From 68eef3b4791572ecb70249c7fb145bb3742dd899 Mon Sep 17 00:00:00 2001 From: Joe Korty Date: Fri, 31 Mar 2006 02:30:32 -0800 Subject: [PATCH] Simplify proc/devices and fix early termination regression Make baby-simple the code for /proc/devices. Based on the proven design for /proc/interrupts. This also fixes the early-termination regression 2.6.16 introduced, as demonstrated by: # dd if=/proc/devices bs=1 Character devices: 1 mem 27+0 records in 27+0 records out This should also work (but is untested) when /proc/devices >4096 bytes, which I believe is what the original 2.6.16 rewrite fixed. [akpm@osdl.org: cleanups, simplifications] Signed-off-by: Joe Korty Cc: Neil Horman Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/proc/proc_misc.c | 163 ++++++++++++---------------------------------------- 1 file changed, 36 insertions(+), 127 deletions(-) (limited to 'fs/proc/proc_misc.c') diff --git a/fs/proc/proc_misc.c b/fs/proc/proc_misc.c index ef5a332..5c10ea1 100644 --- a/fs/proc/proc_misc.c +++ b/fs/proc/proc_misc.c @@ -249,144 +249,60 @@ static int cpuinfo_open(struct inode *inode, struct file *file) return seq_open(file, &cpuinfo_op); } -enum devinfo_states { - CHR_HDR, - CHR_LIST, - BLK_HDR, - BLK_LIST, - DEVINFO_DONE -}; - -struct devinfo_state { - void *chrdev; - void *blkdev; - unsigned int num_records; - unsigned int cur_record; - enum devinfo_states state; +static struct file_operations proc_cpuinfo_operations = { + .open = cpuinfo_open, + .read = seq_read, + .llseek = seq_lseek, + .release = seq_release, }; -static void *devinfo_start(struct seq_file *f, loff_t *pos) +static int devinfo_show(struct seq_file *f, void *v) { - struct devinfo_state *info = f->private; + int i = *(loff_t *) v; - if (*pos) { - if ((info) && (*pos <= info->num_records)) - return info; - return NULL; + if (i < CHRDEV_MAJOR_HASH_SIZE) { + if (i == 0) + seq_printf(f, "Character devices:\n"); + chrdev_show(f, i); + } else { + i -= CHRDEV_MAJOR_HASH_SIZE; + if (i == 0) + seq_printf(f, "\nBlock devices:\n"); + blkdev_show(f, i); } - info = kmalloc(sizeof(*info), GFP_KERNEL); - f->private = info; - info->chrdev = acquire_chrdev_list(); - info->blkdev = acquire_blkdev_list(); - info->state = CHR_HDR; - info->num_records = count_chrdev_list(); - info->num_records += count_blkdev_list(); - info->num_records += 2; /* Character and Block headers */ - *pos = 1; - info->cur_record = *pos; - return info; + return 0; } -static void *devinfo_next(struct seq_file *f, void *v, loff_t *pos) +static void *devinfo_start(struct seq_file *f, loff_t *pos) { - int idummy; - char *ndummy; - struct devinfo_state *info = f->private; - - switch (info->state) { - case CHR_HDR: - info->state = CHR_LIST; - (*pos)++; - /*fallthrough*/ - case CHR_LIST: - if (get_chrdev_info(info->chrdev,&idummy,&ndummy)) { - /* - * The character dev list is complete - */ - info->state = BLK_HDR; - } else { - info->chrdev = get_next_chrdev(info->chrdev); - } - (*pos)++; - break; - case BLK_HDR: - info->state = BLK_LIST; - (*pos)++; - /*fallthrough*/ - case BLK_LIST: - if (get_blkdev_info(info->blkdev,&idummy,&ndummy)) { - /* - * The block dev list is complete - */ - info->state = DEVINFO_DONE; - } else { - info->blkdev = get_next_blkdev(info->blkdev); - } - (*pos)++; - break; - case DEVINFO_DONE: - (*pos)++; - info->cur_record = *pos; - info = NULL; - break; - default: - break; - } - if (info) - info->cur_record = *pos; - return info; + if (*pos < (BLKDEV_MAJOR_HASH_SIZE + CHRDEV_MAJOR_HASH_SIZE)) + return pos; + return NULL; } -static void devinfo_stop(struct seq_file *f, void *v) +static void *devinfo_next(struct seq_file *f, void *v, loff_t *pos) { - struct devinfo_state *info = f->private; - - if (info) { - release_chrdev_list(info->chrdev); - release_blkdev_list(info->blkdev); - f->private = NULL; - kfree(info); - } + (*pos)++; + if (*pos >= (BLKDEV_MAJOR_HASH_SIZE + CHRDEV_MAJOR_HASH_SIZE)) + return NULL; + return pos; } -static int devinfo_show(struct seq_file *f, void *arg) -{ - int major; - char *name; - struct devinfo_state *info = f->private; - - switch(info->state) { - case CHR_HDR: - seq_printf(f,"Character devices:\n"); - /* fallthrough */ - case CHR_LIST: - if (!get_chrdev_info(info->chrdev,&major,&name)) - seq_printf(f,"%3d %s\n",major,name); - break; - case BLK_HDR: - seq_printf(f,"\nBlock devices:\n"); - /* fallthrough */ - case BLK_LIST: - if (!get_blkdev_info(info->blkdev,&major,&name)) - seq_printf(f,"%3d %s\n",major,name); - break; - default: - break; - } - - return 0; +static void devinfo_stop(struct seq_file *f, void *v) +{ + /* Nothing to do */ } -static struct seq_operations devinfo_op = { - .start = devinfo_start, - .next = devinfo_next, - .stop = devinfo_stop, - .show = devinfo_show, +static struct seq_operations devinfo_ops = { + .start = devinfo_start, + .next = devinfo_next, + .stop = devinfo_stop, + .show = devinfo_show }; -static int devinfo_open(struct inode *inode, struct file *file) +static int devinfo_open(struct inode *inode, struct file *filp) { - return seq_open(file, &devinfo_op); + return seq_open(filp, &devinfo_ops); } static struct file_operations proc_devinfo_operations = { @@ -396,13 +312,6 @@ static struct file_operations proc_devinfo_operations = { .release = seq_release, }; -static struct file_operations proc_cpuinfo_operations = { - .open = cpuinfo_open, - .read = seq_read, - .llseek = seq_lseek, - .release = seq_release, -}; - extern struct seq_operations vmstat_op; static int vmstat_open(struct inode *inode, struct file *file) { -- cgit v1.1