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-rw-r--r--fs/pipe.c155
-rw-r--r--include/linux/fs.h3
2 files changed, 96 insertions, 62 deletions
diff --git a/fs/pipe.c b/fs/pipe.c
index 2e60e1c8815e..b1626f269a34 100644
--- a/fs/pipe.c
+++ b/fs/pipe.c
@@ -874,87 +874,118 @@ fail_inode:
return NULL;
}
-int do_pipe(int *fd)
+struct file *create_write_pipe(void)
{
- struct qstr this;
- char name[32];
+ int err;
+ struct inode *inode;
+ struct file *f;
struct dentry *dentry;
- struct inode * inode;
- struct file *f1, *f2;
- int error;
- int i, j;
-
- error = -ENFILE;
- f1 = get_empty_filp();
- if (!f1)
- goto no_files;
-
- f2 = get_empty_filp();
- if (!f2)
- goto close_f1;
+ char name[32];
+ struct qstr this;
+ f = get_empty_filp();
+ if (!f)
+ return ERR_PTR(-ENFILE);
+ err = -ENFILE;
inode = get_pipe_inode();
if (!inode)
- goto close_f12;
+ goto err_file;
- error = get_unused_fd();
- if (error < 0)
- goto close_f12_inode;
- i = error;
-
- error = get_unused_fd();
- if (error < 0)
- goto close_f12_inode_i;
- j = error;
-
- error = -ENOMEM;
sprintf(name, "[%lu]", inode->i_ino);
this.name = name;
this.len = strlen(name);
this.hash = inode->i_ino; /* will go */
+ err = -ENOMEM;
dentry = d_alloc(pipe_mnt->mnt_sb->s_root, &this);
if (!dentry)
- goto close_f12_inode_i_j;
+ goto err_inode;
dentry->d_op = &pipefs_dentry_operations;
d_add(dentry, inode);
- f1->f_vfsmnt = f2->f_vfsmnt = mntget(mntget(pipe_mnt));
- f1->f_dentry = f2->f_dentry = dget(dentry);
- f1->f_mapping = f2->f_mapping = inode->i_mapping;
-
- /* read file */
- f1->f_pos = f2->f_pos = 0;
- f1->f_flags = O_RDONLY;
- f1->f_op = &read_pipe_fops;
- f1->f_mode = FMODE_READ;
- f1->f_version = 0;
-
- /* write file */
- f2->f_flags = O_WRONLY;
- f2->f_op = &write_pipe_fops;
- f2->f_mode = FMODE_WRITE;
- f2->f_version = 0;
-
- fd_install(i, f1);
- fd_install(j, f2);
- fd[0] = i;
- fd[1] = j;
+ f->f_vfsmnt = mntget(pipe_mnt);
+ f->f_dentry = dentry;
+ f->f_mapping = inode->i_mapping;
- return 0;
+ f->f_flags = O_WRONLY;
+ f->f_op = &write_pipe_fops;
+ f->f_mode = FMODE_WRITE;
+ f->f_version = 0;
-close_f12_inode_i_j:
- put_unused_fd(j);
-close_f12_inode_i:
- put_unused_fd(i);
-close_f12_inode:
+ return f;
+
+ err_inode:
free_pipe_info(inode);
iput(inode);
-close_f12:
- put_filp(f2);
-close_f1:
- put_filp(f1);
-no_files:
- return error;
+ err_file:
+ put_filp(f);
+ return ERR_PTR(err);
+}
+
+void free_write_pipe(struct file *f)
+{
+ mntput(f->f_vfsmnt);
+ dput(f->f_dentry);
+ put_filp(f);
+}
+
+struct file *create_read_pipe(struct file *wrf)
+{
+ struct file *f = get_empty_filp();
+ if (!f)
+ return ERR_PTR(-ENFILE);
+
+ /* Grab pipe from the writer */
+ f->f_vfsmnt = mntget(wrf->f_vfsmnt);
+ f->f_dentry = dget(wrf->f_dentry);
+ f->f_mapping = wrf->f_dentry->d_inode->i_mapping;
+
+ f->f_pos = 0;
+ f->f_flags = O_RDONLY;
+ f->f_op = &read_pipe_fops;
+ f->f_mode = FMODE_READ;
+ f->f_version = 0;
+
+ return f;
+}
+
+int do_pipe(int *fd)
+{
+ struct file *fw, *fr;
+ int error;
+ int fdw, fdr;
+
+ fw = create_write_pipe();
+ if (IS_ERR(fw))
+ return PTR_ERR(fw);
+ fr = create_read_pipe(fw);
+ error = PTR_ERR(fr);
+ if (IS_ERR(fr))
+ goto err_write_pipe;
+
+ error = get_unused_fd();
+ if (error < 0)
+ goto err_read_pipe;
+ fdr = error;
+
+ error = get_unused_fd();
+ if (error < 0)
+ goto err_fdr;
+ fdw = error;
+
+ fd_install(fdr, fr);
+ fd_install(fdw, fw);
+ fd[0] = fdr;
+ fd[1] = fdw;
+
+ return 0;
+
+ err_fdr:
+ put_unused_fd(fdr);
+ err_read_pipe:
+ put_filp(fr);
+ err_write_pipe:
+ free_write_pipe(fw);
+ return error;
}
/*
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 3493d2828f7d..2e29a2edaeec 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1641,6 +1641,9 @@ static inline void allow_write_access(struct file *file)
atomic_inc(&file->f_dentry->d_inode->i_writecount);
}
extern int do_pipe(int *);
+extern struct file *create_read_pipe(struct file *f);
+extern struct file *create_write_pipe(void);
+extern void free_write_pipe(struct file *);
extern int open_namei(int dfd, const char *, int, int, struct nameidata *);
extern int may_open(struct nameidata *, int, int);