Re: [PATCH] cifs: Push the BKL down into the fs ioctl code

From: Steve French
Date: Thu May 22 2008 - 21:58:11 EST


cifs already converted to unlocked ioctl last week.

On Thu, May 22, 2008 at 4:52 PM, Alan Cox <alan@xxxxxxxxxxxxxxxxxxx> wrote:
> Switch to unlocked_ioctl. Wrap the ioctl handler internally with
> lock_kernel until someone can prove it isn't needed or fix it so it isn't.
>
> Signed-off-by: Alan Cox <alan@xxxxxxxxxx>
>
> diff --git a/fs/cifs/cifsfs.c b/fs/cifs/cifsfs.c
> index 427a7c6..b6436b8 100644
> --- a/fs/cifs/cifsfs.c
> +++ b/fs/cifs/cifsfs.c
> @@ -657,7 +657,7 @@ const struct file_operations cifs_file_ops = {
> .splice_read = generic_file_splice_read,
> .llseek = cifs_llseek,
> #ifdef CONFIG_CIFS_POSIX
> - .ioctl = cifs_ioctl,
> + .unlocked_ioctl = cifs_ioctl,
> #endif /* CONFIG_CIFS_POSIX */
>
> #ifdef CONFIG_CIFS_EXPERIMENTAL
> @@ -677,7 +677,7 @@ const struct file_operations cifs_file_direct_ops = {
> .flush = cifs_flush,
> .splice_read = generic_file_splice_read,
> #ifdef CONFIG_CIFS_POSIX
> - .ioctl = cifs_ioctl,
> + .unlocked_ioctl = cifs_ioctl,
> #endif /* CONFIG_CIFS_POSIX */
> .llseek = cifs_llseek,
> #ifdef CONFIG_CIFS_EXPERIMENTAL
> @@ -697,7 +697,7 @@ const struct file_operations cifs_file_nobrl_ops = {
> .splice_read = generic_file_splice_read,
> .llseek = cifs_llseek,
> #ifdef CONFIG_CIFS_POSIX
> - .ioctl = cifs_ioctl,
> + .unlocked_ioctl = cifs_ioctl,
> #endif /* CONFIG_CIFS_POSIX */
>
> #ifdef CONFIG_CIFS_EXPERIMENTAL
> @@ -716,7 +716,7 @@ const struct file_operations cifs_file_direct_nobrl_ops = {
> .flush = cifs_flush,
> .splice_read = generic_file_splice_read,
> #ifdef CONFIG_CIFS_POSIX
> - .ioctl = cifs_ioctl,
> + .unlocked_ioctl = cifs_ioctl,
> #endif /* CONFIG_CIFS_POSIX */
> .llseek = cifs_llseek,
> #ifdef CONFIG_CIFS_EXPERIMENTAL
> @@ -731,7 +731,7 @@ const struct file_operations cifs_dir_ops = {
> #ifdef CONFIG_CIFS_EXPERIMENTAL
> .dir_notify = cifs_dir_notify,
> #endif /* CONFIG_CIFS_EXPERIMENTAL */
> - .ioctl = cifs_ioctl,
> + .unlocked_ioctl = cifs_ioctl,
> };
>
> static void
> diff --git a/fs/cifs/cifsfs.h b/fs/cifs/cifsfs.h
> index cd1301a..1312ae7 100644
> --- a/fs/cifs/cifsfs.h
> +++ b/fs/cifs/cifsfs.h
> @@ -95,8 +95,8 @@ extern int cifs_setxattr(struct dentry *, const char *, const void *,
> size_t, int);
> extern ssize_t cifs_getxattr(struct dentry *, const char *, void *, size_t);
> extern ssize_t cifs_listxattr(struct dentry *, char *, size_t);
> -extern int cifs_ioctl(struct inode *inode, struct file *filep,
> - unsigned int command, unsigned long arg);
> +extern long cifs_ioctl(struct file *filep, unsigned int command,
> + unsigned long arg);
>
> #ifdef CONFIG_CIFS_EXPERIMENTAL
> extern const struct export_operations cifs_export_ops;
> diff --git a/fs/cifs/ioctl.c b/fs/cifs/ioctl.c
> index 5c792df..396811f 100644
> --- a/fs/cifs/ioctl.c
> +++ b/fs/cifs/ioctl.c
> @@ -22,6 +22,7 @@
> */
>
> #include <linux/fs.h>
> +#include <linux/smp_lock.h>
> #include "cifspdu.h"
> #include "cifsglob.h"
> #include "cifsproto.h"
> @@ -30,9 +31,9 @@
>
> #define CIFS_IOC_CHECKUMOUNT _IO(0xCF, 2)
>
> -int cifs_ioctl(struct inode *inode, struct file *filep,
> - unsigned int command, unsigned long arg)
> +long cifs_ioctl(struct file *filep, unsigned int command, unsigned long arg)
> {
> + struct inode *inode = filep->f_path.dentry->d_inode;
> int rc = -ENOTTY; /* strange error - but the precedent */
> int xid;
> struct cifs_sb_info *cifs_sb;
> @@ -45,6 +46,8 @@ int cifs_ioctl(struct inode *inode, struct file *filep,
> (struct cifsFileInfo *)filep->private_data;
> #endif /* CONFIG_CIFS_POSIX */
>
> + lock_kernel();
> +
> xid = GetXid();
>
> cFYI(1, ("ioctl file %p cmd %u arg %lu", filep, command, arg));
> @@ -58,6 +61,7 @@ int cifs_ioctl(struct inode *inode, struct file *filep,
> else {
> rc = -EIO;
> FreeXid(xid);
> + unlock_kernel();
> return -EIO;
> }
> #endif /* CONFIG_CIFS_POSIX */
> @@ -106,5 +110,6 @@ int cifs_ioctl(struct inode *inode, struct file *filep,
> }
>
> FreeXid(xid);
> + unlock_kernel();
> return rc;
> }
>



--
Thanks,

Steve
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