From 54018131e663a1df05021fcb22a18d6c5ebef734 Mon Sep 17 00:00:00 2001 From: Mateusz Guzik Date: Sun, 2 Jun 2024 14:37:19 +0200 Subject: vfs: replace WARN(down_read_trylock, ...) abuse with proper asserts Note the macro used here works regardless of LOCKDEP. Signed-off-by: Mateusz Guzik Link: https://lore.kernel.org/r/20240602123720.775702-1-mjguzik@gmail.com Reviewed-by: Jan Kara Signed-off-by: Christian Brauner --- fs/dcache.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'fs/dcache.c') diff --git a/fs/dcache.c b/fs/dcache.c index 1ee6404b430b..58b89c9e9b0c 100644 --- a/fs/dcache.c +++ b/fs/dcache.c @@ -1548,7 +1548,7 @@ void shrink_dcache_for_umount(struct super_block *sb) { struct dentry *dentry; - WARN(down_read_trylock(&sb->s_umount), "s_umount should've been locked"); + rwsem_assert_held_write(&sb->s_umount); dentry = sb->s_root; sb->s_root = NULL; -- cgit v1.2.3-58-ga151 From f378ec4eec8b7e607dbc0112913fd3d5d84eb1b8 Mon Sep 17 00:00:00 2001 From: Mateusz Guzik Date: Thu, 27 Jun 2024 18:11:52 +0200 Subject: vfs: rename parent_ino to d_parent_ino and make it use RCU The routine is used by procfs through dir_emit_dots. The combined RCU and lock fallback implementation is too big for an inline. Given that the routine takes a dentry argument fs/dcache.c seems like the place to put it in. Signed-off-by: Mateusz Guzik Link: https://lore.kernel.org/r/20240627161152.802567-1-mjguzik@gmail.com Signed-off-by: Christian Brauner --- fs/dcache.c | 28 ++++++++++++++++++++++++++++ fs/f2fs/file.c | 2 +- fs/hfsplus/ioctl.c | 4 ++-- include/linux/dcache.h | 2 ++ include/linux/fs.h | 16 +--------------- 5 files changed, 34 insertions(+), 18 deletions(-) (limited to 'fs/dcache.c') diff --git a/fs/dcache.c b/fs/dcache.c index 58b89c9e9b0c..68e843e78337 100644 --- a/fs/dcache.c +++ b/fs/dcache.c @@ -3099,6 +3099,34 @@ void d_tmpfile(struct file *file, struct inode *inode) } EXPORT_SYMBOL(d_tmpfile); +/* + * Obtain inode number of the parent dentry. + */ +ino_t d_parent_ino(struct dentry *dentry) +{ + struct dentry *parent; + struct inode *iparent; + unsigned seq; + ino_t ret; + + scoped_guard(rcu) { + seq = raw_seqcount_begin(&dentry->d_seq); + parent = READ_ONCE(dentry->d_parent); + iparent = d_inode_rcu(parent); + if (likely(iparent)) { + ret = iparent->i_ino; + if (!read_seqcount_retry(&dentry->d_seq, seq)) + return ret; + } + } + + spin_lock(&dentry->d_lock); + ret = dentry->d_parent->d_inode->i_ino; + spin_unlock(&dentry->d_lock); + return ret; +} +EXPORT_SYMBOL(d_parent_ino); + static __initdata unsigned long dhash_entries; static int __init set_dhash_entries(char *str) { diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c index 7a23434963d1..c1ad9b278c47 100644 --- a/fs/f2fs/file.c +++ b/fs/f2fs/file.c @@ -185,7 +185,7 @@ static int get_parent_ino(struct inode *inode, nid_t *pino) if (!dentry) return 0; - *pino = parent_ino(dentry); + *pino = d_parent_ino(dentry); dput(dentry); return 1; } diff --git a/fs/hfsplus/ioctl.c b/fs/hfsplus/ioctl.c index 5661a2e24d03..40d04dba13ac 100644 --- a/fs/hfsplus/ioctl.c +++ b/fs/hfsplus/ioctl.c @@ -40,7 +40,7 @@ static int hfsplus_ioctl_bless(struct file *file, int __user *user_flags) /* Directory containing the bootable system */ vh->finder_info[0] = bvh->finder_info[0] = - cpu_to_be32(parent_ino(dentry)); + cpu_to_be32(d_parent_ino(dentry)); /* * Bootloader. Just using the inode here breaks in the case of @@ -51,7 +51,7 @@ static int hfsplus_ioctl_bless(struct file *file, int __user *user_flags) /* Per spec, the OS X system folder - same as finder_info[0] here */ vh->finder_info[5] = bvh->finder_info[5] = - cpu_to_be32(parent_ino(dentry)); + cpu_to_be32(d_parent_ino(dentry)); mutex_unlock(&sbi->vh_mutex); return 0; diff --git a/include/linux/dcache.h b/include/linux/dcache.h index bf53e3894aae..ea58843942b9 100644 --- a/include/linux/dcache.h +++ b/include/linux/dcache.h @@ -278,6 +278,8 @@ static inline unsigned d_count(const struct dentry *dentry) return dentry->d_lockref.count; } +ino_t d_parent_ino(struct dentry *dentry); + /* * helper function for dentry_operations.d_dname() members */ diff --git a/include/linux/fs.h b/include/linux/fs.h index 5ff362277834..2fa06a4d197a 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -3454,20 +3454,6 @@ static inline int kiocb_set_rw_flags(struct kiocb *ki, rwf_t flags) return 0; } -static inline ino_t parent_ino(struct dentry *dentry) -{ - ino_t res; - - /* - * Don't strictly need d_lock here? If the parent ino could change - * then surely we'd have a deeper race in the caller? - */ - spin_lock(&dentry->d_lock); - res = dentry->d_parent->d_inode->i_ino; - spin_unlock(&dentry->d_lock); - return res; -} - /* Transaction based IO helpers */ /* @@ -3592,7 +3578,7 @@ static inline bool dir_emit_dot(struct file *file, struct dir_context *ctx) static inline bool dir_emit_dotdot(struct file *file, struct dir_context *ctx) { return ctx->actor(ctx, "..", 2, ctx->pos, - parent_ino(file->f_path.dentry), DT_DIR); + d_parent_ino(file->f_path.dentry), DT_DIR); } static inline bool dir_emit_dots(struct file *file, struct dir_context *ctx) { -- cgit v1.2.3-58-ga151