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path: root/fs/overlayfs/super.c
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Diffstat (limited to 'fs/overlayfs/super.c')
-rw-r--r--fs/overlayfs/super.c39
1 files changed, 37 insertions, 2 deletions
diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c
index 9aa37c2f7f7d..c9e70d39c1ea 100644
--- a/fs/overlayfs/super.c
+++ b/fs/overlayfs/super.c
@@ -161,6 +161,25 @@ static void ovl_put_super(struct super_block *sb)
kfree(ufs);
}
+static int ovl_sync_fs(struct super_block *sb, int wait)
+{
+ struct ovl_fs *ufs = sb->s_fs_info;
+ struct super_block *upper_sb;
+ int ret;
+
+ if (!ufs->upper_mnt)
+ return 0;
+ upper_sb = ufs->upper_mnt->mnt_sb;
+ if (!upper_sb->s_op->sync_fs)
+ return 0;
+
+ /* real inodes have already been synced by sync_filesystem(ovl_sb) */
+ down_read(&upper_sb->s_umount);
+ ret = upper_sb->s_op->sync_fs(upper_sb, wait);
+ up_read(&upper_sb->s_umount);
+ return ret;
+}
+
/**
* ovl_statfs
* @sb: The overlayfs super block
@@ -223,6 +242,7 @@ static int ovl_remount(struct super_block *sb, int *flags, char *data)
static const struct super_operations ovl_super_operations = {
.put_super = ovl_put_super,
+ .sync_fs = ovl_sync_fs,
.statfs = ovl_statfs,
.show_options = ovl_show_options,
.remount_fs = ovl_remount,
@@ -702,6 +722,7 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent)
unsigned int stacklen = 0;
unsigned int i;
bool remote = false;
+ struct cred *cred;
int err;
err = -ENOMEM;
@@ -709,6 +730,7 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent)
if (!ufs)
goto out;
+ init_waitqueue_head(&ufs->copyup_wq);
ufs->config.redirect_dir = ovl_redirect_dir_def;
err = ovl_parse_opt((char *) data, &ufs->config);
if (err)
@@ -826,6 +848,8 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent)
* creation of workdir in previous step.
*/
if (ufs->workdir) {
+ struct dentry *temp;
+
err = ovl_check_d_type_supported(&workpath);
if (err < 0)
goto out_put_workdir;
@@ -837,6 +861,14 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent)
*/
if (!err)
pr_warn("overlayfs: upper fs needs to support d_type.\n");
+
+ /* Check if upper/work fs supports O_TMPFILE */
+ temp = ovl_do_tmpfile(ufs->workdir, S_IFREG | 0);
+ ufs->tmpfile = !IS_ERR(temp);
+ if (ufs->tmpfile)
+ dput(temp);
+ else
+ pr_warn("overlayfs: upper fs does not support tmpfile.\n");
}
}
@@ -871,10 +903,13 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent)
else
sb->s_d_op = &ovl_dentry_operations;
- ufs->creator_cred = prepare_creds();
- if (!ufs->creator_cred)
+ ufs->creator_cred = cred = prepare_creds();
+ if (!cred)
goto out_put_lower_mnt;
+ /* Never override disk quota limits or use reserved space */
+ cap_lower(cred->cap_effective, CAP_SYS_RESOURCE);
+
err = -ENOMEM;
oe = ovl_alloc_entry(numlower);
if (!oe)