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>

1 files changed, 39 insertions, 29 deletions

diff --git a/sound/core/memalloc.c b/sound/core/memalloc.c
index f057430db0d0..9b5656d8bcca 100644
--- 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;
 }