Convert snd-page-alloc proc file to use seq_file

Use seq_file for the proc file read/write of snd-page-alloc module.
This automatically fixes bugs in the old proc code.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/sound/core/memalloc.c b/sound/core/memalloc.c
index f057430db0d01021d6b2c27df157b64a4958fd7a..9b5656d8bccac7d140168bfbd1e65af4a0e96c13 100644 (file)
--- a/sound/core/memalloc.c
+++ b/sound/core/memalloc.c
@@ -27,6 +27,7 @@
 #include <linux/pci.h>
 #include <linux/slab.h>
 #include <linux/mm.h>
+#include <linux/seq_file.h>
 #include <asm/uaccess.h>
 #include <linux/dma-mapping.h>
 #include <linux/moduleparam.h>
@@ -481,53 +482,54 @@ static void free_all_reserved_pages(void)
 #define SND_MEM_PROC_FILE      "driver/snd-page-alloc"
 static struct proc_dir_entry *snd_mem_proc;
 
-static int snd_mem_proc_read(char *page, char **start, off_t off,
-                            int count, int *eof, void *data)
+static int snd_mem_proc_read(struct seq_file *seq, void *offset)
 {
-       int len = 0;
        long pages = snd_allocated_pages >> (PAGE_SHIFT-12);
        struct snd_mem_list *mem;
        int devno;
        static char *types[] = { "UNKNOWN", "CONT", "DEV", "DEV-SG", "SBUS" };
 
        mutex_lock(&list_mutex);
-       len += snprintf(page + len, count - len,
-                       "pages  : %li bytes (%li pages per %likB)\n",
-                       pages * PAGE_SIZE, pages, PAGE_SIZE / 1024);
+       seq_printf(seq, "pages  : %li bytes (%li pages per %likB)\n",
+                  pages * PAGE_SIZE, pages, PAGE_SIZE / 1024);
        devno = 0;
        list_for_each_entry(mem, &mem_list_head, list) {
                devno++;
-               len += snprintf(page + len, count - len,
-                               "buffer %d : ID %08x : type %s\n",
-                               devno, mem->id, types[mem->buffer.dev.type]);
-               len += snprintf(page + len, count - len,
-                               "  addr = 0x%lx, size = %d bytes\n",
-                               (unsigned long)mem->buffer.addr, (int)mem->buffer.bytes);
+               seq_printf(seq, "buffer %d : ID %08x : type %s\n",
+                          devno, mem->id, types[mem->buffer.dev.type]);
+               seq_printf(seq, "  addr = 0x%lx, size = %d bytes\n",
+                          (unsigned long)mem->buffer.addr,
+                          (int)mem->buffer.bytes);
        }
        mutex_unlock(&list_mutex);
-       return len;
+       return 0;
+}
+
+static int snd_mem_proc_open(struct inode *inode, struct file *file)
+{
+       return single_open(file, snd_mem_proc_read, NULL);
 }
 
 /* FIXME: for pci only - other bus? */
 #ifdef CONFIG_PCI
 #define gettoken(bufp) strsep(bufp, " \t\n")
 
-static int snd_mem_proc_write(struct file *file, const char __user *buffer,
-                             unsigned long count, void *data)
+static ssize_t snd_mem_proc_write(struct file *file, const char __user * buffer,
+                                 size_t count, loff_t * ppos)
 {
        char buf[128];
        char *token, *p;
 
-       if (count > ARRAY_SIZE(buf) - 1)
-               count = ARRAY_SIZE(buf) - 1;
+       if (count > sizeof(buf) - 1)
+               return -EINVAL;
        if (copy_from_user(buf, buffer, count))
                return -EFAULT;
-       buf[ARRAY_SIZE(buf) - 1] = '\0';
+       buf[count] = '\0';
 
        p = buf;
        token = gettoken(&p);
        if (! token || *token == '#')
-               return (int)count;
+               return count;
        if (strcmp(token, "add") == 0) {
                char *endp;
                int vendor, device, size, buffers;
@@ -548,7 +550,7 @@ static int snd_mem_proc_write(struct file *file, const char __user *buffer,
                    (buffers = simple_strtol(token, NULL, 0)) <= 0 ||
                    buffers > 4) {
                        printk(KERN_ERR "snd-page-alloc: invalid proc write format\n");
-                       return (int)count;
+                       return count;
                }
                vendor &= 0xffff;
                device &= 0xffff;
@@ -560,7 +562,7 @@ static int snd_mem_proc_write(struct file *file, const char __user *buffer,
                                if (pci_set_dma_mask(pci, mask) < 0 ||
                                    pci_set_consistent_dma_mask(pci, mask) < 0) {
                                        printk(KERN_ERR "snd-page-alloc: cannot set DMA mask %lx for pci %04x:%04x\n", mask, vendor, device);
-                                       return (int)count;
+                                       return count;
                                }
                        }
                        for (i = 0; i < buffers; i++) {
@@ -570,7 +572,7 @@ static int snd_mem_proc_write(struct file *file, const char __user *buffer,
                                                        size, &dmab) < 0) {
                                        printk(KERN_ERR "snd-page-alloc: cannot allocate buffer pages (size = %d)\n", size);
                                        pci_dev_put(pci);
-                                       return (int)count;
+                                       return count;
                                }
                                snd_dma_reserve_buf(&dmab, snd_dma_pci_buf_id(pci));
                        }
@@ -596,9 +598,21 @@ static int snd_mem_proc_write(struct file *file, const char __user *buffer,
                free_all_reserved_pages();
        else
                printk(KERN_ERR "snd-page-alloc: invalid proc cmd\n");
-       return (int)count;
+       return count;
 }
 #endif /* CONFIG_PCI */
+
+static const struct file_operations snd_mem_proc_fops = {
+       .owner          = THIS_MODULE,
+       .open           = snd_mem_proc_open,
+       .read           = seq_read,
+#ifdef CONFIG_PCI
+       .write          = snd_mem_proc_write,
+#endif
+       .llseek         = seq_lseek,
+       .release        = single_release,
+};
+
 #endif /* CONFIG_PROC_FS */
 
 /*
@@ -609,12 +623,8 @@ static int __init snd_mem_init(void)
 {
 #ifdef CONFIG_PROC_FS
        snd_mem_proc = create_proc_entry(SND_MEM_PROC_FILE, 0644, NULL);
-       if (snd_mem_proc) {
-               snd_mem_proc->read_proc = snd_mem_proc_read;
-#ifdef CONFIG_PCI
-               snd_mem_proc->write_proc = snd_mem_proc_write;
-#endif
-       }
+       if (snd_mem_proc)
+               snd_mem_proc->proc_fops = &snd_mem_proc_fops;
 #endif
        return 0;
 }