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b74d24f7a7
Convert to struct mnt_idmap.
Last cycle we merged the necessary infrastructure in
256c8aed2b ("fs: introduce dedicated idmap type for mounts").
This is just the conversion to struct mnt_idmap.
Currently we still pass around the plain namespace that was attached to a
mount. This is in general pretty convenient but it makes it easy to
conflate namespaces that are relevant on the filesystem with namespaces
that are relevent on the mount level. Especially for non-vfs developers
without detailed knowledge in this area this can be a potential source for
bugs.
Once the conversion to struct mnt_idmap is done all helpers down to the
really low-level helpers will take a struct mnt_idmap argument instead of
two namespace arguments. This way it becomes impossible to conflate the two
eliminating the possibility of any bugs. All of the vfs and all filesystems
only operate on struct mnt_idmap.
Acked-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
135 lines
3.1 KiB
C
135 lines
3.1 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* linux/fs/ext4/symlink.c
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*
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* Only fast symlinks left here - the rest is done by generic code. AV, 1999
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*
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* Copyright (C) 1992, 1993, 1994, 1995
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* Remy Card (card@masi.ibp.fr)
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* Laboratoire MASI - Institut Blaise Pascal
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* Universite Pierre et Marie Curie (Paris VI)
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*
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* from
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*
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* linux/fs/minix/symlink.c
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*
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* Copyright (C) 1991, 1992 Linus Torvalds
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*
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* ext4 symlink handling code
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*/
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#include <linux/fs.h>
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#include <linux/namei.h>
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#include "ext4.h"
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#include "xattr.h"
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static const char *ext4_encrypted_get_link(struct dentry *dentry,
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struct inode *inode,
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struct delayed_call *done)
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{
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struct buffer_head *bh = NULL;
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const void *caddr;
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unsigned int max_size;
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const char *paddr;
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if (!dentry)
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return ERR_PTR(-ECHILD);
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if (ext4_inode_is_fast_symlink(inode)) {
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caddr = EXT4_I(inode)->i_data;
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max_size = sizeof(EXT4_I(inode)->i_data);
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} else {
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bh = ext4_bread(NULL, inode, 0, 0);
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if (IS_ERR(bh))
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return ERR_CAST(bh);
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if (!bh) {
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EXT4_ERROR_INODE(inode, "bad symlink.");
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return ERR_PTR(-EFSCORRUPTED);
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}
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caddr = bh->b_data;
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max_size = inode->i_sb->s_blocksize;
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}
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paddr = fscrypt_get_symlink(inode, caddr, max_size, done);
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brelse(bh);
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return paddr;
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}
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static int ext4_encrypted_symlink_getattr(struct mnt_idmap *idmap,
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const struct path *path,
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struct kstat *stat, u32 request_mask,
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unsigned int query_flags)
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{
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ext4_getattr(idmap, path, stat, request_mask, query_flags);
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return fscrypt_symlink_getattr(path, stat);
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}
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static void ext4_free_link(void *bh)
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{
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brelse(bh);
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}
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static const char *ext4_get_link(struct dentry *dentry, struct inode *inode,
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struct delayed_call *callback)
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{
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struct buffer_head *bh;
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char *inline_link;
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/*
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* Create a new inlined symlink is not supported, just provide a
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* method to read the leftovers.
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*/
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if (ext4_has_inline_data(inode)) {
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if (!dentry)
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return ERR_PTR(-ECHILD);
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inline_link = ext4_read_inline_link(inode);
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if (!IS_ERR(inline_link))
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set_delayed_call(callback, kfree_link, inline_link);
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return inline_link;
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}
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if (!dentry) {
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bh = ext4_getblk(NULL, inode, 0, EXT4_GET_BLOCKS_CACHED_NOWAIT);
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if (IS_ERR(bh))
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return ERR_CAST(bh);
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if (!bh || !ext4_buffer_uptodate(bh))
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return ERR_PTR(-ECHILD);
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} else {
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bh = ext4_bread(NULL, inode, 0, 0);
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if (IS_ERR(bh))
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return ERR_CAST(bh);
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if (!bh) {
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EXT4_ERROR_INODE(inode, "bad symlink.");
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return ERR_PTR(-EFSCORRUPTED);
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}
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}
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set_delayed_call(callback, ext4_free_link, bh);
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nd_terminate_link(bh->b_data, inode->i_size,
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inode->i_sb->s_blocksize - 1);
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return bh->b_data;
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}
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const struct inode_operations ext4_encrypted_symlink_inode_operations = {
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.get_link = ext4_encrypted_get_link,
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.setattr = ext4_setattr,
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.getattr = ext4_encrypted_symlink_getattr,
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.listxattr = ext4_listxattr,
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};
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const struct inode_operations ext4_symlink_inode_operations = {
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.get_link = ext4_get_link,
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.setattr = ext4_setattr,
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.getattr = ext4_getattr,
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.listxattr = ext4_listxattr,
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};
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const struct inode_operations ext4_fast_symlink_inode_operations = {
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.get_link = simple_get_link,
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.setattr = ext4_setattr,
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.getattr = ext4_getattr,
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.listxattr = ext4_listxattr,
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};
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