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-rw-r--r--arch/i386/kernel/syscall_table.S1
-rw-r--r--arch/ia64/kernel/entry.S1
-rw-r--r--arch/powerpc/kernel/systbl.S1
-rw-r--r--fs/pipe.c7
-rw-r--r--fs/splice.c186
-rw-r--r--include/asm-i386/unistd.h3
-rw-r--r--include/asm-ia64/unistd.h3
-rw-r--r--include/asm-powerpc/unistd.h3
-rw-r--r--include/asm-x86_64/unistd.h4
-rw-r--r--include/linux/pipe_fs_i.h1
-rw-r--r--include/linux/syscalls.h2
11 files changed, 208 insertions, 4 deletions
diff --git a/arch/i386/kernel/syscall_table.S b/arch/i386/kernel/syscall_table.S
index 4f58b9c0efe3..f48bef15b4f0 100644
--- a/arch/i386/kernel/syscall_table.S
+++ b/arch/i386/kernel/syscall_table.S
@@ -314,3 +314,4 @@ ENTRY(sys_call_table)
.long sys_get_robust_list
.long sys_splice
.long sys_sync_file_range
+ .long sys_tee /* 315 */
diff --git a/arch/ia64/kernel/entry.S b/arch/ia64/kernel/entry.S
index 6e16f6b35bd3..e30798811216 100644
--- a/arch/ia64/kernel/entry.S
+++ b/arch/ia64/kernel/entry.S
@@ -1609,5 +1609,6 @@ sys_call_table:
data8 sys_set_robust_list
data8 sys_get_robust_list
data8 sys_sync_file_range // 1300
+ data8 sys_tee
.org sys_call_table + 8*NR_syscalls // guard against failures to increase NR_syscalls
diff --git a/arch/powerpc/kernel/systbl.S b/arch/powerpc/kernel/systbl.S
index 1424eab450ee..a14c96403840 100644
--- a/arch/powerpc/kernel/systbl.S
+++ b/arch/powerpc/kernel/systbl.S
@@ -323,3 +323,4 @@ COMPAT_SYS(pselect6)
COMPAT_SYS(ppoll)
SYSCALL(unshare)
SYSCALL(splice)
+SYSCALL(tee)
diff --git a/fs/pipe.c b/fs/pipe.c
index e984beb93a0e..7fefb10db8d9 100644
--- a/fs/pipe.c
+++ b/fs/pipe.c
@@ -131,12 +131,19 @@ static int anon_pipe_buf_steal(struct pipe_inode_info *pipe,
return 0;
}
+static void anon_pipe_buf_get(struct pipe_inode_info *info,
+ struct pipe_buffer *buf)
+{
+ page_cache_get(buf->page);
+}
+
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,
+ .get = anon_pipe_buf_get,
};
static ssize_t
diff --git a/fs/splice.c b/fs/splice.c
index 5d3eda64703b..8d57e89924a6 100644
--- a/fs/splice.c
+++ b/fs/splice.c
@@ -125,12 +125,19 @@ static void page_cache_pipe_buf_unmap(struct pipe_inode_info *info,
kunmap(buf->page);
}
+static void page_cache_pipe_buf_get(struct pipe_inode_info *info,
+ struct pipe_buffer *buf)
+{
+ page_cache_get(buf->page);
+}
+
static struct pipe_buf_operations page_cache_pipe_buf_ops = {
.can_merge = 0,
.map = page_cache_pipe_buf_map,
.unmap = page_cache_pipe_buf_unmap,
.release = page_cache_pipe_buf_release,
.steal = page_cache_pipe_buf_steal,
+ .get = page_cache_pipe_buf_get,
};
/*
@@ -963,3 +970,182 @@ asmlinkage long sys_splice(int fd_in, loff_t __user *off_in,
return error;
}
+
+/*
+ * Link contents of ipipe to opipe.
+ */
+static int link_pipe(struct pipe_inode_info *ipipe,
+ struct pipe_inode_info *opipe,
+ size_t len, unsigned int flags)
+{
+ struct pipe_buffer *ibuf, *obuf;
+ int ret = 0, do_wakeup = 0, i;
+
+ /*
+ * Potential ABBA deadlock, work around it by ordering lock
+ * grabbing by inode address. Otherwise two different processes
+ * could deadlock (one doing tee from A -> B, the other from B -> A).
+ */
+ if (ipipe->inode < opipe->inode) {
+ mutex_lock(&ipipe->inode->i_mutex);
+ mutex_lock(&opipe->inode->i_mutex);
+ } else {
+ mutex_lock(&opipe->inode->i_mutex);
+ mutex_lock(&ipipe->inode->i_mutex);
+ }
+
+ for (i = 0;; i++) {
+ if (!opipe->readers) {
+ send_sig(SIGPIPE, current, 0);
+ if (!ret)
+ ret = -EPIPE;
+ break;
+ }
+ if (ipipe->nrbufs - i) {
+ ibuf = ipipe->bufs + ((ipipe->curbuf + i) & (PIPE_BUFFERS - 1));
+
+ /*
+ * If we have room, fill this buffer
+ */
+ if (opipe->nrbufs < PIPE_BUFFERS) {
+ int nbuf = (opipe->curbuf + opipe->nrbufs) & (PIPE_BUFFERS - 1);
+
+ /*
+ * Get a reference to this pipe buffer,
+ * so we can copy the contents over.
+ */
+ ibuf->ops->get(ipipe, ibuf);
+
+ obuf = opipe->bufs + nbuf;
+ *obuf = *ibuf;
+
+ if (obuf->len > len)
+ obuf->len = len;
+
+ opipe->nrbufs++;
+ do_wakeup = 1;
+ ret += obuf->len;
+ len -= obuf->len;
+
+ if (!len)
+ break;
+ if (opipe->nrbufs < PIPE_BUFFERS)
+ continue;
+ }
+
+ /*
+ * We have input available, but no output room.
+ * If we already copied data, return that.
+ */
+ if (flags & SPLICE_F_NONBLOCK) {
+ if (!ret)
+ ret = -EAGAIN;
+ break;
+ }
+ if (signal_pending(current)) {
+ if (!ret)
+ ret = -ERESTARTSYS;
+ break;
+ }
+ if (do_wakeup) {
+ smp_mb();
+ if (waitqueue_active(&opipe->wait))
+ wake_up_interruptible(&opipe->wait);
+ kill_fasync(&opipe->fasync_readers, SIGIO, POLL_IN);
+ do_wakeup = 0;
+ }
+
+ opipe->waiting_writers++;
+ pipe_wait(opipe);
+ opipe->waiting_writers--;
+ continue;
+ }
+
+ /*
+ * No input buffers, do the usual checks for available
+ * writers and blocking and wait if necessary
+ */
+ if (!ipipe->writers)
+ break;
+ if (!ipipe->waiting_writers) {
+ if (ret)
+ break;
+ }
+ if (flags & SPLICE_F_NONBLOCK) {
+ if (!ret)
+ ret = -EAGAIN;
+ break;
+ }
+ if (signal_pending(current)) {
+ if (!ret)
+ ret = -ERESTARTSYS;
+ break;
+ }
+
+ if (waitqueue_active(&ipipe->wait))
+ wake_up_interruptible_sync(&ipipe->wait);
+ kill_fasync(&ipipe->fasync_writers, SIGIO, POLL_OUT);
+
+ pipe_wait(ipipe);
+ }
+
+ mutex_unlock(&ipipe->inode->i_mutex);
+ mutex_unlock(&opipe->inode->i_mutex);
+
+ if (do_wakeup) {
+ smp_mb();
+ if (waitqueue_active(&opipe->wait))
+ wake_up_interruptible(&opipe->wait);
+ kill_fasync(&opipe->fasync_readers, SIGIO, POLL_IN);
+ }
+
+ return ret;
+}
+
+/*
+ * This is a tee(1) implementation that works on pipes. It doesn't copy
+ * any data, it simply references the 'in' pages on the 'out' pipe.
+ * The 'flags' used are the SPLICE_F_* variants, currently the only
+ * applicable one is SPLICE_F_NONBLOCK.
+ */
+static long do_tee(struct file *in, struct file *out, size_t len,
+ unsigned int flags)
+{
+ struct pipe_inode_info *ipipe = in->f_dentry->d_inode->i_pipe;
+ struct pipe_inode_info *opipe = out->f_dentry->d_inode->i_pipe;
+
+ /*
+ * Link ipipe to the two output pipes, consuming as we go along.
+ */
+ if (ipipe && opipe)
+ return link_pipe(ipipe, opipe, len, flags);
+
+ return -EINVAL;
+}
+
+asmlinkage long sys_tee(int fdin, int fdout, size_t len, unsigned int flags)
+{
+ struct file *in;
+ int error, fput_in;
+
+ if (unlikely(!len))
+ return 0;
+
+ error = -EBADF;
+ in = fget_light(fdin, &fput_in);
+ if (in) {
+ if (in->f_mode & FMODE_READ) {
+ int fput_out;
+ struct file *out = fget_light(fdout, &fput_out);
+
+ if (out) {
+ if (out->f_mode & FMODE_WRITE)
+ error = do_tee(in, out, len, flags);
+ fput_light(out, fput_out);
+ }
+ }
+ fput_light(in, fput_in);
+ }
+
+ return error;
+}
diff --git a/include/asm-i386/unistd.h b/include/asm-i386/unistd.h
index 6a8dd83c350f..d81d6cfc1bb4 100644
--- a/include/asm-i386/unistd.h
+++ b/include/asm-i386/unistd.h
@@ -320,8 +320,9 @@
#define __NR_get_robust_list 312
#define __NR_splice 313
#define __NR_sync_file_range 314
+#define __NR_tee 315
-#define NR_syscalls 315
+#define NR_syscalls 316
/*
* user-visible error numbers are in the range -1 - -128: see
diff --git a/include/asm-ia64/unistd.h b/include/asm-ia64/unistd.h
index 1c749acca021..a40ebec6aeeb 100644
--- a/include/asm-ia64/unistd.h
+++ b/include/asm-ia64/unistd.h
@@ -289,12 +289,13 @@
#define __NR_set_robust_list 1298
#define __NR_get_robust_list 1299
#define __NR_sync_file_range 1300
+#define __NR_tee 1301
#ifdef __KERNEL__
#include <linux/config.h>
-#define NR_syscalls 277 /* length of syscall table */
+#define NR_syscalls 278 /* length of syscall table */
#define __ARCH_WANT_SYS_RT_SIGACTION
diff --git a/include/asm-powerpc/unistd.h b/include/asm-powerpc/unistd.h
index 536ba0873052..c612f1a62772 100644
--- a/include/asm-powerpc/unistd.h
+++ b/include/asm-powerpc/unistd.h
@@ -302,8 +302,9 @@
#define __NR_ppoll 281
#define __NR_unshare 282
#define __NR_splice 283
+#define __NR_tee 284
-#define __NR_syscalls 284
+#define __NR_syscalls 285
#ifdef __KERNEL__
#define __NR__exit __NR_exit
diff --git a/include/asm-x86_64/unistd.h b/include/asm-x86_64/unistd.h
index f21ff2c1e960..d86494e23b63 100644
--- a/include/asm-x86_64/unistd.h
+++ b/include/asm-x86_64/unistd.h
@@ -611,8 +611,10 @@ __SYSCALL(__NR_set_robust_list, sys_set_robust_list)
__SYSCALL(__NR_get_robust_list, sys_get_robust_list)
#define __NR_splice 275
__SYSCALL(__NR_splice, sys_splice)
+#define __NR_tee 276
+__SYSCALL(__NR_tee, sys_tee)
-#define __NR_syscall_max __NR_splice
+#define __NR_syscall_max __NR_tee
#ifndef __NO_STUBS
diff --git a/include/linux/pipe_fs_i.h b/include/linux/pipe_fs_i.h
index 123a7c24bc72..ef7f33c0be19 100644
--- a/include/linux/pipe_fs_i.h
+++ b/include/linux/pipe_fs_i.h
@@ -21,6 +21,7 @@ struct pipe_buf_operations {
void (*unmap)(struct pipe_inode_info *, struct pipe_buffer *);
void (*release)(struct pipe_inode_info *, struct pipe_buffer *);
int (*steal)(struct pipe_inode_info *, struct pipe_buffer *);
+ void (*get)(struct pipe_inode_info *, struct pipe_buffer *);
};
struct pipe_inode_info {
diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h
index f001bad28d9a..d3ebc0e68b2b 100644
--- a/include/linux/syscalls.h
+++ b/include/linux/syscalls.h
@@ -574,6 +574,8 @@ asmlinkage long sys_splice(int fd_in, loff_t __user *off_in,
int fd_out, loff_t __user *off_out,
size_t len, unsigned int flags);
+asmlinkage long sys_tee(int fdin, int fdout, size_t len, unsigned int flags);
+
asmlinkage long sys_sync_file_range(int fd, loff_t offset, loff_t nbytes,
unsigned int flags);
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-10 12:11:04 +0000