SUNRPC: cache must take a reference to the cache detail's module on open()

Otherwise we Oops if the module containing the cache detail is removed
before all cache readers have closed the file.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
This commit is contained in:
Trond Myklebust 2009-08-19 18:13:00 -04:00
parent 7d7ea88289
commit f7e86ab92f
1 changed files with 76 additions and 4 deletions

View File

@ -836,6 +836,8 @@ static int cache_open(struct inode *inode, struct file *filp,
{
struct cache_reader *rp = NULL;
if (!cd || !try_module_get(cd->owner))
return -EACCES;
nonseekable_open(inode, filp);
if (filp->f_mode & FMODE_READ) {
rp = kmalloc(sizeof(*rp), GFP_KERNEL);
@ -879,6 +881,7 @@ static int cache_release(struct inode *inode, struct file *filp,
cd->last_close = get_seconds();
atomic_dec(&cd->readers);
}
module_put(cd->owner);
return 0;
}
@ -1215,6 +1218,8 @@ static int content_open(struct inode *inode, struct file *file,
{
struct handle *han;
if (!cd || !try_module_get(cd->owner))
return -EACCES;
han = __seq_open_private(file, &cache_content_op, sizeof(*han));
if (han == NULL)
return -ENOMEM;
@ -1223,6 +1228,29 @@ static int content_open(struct inode *inode, struct file *file,
return 0;
}
static int content_release(struct inode *inode, struct file *file,
struct cache_detail *cd)
{
int ret = seq_release_private(inode, file);
module_put(cd->owner);
return ret;
}
static int open_flush(struct inode *inode, struct file *file,
struct cache_detail *cd)
{
if (!cd || !try_module_get(cd->owner))
return -EACCES;
return nonseekable_open(inode, file);
}
static int release_flush(struct inode *inode, struct file *file,
struct cache_detail *cd)
{
module_put(cd->owner);
return 0;
}
static ssize_t read_flush(struct file *file, char __user *buf,
size_t count, loff_t *ppos,
struct cache_detail *cd)
@ -1331,13 +1359,34 @@ static int content_open_procfs(struct inode *inode, struct file *filp)
return content_open(inode, filp, cd);
}
static int content_release_procfs(struct inode *inode, struct file *filp)
{
struct cache_detail *cd = PDE(inode)->data;
return content_release(inode, filp, cd);
}
static const struct file_operations content_file_operations_procfs = {
.open = content_open_procfs,
.read = seq_read,
.llseek = seq_lseek,
.release = seq_release_private,
.release = content_release_procfs,
};
static int open_flush_procfs(struct inode *inode, struct file *filp)
{
struct cache_detail *cd = PDE(inode)->data;
return open_flush(inode, filp, cd);
}
static int release_flush_procfs(struct inode *inode, struct file *filp)
{
struct cache_detail *cd = PDE(inode)->data;
return release_flush(inode, filp, cd);
}
static ssize_t read_flush_procfs(struct file *filp, char __user *buf,
size_t count, loff_t *ppos)
{
@ -1356,9 +1405,10 @@ static ssize_t write_flush_procfs(struct file *filp,
}
static const struct file_operations cache_flush_operations_procfs = {
.open = nonseekable_open,
.open = open_flush_procfs,
.read = read_flush_procfs,
.write = write_flush_procfs,
.release = release_flush_procfs,
};
static void remove_cache_proc_entries(struct cache_detail *cd)
@ -1503,13 +1553,34 @@ static int content_open_pipefs(struct inode *inode, struct file *filp)
return content_open(inode, filp, cd);
}
static int content_release_pipefs(struct inode *inode, struct file *filp)
{
struct cache_detail *cd = RPC_I(inode)->private;
return content_release(inode, filp, cd);
}
const struct file_operations content_file_operations_pipefs = {
.open = content_open_pipefs,
.read = seq_read,
.llseek = seq_lseek,
.release = seq_release_private,
.release = content_release_pipefs,
};
static int open_flush_pipefs(struct inode *inode, struct file *filp)
{
struct cache_detail *cd = RPC_I(inode)->private;
return open_flush(inode, filp, cd);
}
static int release_flush_pipefs(struct inode *inode, struct file *filp)
{
struct cache_detail *cd = RPC_I(inode)->private;
return release_flush(inode, filp, cd);
}
static ssize_t read_flush_pipefs(struct file *filp, char __user *buf,
size_t count, loff_t *ppos)
{
@ -1528,9 +1599,10 @@ static ssize_t write_flush_pipefs(struct file *filp,
}
const struct file_operations cache_flush_operations_pipefs = {
.open = nonseekable_open,
.open = open_flush_pipefs,
.read = read_flush_pipefs,
.write = write_flush_pipefs,
.release = release_flush_pipefs,
};
int sunrpc_cache_register_pipefs(struct dentry *parent,