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5274f052e7
This adds support for the sys_splice system call. Using a pipe as a transport, it can connect to files or sockets (latter as output only). From the splice.c comments: "splice": joining two ropes together by interweaving their strands. This is the "extended pipe" functionality, where a pipe is used as an arbitrary in-memory buffer. Think of a pipe as a small kernel buffer that you can use to transfer data from one end to the other. The traditional unix read/write is extended with a "splice()" operation that transfers data buffers to or from a pipe buffer. Named by Larry McVoy, original implementation from Linus, extended by Jens to support splicing to files and fixing the initial implementation bugs. Signed-off-by: Jens Axboe <axboe@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
138 lines
3.6 KiB
C
138 lines
3.6 KiB
C
/*
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* linux/fs/ext3/file.c
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*
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* Copyright (C) 1992, 1993, 1994, 1995
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* Remy Card (card@masi.ibp.fr)
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* Laboratoire MASI - Institut Blaise Pascal
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* Universite Pierre et Marie Curie (Paris VI)
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*
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* from
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*
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* linux/fs/minix/file.c
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*
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* Copyright (C) 1991, 1992 Linus Torvalds
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*
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* ext3 fs regular file handling primitives
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*
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* 64-bit file support on 64-bit platforms by Jakub Jelinek
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* (jj@sunsite.ms.mff.cuni.cz)
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*/
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#include <linux/time.h>
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#include <linux/fs.h>
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#include <linux/jbd.h>
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#include <linux/ext3_fs.h>
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#include <linux/ext3_jbd.h>
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#include "xattr.h"
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#include "acl.h"
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/*
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* Called when an inode is released. Note that this is different
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* from ext3_file_open: open gets called at every open, but release
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* gets called only when /all/ the files are closed.
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*/
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static int ext3_release_file (struct inode * inode, struct file * filp)
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{
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/* if we are the last writer on the inode, drop the block reservation */
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if ((filp->f_mode & FMODE_WRITE) &&
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(atomic_read(&inode->i_writecount) == 1))
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{
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mutex_lock(&EXT3_I(inode)->truncate_mutex);
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ext3_discard_reservation(inode);
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mutex_unlock(&EXT3_I(inode)->truncate_mutex);
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}
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if (is_dx(inode) && filp->private_data)
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ext3_htree_free_dir_info(filp->private_data);
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return 0;
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}
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static ssize_t
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ext3_file_write(struct kiocb *iocb, const char __user *buf, size_t count, loff_t pos)
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{
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struct file *file = iocb->ki_filp;
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struct inode *inode = file->f_dentry->d_inode;
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ssize_t ret;
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int err;
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ret = generic_file_aio_write(iocb, buf, count, pos);
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/*
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* Skip flushing if there was an error, or if nothing was written.
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*/
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if (ret <= 0)
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return ret;
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/*
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* If the inode is IS_SYNC, or is O_SYNC and we are doing data
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* journalling then we need to make sure that we force the transaction
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* to disk to keep all metadata uptodate synchronously.
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*/
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if (file->f_flags & O_SYNC) {
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/*
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* If we are non-data-journaled, then the dirty data has
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* already been flushed to backing store by generic_osync_inode,
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* and the inode has been flushed too if there have been any
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* modifications other than mere timestamp updates.
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*
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* Open question --- do we care about flushing timestamps too
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* if the inode is IS_SYNC?
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*/
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if (!ext3_should_journal_data(inode))
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return ret;
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goto force_commit;
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}
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/*
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* So we know that there has been no forced data flush. If the inode
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* is marked IS_SYNC, we need to force one ourselves.
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*/
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if (!IS_SYNC(inode))
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return ret;
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/*
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* Open question #2 --- should we force data to disk here too? If we
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* don't, the only impact is that data=writeback filesystems won't
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* flush data to disk automatically on IS_SYNC, only metadata (but
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* historically, that is what ext2 has done.)
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*/
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force_commit:
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err = ext3_force_commit(inode->i_sb);
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if (err)
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return err;
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return ret;
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}
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const struct file_operations ext3_file_operations = {
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.llseek = generic_file_llseek,
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.read = do_sync_read,
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.write = do_sync_write,
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.aio_read = generic_file_aio_read,
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.aio_write = ext3_file_write,
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.readv = generic_file_readv,
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.writev = generic_file_writev,
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.ioctl = ext3_ioctl,
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.mmap = generic_file_mmap,
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.open = generic_file_open,
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.release = ext3_release_file,
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.fsync = ext3_sync_file,
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.sendfile = generic_file_sendfile,
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.splice_read = generic_file_splice_read,
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.splice_write = generic_file_splice_write,
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};
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struct inode_operations ext3_file_inode_operations = {
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.truncate = ext3_truncate,
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.setattr = ext3_setattr,
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#ifdef CONFIG_EXT3_FS_XATTR
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.setxattr = generic_setxattr,
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.getxattr = generic_getxattr,
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.listxattr = ext3_listxattr,
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.removexattr = generic_removexattr,
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#endif
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.permission = ext3_permission,
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};
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