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a683a5b2ba
The combination of spinlock_t lock and seqcount_spinlock_t seq in struct fs_struct is an open-coded seqlock_t (see linux/seqlock_types.h). Combine and switch to equivalent seqlock_t primitives. AFAICS, that does end up with the same sequence of underlying operations in all cases. While we are at it, get_fs_pwd() is open-coded verbatim in get_path_from_fd(); rather than applying conversion to it, replace with the call of get_fs_pwd() there. Not worth splitting the commit for that, IMO... A bit of historical background - conversion of seqlock_t to use of seqcount_spinlock_t happened several months after the same had been done to struct fs_struct; switching fs_struct to seqlock_t could've been done immediately after that, but it looks like nobody had gotten around to that until now. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Link: https://lore.kernel.org/20250702053437.GC1880847@ZenIV Acked-by: Ahmed S. Darwish <darwi@linutronix.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Christian Brauner <brauner@kernel.org>
44 lines
1 KiB
C
44 lines
1 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef _LINUX_FS_STRUCT_H
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#define _LINUX_FS_STRUCT_H
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#include <linux/path.h>
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#include <linux/spinlock.h>
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#include <linux/seqlock.h>
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struct fs_struct {
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int users;
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seqlock_t seq;
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int umask;
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int in_exec;
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struct path root, pwd;
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} __randomize_layout;
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extern struct kmem_cache *fs_cachep;
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extern void exit_fs(struct task_struct *);
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extern void set_fs_root(struct fs_struct *, const struct path *);
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extern void set_fs_pwd(struct fs_struct *, const struct path *);
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extern struct fs_struct *copy_fs_struct(struct fs_struct *);
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extern void free_fs_struct(struct fs_struct *);
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extern int unshare_fs_struct(void);
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static inline void get_fs_root(struct fs_struct *fs, struct path *root)
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{
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read_seqlock_excl(&fs->seq);
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*root = fs->root;
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path_get(root);
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read_sequnlock_excl(&fs->seq);
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}
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static inline void get_fs_pwd(struct fs_struct *fs, struct path *pwd)
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{
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read_seqlock_excl(&fs->seq);
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*pwd = fs->pwd;
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path_get(pwd);
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read_sequnlock_excl(&fs->seq);
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}
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extern bool current_chrooted(void);
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#endif /* _LINUX_FS_STRUCT_H */
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