From d7cc431edd0a6c69a88b5ff1e304af50bfb2270e Mon Sep 17 00:00:00 2001 From: Bryan Schumaker Date: Thu, 29 Nov 2012 11:40:45 -0500 Subject: [PATCH] NFSD: Add a custom file operations structure for fault injection Controlling the read and write functions allows me to add in "forget client w.x.y.z", since we won't be limited to reading and writing only u64 values. Signed-off-by: Bryan Schumaker Signed-off-by: J. Bruce Fields --- fs/nfsd/fault_inject.c | 56 ++++++++++++++++++++++++++++++++++++------ 1 file changed, 49 insertions(+), 7 deletions(-) diff --git a/fs/nfsd/fault_inject.c b/fs/nfsd/fault_inject.c index 545f8e4ed101..19f9094bbb07 100644 --- a/fs/nfsd/fault_inject.c +++ b/fs/nfsd/fault_inject.c @@ -8,6 +8,7 @@ #include #include #include +#include #include "state.h" @@ -48,10 +49,9 @@ static struct nfsd_fault_inject_op inject_ops[] = { static long int NUM_INJECT_OPS = sizeof(inject_ops) / sizeof(struct nfsd_fault_inject_op); static struct dentry *debug_dir; -static int nfsd_inject_set(void *op_ptr, u64 val) +static void nfsd_inject_set(struct nfsd_fault_inject_op *op, u64 val) { u64 count = 0; - struct nfsd_fault_inject_op *op = op_ptr; if (val == 0) printk(KERN_INFO "NFSD Fault Injection: %s (all)", op->file); @@ -62,19 +62,61 @@ static int nfsd_inject_set(void *op_ptr, u64 val) count = nfsd_for_n_state(val, op->forget); nfs4_unlock_state(); printk(KERN_INFO "NFSD: %s: found %llu", op->file, count); - return 0; } -static int nfsd_inject_get(void *op_ptr, u64 *val) +static void nfsd_inject_get(struct nfsd_fault_inject_op *op, u64 *val) { - struct nfsd_fault_inject_op *op = op_ptr; nfs4_lock_state(); *val = nfsd_for_n_state(0, op->print); nfs4_unlock_state(); - return 0; } -DEFINE_SIMPLE_ATTRIBUTE(fops_nfsd, nfsd_inject_get, nfsd_inject_set, "%llu\n"); +static ssize_t fault_inject_read(struct file *file, char __user *buf, + size_t len, loff_t *ppos) +{ + static u64 val; + char read_buf[25]; + size_t size, ret; + loff_t pos = *ppos; + + if (!pos) + nfsd_inject_get(file->f_dentry->d_inode->i_private, &val); + size = scnprintf(read_buf, sizeof(read_buf), "%llu\n", val); + + if (pos < 0) + return -EINVAL; + if (pos >= size || !len) + return 0; + if (len > size - pos) + len = size - pos; + ret = copy_to_user(buf, read_buf + pos, len); + if (ret == len) + return -EFAULT; + len -= ret; + *ppos = pos + len; + return len; +} + +static ssize_t fault_inject_write(struct file *file, const char __user *buf, + size_t len, loff_t *ppos) +{ + char write_buf[24]; + size_t size = min(sizeof(write_buf), len) - 1; + u64 val; + + if (copy_from_user(write_buf, buf, size)) + return -EFAULT; + + val = simple_strtoll(write_buf, NULL, 0); + nfsd_inject_set(file->f_dentry->d_inode->i_private, val); + return len; /* on success, claim we got the whole input */ +} + +static const struct file_operations fops_nfsd = { + .owner = THIS_MODULE, + .read = fault_inject_read, + .write = fault_inject_write, +}; void nfsd_fault_inject_cleanup(void) {