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Diffstat (limited to 'fs/proc/generic.c')
-rw-r--r--fs/proc/generic.c63
1 files changed, 53 insertions, 10 deletions
diff --git a/fs/proc/generic.c b/fs/proc/generic.c
index 5d2989e9dcc..fa678abc9db 100644
--- a/fs/proc/generic.c
+++ b/fs/proc/generic.c
@@ -37,7 +37,7 @@ static int proc_match(int len, const char *name, struct proc_dir_entry *de)
#define PROC_BLOCK_SIZE (PAGE_SIZE - 1024)
static ssize_t
-proc_file_read(struct file *file, char __user *buf, size_t nbytes,
+__proc_file_read(struct file *file, char __user *buf, size_t nbytes,
loff_t *ppos)
{
struct inode * inode = file->f_path.dentry->d_inode;
@@ -183,19 +183,47 @@ proc_file_read(struct file *file, char __user *buf, size_t nbytes,
}
static ssize_t
+proc_file_read(struct file *file, char __user *buf, size_t nbytes,
+ loff_t *ppos)
+{
+ struct proc_dir_entry *pde = PDE(file->f_path.dentry->d_inode);
+ ssize_t rv = -EIO;
+
+ spin_lock(&pde->pde_unload_lock);
+ if (!pde->proc_fops) {
+ spin_unlock(&pde->pde_unload_lock);
+ return rv;
+ }
+ pde->pde_users++;
+ spin_unlock(&pde->pde_unload_lock);
+
+ rv = __proc_file_read(file, buf, nbytes, ppos);
+
+ pde_users_dec(pde);
+ return rv;
+}
+
+static ssize_t
proc_file_write(struct file *file, const char __user *buffer,
size_t count, loff_t *ppos)
{
- struct inode *inode = file->f_path.dentry->d_inode;
- struct proc_dir_entry * dp;
-
- dp = PDE(inode);
-
- if (!dp->write_proc)
- return -EIO;
+ struct proc_dir_entry *pde = PDE(file->f_path.dentry->d_inode);
+ ssize_t rv = -EIO;
+
+ if (pde->write_proc) {
+ spin_lock(&pde->pde_unload_lock);
+ if (!pde->proc_fops) {
+ spin_unlock(&pde->pde_unload_lock);
+ return rv;
+ }
+ pde->pde_users++;
+ spin_unlock(&pde->pde_unload_lock);
- /* FIXME: does this routine need ppos? probably... */
- return dp->write_proc(file, buffer, count, dp->data);
+ /* FIXME: does this routine need ppos? probably... */
+ rv = pde->write_proc(file, buffer, count, pde->data);
+ pde_users_dec(pde);
+ }
+ return rv;
}
@@ -307,6 +335,21 @@ static DEFINE_SPINLOCK(proc_inum_lock); /* protects the above */
/*
* Return an inode number between PROC_DYNAMIC_FIRST and
* 0xffffffff, or zero on failure.
+ *
+ * Current inode allocations in the proc-fs (hex-numbers):
+ *
+ * 00000000 reserved
+ * 00000001-00000fff static entries (goners)
+ * 001 root-ino
+ *
+ * 00001000-00001fff unused
+ * 0001xxxx-7fffxxxx pid-dir entries for pid 1-7fff
+ * 80000000-efffffff unused
+ * f0000000-ffffffff dynamic entries
+ *
+ * Goal:
+ * Once we split the thing into several virtual filesystems,
+ * we will get rid of magical ranges (and this comment, BTW).
*/
static unsigned int get_inode_number(void)
{