[RFC PATCH v1 1/7] fs: Add inode_get_ino() and implement get_ino() for NFS
From: Mickaël Salaün <mic@digikod.net>
Date: 2024-10-10 15:27:03
Also in:
linux-fsdevel, linux-nfs
Subsystem:
filesystems (vfs and infrastructure), nfs, sunrpc, and lockd clients, the rest · Maintainers:
Alexander Viro, Christian Brauner, Trond Myklebust, Anna Schumaker, Linus Torvalds
When a filesystem manages its own inode numbers, like NFS's fileid shown to user space with getattr(), other part of the kernel may still expose the private inode->ino through kernel logs and audit. Another issue is on 32-bit architectures, on which ino_t is 32 bits, whereas the user space's view of an inode number can still be 64 bits. Add a new inode_get_ino() helper calling the new struct inode_operations' get_ino() when set, to get the user space's view of an inode number. inode_get_ino() is called by generic_fillattr(). Implement get_ino() for NFS. Cc: Trond Myklebust <trondmy@kernel.org> Cc: Anna Schumaker <anna@kernel.org> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Christian Brauner <brauner@kernel.org> Cc: Jan Kara <jack@suse.cz> Signed-off-by: Mickaël Salaün <mic@digikod.net> --- I'm not sure about nfs_namespace_getattr(), please review carefully. I guess there are other filesystems exposing inode numbers different than inode->i_ino, and they should be patched too. --- fs/nfs/inode.c | 6 ++++-- fs/nfs/internal.h | 1 + fs/nfs/namespace.c | 2 ++ fs/stat.c | 2 +- include/linux/fs.h | 9 +++++++++ 5 files changed, 17 insertions(+), 3 deletions(-)
diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c
index 542c7d97b235..5dfc176b6d92 100644
--- a/fs/nfs/inode.c
+++ b/fs/nfs/inode.c@@ -83,18 +83,19 @@ EXPORT_SYMBOL_GPL(nfs_wait_bit_killable); /** * nfs_compat_user_ino64 - returns the user-visible inode number - * @fileid: 64-bit fileid + * @inode: inode pointer * * This function returns a 32-bit inode number if the boot parameter * nfs.enable_ino64 is zero. */ -u64 nfs_compat_user_ino64(u64 fileid) +u64 nfs_compat_user_ino64(const struct *inode) { #ifdef CONFIG_COMPAT compat_ulong_t ino; #else unsigned long ino; #endif + u64 fileid = NFS_FILEID(inode); if (enable_ino64) return fileid;
@@ -103,6 +104,7 @@ u64 nfs_compat_user_ino64(u64 fileid) ino ^= fileid >> (sizeof(fileid)-sizeof(ino)) * 8; return ino; } +EXPORT_SYMBOL_GPL(nfs_compat_user_ino64); int nfs_drop_inode(struct inode *inode) {
diff --git a/fs/nfs/internal.h b/fs/nfs/internal.h
index 430733e3eff2..f5555a71a733 100644
--- a/fs/nfs/internal.h
+++ b/fs/nfs/internal.h@@ -451,6 +451,7 @@ extern void nfs_zap_acl_cache(struct inode *inode); extern void nfs_set_cache_invalid(struct inode *inode, unsigned long flags); extern bool nfs_check_cache_invalid(struct inode *, unsigned long); extern int nfs_wait_bit_killable(struct wait_bit_key *key, int mode); +extern u64 nfs_compat_user_ino64(const struct *inode); #if IS_ENABLED(CONFIG_NFS_LOCALIO) /* localio.c */
diff --git a/fs/nfs/namespace.c b/fs/nfs/namespace.c
index e7494cdd957e..d9b1e0606833 100644
--- a/fs/nfs/namespace.c
+++ b/fs/nfs/namespace.c@@ -232,11 +232,13 @@ nfs_namespace_setattr(struct mnt_idmap *idmap, struct dentry *dentry, const struct inode_operations nfs_mountpoint_inode_operations = { .getattr = nfs_getattr, .setattr = nfs_setattr, + .get_ino = nfs_compat_user_ino64, }; const struct inode_operations nfs_referral_inode_operations = { .getattr = nfs_namespace_getattr, .setattr = nfs_namespace_setattr, + .get_ino = nfs_compat_user_ino64, }; static void nfs_expire_automounts(struct work_struct *work)
diff --git a/fs/stat.c b/fs/stat.c
index 41e598376d7e..05636919f94b 100644
--- a/fs/stat.c
+++ b/fs/stat.c@@ -50,7 +50,7 @@ void generic_fillattr(struct mnt_idmap *idmap, u32 request_mask, vfsgid_t vfsgid = i_gid_into_vfsgid(idmap, inode); stat->dev = inode->i_sb->s_dev; - stat->ino = inode->i_ino; + stat->ino = inode_get_ino(inode); stat->mode = inode->i_mode; stat->nlink = inode->i_nlink; stat->uid = vfsuid_into_kuid(vfsuid);
diff --git a/include/linux/fs.h b/include/linux/fs.h
index e3c603d01337..0eba09a21cf7 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h@@ -2165,6 +2165,7 @@ struct inode_operations { struct dentry *dentry, struct fileattr *fa); int (*fileattr_get)(struct dentry *dentry, struct fileattr *fa); struct offset_ctx *(*get_offset_ctx)(struct inode *inode); + u64 (*get_ino)(const struct inode *inode); } ____cacheline_aligned; static inline int call_mmap(struct file *file, struct vm_area_struct *vma)
@@ -2172,6 +2173,14 @@ static inline int call_mmap(struct file *file, struct vm_area_struct *vma) return file->f_op->mmap(file, vma); } +static inline u64 inode_get_ino(struct inode *inode) +{ + if (unlikely(inode->i_op->get_ino)) + return inode->i_op->get_ino(inode); + + return inode->i_ino; +} + extern ssize_t vfs_read(struct file *, char __user *, size_t, loff_t *); extern ssize_t vfs_write(struct file *, const char __user *, size_t, loff_t *); extern ssize_t vfs_copy_file_range(struct file *, loff_t , struct file *,
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2.46.1