swh:1:snp:32555a3fd8878f019c2ebd6c964bc1edcaeff337
Tip revision: 021c91791a5e7e85c567452f1be3e4c2c6cb6063 authored by Linus Torvalds on 01 July 2018, 23:04:53 UTC
Linux 4.18-rc3
Linux 4.18-rc3
Tip revision: 021c917
file.c
/*
* Copyright 2000 by Hans Reiser, licensing governed by reiserfs/README
*/
#include <linux/time.h>
#include "reiserfs.h"
#include "acl.h"
#include "xattr.h"
#include <linux/uaccess.h>
#include <linux/pagemap.h>
#include <linux/swap.h>
#include <linux/writeback.h>
#include <linux/blkdev.h>
#include <linux/buffer_head.h>
#include <linux/quotaops.h>
/*
* We pack the tails of files on file close, not at the time they are written.
* This implies an unnecessary copy of the tail and an unnecessary indirect item
* insertion/balancing, for files that are written in one write.
* It avoids unnecessary tail packings (balances) for files that are written in
* multiple writes and are small enough to have tails.
*
* file_release is called by the VFS layer when the file is closed. If
* this is the last open file descriptor, and the file
* small enough to have a tail, and the tail is currently in an
* unformatted node, the tail is converted back into a direct item.
*
* We use reiserfs_truncate_file to pack the tail, since it already has
* all the conditions coded.
*/
static int reiserfs_file_release(struct inode *inode, struct file *filp)
{
struct reiserfs_transaction_handle th;
int err;
int jbegin_failure = 0;
BUG_ON(!S_ISREG(inode->i_mode));
if (atomic_add_unless(&REISERFS_I(inode)->openers, -1, 1))
return 0;
mutex_lock(&REISERFS_I(inode)->tailpack);
if (!atomic_dec_and_test(&REISERFS_I(inode)->openers)) {
mutex_unlock(&REISERFS_I(inode)->tailpack);
return 0;
}
/* fast out for when nothing needs to be done */
if ((!(REISERFS_I(inode)->i_flags & i_pack_on_close_mask) ||
!tail_has_to_be_packed(inode)) &&
REISERFS_I(inode)->i_prealloc_count <= 0) {
mutex_unlock(&REISERFS_I(inode)->tailpack);
return 0;
}
reiserfs_write_lock(inode->i_sb);
/*
* freeing preallocation only involves relogging blocks that
* are already in the current transaction. preallocation gets
* freed at the end of each transaction, so it is impossible for
* us to log any additional blocks (including quota blocks)
*/
err = journal_begin(&th, inode->i_sb, 1);
if (err) {
/*
* uh oh, we can't allow the inode to go away while there
* is still preallocation blocks pending. Try to join the
* aborted transaction
*/
jbegin_failure = err;
err = journal_join_abort(&th, inode->i_sb);
if (err) {
/*
* hmpf, our choices here aren't good. We can pin
* the inode which will disallow unmount from ever
* happening, we can do nothing, which will corrupt
* random memory on unmount, or we can forcibly
* remove the file from the preallocation list, which
* will leak blocks on disk. Lets pin the inode
* and let the admin know what is going on.
*/
igrab(inode);
reiserfs_warning(inode->i_sb, "clm-9001",
"pinning inode %lu because the "
"preallocation can't be freed",
inode->i_ino);
goto out;
}
}
reiserfs_update_inode_transaction(inode);
#ifdef REISERFS_PREALLOCATE
reiserfs_discard_prealloc(&th, inode);
#endif
err = journal_end(&th);
/* copy back the error code from journal_begin */
if (!err)
err = jbegin_failure;
if (!err &&
(REISERFS_I(inode)->i_flags & i_pack_on_close_mask) &&
tail_has_to_be_packed(inode)) {
/*
* if regular file is released by last holder and it has been
* appended (we append by unformatted node only) or its direct
* item(s) had to be converted, then it may have to be
* indirect2direct converted
*/
err = reiserfs_truncate_file(inode, 0);
}
out:
reiserfs_write_unlock(inode->i_sb);
mutex_unlock(&REISERFS_I(inode)->tailpack);
return err;
}
static int reiserfs_file_open(struct inode *inode, struct file *file)
{
int err = dquot_file_open(inode, file);
/* somebody might be tailpacking on final close; wait for it */
if (!atomic_inc_not_zero(&REISERFS_I(inode)->openers)) {
mutex_lock(&REISERFS_I(inode)->tailpack);
atomic_inc(&REISERFS_I(inode)->openers);
mutex_unlock(&REISERFS_I(inode)->tailpack);
}
return err;
}
void reiserfs_vfs_truncate_file(struct inode *inode)
{
mutex_lock(&REISERFS_I(inode)->tailpack);
reiserfs_truncate_file(inode, 1);
mutex_unlock(&REISERFS_I(inode)->tailpack);
}
/* Sync a reiserfs file. */
/*
* FIXME: sync_mapping_buffers() never has anything to sync. Can
* be removed...
*/
static int reiserfs_sync_file(struct file *filp, loff_t start, loff_t end,
int datasync)
{
struct inode *inode = filp->f_mapping->host;
int err;
int barrier_done;
err = file_write_and_wait_range(filp, start, end);
if (err)
return err;
inode_lock(inode);
BUG_ON(!S_ISREG(inode->i_mode));
err = sync_mapping_buffers(inode->i_mapping);
reiserfs_write_lock(inode->i_sb);
barrier_done = reiserfs_commit_for_inode(inode);
reiserfs_write_unlock(inode->i_sb);
if (barrier_done != 1 && reiserfs_barrier_flush(inode->i_sb))
blkdev_issue_flush(inode->i_sb->s_bdev, GFP_KERNEL, NULL);
inode_unlock(inode);
if (barrier_done < 0)
return barrier_done;
return (err < 0) ? -EIO : 0;
}
/* taken fs/buffer.c:__block_commit_write */
int reiserfs_commit_page(struct inode *inode, struct page *page,
unsigned from, unsigned to)
{
unsigned block_start, block_end;
int partial = 0;
unsigned blocksize;
struct buffer_head *bh, *head;
unsigned long i_size_index = inode->i_size >> PAGE_SHIFT;
int new;
int logit = reiserfs_file_data_log(inode);
struct super_block *s = inode->i_sb;
int bh_per_page = PAGE_SIZE / s->s_blocksize;
struct reiserfs_transaction_handle th;
int ret = 0;
th.t_trans_id = 0;
blocksize = i_blocksize(inode);
if (logit) {
reiserfs_write_lock(s);
ret = journal_begin(&th, s, bh_per_page + 1);
if (ret)
goto drop_write_lock;
reiserfs_update_inode_transaction(inode);
}
for (bh = head = page_buffers(page), block_start = 0;
bh != head || !block_start;
block_start = block_end, bh = bh->b_this_page) {
new = buffer_new(bh);
clear_buffer_new(bh);
block_end = block_start + blocksize;
if (block_end <= from || block_start >= to) {
if (!buffer_uptodate(bh))
partial = 1;
} else {
set_buffer_uptodate(bh);
if (logit) {
reiserfs_prepare_for_journal(s, bh, 1);
journal_mark_dirty(&th, bh);
} else if (!buffer_dirty(bh)) {
mark_buffer_dirty(bh);
/*
* do data=ordered on any page past the end
* of file and any buffer marked BH_New.
*/
if (reiserfs_data_ordered(inode->i_sb) &&
(new || page->index >= i_size_index)) {
reiserfs_add_ordered_list(inode, bh);
}
}
}
}
if (logit) {
ret = journal_end(&th);
drop_write_lock:
reiserfs_write_unlock(s);
}
/*
* If this is a partial write which happened to make all buffers
* uptodate then we can optimize away a bogus readpage() for
* the next read(). Here we 'discover' whether the page went
* uptodate as a result of this (potentially partial) write.
*/
if (!partial)
SetPageUptodate(page);
return ret;
}
const struct file_operations reiserfs_file_operations = {
.unlocked_ioctl = reiserfs_ioctl,
#ifdef CONFIG_COMPAT
.compat_ioctl = reiserfs_compat_ioctl,
#endif
.mmap = generic_file_mmap,
.open = reiserfs_file_open,
.release = reiserfs_file_release,
.fsync = reiserfs_sync_file,
.read_iter = generic_file_read_iter,
.write_iter = generic_file_write_iter,
.splice_read = generic_file_splice_read,
.splice_write = iter_file_splice_write,
.llseek = generic_file_llseek,
};
const struct inode_operations reiserfs_file_inode_operations = {
.setattr = reiserfs_setattr,
.listxattr = reiserfs_listxattr,
.permission = reiserfs_permission,
.get_acl = reiserfs_get_acl,
.set_acl = reiserfs_set_acl,
};