@@ -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)
@@ -232,7 +233,8 @@ 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 *stat, const char *link,
+ bool tmpfile)
{
struct inode *wdir = workdir->d_inode;
struct inode *udir = upperdir->d_inode;
@@ -262,12 +264,17 @@ static int ovl_copy_up_locked(struct dentry *workdir, struct dentry *upperdir,
if (new_creds)
old_creds = override_creds(new_creds);
- temp = ovl_lookup_temp(workdir, dentry);
+ if (tmpfile)
+ temp = ovl_alloc_tmpfile(upperdir, stat->mode);
+ else
+ temp = ovl_lookup_temp(workdir, dentry);
err = PTR_ERR(temp);
if (IS_ERR(temp))
goto out1;
- err = ovl_create_real(wdir, temp, &cattr, NULL, true);
+ err = 0;
+ if (!tmpfile)
+ err = ovl_create_real(wdir, temp, &cattr, NULL, true);
if (new_creds) {
revert_creds(old_creds);
@@ -299,11 +306,14 @@ static int ovl_copy_up_locked(struct dentry *workdir, struct dentry *upperdir,
if (err)
goto out_cleanup;
- err = ovl_do_rename(wdir, temp, udir, upper, 0);
+ if (tmpfile)
+ err = ovl_link_tmpfile(temp, udir, upper);
+ 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));
out2:
@@ -314,7 +324,8 @@ static int ovl_copy_up_locked(struct dentry *workdir, struct dentry *upperdir,
return err;
out_cleanup:
- ovl_cleanup(wdir, temp);
+ if (!tmpfile)
+ ovl_cleanup(wdir, temp);
goto out2;
}
@@ -338,6 +349,9 @@ 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;
@@ -369,7 +383,7 @@ static int ovl_copy_up_one(struct dentry *parent, struct dentry *dentry,
}
err = ovl_copy_up_locked(workdir, upperdir, dentry, lowerpath,
- stat, link);
+ stat, link, tmpfile);
if (!err) {
/* Restore timestamps on parent (best effort) */
ovl_set_timestamps(upperdir, &pstat);
@@ -178,6 +178,8 @@ u64 ovl_dentry_version_get(struct dentry *dentry);
bool ovl_is_whiteout(struct dentry *dentry);
struct file *ovl_path_open(struct path *path, int flags);
struct dentry *ovl_alloc_tmpfile(struct dentry *parent, umode_t mode);
+int ovl_link_tmpfile(struct dentry *temp, struct inode *dir,
+ struct dentry *dentry);
/* namei.c */
int ovl_path_next(int idx, struct dentry *dentry, struct path *path);
@@ -281,3 +281,23 @@ struct dentry *ovl_alloc_tmpfile(struct dentry *parent, umode_t mode)
return temp;
}
+
+int ovl_link_tmpfile(struct dentry *temp, struct inode *dir,
+ struct dentry *dentry)
+{
+ struct inode *inode = temp->d_inode;
+ int err;
+
+ if (WARN_ON_ONCE(!inode || inode->i_nlink))
+ return -ENOENT;
+
+ /* Make tempfile linkable */
+ spin_lock(&inode->i_lock);
+ if (!inode->i_nlink)
+ inode->i_state |= I_LINKABLE;
+ spin_unlock(&inode->i_lock);
+
+ err = ovl_do_link(temp, dir, dentry, true);
+
+ return err;
+}
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: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Amir Goldstein <amir73il@gmail.com> --- fs/overlayfs/copy_up.c | 28 +++++++++++++++++++++------- fs/overlayfs/overlayfs.h | 2 ++ fs/overlayfs/util.c | 20 ++++++++++++++++++++ 3 files changed, 43 insertions(+), 7 deletions(-)