diff options
| -rw-r--r-- | arch/i386/kernel/syscall_table.S | 1 | ||||
| -rw-r--r-- | arch/ia64/kernel/entry.S | 1 | ||||
| -rw-r--r-- | arch/powerpc/kernel/systbl.S | 1 | ||||
| -rw-r--r-- | fs/pipe.c | 7 | ||||
| -rw-r--r-- | fs/splice.c | 186 | ||||
| -rw-r--r-- | include/asm-i386/unistd.h | 3 | ||||
| -rw-r--r-- | include/asm-ia64/unistd.h | 3 | ||||
| -rw-r--r-- | include/asm-powerpc/unistd.h | 3 | ||||
| -rw-r--r-- | include/asm-x86_64/unistd.h | 4 | ||||
| -rw-r--r-- | include/linux/pipe_fs_i.h | 1 | ||||
| -rw-r--r-- | include/linux/syscalls.h | 2 |
11 files changed, 208 insertions, 4 deletions
diff --git a/arch/i386/kernel/syscall_table.S b/arch/i386/kernel/syscall_table.S index 4f58b9c..f48bef1 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 6e16f6b..e307988 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 1424eab..a14c964 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) @@ -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 5d3eda6..8d57e89 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 6a8dd83..d81d6cf 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 1c749ac..a40ebec 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 536ba08..c612f1a 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 f21ff2c..d86494e 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 123a7c2..ef7f33c 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 f001bad..d3ebc0e 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); |
