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ocfs2: teach extend/truncate about sparse files

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For ocfs2_truncate_file(), we eliminate the "simple" truncate case which no
longer exists since i_size is not tied to i_clusters. In
ocfs2_extend_file(), we skip the allocation / page zeroing code for file
systems which understand sparse files.

The core truncate code is changed to do a bottom up tree traversal. This
gets abstracted out into it's own function. To make things more readable,
most of the special case handling for in-inode extents from
ocfs2_do_truncate() is also removed.

Though write support for sparse files comes in a later patch, we at least
update ocfs2_prepare_inode_for_write() to skip allocation for sparse files.

Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
This commit is contained in:
Mark Fasheh
2007-01-17 12:53:31 -08:00
parent 363041a5f7
commit 3a0782d09c
3 changed files with 320 additions and 237 deletions
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31
fs/ocfs2/file.c
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@ -344,18 +344,6 @@ static int ocfs2_truncate_file(struct inode *inode,
}
ocfs2_data_unlock(inode, 1);
if (le32_to_cpu(fe->i_clusters) ==
ocfs2_clusters_for_bytes(osb->sb, new_i_size)) {
mlog(0, "fe->i_clusters = %u, so we do a simple truncate\n",
fe->i_clusters);
/* No allocation change is required, so lets fast path
* this truncate. */
status = ocfs2_simple_size_update(inode, di_bh, new_i_size);
if (status < 0)
mlog_errno(status);
goto bail;
}
/* alright, we're going to need to do a full blown alloc size
* change. Orphan the inode so that recovery can complete the
* truncate if necessary. This does the task of marking
@ -785,7 +773,7 @@ static int ocfs2_extend_file(struct inode *inode,
size_t tail_to_skip)
{
int ret = 0;
u32 clusters_to_add;
u32 clusters_to_add = 0;
BUG_ON(!tail_to_skip && !di_bh);
@ -797,6 +785,11 @@ static int ocfs2_extend_file(struct inode *inode,
goto out;
BUG_ON(new_i_size < i_size_read(inode));
if (ocfs2_sparse_alloc(OCFS2_SB(inode->i_sb))) {
BUG_ON(tail_to_skip != 0);
goto out_update_size;
}
clusters_to_add = ocfs2_clusters_for_bytes(inode->i_sb, new_i_size) -
OCFS2_I(inode)->ip_clusters;
@ -832,6 +825,7 @@ static int ocfs2_extend_file(struct inode *inode,
goto out_unlock;
}
out_update_size:
if (!tail_to_skip) {
/* We're being called from ocfs2_setattr() which wants
* us to update i_size */
@ -841,7 +835,8 @@ static int ocfs2_extend_file(struct inode *inode,
}
out_unlock:
ocfs2_data_unlock(inode, 1);
if (!ocfs2_sparse_alloc(OCFS2_SB(inode->i_sb)))
ocfs2_data_unlock(inode, 1);
out:
return ret;
@ -1097,6 +1092,14 @@ static int ocfs2_prepare_inode_for_write(struct dentry *dentry,
} else {
saved_pos = *ppos;
}
/*
* The rest of this loop is concerned with legacy file
* systems which don't support sparse files.
*/
if (ocfs2_sparse_alloc(OCFS2_SB(inode->i_sb)))
break;
newsize = count + saved_pos;
mlog(0, "pos=%lld newsize=%lld cursize=%lld\n",