From 01573e231f18eb2d99162747186f59511f56b64d Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Fri, 08 Dec 2023 10:40:48 +0000
Subject: [PATCH] 移去rt
---
kernel/fs/overlayfs/util.c | 315 +++++++++++++++++++++++++++-------------------------
1 files changed, 165 insertions(+), 150 deletions(-)
diff --git a/kernel/fs/overlayfs/util.c b/kernel/fs/overlayfs/util.c
index 0937b07..5edb177 100644
--- a/kernel/fs/overlayfs/util.c
+++ b/kernel/fs/overlayfs/util.c
@@ -1,10 +1,7 @@
+// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2011 Novell Inc.
* Copyright (C) 2016 Red Hat, Inc.
- *
- * This program is free software; you can redistribute it and/or modify it
- * under the terms of the GNU General Public License version 2 as published by
- * the Free Software Foundation.
*/
#include <linux/fs.h>
@@ -21,13 +18,13 @@
int ovl_want_write(struct dentry *dentry)
{
struct ovl_fs *ofs = dentry->d_sb->s_fs_info;
- return mnt_want_write(ofs->upper_mnt);
+ return mnt_want_write(ovl_upper_mnt(ofs));
}
void ovl_drop_write(struct dentry *dentry)
{
struct ovl_fs *ofs = dentry->d_sb->s_fs_info;
- mnt_drop_write(ofs->upper_mnt);
+ mnt_drop_write(ovl_upper_mnt(ofs));
}
struct dentry *ovl_workdir(struct dentry *dentry)
@@ -45,28 +42,10 @@
return override_creds(ofs->creator_cred);
}
-void ovl_revert_creds(const struct cred *old_cred)
+void ovl_revert_creds(struct super_block *sb, const struct cred *old_cred)
{
if (old_cred)
revert_creds(old_cred);
-}
-
-ssize_t ovl_vfs_getxattr(struct dentry *dentry, const char *name, void *buf,
- size_t size)
-{
- return __vfs_getxattr(dentry, d_inode(dentry), name, buf, size);
-}
-
-struct super_block *ovl_same_sb(struct super_block *sb)
-{
- struct ovl_fs *ofs = sb->s_fs_info;
-
- if (!ofs->numlowerfs)
- return ofs->upper_mnt->mnt_sb;
- else if (ofs->numlowerfs == 1 && !ofs->upper_mnt)
- return ofs->lower_fs[0].sb;
- else
- return NULL;
}
/*
@@ -79,8 +58,7 @@
*/
int ovl_can_decode_fh(struct super_block *sb)
{
- if (!sb->s_export_op || !sb->s_export_op->fh_to_dentry ||
- uuid_is_null(&sb->s_uuid))
+ if (!sb->s_export_op || !sb->s_export_op->fh_to_dentry)
return 0;
return sb->s_export_op->encode_fh ? -1 : FILEID_INO32_GEN;
@@ -123,8 +101,24 @@
bool ovl_dentry_remote(struct dentry *dentry)
{
return dentry->d_flags &
- (DCACHE_OP_REVALIDATE | DCACHE_OP_WEAK_REVALIDATE |
- DCACHE_OP_REAL);
+ (DCACHE_OP_REVALIDATE | DCACHE_OP_WEAK_REVALIDATE);
+}
+
+void ovl_dentry_update_reval(struct dentry *dentry, struct dentry *upperdentry,
+ unsigned int mask)
+{
+ struct ovl_entry *oe = OVL_E(dentry);
+ unsigned int i, flags = 0;
+
+ if (upperdentry)
+ flags |= upperdentry->d_flags;
+ for (i = 0; i < oe->numlower; i++)
+ flags |= oe->lowerstack[i].dentry->d_flags;
+
+ spin_lock(&dentry->d_lock);
+ dentry->d_flags &= ~mask;
+ dentry->d_flags |= flags & mask;
+ spin_unlock(&dentry->d_lock);
}
bool ovl_dentry_weird(struct dentry *dentry)
@@ -164,7 +158,7 @@
{
struct ovl_fs *ofs = dentry->d_sb->s_fs_info;
- path->mnt = ofs->upper_mnt;
+ path->mnt = ovl_upper_mnt(ofs);
path->dentry = ovl_dentry_upper(dentry);
}
@@ -216,7 +210,7 @@
return oe->numlower ? oe->lowerstack[0].dentry : NULL;
}
-struct ovl_layer *ovl_layer_lower(struct dentry *dentry)
+const struct ovl_layer *ovl_layer_lower(struct dentry *dentry)
{
struct ovl_entry *oe = dentry->d_fsdata;
@@ -416,24 +410,6 @@
oi->redirect = redirect;
}
-void ovl_inode_init(struct inode *inode, struct dentry *upperdentry,
- struct dentry *lowerdentry, struct dentry *lowerdata)
-{
- struct inode *realinode = d_inode(upperdentry ?: lowerdentry);
-
- if (upperdentry)
- OVL_I(inode)->__upperdentry = upperdentry;
- if (lowerdentry)
- OVL_I(inode)->lower = igrab(d_inode(lowerdentry));
- if (lowerdata)
- OVL_I(inode)->lowerdata = igrab(d_inode(lowerdata));
-
- ovl_copyattr(realinode, inode);
- ovl_copyflags(realinode, inode);
- if (!inode->i_ino)
- inode->i_ino = realinode->i_ino;
-}
-
void ovl_inode_update(struct inode *inode, struct dentry *upperdentry)
{
struct inode *upperinode = d_inode(upperdentry);
@@ -446,25 +422,25 @@
smp_wmb();
OVL_I(inode)->__upperdentry = upperdentry;
if (inode_unhashed(inode)) {
- if (!inode->i_ino)
- inode->i_ino = upperinode->i_ino;
inode->i_private = upperinode;
__insert_inode_hash(inode, (unsigned long) upperinode);
}
}
-static void ovl_dentry_version_inc(struct dentry *dentry, bool impurity)
+static void ovl_dir_version_inc(struct dentry *dentry, bool impurity)
{
struct inode *inode = d_inode(dentry);
WARN_ON(!inode_is_locked(inode));
+ WARN_ON(!d_is_dir(dentry));
/*
- * Version is used by readdir code to keep cache consistent. For merge
- * dirs all changes need to be noted. For non-merge dirs, cache only
- * contains impure (ones which have been copied up and have origins)
- * entries, so only need to note changes to impure entries.
+ * Version is used by readdir code to keep cache consistent.
+ * For merge dirs (or dirs with origin) all changes need to be noted.
+ * For non-merge dirs, cache contains only impure entries (i.e. ones
+ * which have been copied up and have origins), so only need to note
+ * changes to impure entries.
*/
- if (OVL_TYPE_MERGE(ovl_path_type(dentry)) || impurity)
+ if (!ovl_dir_is_real(dentry) || impurity)
OVL_I(inode)->version++;
}
@@ -473,7 +449,7 @@
/* Copy mtime/ctime */
ovl_copyattr(d_inode(ovl_dentry_upper(dentry)), d_inode(dentry));
- ovl_dentry_version_inc(dentry, impurity);
+ ovl_dir_version_inc(dentry, impurity);
}
u64 ovl_dentry_version_get(struct dentry *dentry)
@@ -493,7 +469,32 @@
struct file *ovl_path_open(struct path *path, int flags)
{
- return dentry_open(path, flags | O_NOATIME, current_cred());
+ struct inode *inode = d_inode(path->dentry);
+ int err, acc_mode;
+
+ if (flags & ~(O_ACCMODE | O_LARGEFILE))
+ BUG();
+
+ switch (flags & O_ACCMODE) {
+ case O_RDONLY:
+ acc_mode = MAY_READ;
+ break;
+ case O_WRONLY:
+ acc_mode = MAY_WRITE;
+ break;
+ default:
+ BUG();
+ }
+
+ err = inode_permission(inode, acc_mode | MAY_OPEN);
+ if (err)
+ return ERR_PTR(err);
+
+ /* O_NOATIME is an optimization, don't fail if not permitted */
+ if (inode_owner_or_capable(inode))
+ flags |= O_NOATIME;
+
+ return dentry_open(path, flags, current_cred());
}
/* Caller should hold ovl_inode->lock */
@@ -536,13 +537,13 @@
int ovl_copy_up_start(struct dentry *dentry, int flags)
{
- struct ovl_inode *oi = OVL_I(d_inode(dentry));
+ struct inode *inode = d_inode(dentry);
int err;
- err = mutex_lock_interruptible(&oi->lock);
+ err = ovl_inode_lock_interruptible(inode);
if (!err && ovl_already_copied_up_locked(dentry, flags)) {
err = 1; /* Already copied up */
- mutex_unlock(&oi->lock);
+ ovl_inode_unlock(inode);
}
return err;
@@ -550,14 +551,14 @@
void ovl_copy_up_end(struct dentry *dentry)
{
- mutex_unlock(&OVL_I(d_inode(dentry))->lock);
+ ovl_inode_unlock(d_inode(dentry));
}
-bool ovl_check_origin_xattr(struct dentry *dentry)
+bool ovl_check_origin_xattr(struct ovl_fs *ofs, struct dentry *dentry)
{
ssize_t res;
- res = ovl_vfs_getxattr(dentry, OVL_XATTR_ORIGIN, NULL, 0);
+ res = ovl_do_getxattr(ofs, dentry, OVL_XATTR_ORIGIN, NULL, 0);
/* Zero size value means "copied up but origin unknown" */
if (res >= 0)
@@ -566,7 +567,8 @@
return false;
}
-bool ovl_check_dir_xattr(struct dentry *dentry, const char *name)
+bool ovl_check_dir_xattr(struct super_block *sb, struct dentry *dentry,
+ enum ovl_xattr ox)
{
ssize_t res;
char val;
@@ -574,15 +576,36 @@
if (!d_is_dir(dentry))
return false;
- res = ovl_vfs_getxattr(dentry, name, &val, 1);
+ res = ovl_do_getxattr(OVL_FS(sb), dentry, ox, &val, 1);
if (res == 1 && val == 'y')
return true;
return false;
}
+#define OVL_XATTR_OPAQUE_POSTFIX "opaque"
+#define OVL_XATTR_REDIRECT_POSTFIX "redirect"
+#define OVL_XATTR_ORIGIN_POSTFIX "origin"
+#define OVL_XATTR_IMPURE_POSTFIX "impure"
+#define OVL_XATTR_NLINK_POSTFIX "nlink"
+#define OVL_XATTR_UPPER_POSTFIX "upper"
+#define OVL_XATTR_METACOPY_POSTFIX "metacopy"
+
+#define OVL_XATTR_TAB_ENTRY(x) \
+ [x] = OVL_XATTR_PREFIX x ## _POSTFIX
+
+const char *ovl_xattr_table[] = {
+ OVL_XATTR_TAB_ENTRY(OVL_XATTR_OPAQUE),
+ OVL_XATTR_TAB_ENTRY(OVL_XATTR_REDIRECT),
+ OVL_XATTR_TAB_ENTRY(OVL_XATTR_ORIGIN),
+ OVL_XATTR_TAB_ENTRY(OVL_XATTR_IMPURE),
+ OVL_XATTR_TAB_ENTRY(OVL_XATTR_NLINK),
+ OVL_XATTR_TAB_ENTRY(OVL_XATTR_UPPER),
+ OVL_XATTR_TAB_ENTRY(OVL_XATTR_METACOPY),
+};
+
int ovl_check_setxattr(struct dentry *dentry, struct dentry *upperdentry,
- const char *name, const void *value, size_t size,
+ enum ovl_xattr ox, const void *value, size_t size,
int xerr)
{
int err;
@@ -591,10 +614,10 @@
if (ofs->noxattr)
return xerr;
- err = ovl_do_setxattr(upperdentry, name, value, size, 0);
+ err = ovl_do_setxattr(ofs, upperdentry, ox, value, size);
if (err == -EOPNOTSUPP) {
- pr_warn("overlayfs: cannot set %s xattr on upper\n", name);
+ pr_warn("cannot set %s xattr on upper\n", ovl_xattr(ofs, ox));
ofs->noxattr = true;
return xerr;
}
@@ -619,21 +642,6 @@
ovl_set_flag(OVL_IMPURE, d_inode(dentry));
return err;
-}
-
-void ovl_set_flag(unsigned long flag, struct inode *inode)
-{
- set_bit(flag, &OVL_I(inode)->flags);
-}
-
-void ovl_clear_flag(unsigned long flag, struct inode *inode)
-{
- clear_bit(flag, &OVL_I(inode)->flags);
-}
-
-bool ovl_test_flag(unsigned long flag, struct inode *inode)
-{
- return test_bit(flag, &OVL_I(inode)->flags);
}
/**
@@ -718,7 +726,7 @@
inode = d_inode(upperdentry);
if (!S_ISDIR(inode->i_mode) && inode->i_nlink != 1) {
- pr_warn_ratelimited("overlayfs: cleanup linked index (%pd2, ino=%lu, nlink=%u)\n",
+ pr_warn_ratelimited("cleanup linked index (%pd2, ino=%lu, nlink=%u)\n",
upperdentry, inode->i_ino, inode->i_nlink);
/*
* We either have a bug with persistent union nlink or a lower
@@ -741,7 +749,8 @@
index = NULL;
} else if (ovl_index_all(dentry->d_sb)) {
/* Whiteout orphan index to block future open by handle */
- err = ovl_cleanup_and_whiteout(indexdir, dir, index);
+ err = ovl_cleanup_and_whiteout(OVL_FS(dentry->d_sb),
+ dir, index);
} else {
/* Cleanup orphan index entries */
err = ovl_cleanup(dir, index);
@@ -757,7 +766,7 @@
return;
fail:
- pr_err("overlayfs: cleanup index of '%pd2' failed (%i)\n", dentry, err);
+ pr_err("cleanup index of '%pd2' failed (%i)\n", dentry, err);
goto out;
}
@@ -765,14 +774,14 @@
* Operations that change overlay inode and upper inode nlink need to be
* synchronized with copy up for persistent nlink accounting.
*/
-int ovl_nlink_start(struct dentry *dentry, bool *locked)
+int ovl_nlink_start(struct dentry *dentry)
{
- struct ovl_inode *oi = OVL_I(d_inode(dentry));
+ struct inode *inode = d_inode(dentry);
const struct cred *old_cred;
int err;
- if (!d_inode(dentry))
- return 0;
+ if (WARN_ON(!inode))
+ return -ENOENT;
/*
* With inodes index is enabled, we store the union overlay nlink
@@ -794,11 +803,11 @@
return err;
}
- err = mutex_lock_interruptible(&oi->lock);
+ err = ovl_inode_lock_interruptible(inode);
if (err)
return err;
- if (d_is_dir(dentry) || !ovl_test_flag(OVL_INDEX, d_inode(dentry)))
+ if (d_is_dir(dentry) || !ovl_test_flag(OVL_INDEX, inode))
goto out;
old_cred = ovl_override_creds(dentry->d_sb);
@@ -809,31 +818,28 @@
* value relative to the upper inode nlink in an upper inode xattr.
*/
err = ovl_set_nlink_upper(dentry);
- ovl_revert_creds(old_cred);
+ ovl_revert_creds(dentry->d_sb, old_cred);
out:
if (err)
- mutex_unlock(&oi->lock);
- else
- *locked = true;
+ ovl_inode_unlock(inode);
return err;
}
-void ovl_nlink_end(struct dentry *dentry, bool locked)
+void ovl_nlink_end(struct dentry *dentry)
{
- if (locked) {
- if (ovl_test_flag(OVL_INDEX, d_inode(dentry)) &&
- d_inode(dentry)->i_nlink == 0) {
- const struct cred *old_cred;
+ struct inode *inode = d_inode(dentry);
- old_cred = ovl_override_creds(dentry->d_sb);
- ovl_cleanup_index(dentry);
- ovl_revert_creds(old_cred);
- }
+ if (ovl_test_flag(OVL_INDEX, inode) && inode->i_nlink == 0) {
+ const struct cred *old_cred;
- mutex_unlock(&OVL_I(d_inode(dentry))->lock);
+ old_cred = ovl_override_creds(dentry->d_sb);
+ ovl_cleanup_index(dentry);
+ ovl_revert_creds(dentry->d_sb, old_cred);
}
+
+ ovl_inode_unlock(inode);
}
int ovl_lock_rename_workdir(struct dentry *workdir, struct dentry *upperdir)
@@ -851,12 +857,12 @@
err_unlock:
unlock_rename(workdir, upperdir);
err:
- pr_err("overlayfs: failed to lock workdir+upperdir\n");
+ pr_err("failed to lock workdir+upperdir\n");
return -EIO;
}
/* err < 0, 0 if no metacopy xattr, 1 if metacopy xattr found */
-int ovl_check_metacopy_xattr(struct dentry *dentry)
+int ovl_check_metacopy_xattr(struct ovl_fs *ofs, struct dentry *dentry)
{
ssize_t res;
@@ -864,7 +870,7 @@
if (!S_ISREG(d_inode(dentry)->i_mode))
return 0;
- res = ovl_vfs_getxattr(dentry, OVL_XATTR_METACOPY, NULL, 0);
+ res = ovl_do_getxattr(ofs, dentry, OVL_XATTR_METACOPY, NULL, 0);
if (res < 0) {
if (res == -ENODATA || res == -EOPNOTSUPP)
return 0;
@@ -873,7 +879,7 @@
return 1;
out:
- pr_warn_ratelimited("overlayfs: failed to get metacopy (%zi)\n", res);
+ pr_warn_ratelimited("failed to get metacopy (%zi)\n", res);
return res;
}
@@ -893,49 +899,27 @@
return (oe->numlower > 1);
}
-ssize_t ovl_getxattr(struct dentry *dentry, char *name, char **value,
- size_t padding)
-{
- ssize_t res;
- char *buf = NULL;
-
- res = ovl_vfs_getxattr(dentry, name, NULL, 0);
- if (res < 0) {
- if (res == -ENODATA || res == -EOPNOTSUPP)
- return -ENODATA;
- goto fail;
- }
-
- if (res != 0) {
- buf = kzalloc(res + padding, GFP_KERNEL);
- if (!buf)
- return -ENOMEM;
-
- res = ovl_vfs_getxattr(dentry, name, buf, res);
- if (res < 0)
- goto fail;
- }
- *value = buf;
-
- return res;
-
-fail:
- pr_warn_ratelimited("overlayfs: failed to get xattr %s: err=%zi)\n",
- name, res);
- kfree(buf);
- return res;
-}
-
-char *ovl_get_redirect_xattr(struct dentry *dentry, int padding)
+char *ovl_get_redirect_xattr(struct ovl_fs *ofs, struct dentry *dentry,
+ int padding)
{
int res;
char *s, *next, *buf = NULL;
- res = ovl_getxattr(dentry, OVL_XATTR_REDIRECT, &buf, padding + 1);
- if (res == -ENODATA)
+ res = ovl_do_getxattr(ofs, dentry, OVL_XATTR_REDIRECT, NULL, 0);
+ if (res == -ENODATA || res == -EOPNOTSUPP)
return NULL;
if (res < 0)
- return ERR_PTR(res);
+ goto fail;
+ if (res == 0)
+ goto invalid;
+
+ buf = kzalloc(res + padding + 1, GFP_KERNEL);
+ if (!buf)
+ return ERR_PTR(-ENOMEM);
+
+ res = ovl_do_getxattr(ofs, dentry, OVL_XATTR_REDIRECT, buf, res);
+ if (res < 0)
+ goto fail;
if (res == 0)
goto invalid;
@@ -952,8 +936,39 @@
return buf;
invalid:
- pr_warn_ratelimited("overlayfs: invalid redirect (%s)\n", buf);
+ pr_warn_ratelimited("invalid redirect (%s)\n", buf);
res = -EINVAL;
+ goto err_free;
+fail:
+ pr_warn_ratelimited("failed to get redirect (%i)\n", res);
+err_free:
kfree(buf);
return ERR_PTR(res);
}
+
+/*
+ * ovl_sync_status() - Check fs sync status for volatile mounts
+ *
+ * Returns 1 if this is not a volatile mount and a real sync is required.
+ *
+ * Returns 0 if syncing can be skipped because mount is volatile, and no errors
+ * have occurred on the upperdir since the mount.
+ *
+ * Returns -errno if it is a volatile mount, and the error that occurred since
+ * the last mount. If the error code changes, it'll return the latest error
+ * code.
+ */
+
+int ovl_sync_status(struct ovl_fs *ofs)
+{
+ struct vfsmount *mnt;
+
+ if (ovl_should_sync(ofs))
+ return 1;
+
+ mnt = ovl_upper_mnt(ofs);
+ if (!mnt)
+ return 0;
+
+ return errseq_check(&mnt->mnt_sb->s_wb_err, ofs->errseq);
+}
--
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