| Message ID | 1456429008.2377.4.camel@HansenPartnership.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Thu, Feb 25, 2016 at 11:36:48AM -0800, James Bottomley wrote: > I need an API that allows me to obtain a clone of the current file > pointer to pass in to an exec handler. I've labelled this as an > internal API because I can't see how it would be useful outside of the > fs subsystem. The use case will be a persistent binfmt_misc handler. > > Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com> Thanks, James, worthwhlie feature. Acked-by: Serge Hallyn <serge.hallyn@canonical.com> > --- > fs/internal.h | 1 + > fs/open.c | 20 ++++++++++++++++++++ > 2 files changed, 21 insertions(+) > > diff --git a/fs/internal.h b/fs/internal.h > index b71deee..c8ca0c9 100644 > --- a/fs/internal.h > +++ b/fs/internal.h > @@ -108,6 +108,7 @@ extern long do_handle_open(int mountdirfd, > struct file_handle __user *ufh, int open_flag); > extern int open_check_o_direct(struct file *f); > extern int vfs_open(const struct path *, struct file *, const struct cred *); > +extern struct file *filp_clone_open(struct file *); > > /* > * inode.c > diff --git a/fs/open.c b/fs/open.c > index 55bdc75..bb7ffd6 100644 > --- a/fs/open.c > +++ b/fs/open.c > @@ -1004,6 +1004,26 @@ struct file *file_open_root(struct dentry *dentry, struct vfsmount *mnt, > } > EXPORT_SYMBOL(file_open_root); > > +struct file *filp_clone_open(struct file *oldfile) > +{ > + struct file *file; > + int retval; > + > + file = get_empty_filp(); > + if (IS_ERR(file)) > + return file; > + > + file->f_flags = oldfile->f_flags; > + retval = vfs_open(&oldfile->f_path, file, oldfile->f_cred); > + if (retval) { > + fput(file); > + return ERR_PTR(retval); > + } > + > + return file; > +} > +EXPORT_SYMBOL(filp_clone_open); > + > long do_sys_open(int dfd, const char __user *filename, int flags, umode_t mode) > { > struct open_flags op; > -- > 2.6.2 > > _______________________________________________ > Containers mailing list > Containers@lists.linux-foundation.org > https://lists.linuxfoundation.org/mailman/listinfo/containers -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Thu, Feb 25, 2016 at 11:36:48AM -0800, James Bottomley wrote: > I need an API that allows me to obtain a clone of the current file > pointer to pass in to an exec handler. I've labelled this as an > internal API because I can't see how it would be useful outside of the > fs subsystem. The use case will be a persistent binfmt_misc handler. > > Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com> > --- > fs/internal.h | 1 + > fs/open.c | 20 ++++++++++++++++++++ > 2 files changed, 21 insertions(+) > > diff --git a/fs/internal.h b/fs/internal.h > index b71deee..c8ca0c9 100644 > --- a/fs/internal.h > +++ b/fs/internal.h > @@ -108,6 +108,7 @@ extern long do_handle_open(int mountdirfd, > struct file_handle __user *ufh, int open_flag); > extern int open_check_o_direct(struct file *f); > extern int vfs_open(const struct path *, struct file *, const struct cred *); > +extern struct file *filp_clone_open(struct file *); > > /* > * inode.c > diff --git a/fs/open.c b/fs/open.c > index 55bdc75..bb7ffd6 100644 > --- a/fs/open.c > +++ b/fs/open.c > @@ -1004,6 +1004,26 @@ struct file *file_open_root(struct dentry *dentry, struct vfsmount *mnt, > } > EXPORT_SYMBOL(file_open_root); > > +struct file *filp_clone_open(struct file *oldfile) > +{ > + struct file *file; > + int retval; > + > + file = get_empty_filp(); > + if (IS_ERR(file)) > + return file; > + > + file->f_flags = oldfile->f_flags; > + retval = vfs_open(&oldfile->f_path, file, oldfile->f_cred); > + if (retval) { > + fput(file); You likely want put_file instead, although if I read it right this is only cosmetics for consistency with dentry_open. Also vast majority of the file uses 'error' instead of 'retval'. Any reason to deviate here? > + return ERR_PTR(retval); > + } > + > + return file; > +} > +EXPORT_SYMBOL(filp_clone_open); > + > long do_sys_open(int dfd, const char __user *filename, int flags, umode_t mode) > { > struct open_flags op; > -- > 2.6.2 >
On Tue, 2016-03-08 at 10:17 +0100, Mateusz Guzik wrote: > On Thu, Feb 25, 2016 at 11:36:48AM -0800, James Bottomley wrote: > > I need an API that allows me to obtain a clone of the current file > > pointer to pass in to an exec handler. I've labelled this as an > > internal API because I can't see how it would be useful outside of > > the > > fs subsystem. The use case will be a persistent binfmt_misc > > handler. > > > > Signed-off-by: James Bottomley < > > James.Bottomley@HansenPartnership.com> > > --- > > fs/internal.h | 1 + > > fs/open.c | 20 ++++++++++++++++++++ > > 2 files changed, 21 insertions(+) > > > > diff --git a/fs/internal.h b/fs/internal.h > > index b71deee..c8ca0c9 100644 > > --- a/fs/internal.h > > +++ b/fs/internal.h > > @@ -108,6 +108,7 @@ extern long do_handle_open(int mountdirfd, > > struct file_handle __user *ufh, int > > open_flag); > > extern int open_check_o_direct(struct file *f); > > extern int vfs_open(const struct path *, struct file *, const > > struct cred *); > > +extern struct file *filp_clone_open(struct file *); > > > > /* > > * inode.c > > diff --git a/fs/open.c b/fs/open.c > > index 55bdc75..bb7ffd6 100644 > > --- a/fs/open.c > > +++ b/fs/open.c > > @@ -1004,6 +1004,26 @@ struct file *file_open_root(struct dentry > > *dentry, struct vfsmount *mnt, > > } > > EXPORT_SYMBOL(file_open_root); > > > > +struct file *filp_clone_open(struct file *oldfile) > > +{ > > + struct file *file; > > + int retval; > > + > > + file = get_empty_filp(); > > + if (IS_ERR(file)) > > + return file; > > + > > + file->f_flags = oldfile->f_flags; > > + retval = vfs_open(&oldfile->f_path, file, oldfile > > ->f_cred); > > + if (retval) { > > + fput(file); > > You likely want put_file instead, although if I read it right this is > only cosmetics for consistency with dentry_open. get_empty_filp() is always paired with fput(). There isn't a put_file(); there's a put_files_struct() but that's for something different. > Also vast majority of the file uses 'error' instead of 'retval'. Any > reason to deviate here? it mirrors the close routines which also use retval. James > > + return ERR_PTR(retval); > > + } > > + > > + return file; > > +} > > +EXPORT_SYMBOL(filp_clone_open); > > + > > long do_sys_open(int dfd, const char __user *filename, int flags, > > umode_t mode) > > { > > struct open_flags op; > > -- > > 2.6.2 > > > -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/fs/internal.h b/fs/internal.h index b71deee..c8ca0c9 100644 --- a/fs/internal.h +++ b/fs/internal.h @@ -108,6 +108,7 @@ extern long do_handle_open(int mountdirfd, struct file_handle __user *ufh, int open_flag); extern int open_check_o_direct(struct file *f); extern int vfs_open(const struct path *, struct file *, const struct cred *); +extern struct file *filp_clone_open(struct file *); /* * inode.c diff --git a/fs/open.c b/fs/open.c index 55bdc75..bb7ffd6 100644 --- a/fs/open.c +++ b/fs/open.c @@ -1004,6 +1004,26 @@ struct file *file_open_root(struct dentry *dentry, struct vfsmount *mnt, } EXPORT_SYMBOL(file_open_root); +struct file *filp_clone_open(struct file *oldfile) +{ + struct file *file; + int retval; + + file = get_empty_filp(); + if (IS_ERR(file)) + return file; + + file->f_flags = oldfile->f_flags; + retval = vfs_open(&oldfile->f_path, file, oldfile->f_cred); + if (retval) { + fput(file); + return ERR_PTR(retval); + } + + return file; +} +EXPORT_SYMBOL(filp_clone_open); + long do_sys_open(int dfd, const char __user *filename, int flags, umode_t mode) { struct open_flags op;
I need an API that allows me to obtain a clone of the current file pointer to pass in to an exec handler. I've labelled this as an internal API because I can't see how it would be useful outside of the fs subsystem. The use case will be a persistent binfmt_misc handler. Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com> --- fs/internal.h | 1 + fs/open.c | 20 ++++++++++++++++++++ 2 files changed, 21 insertions(+)