diff options
Diffstat (limited to 'fs/configfs/file.c')
| -rw-r--r-- | fs/configfs/file.c | 75 |
1 files changed, 57 insertions, 18 deletions
diff --git a/fs/configfs/file.c b/fs/configfs/file.c index 9d5e888df60b..fb65b706cc0d 100644 --- a/fs/configfs/file.c +++ b/fs/configfs/file.c @@ -48,22 +48,32 @@ struct configfs_buffer { }; }; +static inline struct configfs_fragment *to_frag(struct file *file) +{ + struct configfs_dirent *sd = file->f_path.dentry->d_fsdata; + + return sd->s_frag; +} -static int fill_read_buffer(struct configfs_buffer * buffer) +static int fill_read_buffer(struct file *file, struct configfs_buffer *buffer) { - ssize_t count; + struct configfs_fragment *frag = to_frag(file); + ssize_t count = -ENOENT; if (!buffer->page) buffer->page = (char *) get_zeroed_page(GFP_KERNEL); if (!buffer->page) return -ENOMEM; - count = buffer->attr->show(buffer->item, buffer->page); + down_read(&frag->frag_sem); + if (!frag->frag_dead) + count = buffer->attr->show(buffer->item, buffer->page); + up_read(&frag->frag_sem); + if (count < 0) return count; if (WARN_ON_ONCE(count > (ssize_t)SIMPLE_ATTR_SIZE)) return -EIO; - buffer->needs_read_fill = 0; buffer->count = count; return 0; @@ -96,7 +106,7 @@ configfs_read_file(struct file *file, char __user *buf, size_t count, loff_t *pp mutex_lock(&buffer->mutex); if (buffer->needs_read_fill) { - retval = fill_read_buffer(buffer); + retval = fill_read_buffer(file, buffer); if (retval) goto out; } @@ -133,6 +143,7 @@ static ssize_t configfs_read_bin_file(struct file *file, char __user *buf, size_t count, loff_t *ppos) { + struct configfs_fragment *frag = to_frag(file); struct configfs_buffer *buffer = file->private_data; ssize_t retval = 0; ssize_t len = min_t(size_t, count, PAGE_SIZE); @@ -148,7 +159,12 @@ configfs_read_bin_file(struct file *file, char __user *buf, if (buffer->needs_read_fill) { /* perform first read with buf == NULL to get extent */ - len = buffer->bin_attr->read(buffer->item, NULL, 0); + down_read(&frag->frag_sem); + if (!frag->frag_dead) + len = buffer->bin_attr->read(buffer->item, NULL, 0); + else + len = -ENOENT; + up_read(&frag->frag_sem); if (len <= 0) { retval = len; goto out; @@ -168,8 +184,13 @@ configfs_read_bin_file(struct file *file, char __user *buf, buffer->bin_buffer_size = len; /* perform second read to fill buffer */ - len = buffer->bin_attr->read(buffer->item, - buffer->bin_buffer, len); + down_read(&frag->frag_sem); + if (!frag->frag_dead) + len = buffer->bin_attr->read(buffer->item, + buffer->bin_buffer, len); + else + len = -ENOENT; + up_read(&frag->frag_sem); if (len < 0) { retval = len; vfree(buffer->bin_buffer); @@ -220,9 +241,16 @@ fill_write_buffer(struct configfs_buffer * buffer, const char __user * buf, size } static int -flush_write_buffer(struct configfs_buffer *buffer, size_t count) +flush_write_buffer(struct file *file, struct configfs_buffer *buffer, size_t count) { - return buffer->attr->store(buffer->item, buffer->page, count); + struct configfs_fragment *frag = to_frag(file); + int res = -ENOENT; + + down_read(&frag->frag_sem); + if (!frag->frag_dead) + res = buffer->attr->store(buffer->item, buffer->page, count); + up_read(&frag->frag_sem); + return res; } @@ -252,7 +280,7 @@ configfs_write_file(struct file *file, const char __user *buf, size_t count, lof mutex_lock(&buffer->mutex); len = fill_write_buffer(buffer, buf, count); if (len > 0) - len = flush_write_buffer(buffer, len); + len = flush_write_buffer(file, buffer, len); if (len > 0) *ppos += len; mutex_unlock(&buffer->mutex); @@ -328,6 +356,7 @@ out: static int __configfs_open_file(struct inode *inode, struct file *file, int type) { struct dentry *dentry = file->f_path.dentry; + struct configfs_fragment *frag = to_frag(file); struct configfs_attribute *attr; struct configfs_buffer *buffer; int error; @@ -337,8 +366,13 @@ static int __configfs_open_file(struct inode *inode, struct file *file, int type if (!buffer) goto out; + error = -ENOENT; + down_read(&frag->frag_sem); + if (unlikely(frag->frag_dead)) + goto out_free_buffer; + error = -EINVAL; - buffer->item = configfs_get_config_item(dentry->d_parent); + buffer->item = to_item(dentry->d_parent); if (!buffer->item) goto out_free_buffer; @@ -396,6 +430,7 @@ static int __configfs_open_file(struct inode *inode, struct file *file, int type buffer->read_in_progress = false; buffer->write_in_progress = false; file->private_data = buffer; + up_read(&frag->frag_sem); return 0; out_put_module: @@ -403,6 +438,7 @@ out_put_module: out_put_item: config_item_put(buffer->item); out_free_buffer: + up_read(&frag->frag_sem); kfree(buffer); out: return error; @@ -412,8 +448,6 @@ static int configfs_release(struct inode *inode, struct file *filp) { struct configfs_buffer *buffer = filp->private_data; - if (buffer->item) - config_item_put(buffer->item); module_put(buffer->owner); if (buffer->page) free_page((unsigned long)buffer->page); @@ -439,12 +473,17 @@ static int configfs_release_bin_file(struct inode *inode, struct file *file) buffer->read_in_progress = false; if (buffer->write_in_progress) { + struct configfs_fragment *frag = to_frag(file); buffer->write_in_progress = false; - /* result of ->release() is ignored */ - buffer->bin_attr->write(buffer->item, buffer->bin_buffer, - buffer->bin_buffer_size); - + down_read(&frag->frag_sem); + if (!frag->frag_dead) { + /* result of ->release() is ignored */ + buffer->bin_attr->write(buffer->item, + buffer->bin_buffer, + buffer->bin_buffer_size); + } + up_read(&frag->frag_sem); /* vfree on NULL is safe */ vfree(buffer->bin_buffer); buffer->bin_buffer = NULL; |