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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.c138
1 files changed, 66 insertions, 72 deletions
diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c
index 43ee4c7296a7..28b2f707cfbc 100644
--- a/fs/overlayfs/super.c
+++ b/fs/overlayfs/super.c
@@ -310,8 +310,7 @@ static struct dentry *ovl_workdir_create(struct ovl_fs *ofs,
bool retried = false;
retry:
- inode_lock_nested(dir, I_MUTEX_PARENT);
- work = ovl_lookup_upper(ofs, name, ofs->workbasedir, strlen(name));
+ work = ovl_start_creating_upper(ofs, ofs->workbasedir, &QSTR(name));
if (!IS_ERR(work)) {
struct iattr attr = {
@@ -320,14 +319,12 @@ retry:
};
if (work->d_inode) {
+ end_creating_keep(work);
+ if (persist)
+ return work;
err = -EEXIST;
- inode_unlock(dir);
if (retried)
goto out_dput;
-
- if (persist)
- return work;
-
retried = true;
err = ovl_workdir_cleanup(ofs, ofs->workbasedir, mnt, work, 0);
dput(work);
@@ -338,7 +335,7 @@ retry:
}
work = ovl_do_mkdir(ofs, dir, work, attr.ia_mode);
- inode_unlock(dir);
+ end_creating_keep(work);
err = PTR_ERR(work);
if (IS_ERR(work))
goto out_err;
@@ -376,7 +373,6 @@ retry:
if (err)
goto out_dput;
} else {
- inode_unlock(dir);
err = PTR_ERR(work);
goto out_err;
}
@@ -567,9 +563,10 @@ static int ovl_check_rename_whiteout(struct ovl_fs *ofs)
{
struct dentry *workdir = ofs->workdir;
struct dentry *temp;
- struct dentry *dest;
struct dentry *whiteout;
struct name_snapshot name;
+ struct renamedata rd = {};
+ char name2[OVL_TEMPNAME_SIZE];
int err;
temp = ovl_create_temp(ofs, workdir, OVL_CATTR(S_IFREG | 0));
@@ -577,23 +574,21 @@ static int ovl_check_rename_whiteout(struct ovl_fs *ofs)
if (IS_ERR(temp))
return err;
- err = ovl_parent_lock(workdir, temp);
+ rd.mnt_idmap = ovl_upper_mnt_idmap(ofs);
+ rd.old_parent = workdir;
+ rd.new_parent = workdir;
+ rd.flags = RENAME_WHITEOUT;
+ ovl_tempname(name2);
+ err = start_renaming_dentry(&rd, 0, temp, &QSTR(name2));
if (err) {
dput(temp);
return err;
}
- dest = ovl_lookup_temp(ofs, workdir);
- err = PTR_ERR(dest);
- if (IS_ERR(dest)) {
- dput(temp);
- ovl_parent_unlock(workdir);
- return err;
- }
/* Name is inline and stable - using snapshot as a copy helper */
take_dentry_name_snapshot(&name, temp);
- err = ovl_do_rename(ofs, workdir, temp, workdir, dest, RENAME_WHITEOUT);
- ovl_parent_unlock(workdir);
+ err = ovl_do_rename_rd(&rd);
+ end_renaming(&rd);
if (err) {
if (err == -EINVAL)
err = 0;
@@ -617,7 +612,6 @@ cleanup_temp:
ovl_cleanup(ofs, workdir, temp);
release_dentry_name_snapshot(&name);
dput(temp);
- dput(dest);
return err;
}
@@ -626,14 +620,15 @@ static struct dentry *ovl_lookup_or_create(struct ovl_fs *ofs,
struct dentry *parent,
const char *name, umode_t mode)
{
- size_t len = strlen(name);
struct dentry *child;
- inode_lock_nested(parent->d_inode, I_MUTEX_PARENT);
- child = ovl_lookup_upper(ofs, name, parent, len);
- if (!IS_ERR(child) && !child->d_inode)
- child = ovl_create_real(ofs, parent, child, OVL_CATTR(mode));
- inode_unlock(parent->d_inode);
+ child = ovl_start_creating_upper(ofs, parent, &QSTR(name));
+ if (!IS_ERR(child)) {
+ if (!child->d_inode)
+ child = ovl_create_real(ofs, parent, child,
+ OVL_CATTR(mode));
+ end_creating_keep(child);
+ }
dput(parent);
return child;
@@ -1369,53 +1364,35 @@ static void ovl_set_d_op(struct super_block *sb)
set_default_d_op(sb, &ovl_dentry_operations);
}
-int ovl_fill_super(struct super_block *sb, struct fs_context *fc)
+static int ovl_fill_super_creds(struct fs_context *fc, struct super_block *sb)
{
struct ovl_fs *ofs = sb->s_fs_info;
+ struct cred *creator_cred = (struct cred *)ofs->creator_cred;
struct ovl_fs_context *ctx = fc->fs_private;
- const struct cred *old_cred = NULL;
- struct dentry *root_dentry;
- struct ovl_entry *oe;
struct ovl_layer *layers;
- struct cred *cred;
+ struct ovl_entry *oe = NULL;
int err;
- err = -EIO;
- if (WARN_ON(fc->user_ns != current_user_ns()))
- goto out_err;
-
- ovl_set_d_op(sb);
-
- err = -ENOMEM;
- if (!ofs->creator_cred)
- ofs->creator_cred = cred = prepare_creds();
- else
- cred = (struct cred *)ofs->creator_cred;
- if (!cred)
- goto out_err;
-
- old_cred = ovl_override_creds(sb);
-
err = ovl_fs_params_verify(ctx, &ofs->config);
if (err)
- goto out_err;
+ return err;
err = -EINVAL;
if (ctx->nr == 0) {
if (!(fc->sb_flags & SB_SILENT))
pr_err("missing 'lowerdir'\n");
- goto out_err;
+ return err;
}
err = -ENOMEM;
layers = kcalloc(ctx->nr + 1, sizeof(struct ovl_layer), GFP_KERNEL);
if (!layers)
- goto out_err;
+ return err;
ofs->config.lowerdirs = kcalloc(ctx->nr + 1, sizeof(char *), GFP_KERNEL);
if (!ofs->config.lowerdirs) {
kfree(layers);
- goto out_err;
+ return err;
}
ofs->layers = layers;
/*
@@ -1448,12 +1425,12 @@ int ovl_fill_super(struct super_block *sb, struct fs_context *fc)
err = -EINVAL;
if (!ofs->config.workdir) {
pr_err("missing 'workdir'\n");
- goto out_err;
+ return err;
}
err = ovl_get_upper(sb, ofs, &layers[0], &ctx->upper);
if (err)
- goto out_err;
+ return err;
upper_sb = ovl_upper_mnt(ofs)->mnt_sb;
if (!ovl_should_sync(ofs)) {
@@ -1461,13 +1438,13 @@ int ovl_fill_super(struct super_block *sb, struct fs_context *fc)
if (errseq_check(&upper_sb->s_wb_err, ofs->errseq)) {
err = -EIO;
pr_err("Cannot mount volatile when upperdir has an unseen error. Sync upperdir fs to clear state.\n");
- goto out_err;
+ return err;
}
}
err = ovl_get_workdir(sb, ofs, &ctx->upper, &ctx->work);
if (err)
- goto out_err;
+ return err;
if (!ofs->workdir)
sb->s_flags |= SB_RDONLY;
@@ -1478,7 +1455,7 @@ int ovl_fill_super(struct super_block *sb, struct fs_context *fc)
oe = ovl_get_lowerstack(sb, ctx, ofs, layers);
err = PTR_ERR(oe);
if (IS_ERR(oe))
- goto out_err;
+ return err;
/* If the upper fs is nonexistent, we mark overlayfs r/o too */
if (!ovl_upper_mnt(ofs))
@@ -1531,7 +1508,7 @@ int ovl_fill_super(struct super_block *sb, struct fs_context *fc)
sb->s_export_op = &ovl_export_fid_operations;
/* Never override disk quota limits or use reserved space */
- cap_lower(cred->cap_effective, CAP_SYS_RESOURCE);
+ cap_lower(creator_cred->cap_effective, CAP_SYS_RESOURCE);
sb->s_magic = OVERLAYFS_SUPER_MAGIC;
sb->s_xattr = ovl_xattr_handlers(ofs);
@@ -1549,27 +1526,44 @@ int ovl_fill_super(struct super_block *sb, struct fs_context *fc)
sb->s_iflags |= SB_I_EVM_HMAC_UNSUPPORTED;
err = -ENOMEM;
- root_dentry = ovl_get_root(sb, ctx->upper.dentry, oe);
- if (!root_dentry)
+ sb->s_root = ovl_get_root(sb, ctx->upper.dentry, oe);
+ if (!sb->s_root)
goto out_free_oe;
- sb->s_root = root_dentry;
-
- ovl_revert_creds(old_cred);
return 0;
out_free_oe:
ovl_free_entry(oe);
+ return err;
+}
+
+int ovl_fill_super(struct super_block *sb, struct fs_context *fc)
+{
+ struct ovl_fs *ofs = sb->s_fs_info;
+ int err;
+
+ err = -EIO;
+ if (WARN_ON(fc->user_ns != current_user_ns()))
+ goto out_err;
+
+ ovl_set_d_op(sb);
+
+ if (!ofs->creator_cred) {
+ err = -ENOMEM;
+ ofs->creator_cred = prepare_creds();
+ if (!ofs->creator_cred)
+ goto out_err;
+ }
+
+ with_ovl_creds(sb)
+ err = ovl_fill_super_creds(fc, sb);
+
out_err:
- /*
- * Revert creds before calling ovl_free_fs() which will call
- * put_cred() and put_cred() requires that the cred's that are
- * put are not the caller's creds, i.e., current->cred.
- */
- if (old_cred)
- ovl_revert_creds(old_cred);
- ovl_free_fs(ofs);
- sb->s_fs_info = NULL;
+ if (err) {
+ ovl_free_fs(ofs);
+ sb->s_fs_info = NULL;
+ }
+
return err;
}
generated by cgit (git 2.34.1) at 2025-12-02 23:22:19 +0000