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path: root/fs/overlayfs/copy_up.c
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Diffstat (limited to 'fs/overlayfs/copy_up.c')
-rw-r--r--fs/overlayfs/copy_up.c91
1 files changed, 66 insertions, 25 deletions
diff --git a/fs/overlayfs/copy_up.c b/fs/overlayfs/copy_up.c
index 2d4985018fdb..906ea6c93260 100644
--- a/fs/overlayfs/copy_up.c
+++ b/fs/overlayfs/copy_up.c
@@ -21,6 +21,7 @@
#include <linux/fdtable.h>
#include <linux/ratelimit.h>
#include "overlayfs.h"
+#include "ovl_entry.h"
#define OVL_COPY_UP_CHUNK_SIZE (1 << 20)
@@ -233,12 +234,14 @@ 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,
+ struct kstat *pstat, bool tmpfile)
{
struct inode *wdir = workdir->d_inode;
struct inode *udir = upperdir->d_inode;
struct dentry *newdentry = NULL;
struct dentry *upper = NULL;
+ struct dentry *temp = NULL;
int err;
const struct cred *old_creds = NULL;
struct cred *new_creds = NULL;
@@ -249,25 +252,30 @@ static int ovl_copy_up_locked(struct dentry *workdir, struct dentry *upperdir,
.link = link
};
- newdentry = ovl_lookup_temp(workdir, dentry);
- err = PTR_ERR(newdentry);
- if (IS_ERR(newdentry))
- goto out;
-
upper = lookup_one_len(dentry->d_name.name, upperdir,
dentry->d_name.len);
err = PTR_ERR(upper);
if (IS_ERR(upper))
- goto out1;
+ goto out;
err = security_inode_copy_up(dentry, &new_creds);
if (err < 0)
- goto out2;
+ goto out1;
if (new_creds)
old_creds = override_creds(new_creds);
- err = ovl_create_real(wdir, newdentry, &cattr, NULL, true);
+ 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) {
revert_creds(old_creds);
@@ -282,39 +290,55 @@ static int ovl_copy_up_locked(struct dentry *workdir, struct dentry *upperdir,
ovl_path_upper(dentry, &upperpath);
BUG_ON(upperpath.dentry != NULL);
- upperpath.dentry = newdentry;
+ upperpath.dentry = temp;
+
+ if (tmpfile) {
+ inode_unlock(udir);
+ err = ovl_copy_up_data(lowerpath, &upperpath,
+ stat->size);
+ inode_lock_nested(udir, I_MUTEX_PARENT);
+ } else {
+ err = ovl_copy_up_data(lowerpath, &upperpath,
+ stat->size);
+ }
- err = ovl_copy_up_data(lowerpath, &upperpath, stat->size);
if (err)
goto out_cleanup;
}
- err = ovl_copy_xattr(lowerpath->dentry, newdentry);
+ err = ovl_copy_xattr(lowerpath->dentry, temp);
if (err)
goto out_cleanup;
- inode_lock(newdentry->d_inode);
- err = ovl_set_attr(newdentry, stat);
- inode_unlock(newdentry->d_inode);
+ inode_lock(temp->d_inode);
+ err = ovl_set_attr(temp, stat);
+ inode_unlock(temp->d_inode);
if (err)
goto out_cleanup;
- err = ovl_do_rename(wdir, newdentry, udir, upper, 0);
+ 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(tmpfile ? upper : temp);
ovl_dentry_update(dentry, newdentry);
ovl_inode_update(d_inode(dentry), d_inode(newdentry));
- newdentry = NULL;
+
+ /* Restore timestamps on parent (best effort) */
+ ovl_set_timestamps(upperdir, pstat);
out2:
- dput(upper);
+ dput(temp);
out1:
- dput(newdentry);
+ dput(upper);
out:
return err;
out_cleanup:
- ovl_cleanup(wdir, newdentry);
+ if (!tmpfile)
+ ovl_cleanup(wdir, temp);
goto out2;
}
@@ -338,6 +362,7 @@ 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;
if (WARN_ON(!workdir))
return -EROFS;
@@ -358,6 +383,25 @@ static int ovl_copy_up_one(struct dentry *parent, struct dentry *dentry,
return PTR_ERR(link);
}
+ /* Should we copyup with O_TMPFILE or with workdir? */
+ if (S_ISREG(stat->mode) && ofs->tmpfile) {
+ err = ovl_copy_up_start(dentry);
+ /* err < 0: interrupted, err > 0: raced with another copy-up */
+ if (unlikely(err)) {
+ pr_debug("ovl_copy_up_start(%pd2) = %i\n", dentry, err);
+ if (err > 0)
+ err = 0;
+ goto out_done;
+ }
+
+ inode_lock_nested(upperdir->d_inode, I_MUTEX_PARENT);
+ err = ovl_copy_up_locked(workdir, upperdir, dentry, lowerpath,
+ stat, link, &pstat, true);
+ inode_unlock(upperdir->d_inode);
+ ovl_copy_up_end(dentry);
+ goto out_done;
+ }
+
err = -EIO;
if (lock_rename(workdir, upperdir) != NULL) {
pr_err("overlayfs: failed to lock workdir+upperdir\n");
@@ -370,13 +414,10 @@ static int ovl_copy_up_one(struct dentry *parent, struct dentry *dentry,
}
err = ovl_copy_up_locked(workdir, upperdir, dentry, lowerpath,
- stat, link);
- if (!err) {
- /* Restore timestamps on parent (best effort) */
- ovl_set_timestamps(upperdir, &pstat);
- }
+ stat, link, &pstat, false);
out_unlock:
unlock_rename(workdir, upperdir);
+out_done:
do_delayed_call(&done);
return err;