[patch 10/22] vfs: create file_truncate() helper

From: Miklos Szeredi
Date: Fri May 16 2008 - 12:35:59 EST


From: Miklos Szeredi <mszeredi@xxxxxxx>

Clean up do_truncate() API:

- create a new function file_truncate()

Signed-off-by: Miklos Szeredi <mszeredi@xxxxxxx>
---
fs/exec.c | 2 +-
fs/open.c | 24 ++++++++++++++++++++----
include/linux/fs.h | 2 ++
mm/tiny-shmem.c | 2 +-
4 files changed, 24 insertions(+), 6 deletions(-)

Index: linux-2.6/fs/exec.c
===================================================================
--- linux-2.6.orig/fs/exec.c 2008-05-16 17:50:35.000000000 +0200
+++ linux-2.6/fs/exec.c 2008-05-16 17:50:46.000000000 +0200
@@ -1763,7 +1763,7 @@ int do_coredump(long signr, int exit_cod
goto close_fail;
if (!file->f_op->write)
goto close_fail;
- if (!ispipe && do_truncate(file->f_path.dentry, 0, 0, file) != 0)
+ if (!ispipe && file_truncate(file, 0, 0) != 0)
goto close_fail;

retval = binfmt->core_dump(signr, regs, file, core_limit);
Index: linux-2.6/fs/open.c
===================================================================
--- linux-2.6.orig/fs/open.c 2008-05-16 17:50:46.000000000 +0200
+++ linux-2.6/fs/open.c 2008-05-16 17:50:46.000000000 +0200
@@ -195,6 +195,13 @@ out:
return error;
}

+/*
+ * do_truncate - truncate (or extend) an inode
+ * @dentry: the dentry to truncate
+ * @length: the new length
+ * @time_attrs: file times to be updated (e.g. ATTR_MTIME|ATTR_CTIME)
+ * @filp: an open file or NULL (see file_truncate() as well)
+ */
int do_truncate(struct dentry *dentry, loff_t length, unsigned int time_attrs,
struct file *filp)
{
@@ -221,6 +228,17 @@ int do_truncate(struct dentry *dentry, l
return err;
}

+/*
+ * file_truncate - truncate (or extend) an open file
+ * @filp: the open file
+ * @length: the new length
+ * @time_attrs: file times to be updated (e.g. ATTR_MTIME|ATTR_CTIME)
+ */
+int file_truncate(struct file *filp, loff_t length, unsigned int time_attrs)
+{
+ return do_truncate(filp->f_path.dentry, length, time_attrs, filp);
+}
+
static long do_sys_truncate(const char __user * path, loff_t length)
{
struct nameidata nd;
@@ -294,7 +312,6 @@ asmlinkage long sys_truncate(const char
static long do_sys_ftruncate(unsigned int fd, loff_t length, int small)
{
struct inode * inode;
- struct dentry *dentry;
struct file * file;
int error;

@@ -310,8 +327,7 @@ static long do_sys_ftruncate(unsigned in
if (file->f_flags & O_LARGEFILE)
small = 0;

- dentry = file->f_path.dentry;
- inode = dentry->d_inode;
+ inode = file->f_path.dentry->d_inode;
error = -EINVAL;
if (!S_ISREG(inode->i_mode) || !(file->f_mode & FMODE_WRITE))
goto out_putf;
@@ -327,7 +343,7 @@ static long do_sys_ftruncate(unsigned in

error = locks_verify_truncate(inode, file, length);
if (!error)
- error = do_truncate(dentry, length, ATTR_MTIME|ATTR_CTIME, file);
+ error = file_truncate(file, length, ATTR_MTIME|ATTR_CTIME);
out_putf:
fput(file);
out:
Index: linux-2.6/include/linux/fs.h
===================================================================
--- linux-2.6.orig/include/linux/fs.h 2008-05-16 17:50:35.000000000 +0200
+++ linux-2.6/include/linux/fs.h 2008-05-16 17:50:46.000000000 +0200
@@ -1600,6 +1600,8 @@ static inline int break_lease(struct ino

extern int do_truncate(struct dentry *, loff_t start, unsigned int time_attrs,
struct file *filp);
+extern int file_truncate(struct file *filp, loff_t start,
+ unsigned int time_attrs);
extern long do_sys_open(int dfd, const char __user *filename, int flags,
int mode);
extern struct file *filp_open(const char *, int, int);
Index: linux-2.6/mm/tiny-shmem.c
===================================================================
--- linux-2.6.orig/mm/tiny-shmem.c 2008-05-16 17:50:35.000000000 +0200
+++ linux-2.6/mm/tiny-shmem.c 2008-05-16 17:50:46.000000000 +0200
@@ -80,7 +80,7 @@ struct file *shmem_file_setup(char *name
inode->i_nlink = 0; /* It is unlinked */

/* notify everyone as to the change of file size */
- error = do_truncate(dentry, size, 0, file);
+ error = file_truncate(file, size, 0);
if (error < 0)
goto close_file;


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