[CIFS] Use posix open on file open when server supports it

Signed-off-by: Steve French <sfrench@us.ibm.com>

1 files changed, 111 insertions, 13 deletions

diff --git a/fs/cifs/file.c b/fs/cifs/file.c
index e4ecb1cb0b13..7bef4cce572a 100644
--- a/fs/cifs/file.c
+++ b/fs/cifs/file.c
@@ -125,6 +125,80 @@ static inline int cifs_get_disposition(unsigned int flags)
 }
 
 /* all arguments to this function must be checked for validity in caller */
+static inline int cifs_posix_open_inode_helper(struct inode *inode,
+                        struct file *file, struct cifsInodeInfo *pCifsInode,
+                        struct cifsFileInfo *pCifsFile, int oplock, u16 netfid)
+{
+        struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
+/*      struct timespec temp; */   /* BB REMOVEME BB */
+
+        file->private_data = kmalloc(sizeof(struct cifsFileInfo), GFP_KERNEL);
+        if (file->private_data == NULL)
+                return -ENOMEM;
+        pCifsFile = cifs_init_private(file->private_data, inode, file, netfid);
+        write_lock(&GlobalSMBSeslock);
+        list_add(&pCifsFile->tlist, &cifs_sb->tcon->openFileList);
+
+        pCifsInode = CIFS_I(file->f_path.dentry->d_inode);
+        if (pCifsInode == NULL) {
+                write_unlock(&GlobalSMBSeslock);
+                return -EINVAL;
+        }
+
+        /* want handles we can use to read with first
+           in the list so we do not have to walk the
+           list to search for one in write_begin */
+        if ((file->f_flags & O_ACCMODE) == O_WRONLY) {
+                list_add_tail(&pCifsFile->flist,
+                              &pCifsInode->openFileList);
+        } else {
+                list_add(&pCifsFile->flist,
+                         &pCifsInode->openFileList);
+        }
+
+        if (pCifsInode->clientCanCacheRead) {
+                /* we have the inode open somewhere else
+                   no need to discard cache data */
+                goto psx_client_can_cache;
+        }
+
+        /* BB FIXME need to fix this check to move it earlier into posix_open
+           BB  fIX following section BB FIXME */
+
+        /* if not oplocked, invalidate inode pages if mtime or file
+           size changed */
+/*      temp = cifs_NTtimeToUnix(le64_to_cpu(buf->LastWriteTime));
+        if (timespec_equal(&file->f_path.dentry->d_inode->i_mtime, &temp) &&
+                           (file->f_path.dentry->d_inode->i_size ==
+                            (loff_t)le64_to_cpu(buf->EndOfFile))) {
+                cFYI(1, ("inode unchanged on server"));
+        } else {
+                if (file->f_path.dentry->d_inode->i_mapping) {
+                        rc = filemap_write_and_wait(file->f_path.dentry->d_inode->i_mapping);
+                        if (rc != 0)
+                                CIFS_I(file->f_path.dentry->d_inode)->write_behind_rc = rc;
+                }
+                cFYI(1, ("invalidating remote inode since open detected it "
+                         "changed"));
+                invalidate_remote_inode(file->f_path.dentry->d_inode);
+        } */
+
+psx_client_can_cache:
+        if ((oplock & 0xF) == OPLOCK_EXCLUSIVE) {
+                pCifsInode->clientCanCacheAll = true;
+                pCifsInode->clientCanCacheRead = true;
+                cFYI(1, ("Exclusive Oplock granted on inode %p",
+                         file->f_path.dentry->d_inode));
+        } else if ((oplock & 0xF) == OPLOCK_READ)
+                pCifsInode->clientCanCacheRead = true;
+
+        /* will have to change the unlock if we reenable the
+           filemap_fdatawrite (which does not seem necessary */
+        write_unlock(&GlobalSMBSeslock);
+        return 0;
+}
+
+/* all arguments to this function must be checked for validity in caller */
 static inline int cifs_open_inode_helper(struct inode *inode, struct file *file,
         struct cifsInodeInfo *pCifsInode, struct cifsFileInfo *pCifsFile,
         struct cifsTconInfo *pTcon, int *oplock, FILE_ALL_INFO *buf,
@@ -195,7 +269,7 @@ int cifs_open(struct inode *inode, struct file *file)
         int rc = -EACCES;
         int xid, oplock;
         struct cifs_sb_info *cifs_sb;
-        struct cifsTconInfo *pTcon;
+        struct cifsTconInfo *tcon;
         struct cifsFileInfo *pCifsFile;
         struct cifsInodeInfo *pCifsInode;
         struct list_head *tmp;
@@ -208,7 +282,7 @@ int cifs_open(struct inode *inode, struct file *file)
         xid = GetXid();
 
         cifs_sb = CIFS_SB(inode->i_sb);
-        pTcon = cifs_sb->tcon;
+        tcon = cifs_sb->tcon;
 
         if (file->f_flags & O_CREAT) {
                 /* search inode for this file and fill in file->private_data */
@@ -248,6 +322,35 @@ int cifs_open(struct inode *inode, struct file *file)
 
         cFYI(1, ("inode = 0x%p file flags are 0x%x for %s",
                  inode, file->f_flags, full_path));
+
+        if (oplockEnabled)
+                oplock = REQ_OPLOCK;
+        else
+                oplock = 0;
+
+        if (tcon->unix_ext && (tcon->ses->capabilities & CAP_UNIX) &&
+            (CIFS_UNIX_POSIX_PATH_OPS_CAP &
+                        le64_to_cpu(tcon->fsUnixInfo.Capability))) {
+                int oflags = (int) cifs_posix_convert_flags(file->f_flags);
+                /* can not refresh inode info since size could be stale */
+                rc = cifs_posix_open(full_path, &inode, inode->i_sb,
+                                     cifs_sb->mnt_file_mode /* ignored */,
+                                     oflags, &oplock, &netfid, xid);
+                if (rc == 0) {
+                        cFYI(1, ("posix open succeeded"));
+                        /* no need for special case handling of setting mode
+                           on read only files needed here */
+
+                        cifs_posix_open_inode_helper(inode, file, pCifsInode,
+                                                     pCifsFile, oplock, netfid);
+                        goto out;
+                } else if ((rc != -EIO) && (rc != -EREMOTE) &&
+                         (rc != -EOPNOTSUPP)) /* path not found or net err */
+                        goto out;
+                /* fallthrough to retry open the old way on operation
+                   not supported or DFS errors */
+        }
+
         desiredAccess = cifs_convert_flags(file->f_flags);
 
 /*********************************************************************
@@ -276,11 +379,6 @@ int cifs_open(struct inode *inode, struct file *file)
 
         disposition = cifs_get_disposition(file->f_flags);
 
-        if (oplockEnabled)
-                oplock = REQ_OPLOCK;
-        else
-                oplock = 0;
-
         /* BB pass O_SYNC flag through on file attributes .. BB */
 
         /* Also refresh inode by passing in file_info buf returned by SMBOpen
@@ -297,7 +395,7 @@ int cifs_open(struct inode *inode, struct file *file)
         }
 
         if (cifs_sb->tcon->ses->capabilities & CAP_NT_SMBS)
-                rc = CIFSSMBOpen(xid, pTcon, full_path, disposition,
+                rc = CIFSSMBOpen(xid, tcon, full_path, disposition,
                          desiredAccess, CREATE_NOT_DIR, &netfid, &oplock, buf,
                          cifs_sb->local_nls, cifs_sb->mnt_cifs_flags
                                  & CIFS_MOUNT_MAP_SPECIAL_CHR);
@@ -306,7 +404,7 @@ int cifs_open(struct inode *inode, struct file *file)
 
         if (rc == -EIO) {
                 /* Old server, try legacy style OpenX */
-                rc = SMBLegacyOpen(xid, pTcon, full_path, disposition,
+                rc = SMBLegacyOpen(xid, tcon, full_path, disposition,
                         desiredAccess, CREATE_NOT_DIR, &netfid, &oplock, buf,
                         cifs_sb->local_nls, cifs_sb->mnt_cifs_flags
                                 & CIFS_MOUNT_MAP_SPECIAL_CHR);
@@ -323,12 +421,12 @@ int cifs_open(struct inode *inode, struct file *file)
         }
         pCifsFile = cifs_init_private(file->private_data, inode, file, netfid);
         write_lock(&GlobalSMBSeslock);
-        list_add(&pCifsFile->tlist, &pTcon->openFileList);
+        list_add(&pCifsFile->tlist, &tcon->openFileList);
 
         pCifsInode = CIFS_I(file->f_path.dentry->d_inode);
         if (pCifsInode) {
                 rc = cifs_open_inode_helper(inode, file, pCifsInode,
-                                            pCifsFile, pTcon,
+                                            pCifsFile, tcon,
                                             &oplock, buf, full_path, xid);
         } else {
                 write_unlock(&GlobalSMBSeslock);
@@ -337,7 +435,7 @@ int cifs_open(struct inode *inode, struct file *file)
         if (oplock & CIFS_CREATE_ACTION) {
                 /* time to set mode which we can not set earlier due to
                    problems creating new read-only files */
-                if (pTcon->unix_ext) {
+                if (tcon->unix_ext) {
                         struct cifs_unix_set_info_args args = {
                                 .mode   = inode->i_mode,
                                 .uid    = NO_CHANGE_64,
@@ -347,7 +445,7 @@ int cifs_open(struct inode *inode, struct file *file)
                                 .mtime  = NO_CHANGE_64,
                                 .device = 0,
                         };
-                        CIFSSMBUnixSetInfo(xid, pTcon, full_path, &args,
+                        CIFSSMBUnixSetInfo(xid, tcon, full_path, &args,
                                             cifs_sb->local_nls,
                                             cifs_sb->mnt_cifs_flags &
                                                 CIFS_MOUNT_MAP_SPECIAL_CHR);