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Merge branch 'overlayfs-next' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs into for-next

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This commit is contained in:
Al Viro
2015-02-20 04:58:52 -05:00
parent a95104fd33 4330397e4e
commit ce7b9facdf
7 changed files with 537 additions and 339 deletions
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fs/overlayfs/copy_up.c
+2 -3
View File
@@ -191,7 +191,6 @@ int ovl_set_attr(struct dentry *upperdentry, struct kstat *stat)
ovl_set_timestamps(upperdentry, stat);
return err;
}
static int ovl_copy_up_locked(struct dentry *workdir, struct dentry *upperdir,
@@ -385,7 +384,7 @@ int ovl_copy_up(struct dentry *dentry)
struct kstat stat;
enum ovl_path_type type = ovl_path_type(dentry);
if (type != OVL_PATH_LOWER)
if (OVL_TYPE_UPPER(type))
break;
next = dget(dentry);
@@ -394,7 +393,7 @@ int ovl_copy_up(struct dentry *dentry)
parent = dget_parent(next);
type = ovl_path_type(parent);
if (type != OVL_PATH_LOWER)
if (OVL_TYPE_UPPER(type))
break;
dput(next);
fs/overlayfs/dir.c
+14 -14
View File
@@ -118,14 +118,14 @@ int ovl_create_real(struct inode *dir, struct dentry *newdentry,
static int ovl_set_opaque(struct dentry *upperdentry)
{
return ovl_do_setxattr(upperdentry, ovl_opaque_xattr, "y", 1, 0);
return ovl_do_setxattr(upperdentry, OVL_XATTR_OPAQUE, "y", 1, 0);
}
static void ovl_remove_opaque(struct dentry *upperdentry)
{
int err;
err = ovl_do_removexattr(upperdentry, ovl_opaque_xattr);
err = ovl_do_removexattr(upperdentry, OVL_XATTR_OPAQUE);
if (err) {
pr_warn("overlayfs: failed to remove opaque from '%s' (%i)\n",
upperdentry->d_name.name, err);
@@ -152,7 +152,7 @@ static int ovl_dir_getattr(struct vfsmount *mnt, struct dentry *dentry,
* correct link count. nlink=1 seems to pacify 'find' and
* other utilities.
*/
if (type == OVL_PATH_MERGE)
if (OVL_TYPE_MERGE(type))
stat->nlink = 1;
return 0;
@@ -506,7 +506,7 @@ static int ovl_remove_and_whiteout(struct dentry *dentry, bool is_dir)
struct dentry *opaquedir = NULL;
int err;
if (is_dir) {
if (is_dir && OVL_TYPE_MERGE_OR_LOWER(ovl_path_type(dentry))) {
opaquedir = ovl_check_empty_and_clear(dentry);
err = PTR_ERR(opaquedir);
if (IS_ERR(opaquedir))
@@ -630,7 +630,7 @@ static int ovl_do_remove(struct dentry *dentry, bool is_dir)
goto out_drop_write;
type = ovl_path_type(dentry);
if (type == OVL_PATH_PURE_UPPER) {
if (OVL_TYPE_PURE_UPPER(type)) {
err = ovl_remove_upper(dentry, is_dir);
} else {
const struct cred *old_cred;
@@ -712,7 +712,7 @@ static int ovl_rename2(struct inode *olddir, struct dentry *old,
/* Don't copy up directory trees */
old_type = ovl_path_type(old);
err = -EXDEV;
if ((old_type == OVL_PATH_LOWER || old_type == OVL_PATH_MERGE) && is_dir)
if (OVL_TYPE_MERGE_OR_LOWER(old_type) && is_dir)
goto out;
if (new->d_inode) {
@@ -725,25 +725,25 @@ static int ovl_rename2(struct inode *olddir, struct dentry *old,
new_type = ovl_path_type(new);
err = -EXDEV;
if (!overwrite && (new_type == OVL_PATH_LOWER || new_type == OVL_PATH_MERGE) && new_is_dir)
if (!overwrite && OVL_TYPE_MERGE_OR_LOWER(new_type) && new_is_dir)
goto out;
err = 0;
if (new_type == OVL_PATH_LOWER && old_type == OVL_PATH_LOWER) {
if (!OVL_TYPE_UPPER(new_type) && !OVL_TYPE_UPPER(old_type)) {
if (ovl_dentry_lower(old)->d_inode ==
ovl_dentry_lower(new)->d_inode)
goto out;
}
if (new_type != OVL_PATH_LOWER && old_type != OVL_PATH_LOWER) {
if (OVL_TYPE_UPPER(new_type) && OVL_TYPE_UPPER(old_type)) {
if (ovl_dentry_upper(old)->d_inode ==
ovl_dentry_upper(new)->d_inode)
goto out;
}
} else {
if (ovl_dentry_is_opaque(new))
new_type = OVL_PATH_UPPER;
new_type = __OVL_PATH_UPPER;
else
new_type = OVL_PATH_PURE_UPPER;
new_type = __OVL_PATH_UPPER | __OVL_PATH_PURE;
}
err = ovl_want_write(old);
@@ -763,8 +763,8 @@ static int ovl_rename2(struct inode *olddir, struct dentry *old,
goto out_drop_write;
}
old_opaque = old_type != OVL_PATH_PURE_UPPER;
new_opaque = new_type != OVL_PATH_PURE_UPPER;
old_opaque = !OVL_TYPE_PURE_UPPER(old_type);
new_opaque = !OVL_TYPE_PURE_UPPER(new_type);
if (old_opaque || new_opaque) {
err = -ENOMEM;
@@ -787,7 +787,7 @@ static int ovl_rename2(struct inode *olddir, struct dentry *old,
old_cred = override_creds(override_cred);
}
if (overwrite && (new_type == OVL_PATH_LOWER || new_type == OVL_PATH_MERGE) && new_is_dir) {
if (overwrite && OVL_TYPE_MERGE_OR_LOWER(new_type) && new_is_dir) {
opaquedir = ovl_check_empty_and_clear(new);
err = PTR_ERR(opaquedir);
if (IS_ERR(opaquedir)) {
fs/overlayfs/inode.c
+7 -5
View File
@@ -205,7 +205,7 @@ static int ovl_readlink(struct dentry *dentry, char __user *buf, int bufsiz)
static bool ovl_is_private_xattr(const char *name)
{
return strncmp(name, "trusted.overlay.", 14) == 0;
return strncmp(name, OVL_XATTR_PRE_NAME, OVL_XATTR_PRE_LEN) == 0;
}
int ovl_setxattr(struct dentry *dentry, const char *name,
@@ -238,7 +238,10 @@ out:
static bool ovl_need_xattr_filter(struct dentry *dentry,
enum ovl_path_type type)
{
return type == OVL_PATH_UPPER && S_ISDIR(dentry->d_inode->i_mode);
if ((type & (__OVL_PATH_PURE | __OVL_PATH_UPPER)) == __OVL_PATH_UPPER)
return S_ISDIR(dentry->d_inode->i_mode);
else
return false;
}
ssize_t ovl_getxattr(struct dentry *dentry, const char *name,
@@ -299,7 +302,7 @@ int ovl_removexattr(struct dentry *dentry, const char *name)
if (ovl_need_xattr_filter(dentry, type) && ovl_is_private_xattr(name))
goto out_drop_write;
if (type == OVL_PATH_LOWER) {
if (!OVL_TYPE_UPPER(type)) {
err = vfs_getxattr(realpath.dentry, name, NULL, 0);
if (err < 0)
goto out_drop_write;
@@ -321,7 +324,7 @@ out:
static bool ovl_open_need_copy_up(int flags, enum ovl_path_type type,
struct dentry *realdentry)
{
if (type != OVL_PATH_LOWER)
if (OVL_TYPE_UPPER(type))
return false;
if (special_file(realdentry->d_inode->i_mode))
@@ -430,5 +433,4 @@ struct inode *ovl_new_inode(struct super_block *sb, umode_t mode,
}
return inode;
}
fs/overlayfs/overlayfs.h
+13 -5
View File
@@ -12,13 +12,20 @@
struct ovl_entry;
enum ovl_path_type {
OVL_PATH_PURE_UPPER,
OVL_PATH_UPPER,
OVL_PATH_MERGE,
OVL_PATH_LOWER,
__OVL_PATH_PURE = (1 << 0),
__OVL_PATH_UPPER = (1 << 1),
__OVL_PATH_MERGE = (1 << 2),
};
extern const char *ovl_opaque_xattr;
#define OVL_TYPE_UPPER(type) ((type) & __OVL_PATH_UPPER)
#define OVL_TYPE_MERGE(type) ((type) & __OVL_PATH_MERGE)
#define OVL_TYPE_PURE_UPPER(type) ((type) & __OVL_PATH_PURE)
#define OVL_TYPE_MERGE_OR_LOWER(type) \
(OVL_TYPE_MERGE(type) || !OVL_TYPE_UPPER(type))
#define OVL_XATTR_PRE_NAME "trusted.overlay."
#define OVL_XATTR_PRE_LEN 16
#define OVL_XATTR_OPAQUE OVL_XATTR_PRE_NAME"opaque"
static inline int ovl_do_rmdir(struct inode *dir, struct dentry *dentry)
{
@@ -130,6 +137,7 @@ void ovl_dentry_version_inc(struct dentry *dentry);
void ovl_path_upper(struct dentry *dentry, struct path *path);
void ovl_path_lower(struct dentry *dentry, struct path *path);
enum ovl_path_type ovl_path_real(struct dentry *dentry, struct path *path);
int ovl_path_next(int idx, struct dentry *dentry, struct path *path);
struct dentry *ovl_dentry_upper(struct dentry *dentry);
struct dentry *ovl_dentry_lower(struct dentry *dentry);
struct dentry *ovl_dentry_real(struct dentry *dentry);
fs/overlayfs/readdir.c
+75 -106
View File
@@ -24,7 +24,6 @@ struct ovl_cache_entry {
struct list_head l_node;
struct rb_node node;
bool is_whiteout;
bool is_cursor;
char name[];
};
@@ -40,6 +39,7 @@ struct ovl_readdir_data {
struct rb_root root;
struct list_head *list;
struct list_head middle;
struct dentry *dir;
int count;
int err;
};
@@ -48,7 +48,7 @@ struct ovl_dir_file {
bool is_real;
bool is_upper;
struct ovl_dir_cache *cache;
struct ovl_cache_entry cursor;
struct list_head *cursor;
struct file *realfile;
struct file *upperfile;
};
@@ -79,23 +79,49 @@ static struct ovl_cache_entry *ovl_cache_entry_find(struct rb_root *root,
return NULL;
}
static struct ovl_cache_entry *ovl_cache_entry_new(const char *name, int len,
static struct ovl_cache_entry *ovl_cache_entry_new(struct dentry *dir,
const char *name, int len,
u64 ino, unsigned int d_type)
{
struct ovl_cache_entry *p;
size_t size = offsetof(struct ovl_cache_entry, name[len + 1]);
p = kmalloc(size, GFP_KERNEL);
if (p) {
memcpy(p->name, name, len);
p->name[len] = '\0';
p->len = len;
p->type = d_type;
p->ino = ino;
p->is_whiteout = false;
p->is_cursor = false;
}
if (!p)
return NULL;
memcpy(p->name, name, len);
p->name[len] = '\0';
p->len = len;
p->type = d_type;
p->ino = ino;
p->is_whiteout = false;
if (d_type == DT_CHR) {
struct dentry *dentry;
const struct cred *old_cred;
struct cred *override_cred;
override_cred = prepare_creds();
if (!override_cred) {
kfree(p);
return NULL;
}
/*
* CAP_DAC_OVERRIDE for lookup
*/
cap_raise(override_cred->cap_effective, CAP_DAC_OVERRIDE);
old_cred = override_creds(override_cred);
dentry = lookup_one_len(name, dir, len);
if (!IS_ERR(dentry)) {
p->is_whiteout = ovl_is_whiteout(dentry);
dput(dentry);
}
revert_creds(old_cred);
put_cred(override_cred);
}
return p;
}
@@ -122,7 +148,7 @@ static int ovl_cache_entry_add_rb(struct ovl_readdir_data *rdd,
return 0;
}
p = ovl_cache_entry_new(name, len, ino, d_type);
p = ovl_cache_entry_new(rdd->dir, name, len, ino, d_type);
if (p == NULL)
return -ENOMEM;
@@ -143,7 +169,7 @@ static int ovl_fill_lower(struct ovl_readdir_data *rdd,
if (p) {
list_move_tail(&p->l_node, &rdd->middle);
} else {
p = ovl_cache_entry_new(name, namelen, ino, d_type);
p = ovl_cache_entry_new(rdd->dir, name, namelen, ino, d_type);
if (p == NULL)
rdd->err = -ENOMEM;
else
@@ -168,7 +194,6 @@ static void ovl_cache_put(struct ovl_dir_file *od, struct dentry *dentry)
{
struct ovl_dir_cache *cache = od->cache;
list_del_init(&od->cursor.l_node);
WARN_ON(cache->refcount <= 0);
cache->refcount--;
if (!cache->refcount) {
@@ -204,6 +229,7 @@ static inline int ovl_dir_read(struct path *realpath,
if (IS_ERR(realfile))
return PTR_ERR(realfile);
rdd->dir = realpath->dentry;
rdd->ctx.pos = 0;
do {
rdd->count = 0;
@@ -227,108 +253,58 @@ static void ovl_dir_reset(struct file *file)
if (cache && ovl_dentry_version_get(dentry) != cache->version) {
ovl_cache_put(od, dentry);
od->cache = NULL;
od->cursor = NULL;
}
WARN_ON(!od->is_real && type != OVL_PATH_MERGE);
if (od->is_real && type == OVL_PATH_MERGE)
WARN_ON(!od->is_real && !OVL_TYPE_MERGE(type));
if (od->is_real && OVL_TYPE_MERGE(type))
od->is_real = false;
}
static int ovl_dir_mark_whiteouts(struct dentry *dir,
struct ovl_readdir_data *rdd)
{
struct ovl_cache_entry *p;
struct dentry *dentry;
const struct cred *old_cred;
struct cred *override_cred;
override_cred = prepare_creds();
if (!override_cred) {
ovl_cache_free(rdd->list);
return -ENOMEM;
}
/*
* CAP_DAC_OVERRIDE for lookup
*/
cap_raise(override_cred->cap_effective, CAP_DAC_OVERRIDE);
old_cred = override_creds(override_cred);
mutex_lock(&dir->d_inode->i_mutex);
list_for_each_entry(p, rdd->list, l_node) {
if (p->is_cursor)
continue;
if (p->type != DT_CHR)
continue;
dentry = lookup_one_len(p->name, dir, p->len);
if (IS_ERR(dentry))
continue;
p->is_whiteout = ovl_is_whiteout(dentry);
dput(dentry);
}
mutex_unlock(&dir->d_inode->i_mutex);
revert_creds(old_cred);
put_cred(override_cred);
return 0;
}
static int ovl_dir_read_merged(struct dentry *dentry, struct list_head *list)
{
int err;
struct path lowerpath;
struct path upperpath;
struct path realpath;
struct ovl_readdir_data rdd = {
.ctx.actor = ovl_fill_merge,
.list = list,
.root = RB_ROOT,
.is_merge = false,
};
int idx, next;
ovl_path_lower(dentry, &lowerpath);
ovl_path_upper(dentry, &upperpath);
for (idx = 0; idx != -1; idx = next) {
next = ovl_path_next(idx, dentry, &realpath);
if (upperpath.dentry) {
err = ovl_dir_read(&upperpath, &rdd);
if (err)
goto out;
if (lowerpath.dentry) {
err = ovl_dir_mark_whiteouts(upperpath.dentry, &rdd);
if (next != -1) {
err = ovl_dir_read(&realpath, &rdd);
if (err)
goto out;
break;
} else {
/*
* Insert lowest layer entries before upper ones, this
* allows offsets to be reasonably constant
*/
list_add(&rdd.middle, rdd.list);
rdd.is_merge = true;
err = ovl_dir_read(&realpath, &rdd);
list_del(&rdd.middle);
}
}
if (lowerpath.dentry) {
/*
* Insert lowerpath entries before upperpath ones, this allows
* offsets to be reasonably constant
*/
list_add(&rdd.middle, rdd.list);
rdd.is_merge = true;
err = ovl_dir_read(&lowerpath, &rdd);
list_del(&rdd.middle);
}
out:
return err;
}
static void ovl_seek_cursor(struct ovl_dir_file *od, loff_t pos)
{
struct ovl_cache_entry *p;
struct list_head *p;
loff_t off = 0;
list_for_each_entry(p, &od->cache->entries, l_node) {
if (p->is_cursor)
continue;
list_for_each(p, &od->cache->entries) {
if (off >= pos)
break;
off++;
}
list_move_tail(&od->cursor.l_node, &p->l_node);
/* Cursor is safe since the cache is stable */
od->cursor = p;
}
static struct ovl_dir_cache *ovl_cache_get(struct dentry *dentry)
@@ -367,6 +343,7 @@ static int ovl_iterate(struct file *file, struct dir_context *ctx)
{
struct ovl_dir_file *od = file->private_data;
struct dentry *dentry = file->f_path.dentry;
struct ovl_cache_entry *p;
if (!ctx->pos)
ovl_dir_reset(file);
@@ -385,19 +362,13 @@ static int ovl_iterate(struct file *file, struct dir_context *ctx)
ovl_seek_cursor(od, ctx->pos);
}
while (od->cursor.l_node.next != &od->cache->entries) {
struct ovl_cache_entry *p;
p = list_entry(od->cursor.l_node.next, struct ovl_cache_entry, l_node);
/* Skip cursors */
if (!p->is_cursor) {
if (!p->is_whiteout) {
if (!dir_emit(ctx, p->name, p->len, p->ino, p->type))
break;
}
ctx->pos++;
}
list_move(&od->cursor.l_node, &p->l_node);
while (od->cursor != &od->cache->entries) {
p = list_entry(od->cursor, struct ovl_cache_entry, l_node);
if (!p->is_whiteout)
if (!dir_emit(ctx, p->name, p->len, p->ino, p->type))
break;
od->cursor = p->l_node.next;
ctx->pos++;
}
return 0;
}
@@ -452,7 +423,7 @@ static int ovl_dir_fsync(struct file *file, loff_t start, loff_t end,
/*
* Need to check if we started out being a lower dir, but got copied up
*/
if (!od->is_upper && ovl_path_type(dentry) != OVL_PATH_LOWER) {
if (!od->is_upper && OVL_TYPE_UPPER(ovl_path_type(dentry))) {
struct inode *inode = file_inode(file);
realfile = lockless_dereference(od->upperfile);
@@ -516,11 +487,9 @@ static int ovl_dir_open(struct inode *inode, struct file *file)
kfree(od);
return PTR_ERR(realfile);
}
INIT_LIST_HEAD(&od->cursor.l_node);
od->realfile = realfile;
od->is_real = (type != OVL_PATH_MERGE);
od->is_upper = (type != OVL_PATH_LOWER);
od->cursor.is_cursor = true;
od->is_real = !OVL_TYPE_MERGE(type);
od->is_upper = OVL_TYPE_UPPER(type);
file->private_data = od;
return 0;
fs/overlayfs/super.c
+398 -206
View File
File diff suppressed because it is too large Load Diff