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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
commitace9429bb58fd418f0c81d4c2835699bddf6bde6 (patch)
treeb2d64bc10158fdd5497876388cd68142ca374ed3 /fs/erofs/xattr.c
parentInitial commit. (diff)
downloadlinux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.tar.xz
linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.zip
Adding upstream version 6.6.15.upstream/6.6.15
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'fs/erofs/xattr.c')
-rw-r--r--fs/erofs/xattr.c560
1 files changed, 560 insertions, 0 deletions
diff --git a/fs/erofs/xattr.c b/fs/erofs/xattr.c
new file mode 100644
index 0000000000..09d341675e
--- /dev/null
+++ b/fs/erofs/xattr.c
@@ -0,0 +1,560 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2017-2018 HUAWEI, Inc.
+ * https://www.huawei.com/
+ * Copyright (C) 2021-2022, Alibaba Cloud
+ */
+#include <linux/security.h>
+#include <linux/xxhash.h>
+#include "xattr.h"
+
+struct erofs_xattr_iter {
+ struct super_block *sb;
+ struct erofs_buf buf;
+ erofs_off_t pos;
+ void *kaddr;
+
+ char *buffer;
+ int buffer_size, buffer_ofs;
+
+ /* getxattr */
+ int index, infix_len;
+ struct qstr name;
+
+ /* listxattr */
+ struct dentry *dentry;
+};
+
+static int erofs_init_inode_xattrs(struct inode *inode)
+{
+ struct erofs_inode *const vi = EROFS_I(inode);
+ struct erofs_xattr_iter it;
+ unsigned int i;
+ struct erofs_xattr_ibody_header *ih;
+ struct super_block *sb = inode->i_sb;
+ int ret = 0;
+
+ /* the most case is that xattrs of this inode are initialized. */
+ if (test_bit(EROFS_I_EA_INITED_BIT, &vi->flags)) {
+ /*
+ * paired with smp_mb() at the end of the function to ensure
+ * fields will only be observed after the bit is set.
+ */
+ smp_mb();
+ return 0;
+ }
+
+ if (wait_on_bit_lock(&vi->flags, EROFS_I_BL_XATTR_BIT, TASK_KILLABLE))
+ return -ERESTARTSYS;
+
+ /* someone has initialized xattrs for us? */
+ if (test_bit(EROFS_I_EA_INITED_BIT, &vi->flags))
+ goto out_unlock;
+
+ /*
+ * bypass all xattr operations if ->xattr_isize is not greater than
+ * sizeof(struct erofs_xattr_ibody_header), in detail:
+ * 1) it is not enough to contain erofs_xattr_ibody_header then
+ * ->xattr_isize should be 0 (it means no xattr);
+ * 2) it is just to contain erofs_xattr_ibody_header, which is on-disk
+ * undefined right now (maybe use later with some new sb feature).
+ */
+ if (vi->xattr_isize == sizeof(struct erofs_xattr_ibody_header)) {
+ erofs_err(sb,
+ "xattr_isize %d of nid %llu is not supported yet",
+ vi->xattr_isize, vi->nid);
+ ret = -EOPNOTSUPP;
+ goto out_unlock;
+ } else if (vi->xattr_isize < sizeof(struct erofs_xattr_ibody_header)) {
+ if (vi->xattr_isize) {
+ erofs_err(sb, "bogus xattr ibody @ nid %llu", vi->nid);
+ DBG_BUGON(1);
+ ret = -EFSCORRUPTED;
+ goto out_unlock; /* xattr ondisk layout error */
+ }
+ ret = -ENOATTR;
+ goto out_unlock;
+ }
+
+ it.buf = __EROFS_BUF_INITIALIZER;
+ erofs_init_metabuf(&it.buf, sb);
+ it.pos = erofs_iloc(inode) + vi->inode_isize;
+
+ /* read in shared xattr array (non-atomic, see kmalloc below) */
+ it.kaddr = erofs_bread(&it.buf, erofs_blknr(sb, it.pos), EROFS_KMAP);
+ if (IS_ERR(it.kaddr)) {
+ ret = PTR_ERR(it.kaddr);
+ goto out_unlock;
+ }
+
+ ih = it.kaddr + erofs_blkoff(sb, it.pos);
+ vi->xattr_name_filter = le32_to_cpu(ih->h_name_filter);
+ vi->xattr_shared_count = ih->h_shared_count;
+ vi->xattr_shared_xattrs = kmalloc_array(vi->xattr_shared_count,
+ sizeof(uint), GFP_KERNEL);
+ if (!vi->xattr_shared_xattrs) {
+ erofs_put_metabuf(&it.buf);
+ ret = -ENOMEM;
+ goto out_unlock;
+ }
+
+ /* let's skip ibody header */
+ it.pos += sizeof(struct erofs_xattr_ibody_header);
+
+ for (i = 0; i < vi->xattr_shared_count; ++i) {
+ it.kaddr = erofs_bread(&it.buf, erofs_blknr(sb, it.pos),
+ EROFS_KMAP);
+ if (IS_ERR(it.kaddr)) {
+ kfree(vi->xattr_shared_xattrs);
+ vi->xattr_shared_xattrs = NULL;
+ ret = PTR_ERR(it.kaddr);
+ goto out_unlock;
+ }
+ vi->xattr_shared_xattrs[i] = le32_to_cpu(*(__le32 *)
+ (it.kaddr + erofs_blkoff(sb, it.pos)));
+ it.pos += sizeof(__le32);
+ }
+ erofs_put_metabuf(&it.buf);
+
+ /* paired with smp_mb() at the beginning of the function. */
+ smp_mb();
+ set_bit(EROFS_I_EA_INITED_BIT, &vi->flags);
+
+out_unlock:
+ clear_and_wake_up_bit(EROFS_I_BL_XATTR_BIT, &vi->flags);
+ return ret;
+}
+
+static bool erofs_xattr_user_list(struct dentry *dentry)
+{
+ return test_opt(&EROFS_SB(dentry->d_sb)->opt, XATTR_USER);
+}
+
+static bool erofs_xattr_trusted_list(struct dentry *dentry)
+{
+ return capable(CAP_SYS_ADMIN);
+}
+
+static int erofs_xattr_generic_get(const struct xattr_handler *handler,
+ struct dentry *unused, struct inode *inode,
+ const char *name, void *buffer, size_t size)
+{
+ if (handler->flags == EROFS_XATTR_INDEX_USER &&
+ !test_opt(&EROFS_I_SB(inode)->opt, XATTR_USER))
+ return -EOPNOTSUPP;
+
+ return erofs_getxattr(inode, handler->flags, name, buffer, size);
+}
+
+const struct xattr_handler erofs_xattr_user_handler = {
+ .prefix = XATTR_USER_PREFIX,
+ .flags = EROFS_XATTR_INDEX_USER,
+ .list = erofs_xattr_user_list,
+ .get = erofs_xattr_generic_get,
+};
+
+const struct xattr_handler erofs_xattr_trusted_handler = {
+ .prefix = XATTR_TRUSTED_PREFIX,
+ .flags = EROFS_XATTR_INDEX_TRUSTED,
+ .list = erofs_xattr_trusted_list,
+ .get = erofs_xattr_generic_get,
+};
+
+#ifdef CONFIG_EROFS_FS_SECURITY
+const struct xattr_handler __maybe_unused erofs_xattr_security_handler = {
+ .prefix = XATTR_SECURITY_PREFIX,
+ .flags = EROFS_XATTR_INDEX_SECURITY,
+ .get = erofs_xattr_generic_get,
+};
+#endif
+
+const struct xattr_handler *erofs_xattr_handlers[] = {
+ &erofs_xattr_user_handler,
+ &erofs_xattr_trusted_handler,
+#ifdef CONFIG_EROFS_FS_SECURITY
+ &erofs_xattr_security_handler,
+#endif
+ NULL,
+};
+
+static int erofs_xattr_copy_to_buffer(struct erofs_xattr_iter *it,
+ unsigned int len)
+{
+ unsigned int slice, processed;
+ struct super_block *sb = it->sb;
+ void *src;
+
+ for (processed = 0; processed < len; processed += slice) {
+ it->kaddr = erofs_bread(&it->buf, erofs_blknr(sb, it->pos),
+ EROFS_KMAP);
+ if (IS_ERR(it->kaddr))
+ return PTR_ERR(it->kaddr);
+
+ src = it->kaddr + erofs_blkoff(sb, it->pos);
+ slice = min_t(unsigned int, sb->s_blocksize -
+ erofs_blkoff(sb, it->pos), len - processed);
+ memcpy(it->buffer + it->buffer_ofs, src, slice);
+ it->buffer_ofs += slice;
+ it->pos += slice;
+ }
+ return 0;
+}
+
+static int erofs_listxattr_foreach(struct erofs_xattr_iter *it)
+{
+ struct erofs_xattr_entry entry;
+ unsigned int base_index, name_total, prefix_len, infix_len = 0;
+ const char *prefix, *infix = NULL;
+ int err;
+
+ /* 1. handle xattr entry */
+ entry = *(struct erofs_xattr_entry *)
+ (it->kaddr + erofs_blkoff(it->sb, it->pos));
+ it->pos += sizeof(struct erofs_xattr_entry);
+
+ base_index = entry.e_name_index;
+ if (entry.e_name_index & EROFS_XATTR_LONG_PREFIX) {
+ struct erofs_sb_info *sbi = EROFS_SB(it->sb);
+ struct erofs_xattr_prefix_item *pf = sbi->xattr_prefixes +
+ (entry.e_name_index & EROFS_XATTR_LONG_PREFIX_MASK);
+
+ if (pf >= sbi->xattr_prefixes + sbi->xattr_prefix_count)
+ return 0;
+ infix = pf->prefix->infix;
+ infix_len = pf->infix_len;
+ base_index = pf->prefix->base_index;
+ }
+
+ prefix = erofs_xattr_prefix(base_index, it->dentry);
+ if (!prefix)
+ return 0;
+ prefix_len = strlen(prefix);
+ name_total = prefix_len + infix_len + entry.e_name_len + 1;
+
+ if (!it->buffer) {
+ it->buffer_ofs += name_total;
+ return 0;
+ }
+
+ if (it->buffer_ofs + name_total > it->buffer_size)
+ return -ERANGE;
+
+ memcpy(it->buffer + it->buffer_ofs, prefix, prefix_len);
+ memcpy(it->buffer + it->buffer_ofs + prefix_len, infix, infix_len);
+ it->buffer_ofs += prefix_len + infix_len;
+
+ /* 2. handle xattr name */
+ err = erofs_xattr_copy_to_buffer(it, entry.e_name_len);
+ if (err)
+ return err;
+
+ it->buffer[it->buffer_ofs++] = '\0';
+ return 0;
+}
+
+static int erofs_getxattr_foreach(struct erofs_xattr_iter *it)
+{
+ struct super_block *sb = it->sb;
+ struct erofs_xattr_entry entry;
+ unsigned int slice, processed, value_sz;
+
+ /* 1. handle xattr entry */
+ entry = *(struct erofs_xattr_entry *)
+ (it->kaddr + erofs_blkoff(sb, it->pos));
+ it->pos += sizeof(struct erofs_xattr_entry);
+ value_sz = le16_to_cpu(entry.e_value_size);
+
+ /* should also match the infix for long name prefixes */
+ if (entry.e_name_index & EROFS_XATTR_LONG_PREFIX) {
+ struct erofs_sb_info *sbi = EROFS_SB(sb);
+ struct erofs_xattr_prefix_item *pf = sbi->xattr_prefixes +
+ (entry.e_name_index & EROFS_XATTR_LONG_PREFIX_MASK);
+
+ if (pf >= sbi->xattr_prefixes + sbi->xattr_prefix_count)
+ return -ENOATTR;
+
+ if (it->index != pf->prefix->base_index ||
+ it->name.len != entry.e_name_len + pf->infix_len)
+ return -ENOATTR;
+
+ if (memcmp(it->name.name, pf->prefix->infix, pf->infix_len))
+ return -ENOATTR;
+
+ it->infix_len = pf->infix_len;
+ } else {
+ if (it->index != entry.e_name_index ||
+ it->name.len != entry.e_name_len)
+ return -ENOATTR;
+
+ it->infix_len = 0;
+ }
+
+ /* 2. handle xattr name */
+ for (processed = 0; processed < entry.e_name_len; processed += slice) {
+ it->kaddr = erofs_bread(&it->buf, erofs_blknr(sb, it->pos),
+ EROFS_KMAP);
+ if (IS_ERR(it->kaddr))
+ return PTR_ERR(it->kaddr);
+
+ slice = min_t(unsigned int,
+ sb->s_blocksize - erofs_blkoff(sb, it->pos),
+ entry.e_name_len - processed);
+ if (memcmp(it->name.name + it->infix_len + processed,
+ it->kaddr + erofs_blkoff(sb, it->pos), slice))
+ return -ENOATTR;
+ it->pos += slice;
+ }
+
+ /* 3. handle xattr value */
+ if (!it->buffer) {
+ it->buffer_ofs = value_sz;
+ return 0;
+ }
+
+ if (it->buffer_size < value_sz)
+ return -ERANGE;
+
+ return erofs_xattr_copy_to_buffer(it, value_sz);
+}
+
+static int erofs_xattr_iter_inline(struct erofs_xattr_iter *it,
+ struct inode *inode, bool getxattr)
+{
+ struct erofs_inode *const vi = EROFS_I(inode);
+ unsigned int xattr_header_sz, remaining, entry_sz;
+ erofs_off_t next_pos;
+ int ret;
+
+ xattr_header_sz = sizeof(struct erofs_xattr_ibody_header) +
+ sizeof(u32) * vi->xattr_shared_count;
+ if (xattr_header_sz >= vi->xattr_isize) {
+ DBG_BUGON(xattr_header_sz > vi->xattr_isize);
+ return -ENOATTR;
+ }
+
+ remaining = vi->xattr_isize - xattr_header_sz;
+ it->pos = erofs_iloc(inode) + vi->inode_isize + xattr_header_sz;
+
+ while (remaining) {
+ it->kaddr = erofs_bread(&it->buf, erofs_blknr(it->sb, it->pos),
+ EROFS_KMAP);
+ if (IS_ERR(it->kaddr))
+ return PTR_ERR(it->kaddr);
+
+ entry_sz = erofs_xattr_entry_size(it->kaddr +
+ erofs_blkoff(it->sb, it->pos));
+ /* xattr on-disk corruption: xattr entry beyond xattr_isize */
+ if (remaining < entry_sz) {
+ DBG_BUGON(1);
+ return -EFSCORRUPTED;
+ }
+ remaining -= entry_sz;
+ next_pos = it->pos + entry_sz;
+
+ if (getxattr)
+ ret = erofs_getxattr_foreach(it);
+ else
+ ret = erofs_listxattr_foreach(it);
+ if ((getxattr && ret != -ENOATTR) || (!getxattr && ret))
+ break;
+
+ it->pos = next_pos;
+ }
+ return ret;
+}
+
+static int erofs_xattr_iter_shared(struct erofs_xattr_iter *it,
+ struct inode *inode, bool getxattr)
+{
+ struct erofs_inode *const vi = EROFS_I(inode);
+ struct super_block *const sb = it->sb;
+ struct erofs_sb_info *sbi = EROFS_SB(sb);
+ unsigned int i;
+ int ret = -ENOATTR;
+
+ for (i = 0; i < vi->xattr_shared_count; ++i) {
+ it->pos = erofs_pos(sb, sbi->xattr_blkaddr) +
+ vi->xattr_shared_xattrs[i] * sizeof(__le32);
+ it->kaddr = erofs_bread(&it->buf, erofs_blknr(sb, it->pos),
+ EROFS_KMAP);
+ if (IS_ERR(it->kaddr))
+ return PTR_ERR(it->kaddr);
+
+ if (getxattr)
+ ret = erofs_getxattr_foreach(it);
+ else
+ ret = erofs_listxattr_foreach(it);
+ if ((getxattr && ret != -ENOATTR) || (!getxattr && ret))
+ break;
+ }
+ return ret;
+}
+
+int erofs_getxattr(struct inode *inode, int index, const char *name,
+ void *buffer, size_t buffer_size)
+{
+ int ret;
+ unsigned int hashbit;
+ struct erofs_xattr_iter it;
+ struct erofs_inode *vi = EROFS_I(inode);
+ struct erofs_sb_info *sbi = EROFS_SB(inode->i_sb);
+
+ if (!name)
+ return -EINVAL;
+
+ ret = erofs_init_inode_xattrs(inode);
+ if (ret)
+ return ret;
+
+ /* reserved flag is non-zero if there's any change of on-disk format */
+ if (erofs_sb_has_xattr_filter(sbi) && !sbi->xattr_filter_reserved) {
+ hashbit = xxh32(name, strlen(name),
+ EROFS_XATTR_FILTER_SEED + index);
+ hashbit &= EROFS_XATTR_FILTER_BITS - 1;
+ if (vi->xattr_name_filter & (1U << hashbit))
+ return -ENOATTR;
+ }
+
+ it.index = index;
+ it.name = (struct qstr)QSTR_INIT(name, strlen(name));
+ if (it.name.len > EROFS_NAME_LEN)
+ return -ERANGE;
+
+ it.sb = inode->i_sb;
+ it.buf = __EROFS_BUF_INITIALIZER;
+ erofs_init_metabuf(&it.buf, it.sb);
+ it.buffer = buffer;
+ it.buffer_size = buffer_size;
+ it.buffer_ofs = 0;
+
+ ret = erofs_xattr_iter_inline(&it, inode, true);
+ if (ret == -ENOATTR)
+ ret = erofs_xattr_iter_shared(&it, inode, true);
+ erofs_put_metabuf(&it.buf);
+ return ret ? ret : it.buffer_ofs;
+}
+
+ssize_t erofs_listxattr(struct dentry *dentry, char *buffer, size_t buffer_size)
+{
+ int ret;
+ struct erofs_xattr_iter it;
+ struct inode *inode = d_inode(dentry);
+
+ ret = erofs_init_inode_xattrs(inode);
+ if (ret == -ENOATTR)
+ return 0;
+ if (ret)
+ return ret;
+
+ it.sb = dentry->d_sb;
+ it.buf = __EROFS_BUF_INITIALIZER;
+ erofs_init_metabuf(&it.buf, it.sb);
+ it.dentry = dentry;
+ it.buffer = buffer;
+ it.buffer_size = buffer_size;
+ it.buffer_ofs = 0;
+
+ ret = erofs_xattr_iter_inline(&it, inode, false);
+ if (!ret || ret == -ENOATTR)
+ ret = erofs_xattr_iter_shared(&it, inode, false);
+ if (ret == -ENOATTR)
+ ret = 0;
+ erofs_put_metabuf(&it.buf);
+ return ret ? ret : it.buffer_ofs;
+}
+
+void erofs_xattr_prefixes_cleanup(struct super_block *sb)
+{
+ struct erofs_sb_info *sbi = EROFS_SB(sb);
+ int i;
+
+ if (sbi->xattr_prefixes) {
+ for (i = 0; i < sbi->xattr_prefix_count; i++)
+ kfree(sbi->xattr_prefixes[i].prefix);
+ kfree(sbi->xattr_prefixes);
+ sbi->xattr_prefixes = NULL;
+ }
+}
+
+int erofs_xattr_prefixes_init(struct super_block *sb)
+{
+ struct erofs_sb_info *sbi = EROFS_SB(sb);
+ struct erofs_buf buf = __EROFS_BUF_INITIALIZER;
+ erofs_off_t pos = (erofs_off_t)sbi->xattr_prefix_start << 2;
+ struct erofs_xattr_prefix_item *pfs;
+ int ret = 0, i, len;
+
+ if (!sbi->xattr_prefix_count)
+ return 0;
+
+ pfs = kzalloc(sbi->xattr_prefix_count * sizeof(*pfs), GFP_KERNEL);
+ if (!pfs)
+ return -ENOMEM;
+
+ if (sbi->packed_inode)
+ buf.inode = sbi->packed_inode;
+ else
+ erofs_init_metabuf(&buf, sb);
+
+ for (i = 0; i < sbi->xattr_prefix_count; i++) {
+ void *ptr = erofs_read_metadata(sb, &buf, &pos, &len);
+
+ if (IS_ERR(ptr)) {
+ ret = PTR_ERR(ptr);
+ break;
+ } else if (len < sizeof(*pfs->prefix) ||
+ len > EROFS_NAME_LEN + sizeof(*pfs->prefix)) {
+ kfree(ptr);
+ ret = -EFSCORRUPTED;
+ break;
+ }
+ pfs[i].prefix = ptr;
+ pfs[i].infix_len = len - sizeof(struct erofs_xattr_long_prefix);
+ }
+
+ erofs_put_metabuf(&buf);
+ sbi->xattr_prefixes = pfs;
+ if (ret)
+ erofs_xattr_prefixes_cleanup(sb);
+ return ret;
+}
+
+#ifdef CONFIG_EROFS_FS_POSIX_ACL
+struct posix_acl *erofs_get_acl(struct inode *inode, int type, bool rcu)
+{
+ struct posix_acl *acl;
+ int prefix, rc;
+ char *value = NULL;
+
+ if (rcu)
+ return ERR_PTR(-ECHILD);
+
+ switch (type) {
+ case ACL_TYPE_ACCESS:
+ prefix = EROFS_XATTR_INDEX_POSIX_ACL_ACCESS;
+ break;
+ case ACL_TYPE_DEFAULT:
+ prefix = EROFS_XATTR_INDEX_POSIX_ACL_DEFAULT;
+ break;
+ default:
+ return ERR_PTR(-EINVAL);
+ }
+
+ rc = erofs_getxattr(inode, prefix, "", NULL, 0);
+ if (rc > 0) {
+ value = kmalloc(rc, GFP_KERNEL);
+ if (!value)
+ return ERR_PTR(-ENOMEM);
+ rc = erofs_getxattr(inode, prefix, "", value, rc);
+ }
+
+ if (rc == -ENOATTR)
+ acl = NULL;
+ else if (rc < 0)
+ acl = ERR_PTR(rc);
+ else
+ acl = posix_acl_from_xattr(&init_user_ns, value, rc);
+ kfree(value);
+ return acl;
+}
+#endif