libfs: Add helper to choose dentry operations at mount-time

In preparation to drop the similar helper that sets d_op at lookup time,
add a version to set the right d_op filesystem-wide, through sb->s_d_op.
The operations structures are shared across filesystems supporting
fscrypt and/or casefolding, therefore we can keep it in common libfs
code.

Reviewed-by: Eric Biggers <ebiggers@google.com>
Link: https://lore.kernel.org/r/20240221171412.10710-7-krisman@suse.de
Signed-off-by: Gabriel Krisman Bertazi <krisman@suse.de>
This commit is contained in:
Gabriel Krisman Bertazi 2024-02-21 12:14:08 -05:00
parent e6ca2883d9
commit 70dfe3f0d2
2 changed files with 29 additions and 0 deletions

View File

@ -1818,6 +1818,34 @@ void generic_set_encrypted_ci_d_ops(struct dentry *dentry)
}
EXPORT_SYMBOL(generic_set_encrypted_ci_d_ops);
/**
* generic_set_sb_d_ops - helper for choosing the set of
* filesystem-wide dentry operations for the enabled features
* @sb: superblock to be configured
*
* Filesystems supporting casefolding and/or fscrypt can call this
* helper at mount-time to configure sb->s_d_op to best set of dentry
* operations required for the enabled features. The helper must be
* called after these have been configured, but before the root dentry
* is created.
*/
void generic_set_sb_d_ops(struct super_block *sb)
{
#if IS_ENABLED(CONFIG_UNICODE)
if (sb->s_encoding) {
sb->s_d_op = &generic_ci_dentry_ops;
return;
}
#endif
#ifdef CONFIG_FS_ENCRYPTION
if (sb->s_cop) {
sb->s_d_op = &generic_encrypted_dentry_ops;
return;
}
#endif
}
EXPORT_SYMBOL(generic_set_sb_d_ops);
/**
* inode_maybe_inc_iversion - increments i_version
* @inode: inode with the i_version that should be updated

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@ -3281,6 +3281,7 @@ extern int generic_file_fsync(struct file *, loff_t, loff_t, int);
extern int generic_check_addressable(unsigned, u64);
extern void generic_set_encrypted_ci_d_ops(struct dentry *dentry);
extern void generic_set_sb_d_ops(struct super_block *sb);
static inline bool sb_has_encoding(const struct super_block *sb)
{