From: Alexey Dobriyan <adobriyan@xxxxxxxxx> Subject: fs/proc: calculate /proc/* and /proc/*/task/* nlink at init time Runtime nlink calculation works but meh. I don't know how to do it at compile time, but I know how to do it at init time. Shift "2+" part into init time as a bonus. Link: http://lkml.kernel.org/r/20161122195549.GB29812@avx2 Signed-off-by: Alexey Dobriyan <adobriyan@xxxxxxxxx> Reviewed-by: Vegard Nossum <vegard.nossum@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- fs/proc/base.c | 19 +++++++++++++------ fs/proc/internal.h | 1 + fs/proc/root.c | 1 + 3 files changed, 15 insertions(+), 6 deletions(-) diff -puN fs/proc/base.c~proc-calculate-proc-and-proc-task-nlink-at-init-time fs/proc/base.c --- a/fs/proc/base.c~proc-calculate-proc-and-proc-task-nlink-at-init-time +++ a/fs/proc/base.c @@ -104,6 +104,9 @@ * in /proc for a task before it execs a suid executable. */ +static u8 nlink_tid; +static u8 nlink_tgid; + struct pid_entry { const char *name; unsigned int len; @@ -139,13 +142,13 @@ struct pid_entry { * Count the number of hardlinks for the pid_entry table, excluding the . * and .. links. */ -static unsigned int pid_entry_count_dirs(const struct pid_entry *entries, +static unsigned int __init pid_entry_nlink(const struct pid_entry *entries, unsigned int n) { unsigned int i; unsigned int count; - count = 0; + count = 2; for (i = 0; i < n; ++i) { if (S_ISDIR(entries[i].mode)) ++count; @@ -3068,8 +3071,7 @@ static int proc_pid_instantiate(struct i inode->i_fop = &proc_tgid_base_operations; inode->i_flags|=S_IMMUTABLE; - set_nlink(inode, 2 + pid_entry_count_dirs(tgid_base_stuff, - ARRAY_SIZE(tgid_base_stuff))); + set_nlink(inode, nlink_tgid); d_set_d_op(dentry, &pid_dentry_operations); @@ -3361,8 +3363,7 @@ static int proc_task_instantiate(struct inode->i_fop = &proc_tid_base_operations; inode->i_flags|=S_IMMUTABLE; - set_nlink(inode, 2 + pid_entry_count_dirs(tid_base_stuff, - ARRAY_SIZE(tid_base_stuff))); + set_nlink(inode, nlink_tid); d_set_d_op(dentry, &pid_dentry_operations); @@ -3552,3 +3553,9 @@ static const struct file_operations proc .iterate_shared = proc_task_readdir, .llseek = generic_file_llseek, }; + +void __init set_proc_pid_nlink(void) +{ + nlink_tid = pid_entry_nlink(tid_base_stuff, ARRAY_SIZE(tid_base_stuff)); + nlink_tgid = pid_entry_nlink(tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff)); +} diff -puN fs/proc/internal.h~proc-calculate-proc-and-proc-task-nlink-at-init-time fs/proc/internal.h --- a/fs/proc/internal.h~proc-calculate-proc-and-proc-task-nlink-at-init-time +++ a/fs/proc/internal.h @@ -211,6 +211,7 @@ extern const struct inode_operations pro extern const struct inode_operations proc_pid_link_inode_operations; extern void proc_init_inodecache(void); +void set_proc_pid_nlink(void); extern struct inode *proc_get_inode(struct super_block *, struct proc_dir_entry *); extern int proc_fill_super(struct super_block *, void *data, int flags); extern void proc_entry_rundown(struct proc_dir_entry *); diff -puN fs/proc/root.c~proc-calculate-proc-and-proc-task-nlink-at-init-time fs/proc/root.c --- a/fs/proc/root.c~proc-calculate-proc-and-proc-task-nlink-at-init-time +++ a/fs/proc/root.c @@ -122,6 +122,7 @@ void __init proc_root_init(void) int err; proc_init_inodecache(); + set_proc_pid_nlink(); err = register_filesystem(&proc_fs_type); if (err) return; _ -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
