tmpfs: depend on shmem (3f96b79a) · Commits · 戴 / test

CONFIG_SHMEM off gives you (ramfs masquerading as) tmpfs, even when CONFIG_TMPFS is off: that's a little anomalous, and I'd intended to make more sense of it by removing CONFIG_TMPFS altogether, always enabling its code when CONFIG_SHMEM; but so many defconfigs have CONFIG_SHMEM on CONFIG_TMPFS off that we'd better leave that as is. But there is no point in asking for CONFIG_TMPFS if CONFIG_SHMEM is off: make TMPFS depend on SHMEM, which also prevents TMPFS_POSIX_ACL shmem_acl.o being pointlessly built into the kernel when SHMEM is off. And a selfish change, to prevent the world from being rebuilt when I switch between CONFIG_SHMEM on and off: the only CONFIG_SHMEM in the header files is mm.h shmem_lock() - give that a shmem.c stub instead. Signed-off-by:

Hugh Dickins <hugh.dickins@tiscali.co.uk> Acked-by:

Matt Mackall <mpm@selenic.com> Signed-off-by:

Andrew Morton <akpm@linux-foundation.org> Signed-off-by:

Linus Torvalds <torvalds@linux-foundation.org>

fs/Kconfig

+1 −0

Original line number	Diff line number	Diff line
		@@ -109,6 +109,7 @@ source "fs/sysfs/Kconfig"

		config TMPFS
		bool "Virtual memory file system support (former shm fs)"
		depends on SHMEM
		help
		Tmpfs is a file system which keeps all files in virtual memory.

include/linux/mm.h

+1 −10

Original line number	Diff line number	Diff line
		@@ -702,17 +702,8 @@ extern void pagefault_out_of_memory(void);

		extern void show_free_areas(void);

		#ifdef CONFIG_SHMEM
		extern int shmem_lock(struct file file, int lock, struct user_struct user);
		#else
		static inline int shmem_lock(struct file *file, int lock,
		struct user_struct *user)
		{
		return 0;
		}
		#endif
		int shmem_lock(struct file file, int lock, struct user_struct user);
		struct file shmem_file_setup(const char name, loff_t size, unsigned long flags);

		int shmem_zero_setup(struct vm_area_struct *);

		#ifndef CONFIG_MMU

mm/shmem.c

+5 −0

Original line number	Diff line number	Diff line
		@@ -2593,6 +2593,11 @@ int shmem_unuse(swp_entry_t entry, struct page *page)
		return 0;
		}

		int shmem_lock(struct file file, int lock, struct user_struct user)
		{
		return 0;
		}

		#define shmem_vm_ops generic_file_vm_ops
		#define shmem_file_operations ramfs_file_operations
		#define shmem_get_inode(sb, mode, dev, flags) ramfs_get_inode(sb, mode, dev)

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