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-rw-r--r--fs/btrfs/props.c473
1 files changed, 473 insertions, 0 deletions
diff --git a/fs/btrfs/props.c b/fs/btrfs/props.c
new file mode 100644
index 000000000..0755af0e5
--- /dev/null
+++ b/fs/btrfs/props.c
@@ -0,0 +1,473 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2014 Filipe David Borba Manana <fdmanana@gmail.com>
+ */
+
+#include <linux/hashtable.h>
+#include "messages.h"
+#include "props.h"
+#include "btrfs_inode.h"
+#include "transaction.h"
+#include "ctree.h"
+#include "xattr.h"
+#include "compression.h"
+#include "space-info.h"
+#include "fs.h"
+#include "accessors.h"
+#include "super.h"
+
+#define BTRFS_PROP_HANDLERS_HT_BITS 8
+static DEFINE_HASHTABLE(prop_handlers_ht, BTRFS_PROP_HANDLERS_HT_BITS);
+
+struct prop_handler {
+ struct hlist_node node;
+ const char *xattr_name;
+ int (*validate)(const struct btrfs_inode *inode, const char *value,
+ size_t len);
+ int (*apply)(struct inode *inode, const char *value, size_t len);
+ const char *(*extract)(struct inode *inode);
+ bool (*ignore)(const struct btrfs_inode *inode);
+ int inheritable;
+};
+
+static const struct hlist_head *find_prop_handlers_by_hash(const u64 hash)
+{
+ struct hlist_head *h;
+
+ h = &prop_handlers_ht[hash_min(hash, BTRFS_PROP_HANDLERS_HT_BITS)];
+ if (hlist_empty(h))
+ return NULL;
+
+ return h;
+}
+
+static const struct prop_handler *
+find_prop_handler(const char *name,
+ const struct hlist_head *handlers)
+{
+ struct prop_handler *h;
+
+ if (!handlers) {
+ u64 hash = btrfs_name_hash(name, strlen(name));
+
+ handlers = find_prop_handlers_by_hash(hash);
+ if (!handlers)
+ return NULL;
+ }
+
+ hlist_for_each_entry(h, handlers, node)
+ if (!strcmp(h->xattr_name, name))
+ return h;
+
+ return NULL;
+}
+
+int btrfs_validate_prop(const struct btrfs_inode *inode, const char *name,
+ const char *value, size_t value_len)
+{
+ const struct prop_handler *handler;
+
+ if (strlen(name) <= XATTR_BTRFS_PREFIX_LEN)
+ return -EINVAL;
+
+ handler = find_prop_handler(name, NULL);
+ if (!handler)
+ return -EINVAL;
+
+ if (value_len == 0)
+ return 0;
+
+ return handler->validate(inode, value, value_len);
+}
+
+/*
+ * Check if a property should be ignored (not set) for an inode.
+ *
+ * @inode: The target inode.
+ * @name: The property's name.
+ *
+ * The caller must be sure the given property name is valid, for example by
+ * having previously called btrfs_validate_prop().
+ *
+ * Returns: true if the property should be ignored for the given inode
+ * false if the property must not be ignored for the given inode
+ */
+bool btrfs_ignore_prop(const struct btrfs_inode *inode, const char *name)
+{
+ const struct prop_handler *handler;
+
+ handler = find_prop_handler(name, NULL);
+ ASSERT(handler != NULL);
+
+ return handler->ignore(inode);
+}
+
+int btrfs_set_prop(struct btrfs_trans_handle *trans, struct inode *inode,
+ const char *name, const char *value, size_t value_len,
+ int flags)
+{
+ const struct prop_handler *handler;
+ int ret;
+
+ handler = find_prop_handler(name, NULL);
+ if (!handler)
+ return -EINVAL;
+
+ if (value_len == 0) {
+ ret = btrfs_setxattr(trans, inode, handler->xattr_name,
+ NULL, 0, flags);
+ if (ret)
+ return ret;
+
+ ret = handler->apply(inode, NULL, 0);
+ ASSERT(ret == 0);
+
+ return ret;
+ }
+
+ ret = btrfs_setxattr(trans, inode, handler->xattr_name, value,
+ value_len, flags);
+ if (ret)
+ return ret;
+ ret = handler->apply(inode, value, value_len);
+ if (ret) {
+ btrfs_setxattr(trans, inode, handler->xattr_name, NULL,
+ 0, flags);
+ return ret;
+ }
+
+ set_bit(BTRFS_INODE_HAS_PROPS, &BTRFS_I(inode)->runtime_flags);
+
+ return 0;
+}
+
+static int iterate_object_props(struct btrfs_root *root,
+ struct btrfs_path *path,
+ u64 objectid,
+ void (*iterator)(void *,
+ const struct prop_handler *,
+ const char *,
+ size_t),
+ void *ctx)
+{
+ int ret;
+ char *name_buf = NULL;
+ char *value_buf = NULL;
+ int name_buf_len = 0;
+ int value_buf_len = 0;
+
+ while (1) {
+ struct btrfs_key key;
+ struct btrfs_dir_item *di;
+ struct extent_buffer *leaf;
+ u32 total_len, cur, this_len;
+ int slot;
+ const struct hlist_head *handlers;
+
+ slot = path->slots[0];
+ leaf = path->nodes[0];
+
+ if (slot >= btrfs_header_nritems(leaf)) {
+ ret = btrfs_next_leaf(root, path);
+ if (ret < 0)
+ goto out;
+ else if (ret > 0)
+ break;
+ continue;
+ }
+
+ btrfs_item_key_to_cpu(leaf, &key, slot);
+ if (key.objectid != objectid)
+ break;
+ if (key.type != BTRFS_XATTR_ITEM_KEY)
+ break;
+
+ handlers = find_prop_handlers_by_hash(key.offset);
+ if (!handlers)
+ goto next_slot;
+
+ di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
+ cur = 0;
+ total_len = btrfs_item_size(leaf, slot);
+
+ while (cur < total_len) {
+ u32 name_len = btrfs_dir_name_len(leaf, di);
+ u32 data_len = btrfs_dir_data_len(leaf, di);
+ unsigned long name_ptr, data_ptr;
+ const struct prop_handler *handler;
+
+ this_len = sizeof(*di) + name_len + data_len;
+ name_ptr = (unsigned long)(di + 1);
+ data_ptr = name_ptr + name_len;
+
+ if (name_len <= XATTR_BTRFS_PREFIX_LEN ||
+ memcmp_extent_buffer(leaf, XATTR_BTRFS_PREFIX,
+ name_ptr,
+ XATTR_BTRFS_PREFIX_LEN))
+ goto next_dir_item;
+
+ if (name_len >= name_buf_len) {
+ kfree(name_buf);
+ name_buf_len = name_len + 1;
+ name_buf = kmalloc(name_buf_len, GFP_NOFS);
+ if (!name_buf) {
+ ret = -ENOMEM;
+ goto out;
+ }
+ }
+ read_extent_buffer(leaf, name_buf, name_ptr, name_len);
+ name_buf[name_len] = '\0';
+
+ handler = find_prop_handler(name_buf, handlers);
+ if (!handler)
+ goto next_dir_item;
+
+ if (data_len > value_buf_len) {
+ kfree(value_buf);
+ value_buf_len = data_len;
+ value_buf = kmalloc(data_len, GFP_NOFS);
+ if (!value_buf) {
+ ret = -ENOMEM;
+ goto out;
+ }
+ }
+ read_extent_buffer(leaf, value_buf, data_ptr, data_len);
+
+ iterator(ctx, handler, value_buf, data_len);
+next_dir_item:
+ cur += this_len;
+ di = (struct btrfs_dir_item *)((char *) di + this_len);
+ }
+
+next_slot:
+ path->slots[0]++;
+ }
+
+ ret = 0;
+out:
+ btrfs_release_path(path);
+ kfree(name_buf);
+ kfree(value_buf);
+
+ return ret;
+}
+
+static void inode_prop_iterator(void *ctx,
+ const struct prop_handler *handler,
+ const char *value,
+ size_t len)
+{
+ struct inode *inode = ctx;
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ int ret;
+
+ ret = handler->apply(inode, value, len);
+ if (unlikely(ret))
+ btrfs_warn(root->fs_info,
+ "error applying prop %s to ino %llu (root %llu): %d",
+ handler->xattr_name, btrfs_ino(BTRFS_I(inode)),
+ root->root_key.objectid, ret);
+ else
+ set_bit(BTRFS_INODE_HAS_PROPS, &BTRFS_I(inode)->runtime_flags);
+}
+
+int btrfs_load_inode_props(struct inode *inode, struct btrfs_path *path)
+{
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ u64 ino = btrfs_ino(BTRFS_I(inode));
+
+ return iterate_object_props(root, path, ino, inode_prop_iterator, inode);
+}
+
+static int prop_compression_validate(const struct btrfs_inode *inode,
+ const char *value, size_t len)
+{
+ if (!btrfs_inode_can_compress(inode))
+ return -EINVAL;
+
+ if (!value)
+ return 0;
+
+ if (btrfs_compress_is_valid_type(value, len))
+ return 0;
+
+ if ((len == 2 && strncmp("no", value, 2) == 0) ||
+ (len == 4 && strncmp("none", value, 4) == 0))
+ return 0;
+
+ return -EINVAL;
+}
+
+static int prop_compression_apply(struct inode *inode, const char *value,
+ size_t len)
+{
+ struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
+ int type;
+
+ /* Reset to defaults */
+ if (len == 0) {
+ BTRFS_I(inode)->flags &= ~BTRFS_INODE_COMPRESS;
+ BTRFS_I(inode)->flags &= ~BTRFS_INODE_NOCOMPRESS;
+ BTRFS_I(inode)->prop_compress = BTRFS_COMPRESS_NONE;
+ return 0;
+ }
+
+ /* Set NOCOMPRESS flag */
+ if ((len == 2 && strncmp("no", value, 2) == 0) ||
+ (len == 4 && strncmp("none", value, 4) == 0)) {
+ BTRFS_I(inode)->flags |= BTRFS_INODE_NOCOMPRESS;
+ BTRFS_I(inode)->flags &= ~BTRFS_INODE_COMPRESS;
+ BTRFS_I(inode)->prop_compress = BTRFS_COMPRESS_NONE;
+
+ return 0;
+ }
+
+ if (!strncmp("lzo", value, 3)) {
+ type = BTRFS_COMPRESS_LZO;
+ btrfs_set_fs_incompat(fs_info, COMPRESS_LZO);
+ } else if (!strncmp("zlib", value, 4)) {
+ type = BTRFS_COMPRESS_ZLIB;
+ } else if (!strncmp("zstd", value, 4)) {
+ type = BTRFS_COMPRESS_ZSTD;
+ btrfs_set_fs_incompat(fs_info, COMPRESS_ZSTD);
+ } else {
+ return -EINVAL;
+ }
+
+ BTRFS_I(inode)->flags &= ~BTRFS_INODE_NOCOMPRESS;
+ BTRFS_I(inode)->flags |= BTRFS_INODE_COMPRESS;
+ BTRFS_I(inode)->prop_compress = type;
+
+ return 0;
+}
+
+static bool prop_compression_ignore(const struct btrfs_inode *inode)
+{
+ /*
+ * Compression only has effect for regular files, and for directories
+ * we set it just to propagate it to new files created inside them.
+ * Everything else (symlinks, devices, sockets, fifos) is pointless as
+ * it will do nothing, so don't waste metadata space on a compression
+ * xattr for anything that is neither a file nor a directory.
+ */
+ if (!S_ISREG(inode->vfs_inode.i_mode) &&
+ !S_ISDIR(inode->vfs_inode.i_mode))
+ return true;
+
+ return false;
+}
+
+static const char *prop_compression_extract(struct inode *inode)
+{
+ switch (BTRFS_I(inode)->prop_compress) {
+ case BTRFS_COMPRESS_ZLIB:
+ case BTRFS_COMPRESS_LZO:
+ case BTRFS_COMPRESS_ZSTD:
+ return btrfs_compress_type2str(BTRFS_I(inode)->prop_compress);
+ default:
+ break;
+ }
+
+ return NULL;
+}
+
+static struct prop_handler prop_handlers[] = {
+ {
+ .xattr_name = XATTR_BTRFS_PREFIX "compression",
+ .validate = prop_compression_validate,
+ .apply = prop_compression_apply,
+ .extract = prop_compression_extract,
+ .ignore = prop_compression_ignore,
+ .inheritable = 1
+ },
+};
+
+int btrfs_inode_inherit_props(struct btrfs_trans_handle *trans,
+ struct inode *inode, struct inode *parent)
+{
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ struct btrfs_fs_info *fs_info = root->fs_info;
+ int ret;
+ int i;
+ bool need_reserve = false;
+
+ if (!test_bit(BTRFS_INODE_HAS_PROPS,
+ &BTRFS_I(parent)->runtime_flags))
+ return 0;
+
+ for (i = 0; i < ARRAY_SIZE(prop_handlers); i++) {
+ const struct prop_handler *h = &prop_handlers[i];
+ const char *value;
+ u64 num_bytes = 0;
+
+ if (!h->inheritable)
+ continue;
+
+ if (h->ignore(BTRFS_I(inode)))
+ continue;
+
+ value = h->extract(parent);
+ if (!value)
+ continue;
+
+ /*
+ * This is not strictly necessary as the property should be
+ * valid, but in case it isn't, don't propagate it further.
+ */
+ ret = h->validate(BTRFS_I(inode), value, strlen(value));
+ if (ret)
+ continue;
+
+ /*
+ * Currently callers should be reserving 1 item for properties,
+ * since we only have 1 property that we currently support. If
+ * we add more in the future we need to try and reserve more
+ * space for them. But we should also revisit how we do space
+ * reservations if we do add more properties in the future.
+ */
+ if (need_reserve) {
+ num_bytes = btrfs_calc_insert_metadata_size(fs_info, 1);
+ ret = btrfs_block_rsv_add(fs_info, trans->block_rsv,
+ num_bytes,
+ BTRFS_RESERVE_NO_FLUSH);
+ if (ret)
+ return ret;
+ }
+
+ ret = btrfs_setxattr(trans, inode, h->xattr_name, value,
+ strlen(value), 0);
+ if (!ret) {
+ ret = h->apply(inode, value, strlen(value));
+ if (ret)
+ btrfs_setxattr(trans, inode, h->xattr_name,
+ NULL, 0, 0);
+ else
+ set_bit(BTRFS_INODE_HAS_PROPS,
+ &BTRFS_I(inode)->runtime_flags);
+ }
+
+ if (need_reserve) {
+ btrfs_block_rsv_release(fs_info, trans->block_rsv,
+ num_bytes, NULL);
+ if (ret)
+ return ret;
+ }
+ need_reserve = true;
+ }
+
+ return 0;
+}
+
+int __init btrfs_props_init(void)
+{
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(prop_handlers); i++) {
+ struct prop_handler *p = &prop_handlers[i];
+ u64 h = btrfs_name_hash(p->xattr_name, strlen(p->xattr_name));
+
+ hash_add(prop_handlers_ht, &p->node, h);
+ }
+ return 0;
+}
+
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