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Commit d8514d8e authored by Amir Goldstein's avatar Amir Goldstein Committed by Miklos Szeredi
Browse files

ovl: copy up regular file using O_TMPFILE 



In preparation for concurrent copy up, implement copy up
of regular file as O_TMPFILE that is linked to upperdir
instead of a file in workdir that is moved to upperdir.

Suggested-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: default avatarAmir Goldstein <amir73il@gmail.com>
Signed-off-by: default avatarMiklos Szeredi <mszeredi@redhat.com>
parent 42f269b9

fs/overlayfs/copy_up.c

+20 −7
Original line number Diff line number Diff line
@@ -20,6 +20,7 @@ 
#include <linux/fdtable.h>

#include <linux/ratelimit.h>

#include "overlayfs.h"

#include "ovl_entry.h"



#define OVL_COPY_UP_CHUNK_SIZE (1 << 20)
@@ -233,7 +234,7 @@ int ovl_set_attr(struct dentry *upperdentry, struct kstat *stat) 
static int ovl_copy_up_locked(struct dentry *workdir, struct dentry *upperdir,

			      struct dentry *dentry, struct path *lowerpath,

			      struct kstat *stat, const char *link,

			      struct kstat *pstat)

			      struct kstat *pstat, bool tmpfile)

{

	struct inode *wdir = workdir->d_inode;

	struct inode *udir = upperdir->d_inode;
@@ -263,11 +264,16 @@ static int ovl_copy_up_locked(struct dentry *workdir, struct dentry *upperdir, 
	if (new_creds)

		old_creds = override_creds(new_creds);



	if (tmpfile)

		temp = ovl_do_tmpfile(upperdir, stat->mode);

	else

		temp = ovl_lookup_temp(workdir, dentry);

	err = PTR_ERR(temp);

	if (IS_ERR(temp))

		goto out1;



	err = 0;

	if (!tmpfile)

		err = ovl_create_real(wdir, temp, &cattr, NULL, true);



	if (new_creds) {
@@ -300,11 +306,14 @@ static int ovl_copy_up_locked(struct dentry *workdir, struct dentry *upperdir, 
	if (err)

		goto out_cleanup;



	if (tmpfile)

		err = ovl_do_link(temp, udir, upper, true);

	else

		err = ovl_do_rename(wdir, temp, udir, upper, 0);

	if (err)

		goto out_cleanup;



	newdentry = dget(temp);

	newdentry = dget(tmpfile ? upper : temp);

	ovl_dentry_update(dentry, newdentry);

	ovl_inode_update(d_inode(dentry), d_inode(newdentry));
@@ -318,6 +327,7 @@ static int ovl_copy_up_locked(struct dentry *workdir, struct dentry *upperdir, 
	return err;



out_cleanup:

	if (!tmpfile)

		ovl_cleanup(wdir, temp);

	goto out2;

}
@@ -342,6 +352,9 @@ static int ovl_copy_up_one(struct dentry *parent, struct dentry *dentry, 
	struct dentry *lowerdentry = lowerpath->dentry;

	struct dentry *upperdir;

	const char *link = NULL;

	struct ovl_fs *ofs = dentry->d_sb->s_fs_info;

	/* Should we copyup with O_TMPFILE or with workdir? */

	bool tmpfile = S_ISREG(stat->mode) && ofs->tmpfile;



	if (WARN_ON(!workdir))

		return -EROFS;
@@ -373,7 +386,7 @@ static int ovl_copy_up_one(struct dentry *parent, struct dentry *dentry, 
	}



	err = ovl_copy_up_locked(workdir, upperdir, dentry, lowerpath,

				 stat, link, &pstat);

				 stat, link, &pstat, tmpfile);

out_unlock:

	unlock_rename(workdir, upperdir);

	do_delayed_call(&done);