buf, NULL, 0);
         CIFSSMBClose(xid, tcon, netfid);
         kfree(buf);
         if (rc != 0)