From dcfadfa4ec5a12404a99ad6426871a6b03a62b37 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Sun, 12 Aug 2012 17:27:30 -0400 Subject: new helper: __alloc_fd() Essentially, alloc_fd() in a files_struct we own a reference to. Most of the time wanting to use it is a sign of lousy API design (such as android/binder). It's *not* a general-purpose interface; better that than open-coding its guts, but again, playing with other process' descriptor table is a sign of bad design. Signed-off-by: Al Viro --- include/linux/fdtable.h | 3 +++ 1 file changed, 3 insertions(+) (limited to 'include/linux/fdtable.h') diff --git a/include/linux/fdtable.h b/include/linux/fdtable.h index 158a41eed314..b84ca064f727 100644 --- a/include/linux/fdtable.h +++ b/include/linux/fdtable.h @@ -125,6 +125,9 @@ void reset_files_struct(struct files_struct *); int unshare_files(struct files_struct **); struct files_struct *dup_fd(struct files_struct *, int *); +extern int __alloc_fd(struct files_struct *files, + unsigned start, unsigned end, unsigned flags); + extern struct kmem_cache *files_cachep; #endif /* __LINUX_FDTABLE_H */ -- cgit v1.2.3 From 7cf4dc3c8dbfdfde163d4636f621cf99a1f63bfb Mon Sep 17 00:00:00 2001 From: Al Viro Date: Wed, 15 Aug 2012 19:56:12 -0400 Subject: move files_struct-related bits from kernel/exit.c to fs/file.c Signed-off-by: Al Viro --- include/linux/fdtable.h | 6 ------ 1 file changed, 6 deletions(-) (limited to 'include/linux/fdtable.h') diff --git a/include/linux/fdtable.h b/include/linux/fdtable.h index b84ca064f727..3855f4febe70 100644 --- a/include/linux/fdtable.h +++ b/include/linux/fdtable.h @@ -94,14 +94,8 @@ struct vfsmount; struct dentry; extern int expand_files(struct files_struct *, int nr); -extern void free_fdtable_rcu(struct rcu_head *rcu); extern void __init files_defer_init(void); -static inline void free_fdtable(struct fdtable *fdt) -{ - call_rcu(&fdt->rcu, free_fdtable_rcu); -} - static inline struct file * fcheck_files(struct files_struct *files, unsigned int fd) { struct file * file = NULL; -- cgit v1.2.3 From f869e8a7f753e3fd43d6483e796774776f645edb Mon Sep 17 00:00:00 2001 From: Al Viro Date: Wed, 15 Aug 2012 21:06:33 -0400 Subject: expose a low-level variant of fd_install() for binder Similar situation to that of __alloc_fd(); do not use unless you really have to. You should not touch any descriptor table other than your own; it's a sure sign of a really bad API design. As with __alloc_fd(), you *must* use a first-class reference to struct files_struct; something obtained by get_files_struct(some task) (let alone direct task->files) will not do. It must be either current->files, or obtained by get_files_struct(current) by the owner of that sucker and given to you. Signed-off-by: Al Viro --- include/linux/fdtable.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'include/linux/fdtable.h') diff --git a/include/linux/fdtable.h b/include/linux/fdtable.h index 3855f4febe70..59d4fc7f10c8 100644 --- a/include/linux/fdtable.h +++ b/include/linux/fdtable.h @@ -121,6 +121,8 @@ struct files_struct *dup_fd(struct files_struct *, int *); extern int __alloc_fd(struct files_struct *files, unsigned start, unsigned end, unsigned flags); +extern void __fd_install(struct files_struct *files, + unsigned int fd, struct file *file); extern struct kmem_cache *files_cachep; -- cgit v1.2.3 From 483ce1d4b8c3b82bc9c9a1dd9dbc44f50b3aaf5a Mon Sep 17 00:00:00 2001 From: Al Viro Date: Sun, 19 Aug 2012 12:04:24 -0400 Subject: take descriptor-related part of close() to file.c Signed-off-by: Al Viro --- include/linux/fdtable.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'include/linux/fdtable.h') diff --git a/include/linux/fdtable.h b/include/linux/fdtable.h index 59d4fc7f10c8..59488f2392bc 100644 --- a/include/linux/fdtable.h +++ b/include/linux/fdtable.h @@ -123,6 +123,8 @@ extern int __alloc_fd(struct files_struct *files, unsigned start, unsigned end, unsigned flags); extern void __fd_install(struct files_struct *files, unsigned int fd, struct file *file); +extern int __close_fd(struct files_struct *files, + unsigned int fd); extern struct kmem_cache *files_cachep; -- cgit v1.2.3 From 6a6d27de340c89c5323565b49f7851362619925d Mon Sep 17 00:00:00 2001 From: Al Viro Date: Tue, 21 Aug 2012 09:56:33 -0400 Subject: take close-on-exec logics to fs/file.c, clean it up a bit ... and add cond_resched() there, while we are at it. We can get large latencies as is... Signed-off-by: Al Viro --- include/linux/fdtable.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux/fdtable.h') diff --git a/include/linux/fdtable.h b/include/linux/fdtable.h index 59488f2392bc..ef4b2137e6bc 100644 --- a/include/linux/fdtable.h +++ b/include/linux/fdtable.h @@ -118,6 +118,7 @@ void put_files_struct(struct files_struct *fs); void reset_files_struct(struct files_struct *); int unshare_files(struct files_struct **); struct files_struct *dup_fd(struct files_struct *, int *); +void do_close_on_exec(struct files_struct *); extern int __alloc_fd(struct files_struct *files, unsigned start, unsigned end, unsigned flags); -- cgit v1.2.3 From b8318b01a8f7f760ae3ecae052ccc7fc123d9508 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Tue, 21 Aug 2012 20:09:42 -0400 Subject: take __{set,clear}_{open_fd,close_on_exec}() into fs/file.c nobody uses those outside anymore. Signed-off-by: Al Viro --- include/linux/fdtable.h | 20 -------------------- 1 file changed, 20 deletions(-) (limited to 'include/linux/fdtable.h') diff --git a/include/linux/fdtable.h b/include/linux/fdtable.h index ef4b2137e6bc..9ff26319d44f 100644 --- a/include/linux/fdtable.h +++ b/include/linux/fdtable.h @@ -30,31 +30,11 @@ struct fdtable { struct fdtable *next; }; -static inline void __set_close_on_exec(int fd, struct fdtable *fdt) -{ - __set_bit(fd, fdt->close_on_exec); -} - -static inline void __clear_close_on_exec(int fd, struct fdtable *fdt) -{ - __clear_bit(fd, fdt->close_on_exec); -} - static inline bool close_on_exec(int fd, const struct fdtable *fdt) { return test_bit(fd, fdt->close_on_exec); } -static inline void __set_open_fd(int fd, struct fdtable *fdt) -{ - __set_bit(fd, fdt->open_fds); -} - -static inline void __clear_open_fd(int fd, struct fdtable *fdt) -{ - __clear_bit(fd, fdt->open_fds); -} - static inline bool fd_is_open(int fd, const struct fdtable *fdt) { return test_bit(fd, fdt->open_fds); -- cgit v1.2.3 From ad47bd7252bf402fe7dba92f5240b5ed16832ae7 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Tue, 21 Aug 2012 20:11:34 -0400 Subject: make expand_files() and alloc_fd() static no callers outside of fs/file.c left Signed-off-by: Al Viro --- include/linux/fdtable.h | 1 - 1 file changed, 1 deletion(-) (limited to 'include/linux/fdtable.h') diff --git a/include/linux/fdtable.h b/include/linux/fdtable.h index 9ff26319d44f..de2b71caa0f0 100644 --- a/include/linux/fdtable.h +++ b/include/linux/fdtable.h @@ -73,7 +73,6 @@ struct file_operations; struct vfsmount; struct dentry; -extern int expand_files(struct files_struct *, int nr); extern void __init files_defer_init(void); static inline struct file * fcheck_files(struct files_struct *files, unsigned int fd) -- cgit v1.2.3 From c3c073f808b22dfae15ef8412b6f7b998644139a Mon Sep 17 00:00:00 2001 From: Al Viro Date: Tue, 21 Aug 2012 22:32:06 -0400 Subject: new helper: iterate_fd() iterates through the opened files in given descriptor table, calling a supplied function; we stop once non-zero is returned. Callback gets struct file *, descriptor number and const void * argument passed to iterator. It is called with files->file_lock held, so it is not allowed to block. tty_io, netprio_cgroup and selinux flush_unauthorized_files() converted to its use. Signed-off-by: Al Viro --- include/linux/fdtable.h | 3 +++ 1 file changed, 3 insertions(+) (limited to 'include/linux/fdtable.h') diff --git a/include/linux/fdtable.h b/include/linux/fdtable.h index de2b71caa0f0..fb7dacae0522 100644 --- a/include/linux/fdtable.h +++ b/include/linux/fdtable.h @@ -98,6 +98,9 @@ void reset_files_struct(struct files_struct *); int unshare_files(struct files_struct **); struct files_struct *dup_fd(struct files_struct *, int *); void do_close_on_exec(struct files_struct *); +int iterate_fd(struct files_struct *, unsigned, + int (*)(const void *, struct file *, unsigned), + const void *); extern int __alloc_fd(struct files_struct *files, unsigned start, unsigned end, unsigned flags); -- cgit v1.2.3 From 864bdb3b6cbd9911222543fef1cfe36f88183f44 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Wed, 22 Aug 2012 18:42:10 -0400 Subject: new helper: daemonize_descriptors() descriptor-related parts of daemonize, done right. As the result we simplify the locking rules for ->files - we hold task_lock in *all* cases when we modify ->files. Signed-off-by: Al Viro --- include/linux/fdtable.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux/fdtable.h') diff --git a/include/linux/fdtable.h b/include/linux/fdtable.h index fb7dacae0522..45052aa814c8 100644 --- a/include/linux/fdtable.h +++ b/include/linux/fdtable.h @@ -95,6 +95,7 @@ struct task_struct; struct files_struct *get_files_struct(struct task_struct *); void put_files_struct(struct files_struct *fs); void reset_files_struct(struct files_struct *); +void daemonize_descriptors(void); int unshare_files(struct files_struct **); struct files_struct *dup_fd(struct files_struct *, int *); void do_close_on_exec(struct files_struct *); -- cgit v1.2.3