BKL: Remove BKL from ncpfs

Dozen of changes in ncpfs to provide some locking other than BKL.

In readdir cache unlock and mark complete first page as last operation,
so it can be used for synchronization, as code intended.

When updating dentry name on case insensitive filesystems do at least
some basic locking...

Hold i_mutex when updating inode fields.

Push some ncp_conn_is_valid down to ncp_request.  Connection can become
invalid at any moment, and fewer error code paths to test the better.

Use i_size_{read,write} to modify file size.

Set inode's backing_dev_info as ncpfs has its own special bdi.

In ioctl unbreak ioctls invoked on filesystem mounted 'ro' - tests are
for inode writeable or owner match, but were turned to filesystem
writeable and inode writeable or owner match.  Also collect all permission
checks in single place.

Add some locking, and remove comments saying that it would be cool to
add some locks to the code.

Constify some pointers.

Signed-off-by: Petr Vandrovec <petr@vandrovec.name>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

1 files changed, 7 insertions, 18 deletions

diff --git a/fs/ncpfs/file.c b/fs/ncpfs/file.c
index 3639cc5cbdae..6c754f70c529 100644
--- a/fs/ncpfs/file.c
+++ b/fs/ncpfs/file.c
@@ -113,9 +113,6 @@ ncp_file_read(struct file *file, char __user *buf, size_t count, loff_t *ppos)
         DPRINTK("ncp_file_read: enter %s/%s\n",
                 dentry->d_parent->d_name.name, dentry->d_name.name);
 
-        if (!ncp_conn_valid(NCP_SERVER(inode)))
-                return -EIO;
-
         pos = *ppos;
 
         if ((ssize_t) count < 0) {
@@ -192,13 +189,11 @@ ncp_file_write(struct file *file, const char __user *buf, size_t count, loff_t *
 
         DPRINTK("ncp_file_write: enter %s/%s\n",
                 dentry->d_parent->d_name.name, dentry->d_name.name);
-        if (!ncp_conn_valid(NCP_SERVER(inode)))
-                return -EIO;
         if ((ssize_t) count < 0)
                 return -EINVAL;
         pos = *ppos;
         if (file->f_flags & O_APPEND) {
-                pos = inode->i_size;
+                pos = i_size_read(inode);
         }
 
         if (pos + count > MAX_NON_LFS && !(file->f_flags&O_LARGEFILE)) {
@@ -264,8 +259,11 @@ ncp_file_write(struct file *file, const char __user *buf, size_t count, loff_t *
 
         *ppos = pos;
 
-        if (pos > inode->i_size) {
-                inode->i_size = pos;
+        if (pos > i_size_read(inode)) {
+                mutex_lock(&inode->i_mutex);
+                if (pos > i_size_read(inode))
+                        i_size_write(inode, pos);
+                mutex_unlock(&inode->i_mutex);
         }
         DPRINTK("ncp_file_write: exit %s/%s\n",
                 dentry->d_parent->d_name.name, dentry->d_name.name);
@@ -281,18 +279,9 @@ static int ncp_release(struct inode *inode, struct file *file) {
         return 0;
 }
 
-static loff_t ncp_remote_llseek(struct file *file, loff_t offset, int origin)
-{
-        loff_t ret;
-        lock_kernel();
-        ret = generic_file_llseek_unlocked(file, offset, origin);
-        unlock_kernel();
-        return ret;
-}
-
 const struct file_operations ncp_file_operations =
 {
-        .llseek         = ncp_remote_llseek,
+        .llseek         = generic_file_llseek,
         .read           = ncp_file_read,
         .write          = ncp_file_write,
         .unlocked_ioctl = ncp_ioctl,