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-rw-r--r--fs/overlayfs/super.c688
1 files changed, 382 insertions, 306 deletions
diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c
index f5738e96a052..be03578181d2 100644
--- a/fs/overlayfs/super.c
+++ b/fs/overlayfs/super.c
@@ -18,7 +18,6 @@
#include <linux/seq_file.h>
#include <linux/posix_acl_xattr.h>
#include "overlayfs.h"
-#include "ovl_entry.h"
MODULE_AUTHOR("Miklos Szeredi <miklos@szeredi.hu>");
MODULE_DESCRIPTION("Overlay filesystem");
@@ -39,15 +38,20 @@ module_param_named(index, ovl_index_def, bool, 0644);
MODULE_PARM_DESC(ovl_index_def,
"Default to on or off for the inodes index feature");
+static void ovl_entry_stack_free(struct ovl_entry *oe)
+{
+ unsigned int i;
+
+ for (i = 0; i < oe->numlower; i++)
+ dput(oe->lowerstack[i].dentry);
+}
+
static void ovl_dentry_release(struct dentry *dentry)
{
struct ovl_entry *oe = dentry->d_fsdata;
if (oe) {
- unsigned int i;
-
- for (i = 0; i < oe->numlower; i++)
- dput(oe->lowerstack[i].dentry);
+ ovl_entry_stack_free(oe);
kfree_rcu(oe, rcu);
}
}
@@ -207,39 +211,48 @@ static void ovl_destroy_inode(struct inode *inode)
call_rcu(&inode->i_rcu, ovl_i_callback);
}
-static void ovl_put_super(struct super_block *sb)
+static void ovl_free_fs(struct ovl_fs *ofs)
{
- struct ovl_fs *ufs = sb->s_fs_info;
unsigned i;
- dput(ufs->indexdir);
- dput(ufs->workdir);
- if (ufs->workdir_locked)
- ovl_inuse_unlock(ufs->workbasedir);
- dput(ufs->workbasedir);
- if (ufs->upper_mnt && ufs->upperdir_locked)
- ovl_inuse_unlock(ufs->upper_mnt->mnt_root);
- mntput(ufs->upper_mnt);
- for (i = 0; i < ufs->numlower; i++)
- mntput(ufs->lower_mnt[i]);
- kfree(ufs->lower_mnt);
-
- kfree(ufs->config.lowerdir);
- kfree(ufs->config.upperdir);
- kfree(ufs->config.workdir);
- put_cred(ufs->creator_cred);
- kfree(ufs);
+ dput(ofs->indexdir);
+ dput(ofs->workdir);
+ if (ofs->workdir_locked)
+ ovl_inuse_unlock(ofs->workbasedir);
+ dput(ofs->workbasedir);
+ if (ofs->upperdir_locked)
+ ovl_inuse_unlock(ofs->upper_mnt->mnt_root);
+ mntput(ofs->upper_mnt);
+ for (i = 0; i < ofs->numlower; i++) {
+ mntput(ofs->lower_layers[i].mnt);
+ free_anon_bdev(ofs->lower_layers[i].pseudo_dev);
+ }
+ kfree(ofs->lower_layers);
+
+ kfree(ofs->config.lowerdir);
+ kfree(ofs->config.upperdir);
+ kfree(ofs->config.workdir);
+ if (ofs->creator_cred)
+ put_cred(ofs->creator_cred);
+ kfree(ofs);
+}
+
+static void ovl_put_super(struct super_block *sb)
+{
+ struct ovl_fs *ofs = sb->s_fs_info;
+
+ ovl_free_fs(ofs);
}
static int ovl_sync_fs(struct super_block *sb, int wait)
{
- struct ovl_fs *ufs = sb->s_fs_info;
+ struct ovl_fs *ofs = sb->s_fs_info;
struct super_block *upper_sb;
int ret;
- if (!ufs->upper_mnt)
+ if (!ofs->upper_mnt)
return 0;
- upper_sb = ufs->upper_mnt->mnt_sb;
+ upper_sb = ofs->upper_mnt->mnt_sb;
if (!upper_sb->s_op->sync_fs)
return 0;
@@ -277,9 +290,9 @@ static int ovl_statfs(struct dentry *dentry, struct kstatfs *buf)
}
/* Will this overlay be forced to mount/remount ro? */
-static bool ovl_force_readonly(struct ovl_fs *ufs)
+static bool ovl_force_readonly(struct ovl_fs *ofs)
{
- return (!ufs->upper_mnt || !ufs->workdir);
+ return (!ofs->upper_mnt || !ofs->workdir);
}
/**
@@ -291,29 +304,29 @@ static bool ovl_force_readonly(struct ovl_fs *ufs)
static int ovl_show_options(struct seq_file *m, struct dentry *dentry)
{
struct super_block *sb = dentry->d_sb;
- struct ovl_fs *ufs = sb->s_fs_info;
+ struct ovl_fs *ofs = sb->s_fs_info;
- seq_show_option(m, "lowerdir", ufs->config.lowerdir);
- if (ufs->config.upperdir) {
- seq_show_option(m, "upperdir", ufs->config.upperdir);
- seq_show_option(m, "workdir", ufs->config.workdir);
+ seq_show_option(m, "lowerdir", ofs->config.lowerdir);
+ if (ofs->config.upperdir) {
+ seq_show_option(m, "upperdir", ofs->config.upperdir);
+ seq_show_option(m, "workdir", ofs->config.workdir);
}
- if (ufs->config.default_permissions)
+ if (ofs->config.default_permissions)
seq_puts(m, ",default_permissions");
- if (ufs->config.redirect_dir != ovl_redirect_dir_def)
+ if (ofs->config.redirect_dir != ovl_redirect_dir_def)
seq_printf(m, ",redirect_dir=%s",
- ufs->config.redirect_dir ? "on" : "off");
- if (ufs->config.index != ovl_index_def)
+ ofs->config.redirect_dir ? "on" : "off");
+ if (ofs->config.index != ovl_index_def)
seq_printf(m, ",index=%s",
- ufs->config.index ? "on" : "off");
+ ofs->config.index ? "on" : "off");
return 0;
}
static int ovl_remount(struct super_block *sb, int *flags, char *data)
{
- struct ovl_fs *ufs = sb->s_fs_info;
+ struct ovl_fs *ofs = sb->s_fs_info;
- if (!(*flags & MS_RDONLY) && ovl_force_readonly(ufs))
+ if (!(*flags & MS_RDONLY) && ovl_force_readonly(ofs))
return -EROFS;
return 0;
@@ -451,13 +464,11 @@ static int ovl_parse_opt(char *opt, struct ovl_config *config)
#define OVL_WORKDIR_NAME "work"
#define OVL_INDEXDIR_NAME "index"
-static struct dentry *ovl_workdir_create(struct super_block *sb,
- struct ovl_fs *ufs,
- struct dentry *dentry,
+static struct dentry *ovl_workdir_create(struct ovl_fs *ofs,
const char *name, bool persist)
{
- struct inode *dir = dentry->d_inode;
- struct vfsmount *mnt = ufs->upper_mnt;
+ struct inode *dir = ofs->workbasedir->d_inode;
+ struct vfsmount *mnt = ofs->upper_mnt;
struct dentry *work;
int err;
bool retried = false;
@@ -471,7 +482,7 @@ static struct dentry *ovl_workdir_create(struct super_block *sb,
locked = true;
retry:
- work = lookup_one_len(name, dentry, strlen(name));
+ work = lookup_one_len(name, ofs->workbasedir, strlen(name));
if (!IS_ERR(work)) {
struct iattr attr = {
@@ -541,8 +552,7 @@ out_dput:
dput(work);
out_err:
pr_warn("overlayfs: failed to create directory %s/%s (errno: %i); mounting read-only\n",
- ufs->config.workdir, name, -err);
- sb->s_flags |= MS_RDONLY;
+ ofs->config.workdir, name, -err);
work = NULL;
goto out_unlock;
}
@@ -585,7 +595,7 @@ static int ovl_mount_dir_noesc(const char *name, struct path *path)
return 0;
out_put:
- path_put(path);
+ path_put_init(path);
out:
return err;
}
@@ -603,7 +613,7 @@ static int ovl_mount_dir(const char *name, struct path *path)
if (ovl_dentry_remote(path->dentry)) {
pr_err("overlayfs: filesystem on '%s' not supported as upperdir\n",
tmp);
- path_put(path);
+ path_put_init(path);
err = -EINVAL;
}
kfree(tmp);
@@ -655,7 +665,7 @@ static int ovl_lower_dir(const char *name, struct path *path,
return 0;
out_put:
- path_put(path);
+ path_put_init(path);
out:
return err;
}
@@ -826,129 +836,269 @@ static const struct xattr_handler *ovl_xattr_handlers[] = {
NULL
};
-static int ovl_fill_super(struct super_block *sb, void *data, int silent)
+static int ovl_get_upper(struct ovl_fs *ofs, struct path *upperpath)
{
- struct path upperpath = { };
- struct path workpath = { };
- struct dentry *root_dentry;
- struct ovl_entry *oe;
- struct ovl_fs *ufs;
- struct path *stack = NULL;
- char *lowertmp;
- char *lower;
- unsigned int numlower;
- unsigned int stacklen = 0;
- unsigned int i;
- bool remote = false;
- struct cred *cred;
+ struct vfsmount *upper_mnt;
int err;
- err = -ENOMEM;
- ufs = kzalloc(sizeof(struct ovl_fs), GFP_KERNEL);
- if (!ufs)
+ err = ovl_mount_dir(ofs->config.upperdir, upperpath);
+ if (err)
goto out;
- ufs->config.redirect_dir = ovl_redirect_dir_def;
- ufs->config.index = ovl_index_def;
- err = ovl_parse_opt((char *) data, &ufs->config);
+ /* Upper fs should not be r/o */
+ if (sb_rdonly(upperpath->mnt->mnt_sb)) {
+ pr_err("overlayfs: upper fs is r/o, try multi-lower layers mount\n");
+ err = -EINVAL;
+ goto out;
+ }
+
+ err = ovl_check_namelen(upperpath, ofs, ofs->config.upperdir);
if (err)
- goto out_free_config;
+ goto out;
+
+ err = -EBUSY;
+ if (ovl_inuse_trylock(upperpath->dentry)) {
+ ofs->upperdir_locked = true;
+ } else if (ofs->config.index) {
+ pr_err("overlayfs: upperdir is in-use by another mount, mount with '-o index=off' to override exclusive upperdir protection.\n");
+ goto out;
+ } else {
+ pr_warn("overlayfs: upperdir is in-use by another mount, accessing files from both mounts will result in undefined behavior.\n");
+ }
+
+ upper_mnt = clone_private_mount(upperpath);
+ err = PTR_ERR(upper_mnt);
+ if (IS_ERR(upper_mnt)) {
+ pr_err("overlayfs: failed to clone upperpath\n");
+ goto out;
+ }
+
+ /* Don't inherit atime flags */
+ upper_mnt->mnt_flags &= ~(MNT_NOATIME | MNT_NODIRATIME | MNT_RELATIME);
+ ofs->upper_mnt = upper_mnt;
+ err = 0;
+out:
+ return err;
+}
+
+static int ovl_make_workdir(struct ovl_fs *ofs, struct path *workpath)
+{
+ struct dentry *temp;
+ int err;
+
+ ofs->workdir = ovl_workdir_create(ofs, OVL_WORKDIR_NAME, false);
+ if (!ofs->workdir)
+ return 0;
+
+ /*
+ * Upper should support d_type, else whiteouts are visible. Given
+ * workdir and upper are on same fs, we can do iterate_dir() on
+ * workdir. This check requires successful creation of workdir in
+ * previous step.
+ */
+ err = ovl_check_d_type_supported(workpath);
+ if (err < 0)
+ return err;
+
+ /*
+ * We allowed this configuration and don't want to break users over
+ * kernel upgrade. So warn instead of erroring out.
+ */
+ 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(ofs->workdir, S_IFREG | 0);
+ ofs->tmpfile = !IS_ERR(temp);
+ if (ofs->tmpfile)
+ dput(temp);
+ else
+ pr_warn("overlayfs: upper fs does not support tmpfile.\n");
+
+ /*
+ * Check if upper/work fs supports trusted.overlay.* xattr
+ */
+ err = ovl_do_setxattr(ofs->workdir, OVL_XATTR_OPAQUE, "0", 1, 0);
+ if (err) {
+ ofs->noxattr = true;
+ pr_warn("overlayfs: upper fs does not support xattr.\n");
+ } else {
+ vfs_removexattr(ofs->workdir, OVL_XATTR_OPAQUE);
+ }
+
+ /* Check if upper/work fs supports file handles */
+ if (ofs->config.index &&
+ !ovl_can_decode_fh(ofs->workdir->d_sb)) {
+ ofs->config.index = false;
+ pr_warn("overlayfs: upper fs does not support file handles, falling back to index=off.\n");
+ }
+
+ return 0;
+}
+
+static int ovl_get_workdir(struct ovl_fs *ofs, struct path *upperpath)
+{
+ int err;
+ struct path workpath = { };
+
+ err = ovl_mount_dir(ofs->config.workdir, &workpath);
+ if (err)
+ goto out;
err = -EINVAL;
- if (!ufs->config.lowerdir) {
- if (!silent)
- pr_err("overlayfs: missing 'lowerdir'\n");
- goto out_free_config;
+ if (upperpath->mnt != workpath.mnt) {
+ pr_err("overlayfs: workdir and upperdir must reside under the same mount\n");
+ goto out;
+ }
+ if (!ovl_workdir_ok(workpath.dentry, upperpath->dentry)) {
+ pr_err("overlayfs: workdir and upperdir must be separate subtrees\n");
+ goto out;
}
- sb->s_stack_depth = 0;
- sb->s_maxbytes = MAX_LFS_FILESIZE;
- if (ufs->config.upperdir) {
- if (!ufs->config.workdir) {
- pr_err("overlayfs: missing 'workdir'\n");
- goto out_free_config;
- }
+ err = -EBUSY;
+ if (ovl_inuse_trylock(workpath.dentry)) {
+ ofs->workdir_locked = true;
+ } else if (ofs->config.index) {
+ pr_err("overlayfs: workdir is in-use by another mount, mount with '-o index=off' to override exclusive workdir protection.\n");
+ goto out;
+ } else {
+ pr_warn("overlayfs: workdir is in-use by another mount, accessing files from both mounts will result in undefined behavior.\n");
+ }
- err = ovl_mount_dir(ufs->config.upperdir, &upperpath);
- if (err)
- goto out_free_config;
+ ofs->workbasedir = dget(workpath.dentry);
+ err = ovl_make_workdir(ofs, &workpath);
+ if (err)
+ goto out;
- /* Upper fs should not be r/o */
- if (sb_rdonly(upperpath.mnt->mnt_sb)) {
- pr_err("overlayfs: upper fs is r/o, try multi-lower layers mount\n");
- err = -EINVAL;
- goto out_put_upperpath;
- }
+ err = 0;
+out:
+ path_put(&workpath);
- err = ovl_check_namelen(&upperpath, ufs, ufs->config.upperdir);
- if (err)
- goto out_put_upperpath;
-
- err = -EBUSY;
- if (ovl_inuse_trylock(upperpath.dentry)) {
- ufs->upperdir_locked = true;
- } else if (ufs->config.index) {
- pr_err("overlayfs: upperdir is in-use by another mount, mount with '-o index=off' to override exclusive upperdir protection.\n");
- goto out_put_upperpath;
- } else {
- pr_warn("overlayfs: upperdir is in-use by another mount, accessing files from both mounts will result in undefined behavior.\n");
- }
+ return err;
+}
+
+static int ovl_get_indexdir(struct ovl_fs *ofs, struct ovl_entry *oe,
+ struct path *upperpath)
+{
+ int err;
- err = ovl_mount_dir(ufs->config.workdir, &workpath);
+ /* Verify lower root is upper root origin */
+ err = ovl_verify_origin(upperpath->dentry, oe->lowerstack[0].dentry,
+ false, true);
+ if (err) {
+ pr_err("overlayfs: failed to verify upper root origin\n");
+ goto out;
+ }
+
+ ofs->indexdir = ovl_workdir_create(ofs, OVL_INDEXDIR_NAME, true);
+ if (ofs->indexdir) {
+ /* Verify upper root is index dir origin */
+ err = ovl_verify_origin(ofs->indexdir, upperpath->dentry,
+ true, true);
if (err)
- goto out_unlock_upperdentry;
+ pr_err("overlayfs: failed to verify index dir origin\n");
- err = -EINVAL;
- if (upperpath.mnt != workpath.mnt) {
- pr_err("overlayfs: workdir and upperdir must reside under the same mount\n");
- goto out_put_workpath;
- }
- if (!ovl_workdir_ok(workpath.dentry, upperpath.dentry)) {
- pr_err("overlayfs: workdir and upperdir must be separate subtrees\n");
- goto out_put_workpath;
+ /* Cleanup bad/stale/orphan index entries */
+ if (!err)
+ err = ovl_indexdir_cleanup(ofs->indexdir,
+ ofs->upper_mnt,
+ oe->lowerstack,
+ oe->numlower);
+ }
+ if (err || !ofs->indexdir)
+ pr_warn("overlayfs: try deleting index dir or mounting with '-o index=off' to disable inodes index.\n");
+
+out:
+ return err;
+}
+
+static int ovl_get_lower_layers(struct ovl_fs *ofs, struct path *stack,
+ unsigned int numlower)
+{
+ int err;
+ unsigned int i;
+
+ err = -ENOMEM;
+ ofs->lower_layers = kcalloc(numlower, sizeof(struct ovl_layer),
+ GFP_KERNEL);
+ if (ofs->lower_layers == NULL)
+ goto out;
+ for (i = 0; i < numlower; i++) {
+ struct vfsmount *mnt;
+ dev_t dev;
+
+ err = get_anon_bdev(&dev);
+ if (err) {
+ pr_err("overlayfs: failed to get anonymous bdev for lowerpath\n");
+ goto out;
}
- err = -EBUSY;
- if (ovl_inuse_trylock(workpath.dentry)) {
- ufs->workdir_locked = true;
- } else if (ufs->config.index) {
- pr_err("overlayfs: workdir is in-use by another mount, mount with '-o index=off' to override exclusive workdir protection.\n");
- goto out_put_workpath;
- } else {
- pr_warn("overlayfs: workdir is in-use by another mount, accessing files from both mounts will result in undefined behavior.\n");
+ mnt = clone_private_mount(&stack[i]);
+ err = PTR_ERR(mnt);
+ if (IS_ERR(mnt)) {
+ pr_err("overlayfs: failed to clone lowerpath\n");
+ free_anon_bdev(dev);
+ goto out;
}
+ /*
+ * Make lower layers R/O. That way fchmod/fchown on lower file
+ * will fail instead of modifying lower fs.
+ */
+ mnt->mnt_flags |= MNT_READONLY | MNT_NOATIME;
- ufs->workbasedir = workpath.dentry;
- sb->s_stack_depth = upperpath.mnt->mnt_sb->s_stack_depth;
+ ofs->lower_layers[ofs->numlower].mnt = mnt;
+ ofs->lower_layers[ofs->numlower].pseudo_dev = dev;
+ ofs->numlower++;
+
+ /* Check if all lower layers are on same sb */
+ if (i == 0)
+ ofs->same_sb = mnt->mnt_sb;
+ else if (ofs->same_sb != mnt->mnt_sb)
+ ofs->same_sb = NULL;
}
+ err = 0;
+out:
+ return err;
+}
+
+static struct ovl_entry *ovl_get_lowerstack(struct super_block *sb,
+ struct ovl_fs *ofs)
+{
+ int err;
+ char *lowertmp, *lower;
+ struct path *stack = NULL;
+ unsigned int stacklen, numlower = 0, i;
+ bool remote = false;
+ struct ovl_entry *oe;
+
err = -ENOMEM;
- lowertmp = kstrdup(ufs->config.lowerdir, GFP_KERNEL);
+ lowertmp = kstrdup(ofs->config.lowerdir, GFP_KERNEL);
if (!lowertmp)
- goto out_unlock_workdentry;
+ goto out_err;
err = -EINVAL;
stacklen = ovl_split_lowerdirs(lowertmp);
if (stacklen > OVL_MAX_STACK) {
pr_err("overlayfs: too many lower directories, limit is %d\n",
OVL_MAX_STACK);
- goto out_free_lowertmp;
- } else if (!ufs->config.upperdir && stacklen == 1) {
+ goto out_err;
+ } else if (!ofs->config.upperdir && stacklen == 1) {
pr_err("overlayfs: at least 2 lowerdir are needed while upperdir nonexistent\n");
- goto out_free_lowertmp;
+ goto out_err;
}
err = -ENOMEM;
stack = kcalloc(stacklen, sizeof(struct path), GFP_KERNEL);
if (!stack)
- goto out_free_lowertmp;
+ goto out_err;
err = -EINVAL;
lower = lowertmp;
for (numlower = 0; numlower < stacklen; numlower++) {
- err = ovl_lower_dir(lower, &stack[numlower], ufs,
+ err = ovl_lower_dir(lower, &stack[numlower], ofs,
&sb->s_stack_depth, &remote);
if (err)
- goto out_put_lowerpath;
+ goto out_err;
lower = strchr(lower, '\0') + 1;
}
@@ -957,190 +1107,144 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent)
sb->s_stack_depth++;
if (sb->s_stack_depth > FILESYSTEM_MAX_STACK_DEPTH) {
pr_err("overlayfs: maximum fs stacking depth exceeded\n");
- goto out_put_lowerpath;
+ goto out_err;
}
- if (ufs->config.upperdir) {
- ufs->upper_mnt = clone_private_mount(&upperpath);
- err = PTR_ERR(ufs->upper_mnt);
- if (IS_ERR(ufs->upper_mnt)) {
- pr_err("overlayfs: failed to clone upperpath\n");
- goto out_put_lowerpath;
- }
+ err = ovl_get_lower_layers(ofs, stack, numlower);
+ if (err)
+ goto out_err;
+
+ err = -ENOMEM;
+ oe = ovl_alloc_entry(numlower);
+ if (!oe)
+ goto out_err;
+
+ for (i = 0; i < numlower; i++) {
+ oe->lowerstack[i].dentry = dget(stack[i].dentry);
+ oe->lowerstack[i].layer = &ofs->lower_layers[i];
+ }
- /* Don't inherit atime flags */
- ufs->upper_mnt->mnt_flags &= ~(MNT_NOATIME | MNT_NODIRATIME | MNT_RELATIME);
+ if (remote)
+ sb->s_d_op = &ovl_reval_dentry_operations;
+ else
+ sb->s_d_op = &ovl_dentry_operations;
- sb->s_time_gran = ufs->upper_mnt->mnt_sb->s_time_gran;
+out:
+ for (i = 0; i < numlower; i++)
+ path_put(&stack[i]);
+ kfree(stack);
+ kfree(lowertmp);
- ufs->workdir = ovl_workdir_create(sb, ufs, workpath.dentry,
- OVL_WORKDIR_NAME, false);
- /*
- * Upper should support d_type, else whiteouts are visible.
- * Given workdir and upper are on same fs, we can do
- * iterate_dir() on workdir. This check requires successful
- * 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;
-
- /*
- * We allowed this configuration and don't want to
- * break users over kernel upgrade. So warn instead
- * of erroring out.
- */
- 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");
-
- /*
- * Check if upper/work fs supports trusted.overlay.*
- * xattr
- */
- err = ovl_do_setxattr(ufs->workdir, OVL_XATTR_OPAQUE,
- "0", 1, 0);
- if (err) {
- ufs->noxattr = true;
- pr_warn("overlayfs: upper fs does not support xattr.\n");
- } else {
- vfs_removexattr(ufs->workdir, OVL_XATTR_OPAQUE);
- }
+ return oe;
- /* Check if upper/work fs supports file handles */
- if (ufs->config.index &&
- !ovl_can_decode_fh(ufs->workdir->d_sb)) {
- ufs->config.index = false;
- pr_warn("overlayfs: upper fs does not support file handles, falling back to index=off.\n");
- }
- }
- }
+out_err:
+ oe = ERR_PTR(err);
+ goto out;
+}
+
+static int ovl_fill_super(struct super_block *sb, void *data, int silent)
+{
+ struct path upperpath = { };
+ struct dentry *root_dentry;
+ struct ovl_entry *oe;
+ struct ovl_fs *ofs;
+ struct cred *cred;
+ int err;
err = -ENOMEM;
- ufs->lower_mnt = kcalloc(numlower, sizeof(struct vfsmount *), GFP_KERNEL);
- if (ufs->lower_mnt == NULL)
- goto out_put_workdir;
- for (i = 0; i < numlower; i++) {
- struct vfsmount *mnt = clone_private_mount(&stack[i]);
+ ofs = kzalloc(sizeof(struct ovl_fs), GFP_KERNEL);
+ if (!ofs)
+ goto out;
- err = PTR_ERR(mnt);
- if (IS_ERR(mnt)) {
- pr_err("overlayfs: failed to clone lowerpath\n");
- goto out_put_lower_mnt;
- }
- /*
- * Make lower_mnt R/O. That way fchmod/fchown on lower file
- * will fail instead of modifying lower fs.
- */
- mnt->mnt_flags |= MNT_READONLY | MNT_NOATIME;
+ ofs->creator_cred = cred = prepare_creds();
+ if (!cred)
+ goto out_err;
- ufs->lower_mnt[ufs->numlower] = mnt;
- ufs->numlower++;
+ ofs->config.redirect_dir = ovl_redirect_dir_def;
+ ofs->config.index = ovl_index_def;
+ err = ovl_parse_opt((char *) data, &ofs->config);
+ if (err)
+ goto out_err;
- /* Check if all lower layers are on same sb */
- if (i == 0)
- ufs->same_sb = mnt->mnt_sb;
- else if (ufs->same_sb != mnt->mnt_sb)
- ufs->same_sb = NULL;
+ err = -EINVAL;
+ if (!ofs->config.lowerdir) {
+ if (!silent)
+ pr_err("overlayfs: missing 'lowerdir'\n");
+ goto out_err;
}
- /* If the upper fs is nonexistent, we mark overlayfs r/o too */
- if (!ufs->upper_mnt)
- sb->s_flags |= MS_RDONLY;
- else if (ufs->upper_mnt->mnt_sb != ufs->same_sb)
- ufs->same_sb = NULL;
-
- if (!(ovl_force_readonly(ufs)) && ufs->config.index) {
- /* Verify lower root is upper root origin */
- err = ovl_verify_origin(upperpath.dentry, ufs->lower_mnt[0],
- stack[0].dentry, false, true);
- if (err) {
- pr_err("overlayfs: failed to verify upper root origin\n");
- goto out_put_lower_mnt;
+ sb->s_stack_depth = 0;
+ sb->s_maxbytes = MAX_LFS_FILESIZE;
+ if (ofs->config.upperdir) {
+ if (!ofs->config.workdir) {
+ pr_err("overlayfs: missing 'workdir'\n");
+ goto out_err;
}
- ufs->indexdir = ovl_workdir_create(sb, ufs, workpath.dentry,
- OVL_INDEXDIR_NAME, true);
- if (ufs->indexdir) {
- /* Verify upper root is index dir origin */
- err = ovl_verify_origin(ufs->indexdir, ufs->upper_mnt,
- upperpath.dentry, true, true);
- if (err)
- pr_err("overlayfs: failed to verify index dir origin\n");
+ err = ovl_get_upper(ofs, &upperpath);
+ if (err)
+ goto out_err;
- /* Cleanup bad/stale/orphan index entries */
- if (!err)
- err = ovl_indexdir_cleanup(ufs->indexdir,
- ufs->upper_mnt,
- stack, numlower);
- }
- if (err || !ufs->indexdir)
- pr_warn("overlayfs: try deleting index dir or mounting with '-o index=off' to disable inodes index.\n");
+ err = ovl_get_workdir(ofs, &upperpath);
if (err)
- goto out_put_indexdir;
+ goto out_err;
+
+ if (!ofs->workdir)
+ sb->s_flags |= MS_RDONLY;
+
+ sb->s_stack_depth = ofs->upper_mnt->mnt_sb->s_stack_depth;
+ sb->s_time_gran = ofs->upper_mnt->mnt_sb->s_time_gran;
+
}
+ oe = ovl_get_lowerstack(sb, ofs);
+ err = PTR_ERR(oe);
+ if (IS_ERR(oe))
+ goto out_err;
- /* Show index=off/on in /proc/mounts for any of the reasons above */
- if (!ufs->indexdir)
- ufs->config.index = false;
+ /* If the upper fs is nonexistent, we mark overlayfs r/o too */
+ if (!ofs->upper_mnt)
+ sb->s_flags |= MS_RDONLY;
+ else if (ofs->upper_mnt->mnt_sb != ofs->same_sb)
+ ofs->same_sb = NULL;
- if (remote)
- sb->s_d_op = &ovl_reval_dentry_operations;
- else
- sb->s_d_op = &ovl_dentry_operations;
+ if (!(ovl_force_readonly(ofs)) && ofs->config.index) {
+ err = ovl_get_indexdir(ofs, oe, &upperpath);
+ if (err)
+ goto out_free_oe;
- err = -ENOMEM;
- ufs->creator_cred = cred = prepare_creds();
- if (!cred)
- goto out_put_indexdir;
+ if (!ofs->indexdir)
+ sb->s_flags |= MS_RDONLY;
+ }
+
+ /* Show index=off/on in /proc/mounts for any of the reasons above */
+ if (!ofs->indexdir)
+ ofs->config.index = false;
/* 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)
- goto out_put_cred;
-
sb->s_magic = OVERLAYFS_SUPER_MAGIC;
sb->s_op = &ovl_super_operations;
sb->s_xattr = ovl_xattr_handlers;
- sb->s_fs_info = ufs;
+ sb->s_fs_info = ofs;
sb->s_flags |= MS_POSIXACL | MS_NOREMOTELOCK;
+ err = -ENOMEM;
root_dentry = d_make_root(ovl_new_inode(sb, S_IFDIR, 0));
if (!root_dentry)
goto out_free_oe;
mntput(upperpath.mnt);
- for (i = 0; i < numlower; i++)
- mntput(stack[i].mnt);
- mntput(workpath.mnt);
- kfree(lowertmp);
-
if (upperpath.dentry) {
oe->has_upper = true;
if (ovl_is_impuredir(upperpath.dentry))
ovl_set_flag(OVL_IMPURE, d_inode(root_dentry));
}
- for (i = 0; i < numlower; i++) {
- oe->lowerstack[i].dentry = stack[i].dentry;
- oe->lowerstack[i].mnt = ufs->lower_mnt[i];
- }
- kfree(stack);
root_dentry->d_fsdata = oe;
+ /* Root is always merge -> can have whiteouts */
+ ovl_set_flag(OVL_WHITEOUTS, d_inode(root_dentry));
ovl_inode_init(d_inode(root_dentry), upperpath.dentry,
ovl_dentry_lower(root_dentry));
@@ -1149,39 +1253,11 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent)
return 0;
out_free_oe:
+ ovl_entry_stack_free(oe);
kfree(oe);
-out_put_cred:
- put_cred(ufs->creator_cred);
-out_put_indexdir:
- dput(ufs->indexdir);
-out_put_lower_mnt:
- for (i = 0; i < ufs->numlower; i++)
- mntput(ufs->lower_mnt[i]);
- kfree(ufs->lower_mnt);
-out_put_workdir:
- dput(ufs->workdir);
- mntput(ufs->upper_mnt);
-out_put_lowerpath:
- for (i = 0; i < numlower; i++)
- path_put(&stack[i]);
- kfree(stack);
-out_free_lowertmp:
- kfree(lowertmp);
-out_unlock_workdentry:
- if (ufs->workdir_locked)
- ovl_inuse_unlock(workpath.dentry);
-out_put_workpath:
- path_put(&workpath);
-out_unlock_upperdentry:
- if (ufs->upperdir_locked)
- ovl_inuse_unlock(upperpath.dentry);
-out_put_upperpath:
+out_err:
path_put(&upperpath);
-out_free_config:
- kfree(ufs->config.lowerdir);
- kfree(ufs->config.upperdir);
- kfree(ufs->config.workdir);
- kfree(ufs);
+ ovl_free_fs(ofs);
out:
return err;
}