diff options
Diffstat (limited to 'fs/proc/generic.c')
-rw-r--r-- | fs/proc/generic.c | 65 |
1 files changed, 54 insertions, 11 deletions
diff --git a/fs/proc/generic.c b/fs/proc/generic.c index db7fa5c..fa678ab 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) { @@ -363,7 +406,7 @@ static int proc_delete_dentry(struct dentry * dentry) return 1; } -static struct dentry_operations proc_dentry_operations = +static const struct dentry_operations proc_dentry_operations = { .d_delete = proc_delete_dentry, }; |