diff options
Diffstat (limited to 'fs/pipe.c')
| -rw-r--r-- | fs/pipe.c | 52 |
1 files changed, 41 insertions, 11 deletions
@@ -15,6 +15,7 @@ #include <linux/pipe_fs_i.h> #include <linux/uio.h> #include <linux/highmem.h> +#include <linux/pagemap.h> #include <asm/uaccess.h> #include <asm/ioctls.h> @@ -94,11 +95,20 @@ static void anon_pipe_buf_release(struct pipe_inode_info *info, struct pipe_buff { struct page *page = buf->page; - if (info->tmp_page) { - __free_page(page); + /* + * If nobody else uses this page, and we don't already have a + * temporary page, let's keep track of it as a one-deep + * allocation cache + */ + if (page_count(page) == 1 && !info->tmp_page) { + info->tmp_page = page; return; } - info->tmp_page = page; + + /* + * Otherwise just release our reference to it + */ + page_cache_release(page); } static void *anon_pipe_buf_map(struct file *file, struct pipe_inode_info *info, struct pipe_buffer *buf) @@ -111,11 +121,19 @@ static void anon_pipe_buf_unmap(struct pipe_inode_info *info, struct pipe_buffer kunmap(buf->page); } +static int anon_pipe_buf_steal(struct pipe_inode_info *info, + struct pipe_buffer *buf) +{ + buf->stolen = 1; + return 0; +} + static struct pipe_buf_operations anon_pipe_buf_ops = { .can_merge = 1, .map = anon_pipe_buf_map, .unmap = anon_pipe_buf_unmap, .release = anon_pipe_buf_release, + .steal = anon_pipe_buf_steal, }; static ssize_t @@ -152,6 +170,11 @@ pipe_readv(struct file *filp, const struct iovec *_iov, chars = total_len; addr = ops->map(filp, info, buf); + if (IS_ERR(addr)) { + if (!ret) + ret = PTR_ERR(addr); + break; + } error = pipe_iov_copy_to_user(iov, addr + buf->offset, chars); ops->unmap(info, buf); if (unlikely(error)) { @@ -254,8 +277,16 @@ pipe_writev(struct file *filp, const struct iovec *_iov, struct pipe_buf_operations *ops = buf->ops; int offset = buf->offset + buf->len; if (ops->can_merge && offset + chars <= PAGE_SIZE) { - void *addr = ops->map(filp, info, buf); - int error = pipe_iov_copy_from_user(offset + addr, iov, chars); + void *addr; + int error; + + addr = ops->map(filp, info, buf); + if (IS_ERR(addr)) { + error = PTR_ERR(addr); + goto out; + } + error = pipe_iov_copy_from_user(offset + addr, iov, + chars); ops->unmap(info, buf); ret = error; do_wakeup = 1; @@ -568,7 +599,7 @@ pipe_rdwr_open(struct inode *inode, struct file *filp) * The file_operations structs are not static because they * are also used in linux/fs/fifo.c to do operations on FIFOs. */ -struct file_operations read_fifo_fops = { +const struct file_operations read_fifo_fops = { .llseek = no_llseek, .read = pipe_read, .readv = pipe_readv, @@ -580,7 +611,7 @@ struct file_operations read_fifo_fops = { .fasync = pipe_read_fasync, }; -struct file_operations write_fifo_fops = { +const struct file_operations write_fifo_fops = { .llseek = no_llseek, .read = bad_pipe_r, .write = pipe_write, @@ -592,7 +623,7 @@ struct file_operations write_fifo_fops = { .fasync = pipe_write_fasync, }; -struct file_operations rdwr_fifo_fops = { +const struct file_operations rdwr_fifo_fops = { .llseek = no_llseek, .read = pipe_read, .readv = pipe_readv, @@ -662,10 +693,9 @@ struct inode* pipe_new(struct inode* inode) { struct pipe_inode_info *info; - info = kmalloc(sizeof(struct pipe_inode_info), GFP_KERNEL); + info = kzalloc(sizeof(struct pipe_inode_info), GFP_KERNEL); if (!info) goto fail_page; - memset(info, 0, sizeof(*info)); inode->i_pipe = info; init_waitqueue_head(PIPE_WAIT(*inode)); @@ -676,7 +706,7 @@ fail_page: return NULL; } -static struct vfsmount *pipe_mnt; +static struct vfsmount *pipe_mnt __read_mostly; static int pipefs_delete_dentry(struct dentry *dentry) { return 1; |
