a2df2a6340
This patch implements ->fallocate() inode operation in ext4. With this patch users of ext4 file systems will be able to use fallocate() system call for persistent preallocation. Current implementation only supports preallocation for regular files (directories not supported as of date) with extent maps. This patch does not support block-mapped files currently. Only FALLOC_ALLOCATE and FALLOC_RESV_SPACE modes are being supported as of now. Signed-off-by: Amit Arora <aarora@in.ibm.com>
140 lines
3.6 KiB
C
140 lines
3.6 KiB
C
/*
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* linux/fs/ext4/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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* ext4 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/jbd2.h>
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#include <linux/ext4_fs.h>
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#include <linux/ext4_jbd2.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 ext4_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 ext4_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(&EXT4_I(inode)->truncate_mutex);
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ext4_discard_reservation(inode);
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mutex_unlock(&EXT4_I(inode)->truncate_mutex);
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}
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if (is_dx(inode) && filp->private_data)
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ext4_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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ext4_file_write(struct kiocb *iocb, const struct iovec *iov,
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unsigned long nr_segs, 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_path.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, iov, nr_segs, 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 (!ext4_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 = ext4_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 ext4_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 = ext4_file_write,
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.ioctl = ext4_ioctl,
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#ifdef CONFIG_COMPAT
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.compat_ioctl = ext4_compat_ioctl,
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#endif
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.mmap = generic_file_mmap,
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.open = generic_file_open,
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.release = ext4_release_file,
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.fsync = ext4_sync_file,
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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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const struct inode_operations ext4_file_inode_operations = {
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.truncate = ext4_truncate,
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.setattr = ext4_setattr,
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#ifdef CONFIG_EXT4DEV_FS_XATTR
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.setxattr = generic_setxattr,
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.getxattr = generic_getxattr,
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.listxattr = ext4_listxattr,
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.removexattr = generic_removexattr,
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#endif
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.permission = ext4_permission,
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.fallocate = ext4_fallocate,
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};
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