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4996ec700c
As we released this in the beta channel, and it is a nice feature that our users love, backporting this to 4.4 so we don't have to revert it or conditionally behave differently. This is upstream Linux commits - 9a08c352d05305ca7651540c3b107da1e4e1f40b fs: add filp_clone_open API - 948b701a607f123df92ed29084413e5dd8cda2ed binfmt_misc: add persistent opened binary handler for containers Signed-off-by: Justin Cormack <justin.cormack@docker.com>
65 lines
1.9 KiB
Diff
65 lines
1.9 KiB
Diff
From 9a08c352d05305ca7651540c3b107da1e4e1f40b Mon Sep 17 00:00:00 2001
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From: James Bottomley <James.Bottomley@HansenPartnership.com>
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Date: Wed, 17 Feb 2016 16:49:38 -0800
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Subject: [PATCH] fs: add filp_clone_open API
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I need an API that allows me to obtain a clone of the current file
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pointer to pass in to an exec handler. I've labelled this as an
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internal API because I can't see how it would be useful outside of the
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fs subsystem. The use case will be a persistent binfmt_misc handler.
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Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
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Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
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Acked-by: Jan Kara <jack@suse.cz>
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---
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fs/internal.h | 1 +
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fs/open.c | 20 ++++++++++++++++++++
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2 files changed, 21 insertions(+)
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diff --git a/fs/internal.h b/fs/internal.h
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index b71deee..c8ca0c9 100644
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--- a/fs/internal.h
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+++ b/fs/internal.h
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@@ -108,6 +108,7 @@ extern long do_handle_open(int mountdirfd,
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struct file_handle __user *ufh, int open_flag);
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extern int open_check_o_direct(struct file *f);
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extern int vfs_open(const struct path *, struct file *, const struct cred *);
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+extern struct file *filp_clone_open(struct file *);
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/*
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* inode.c
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diff --git a/fs/open.c b/fs/open.c
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index 17cb6b1..bfe6f2b 100644
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--- a/fs/open.c
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+++ b/fs/open.c
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@@ -1002,6 +1002,26 @@ struct file *file_open_root(struct dentry *dentry, struct vfsmount *mnt,
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}
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EXPORT_SYMBOL(file_open_root);
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+struct file *filp_clone_open(struct file *oldfile)
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+{
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+ struct file *file;
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+ int retval;
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+
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+ file = get_empty_filp();
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+ if (IS_ERR(file))
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+ return file;
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+
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+ file->f_flags = oldfile->f_flags;
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+ retval = vfs_open(&oldfile->f_path, file, oldfile->f_cred);
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+ if (retval) {
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+ put_filp(file);
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+ return ERR_PTR(retval);
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+ }
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+
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+ return file;
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+}
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+EXPORT_SYMBOL(filp_clone_open);
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+
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long do_sys_open(int dfd, const char __user *filename, int flags, umode_t mode)
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{
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struct open_flags op;
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--
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1.9.1
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