From 958e46acc8e900e8569dd467c1af9b8d2d019394 Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Sat, 09 Dec 2023 08:38:54 +0000
Subject: [PATCH] disable cpu isolcpus
---
kernel/fs/overlayfs/readdir.c | 209 +++++++++++++++++++++++++++++++++++-----------------
1 files changed, 140 insertions(+), 69 deletions(-)
diff --git a/kernel/fs/overlayfs/readdir.c b/kernel/fs/overlayfs/readdir.c
index 47710c1..5a35f87 100644
--- a/kernel/fs/overlayfs/readdir.c
+++ b/kernel/fs/overlayfs/readdir.c
@@ -1,10 +1,7 @@
+// SPDX-License-Identifier: GPL-2.0-only
/*
*
* Copyright (C) 2011 Novell 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>
@@ -289,7 +286,7 @@
}
inode_unlock(dir->d_inode);
}
- ovl_revert_creds(old_cred);
+ ovl_revert_creds(rdd->dentry->d_sb, old_cred);
return err;
}
@@ -300,7 +297,7 @@
struct file *realfile;
int err;
- realfile = ovl_path_open(realpath, O_RDONLY | O_DIRECTORY);
+ realfile = ovl_path_open(realpath, O_RDONLY | O_LARGEFILE);
if (IS_ERR(realfile))
return PTR_ERR(realfile);
@@ -320,18 +317,6 @@
fput(realfile);
return err;
-}
-
-/*
- * Can we iterate real dir directly?
- *
- * Non-merge dir may contain whiteouts from a time it was a merge upper, before
- * lower dir was removed under it and possibly before it was rotated from upper
- * to lower layer.
- */
-static bool ovl_dir_is_real(struct dentry *dir)
-{
- return !ovl_test_flag(OVL_WHITEOUTS, d_inode(dir));
}
static void ovl_dir_reset(struct file *file)
@@ -441,15 +426,23 @@
/* Map inode number to lower fs unique range */
static u64 ovl_remap_lower_ino(u64 ino, int xinobits, int fsid,
- const char *name, int namelen)
+ const char *name, int namelen, bool warn)
{
- if (ino >> (64 - xinobits)) {
- pr_warn_ratelimited("overlayfs: d_ino too big (%.*s, ino=%llu, xinobits=%d)\n",
- namelen, name, ino, xinobits);
+ unsigned int xinoshift = 64 - xinobits;
+
+ if (unlikely(ino >> xinoshift)) {
+ if (warn) {
+ pr_warn_ratelimited("d_ino too big (%.*s, ino=%llu, xinobits=%d)\n",
+ namelen, name, ino, xinobits);
+ }
return ino;
}
- return ino | ((u64)fsid) << (64 - xinobits);
+ /*
+ * The lowest xinobit is reserved for mapping the non-peresistent inode
+ * numbers range, but this range is only exposed via st_ino, not here.
+ */
+ return ino | ((u64)fsid) << (xinoshift + 1);
}
/*
@@ -472,7 +465,7 @@
int xinobits = ovl_xino_bits(dir->d_sb);
int err = 0;
- if (!ovl_same_sb(dir->d_sb) && !xinobits)
+ if (!ovl_same_dev(dir->d_sb))
goto out;
if (p->name[0] == '.') {
@@ -518,7 +511,8 @@
} else if (xinobits && !OVL_TYPE_UPPER(type)) {
ino = ovl_remap_lower_ino(ino, xinobits,
ovl_layer_lower(this)->fsid,
- p->name, p->len);
+ p->name, p->len,
+ ovl_xino_warn(dir->d_sb));
}
out:
@@ -527,7 +521,7 @@
return err;
fail:
- pr_warn_ratelimited("overlayfs: failed to look up (%s) for ino (%i)\n",
+ pr_warn_ratelimited("failed to look up (%s) for ino (%i)\n",
p->name, err);
goto out;
}
@@ -600,6 +594,7 @@
{
int res;
struct dentry *dentry = path->dentry;
+ struct ovl_fs *ofs = OVL_FS(dentry->d_sb);
struct ovl_dir_cache *cache;
cache = ovl_dir_cache(d_inode(dentry));
@@ -626,7 +621,7 @@
* Removing the "impure" xattr is best effort.
*/
if (!ovl_want_write(dentry)) {
- ovl_do_removexattr(ovl_dentry_upper(dentry),
+ ovl_do_removexattr(ofs, ovl_dentry_upper(dentry),
OVL_XATTR_IMPURE);
ovl_drop_write(dentry);
}
@@ -648,6 +643,7 @@
u64 parent_ino;
int fsid;
int xinobits;
+ bool xinowarn;
};
static int ovl_fill_real(struct dir_context *ctx, const char *name,
@@ -668,7 +664,7 @@
ino = p->ino;
} else if (rdt->xinobits) {
ino = ovl_remap_lower_ino(ino, rdt->xinobits, rdt->fsid,
- name, namelen);
+ name, namelen, rdt->xinowarn);
}
return orig_ctx->actor(orig_ctx, name, namelen, offset, ino, d_type);
@@ -694,11 +690,12 @@
int err;
struct ovl_dir_file *od = file->private_data;
struct dentry *dir = file->f_path.dentry;
- struct ovl_layer *lower_layer = ovl_layer_lower(dir);
+ const struct ovl_layer *lower_layer = ovl_layer_lower(dir);
struct ovl_readdir_translate rdt = {
.ctx.actor = ovl_fill_real,
.orig_ctx = ctx,
.xinobits = ovl_xino_bits(dir->d_sb),
+ .xinowarn = ovl_xino_warn(dir->d_sb),
};
if (rdt.xinobits && lower_layer)
@@ -735,8 +732,10 @@
struct ovl_dir_file *od = file->private_data;
struct dentry *dentry = file->f_path.dentry;
struct ovl_cache_entry *p;
+ const struct cred *old_cred;
int err;
+ old_cred = ovl_override_creds(dentry->d_sb);
if (!ctx->pos)
ovl_dir_reset(file);
@@ -747,20 +746,23 @@
* entries.
*/
if (ovl_xino_bits(dentry->d_sb) ||
- (ovl_same_sb(dentry->d_sb) &&
+ (ovl_same_fs(dentry->d_sb) &&
(ovl_is_impure_dir(file) ||
OVL_TYPE_MERGE(ovl_path_type(dentry->d_parent))))) {
- return ovl_iterate_real(file, ctx);
+ err = ovl_iterate_real(file, ctx);
+ } else {
+ err = iterate_dir(od->realfile, ctx);
}
- return iterate_dir(od->realfile, ctx);
+ goto out;
}
if (!od->cache) {
struct ovl_dir_cache *cache;
cache = ovl_cache_get(dentry);
+ err = PTR_ERR(cache);
if (IS_ERR(cache))
- return PTR_ERR(cache);
+ goto out;
od->cache = cache;
ovl_seek_cursor(od, ctx->pos);
@@ -772,7 +774,7 @@
if (!p->ino) {
err = ovl_cache_update_ino(&file->f_path, p);
if (err)
- return err;
+ goto out;
}
if (!dir_emit(ctx, p->name, p->len, p->ino, p->type))
break;
@@ -780,7 +782,10 @@
od->cursor = p->l_node.next;
ctx->pos++;
}
- return 0;
+ err = 0;
+out:
+ ovl_revert_creds(dentry->d_sb, old_cred);
+ return err;
}
static loff_t ovl_dir_llseek(struct file *file, loff_t offset, int origin)
@@ -823,46 +828,76 @@
return res;
}
-static int ovl_dir_fsync(struct file *file, loff_t start, loff_t end,
- int datasync)
+static struct file *ovl_dir_open_realfile(const struct file *file,
+ struct path *realpath)
{
+ struct file *res;
+ const struct cred *old_cred;
+
+ old_cred = ovl_override_creds(file_inode(file)->i_sb);
+ res = ovl_path_open(realpath, O_RDONLY | (file->f_flags & O_LARGEFILE));
+ ovl_revert_creds(file_inode(file)->i_sb, old_cred);
+
+ return res;
+}
+
+/*
+ * Like ovl_real_fdget(), returns upperfile if dir was copied up since open.
+ * Unlike ovl_real_fdget(), this caches upperfile in file->private_data.
+ *
+ * TODO: use same abstract type for file->private_data of dir and file so
+ * upperfile could also be cached for files as well.
+ */
+struct file *ovl_dir_real_file(const struct file *file, bool want_upper)
+{
+
struct ovl_dir_file *od = file->private_data;
struct dentry *dentry = file->f_path.dentry;
- struct file *realfile = od->realfile;
+ struct file *old, *realfile = od->realfile;
- /* Nothing to sync for lower */
if (!OVL_TYPE_UPPER(ovl_path_type(dentry)))
- return 0;
+ return want_upper ? NULL : realfile;
/*
* Need to check if we started out being a lower dir, but got copied up
*/
if (!od->is_upper) {
- struct inode *inode = file_inode(file);
-
realfile = READ_ONCE(od->upperfile);
if (!realfile) {
struct path upperpath;
ovl_path_upper(dentry, &upperpath);
- realfile = ovl_path_open(&upperpath, O_RDONLY);
+ realfile = ovl_dir_open_realfile(file, &upperpath);
+ if (IS_ERR(realfile))
+ return realfile;
- inode_lock(inode);
- if (!od->upperfile) {
- if (IS_ERR(realfile)) {
- inode_unlock(inode);
- return PTR_ERR(realfile);
- }
- smp_store_release(&od->upperfile, realfile);
- } else {
- /* somebody has beaten us to it */
- if (!IS_ERR(realfile))
- fput(realfile);
- realfile = od->upperfile;
+ old = cmpxchg_release(&od->upperfile, NULL, realfile);
+ if (old) {
+ fput(realfile);
+ realfile = old;
}
- inode_unlock(inode);
}
}
+
+ return realfile;
+}
+
+static int ovl_dir_fsync(struct file *file, loff_t start, loff_t end,
+ int datasync)
+{
+ struct file *realfile;
+ int err;
+
+ err = ovl_sync_status(OVL_FS(file->f_path.dentry->d_sb));
+ if (err <= 0)
+ return err;
+
+ realfile = ovl_dir_real_file(file, true);
+ err = PTR_ERR_OR_ZERO(realfile);
+
+ /* Nothing to sync for lower */
+ if (!realfile || err)
+ return err;
return vfs_fsync_range(realfile, start, end, datasync);
}
@@ -896,7 +931,7 @@
return -ENOMEM;
type = ovl_path_real(file->f_path.dentry, &realpath);
- realfile = ovl_path_open(&realpath, file->f_flags);
+ realfile = ovl_dir_open_realfile(file, &realpath);
if (IS_ERR(realfile)) {
kfree(od);
return PTR_ERR(realfile);
@@ -916,6 +951,10 @@
.llseek = ovl_dir_llseek,
.fsync = ovl_dir_fsync,
.release = ovl_dir_release,
+ .unlocked_ioctl = ovl_ioctl,
+#ifdef CONFIG_COMPAT
+ .compat_ioctl = ovl_compat_ioctl,
+#endif
};
int ovl_check_empty_dir(struct dentry *dentry, struct list_head *list)
@@ -927,7 +966,7 @@
old_cred = ovl_override_creds(dentry->d_sb);
err = ovl_dir_read_merged(dentry, list, &root);
- ovl_revert_creds(old_cred);
+ ovl_revert_creds(dentry->d_sb, old_cred);
if (err)
return err;
@@ -974,7 +1013,7 @@
dentry = lookup_one_len(p->name, upper, p->len);
if (IS_ERR(dentry)) {
- pr_err("overlayfs: lookup '%s/%.*s' failed (%i)\n",
+ pr_err("lookup '%s/%.*s' failed (%i)\n",
upper->d_name.name, p->len, p->name,
(int) PTR_ERR(dentry));
continue;
@@ -1022,7 +1061,9 @@
return rdd.d_type_supported;
}
-static void ovl_workdir_cleanup_recurse(struct path *path, int level)
+#define OVL_INCOMPATDIR_NAME "incompat"
+
+static int ovl_workdir_cleanup_recurse(struct path *path, int level)
{
int err;
struct inode *dir = path->dentry->d_inode;
@@ -1036,6 +1077,19 @@
.root = &root,
.is_lowest = false,
};
+ bool incompat = false;
+
+ /*
+ * The "work/incompat" directory is treated specially - if it is not
+ * empty, instead of printing a generic error and mounting read-only,
+ * we will error about incompat features and fail the mount.
+ *
+ * When called from ovl_indexdir_cleanup(), path->dentry->d_name.name
+ * starts with '#'.
+ */
+ if (level == 2 &&
+ !strcmp(path->dentry->d_name.name, OVL_INCOMPATDIR_NAME))
+ incompat = true;
err = ovl_dir_read(path, &rdd);
if (err)
@@ -1050,27 +1104,34 @@
continue;
if (p->len == 2 && p->name[1] == '.')
continue;
+ } else if (incompat) {
+ pr_err("overlay with incompat feature '%s' cannot be mounted\n",
+ p->name);
+ err = -EINVAL;
+ break;
}
dentry = lookup_one_len(p->name, path->dentry, p->len);
if (IS_ERR(dentry))
continue;
if (dentry->d_inode)
- ovl_workdir_cleanup(dir, path->mnt, dentry, level);
+ err = ovl_workdir_cleanup(dir, path->mnt, dentry, level);
dput(dentry);
+ if (err)
+ break;
}
inode_unlock(dir);
out:
ovl_cache_free(&list);
+ return err;
}
-void ovl_workdir_cleanup(struct inode *dir, struct vfsmount *mnt,
+int ovl_workdir_cleanup(struct inode *dir, struct vfsmount *mnt,
struct dentry *dentry, int level)
{
int err;
if (!d_is_dir(dentry) || level > 1) {
- ovl_cleanup(dir, dentry);
- return;
+ return ovl_cleanup(dir, dentry);
}
err = ovl_do_rmdir(dir, dentry);
@@ -1078,10 +1139,13 @@
struct path path = { .mnt = mnt, .dentry = dentry };
inode_unlock(dir);
- ovl_workdir_cleanup_recurse(&path, level + 1);
+ err = ovl_workdir_cleanup_recurse(&path, level + 1);
inode_lock_nested(dir, I_MUTEX_PARENT);
- ovl_cleanup(dir, dentry);
+ if (!err)
+ err = ovl_cleanup(dir, dentry);
}
+
+ return err;
}
int ovl_indexdir_cleanup(struct ovl_fs *ofs)
@@ -1090,7 +1154,7 @@
struct dentry *indexdir = ofs->indexdir;
struct dentry *index = NULL;
struct inode *dir = indexdir->d_inode;
- struct path path = { .mnt = ofs->upper_mnt, .dentry = indexdir };
+ struct path path = { .mnt = ovl_upper_mnt(ofs), .dentry = indexdir };
LIST_HEAD(list);
struct rb_root root = RB_ROOT;
struct ovl_cache_entry *p;
@@ -1120,6 +1184,13 @@
index = NULL;
break;
}
+ /* Cleanup leftover from index create/cleanup attempt */
+ if (index->d_name.name[0] == '#') {
+ err = ovl_workdir_cleanup(dir, path.mnt, index, 1);
+ if (err)
+ break;
+ goto next;
+ }
err = ovl_verify_index(ofs, index);
if (!err) {
goto next;
@@ -1138,7 +1209,7 @@
* Whiteout orphan index to block future open by
* handle after overlay nlink dropped to zero.
*/
- err = ovl_cleanup_and_whiteout(indexdir, dir, index);
+ err = ovl_cleanup_and_whiteout(ofs, dir, index);
} else {
/* Cleanup orphan index entries */
err = ovl_cleanup(dir, index);
@@ -1156,6 +1227,6 @@
out:
ovl_cache_free(&list);
if (err)
- pr_err("overlayfs: failed index dir cleanup (%i)\n", err);
+ pr_err("failed index dir cleanup (%i)\n", err);
return err;
}
--
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