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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.c67
1 files changed, 48 insertions, 19 deletions
diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c
index cc8977498c48..3fa2416264a4 100644
--- a/fs/overlayfs/super.c
+++ b/fs/overlayfs/super.c
@@ -32,6 +32,7 @@ static struct dentry *ovl_d_real(struct dentry *dentry,
const struct inode *inode)
{
struct dentry *real = NULL, *lower;
+ int err;
/* It's an overlay file */
if (inode && d_inode(dentry) == inode)
@@ -58,7 +59,9 @@ static struct dentry *ovl_d_real(struct dentry *dentry,
* uprobes on offset within the file, so lowerdata should be available
* when setting the uprobe.
*/
- ovl_maybe_lookup_lowerdata(dentry);
+ err = ovl_verify_lowerdata(dentry);
+ if (err)
+ goto bug;
lower = ovl_dentry_lowerdata(dentry);
if (!lower)
goto bug;
@@ -101,8 +104,8 @@ static int ovl_revalidate_real(struct dentry *d, unsigned int flags, bool weak)
static int ovl_dentry_revalidate_common(struct dentry *dentry,
unsigned int flags, bool weak)
{
- struct ovl_entry *oe = OVL_E(dentry);
- struct ovl_path *lowerstack = ovl_lowerstack(oe);
+ struct ovl_entry *oe;
+ struct ovl_path *lowerstack;
struct inode *inode = d_inode_rcu(dentry);
struct dentry *upper;
unsigned int i;
@@ -112,6 +115,8 @@ static int ovl_dentry_revalidate_common(struct dentry *dentry,
if (!inode)
return -ECHILD;
+ oe = OVL_I_E(inode);
+ lowerstack = ovl_lowerstack(oe);
upper = ovl_i_dentry_upper(inode);
if (upper)
ret = ovl_revalidate_real(upper, flags, weak);
@@ -164,6 +169,7 @@ static void ovl_free_inode(struct inode *inode)
struct ovl_inode *oi = OVL_I(inode);
kfree(oi->redirect);
+ kfree(oi->oe);
mutex_destroy(&oi->lock);
kmem_cache_free(ovl_inode_cachep, oi);
}
@@ -173,7 +179,7 @@ static void ovl_destroy_inode(struct inode *inode)
struct ovl_inode *oi = OVL_I(inode);
dput(oi->__upperdentry);
- ovl_free_entry(oi->oe);
+ ovl_stack_put(ovl_lowerstack(oi->oe), ovl_numlower(oi->oe));
if (S_ISDIR(inode->i_mode))
ovl_dir_cache_free(inode);
else
@@ -182,7 +188,7 @@ static void ovl_destroy_inode(struct inode *inode)
static void ovl_put_super(struct super_block *sb)
{
- struct ovl_fs *ofs = sb->s_fs_info;
+ struct ovl_fs *ofs = OVL_FS(sb);
if (ofs)
ovl_free_fs(ofs);
@@ -191,7 +197,7 @@ static void ovl_put_super(struct super_block *sb)
/* Sync real dirty inodes in upper filesystem (if it exists) */
static int ovl_sync_fs(struct super_block *sb, int wait)
{
- struct ovl_fs *ofs = sb->s_fs_info;
+ struct ovl_fs *ofs = OVL_FS(sb);
struct super_block *upper_sb;
int ret;
@@ -239,8 +245,9 @@ static int ovl_sync_fs(struct super_block *sb, int wait)
*/
static int ovl_statfs(struct dentry *dentry, struct kstatfs *buf)
{
- struct ovl_fs *ofs = dentry->d_sb->s_fs_info;
- struct dentry *root_dentry = dentry->d_sb->s_root;
+ struct super_block *sb = dentry->d_sb;
+ struct ovl_fs *ofs = OVL_FS(sb);
+ struct dentry *root_dentry = sb->s_root;
struct path path;
int err;
@@ -250,6 +257,8 @@ static int ovl_statfs(struct dentry *dentry, struct kstatfs *buf)
if (!err) {
buf->f_namelen = ofs->namelen;
buf->f_type = OVERLAYFS_SUPER_MAGIC;
+ if (ovl_has_fsid(ofs))
+ buf->f_fsid = uuid_to_fsid(sb->s_uuid.b);
}
return err;
@@ -397,6 +406,7 @@ static int ovl_lower_dir(const char *name, struct path *path,
pr_warn("fs on '%s' does not support file handles, falling back to index=off,nfs_export=off.\n",
name);
}
+ ofs->nofh |= !fh_type;
/*
* Decoding origin file handle is required for persistent st_ino.
* Without persistent st_ino, xino=auto falls back to xino=off.
@@ -562,11 +572,6 @@ static int ovl_get_upper(struct super_block *sb, struct ovl_fs *ofs,
upper_layer->idx = 0;
upper_layer->fsid = 0;
- err = -ENOMEM;
- upper_layer->name = kstrdup(ofs->config.upperdir, GFP_KERNEL);
- if (!upper_layer->name)
- goto out;
-
/*
* Inherit SB_NOSEC flag from upperdir.
*
@@ -770,6 +775,10 @@ static int ovl_make_workdir(struct super_block *sb, struct ovl_fs *ofs,
ofs->config.index = false;
pr_warn("...falling back to index=off.\n");
}
+ if (ovl_has_fsid(ofs)) {
+ ofs->config.uuid = OVL_UUID_NULL;
+ pr_warn("...falling back to uuid=null.\n");
+ }
/*
* xattr support is required for persistent st_ino.
* Without persistent st_ino, xino=auto falls back to xino=off.
@@ -815,6 +824,7 @@ static int ovl_make_workdir(struct super_block *sb, struct ovl_fs *ofs,
ofs->config.index = false;
pr_warn("upper fs does not support file handles, falling back to index=off.\n");
}
+ ofs->nofh |= !fh_type;
/* Check if upper fs has 32bit inode numbers */
if (fh_type != FILEID_INO32_GEN)
@@ -1110,7 +1120,8 @@ static int ovl_get_layers(struct super_block *sb, struct ovl_fs *ofs,
layers[ofs->numlayer].idx = ofs->numlayer;
layers[ofs->numlayer].fsid = fsid;
layers[ofs->numlayer].fs = &ofs->fs[fsid];
- layers[ofs->numlayer].name = l->name;
+ /* Store for printing lowerdir=... in ovl_show_options() */
+ ofs->config.lowerdirs[ofs->numlayer] = l->name;
l->name = NULL;
ofs->numlayer++;
ofs->fs[fsid].is_lower = true;
@@ -1355,8 +1366,16 @@ int ovl_fill_super(struct super_block *sb, struct fs_context *fc)
if (!layers)
goto out_err;
+ ofs->config.lowerdirs = kcalloc(ctx->nr + 1, sizeof(char *), GFP_KERNEL);
+ if (!ofs->config.lowerdirs) {
+ kfree(layers);
+ goto out_err;
+ }
ofs->layers = layers;
- /* Layer 0 is reserved for upper even if there's no upper */
+ /*
+ * Layer 0 is reserved for upper even if there's no upper.
+ * For consistency, config.lowerdirs[0] is NULL.
+ */
ofs->numlayer = 1;
sb->s_stack_depth = 0;
@@ -1416,9 +1435,12 @@ int ovl_fill_super(struct super_block *sb, struct fs_context *fc)
if (!ovl_upper_mnt(ofs))
sb->s_flags |= SB_RDONLY;
- if (!ofs->config.uuid && ofs->numfs > 1) {
- pr_warn("The uuid=off requires a single fs for lower and upper, falling back to uuid=on.\n");
- ofs->config.uuid = true;
+ if (!ovl_origin_uuid(ofs) && ofs->numfs > 1) {
+ pr_warn("The uuid=off requires a single fs for lower and upper, falling back to uuid=null.\n");
+ ofs->config.uuid = OVL_UUID_NULL;
+ } else if (ovl_has_fsid(ofs) && ovl_upper_mnt(ofs)) {
+ /* Use per instance persistent uuid/fsid */
+ ovl_init_uuid_xattr(sb, ofs, &ctx->upper);
}
if (!ovl_force_readonly(ofs) && ofs->config.index) {
@@ -1449,8 +1471,15 @@ int ovl_fill_super(struct super_block *sb, struct fs_context *fc)
ofs->config.nfs_export = false;
}
+ /*
+ * Support encoding decodable file handles with nfs_export=on
+ * and encoding non-decodable file handles with nfs_export=off
+ * if all layers support file handles.
+ */
if (ofs->config.nfs_export)
sb->s_export_op = &ovl_export_operations;
+ else if (!ofs->nofh)
+ 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);
@@ -1479,7 +1508,7 @@ out_err:
return err;
}
-static struct file_system_type ovl_fs_type = {
+struct file_system_type ovl_fs_type = {
.owner = THIS_MODULE,
.name = "overlay",
.init_fs_context = ovl_init_fs_context,
generated by cgit v1.2.3 (git 2.39.0) at 2024-08-20 14:33:09 +0300