diff options
Diffstat (limited to 'fs/sysfs/file.c')
| -rw-r--r-- | fs/sysfs/file.c | 14 |
1 files changed, 10 insertions, 4 deletions
diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c index a271c87c4472..ade9a7e6a757 100644 --- a/fs/sysfs/file.c +++ b/fs/sysfs/file.c @@ -12,6 +12,8 @@ #include <linux/module.h> #include <linux/kobject.h> +#include <linux/kallsyms.h> +#include <linux/slab.h> #include <linux/namei.h> #include <linux/poll.h> #include <linux/list.h> @@ -86,7 +88,12 @@ static int fill_read_buffer(struct dentry * dentry, struct sysfs_buffer * buffer * The code works fine with PAGE_SIZE return but it's likely to * indicate truncated result or overflow in normal use cases. */ - BUG_ON(count >= (ssize_t)PAGE_SIZE); + if (count >= (ssize_t)PAGE_SIZE) { + print_symbol("fill_read_buffer: %s returned bad count\n", + (unsigned long)ops->show); + /* Try to struggle along */ + count = PAGE_SIZE - 1; + } if (count >= 0) { buffer->needs_read_fill = 0; buffer->count = count; @@ -122,7 +129,7 @@ sysfs_read_file(struct file *file, char __user *buf, size_t count, loff_t *ppos) ssize_t retval = 0; mutex_lock(&buffer->mutex); - if (buffer->needs_read_fill) { + if (buffer->needs_read_fill || *ppos == 0) { retval = fill_read_buffer(file->f_path.dentry,buffer); if (retval) goto out; @@ -403,8 +410,7 @@ static int sysfs_release(struct inode *inode, struct file *filp) * return POLLERR|POLLPRI, and select will return the fd whether * it is waiting for read, write, or exceptions. * Once poll/select indicates that the value has changed, you - * need to close and re-open the file, as simply seeking and reading - * again will not get new data, or reset the state of 'poll'. + * need to close and re-open the file, or seek to 0 and read again. * Reminder: this only works for attributes which actively support * it, and it is not possible to test an attribute from userspace * to see if it supports poll (Neither 'poll' nor 'select' return |