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- Clear newly allocated space in ntfs_resident_attr_value_resize(). 

- Rename ntfs_resident_attr_shrink() to ntfs_resident_attr_resize()
  and make it resize upwards as well as downwards.
- Change ntfs_attr_truncate() to allow resizing upwards of resident
  attributes.

(Logical change 1.75)
edge.strict_endians
cantab.net!aia21 2002-12-30 12:23:10 +00:00
parent f7e003fd49
commit 08ef32703a
1 changed files with 77 additions and 21 deletions
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98
libntfs/attrib.c
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@ -1963,10 +1963,11 @@ int ntfs_attr_size_bounds_check(const ntfs_volume *vol, const ATTR_TYPES type,
* @newsize: new size in bytes to which to resize the attribute value of @a
*
* Resize the value of the attribute @a in the mft record @m to @newsize bytes.
* If the value is made bigger, the newly "allocated" space is cleared.
*
* Return 0 on success and -1 on error with errno set to the error code.
* The following error codes are defined:
* ENOSPC - Not enough space in mft record to perform the resize.
* ENOSPC - Not enough space in the mft record @m to perform the resize.
* Note that on error no modifications have been performed whatsoever.
*/
int ntfs_resident_attr_value_resize(MFT_RECORD *m, ATTR_RECORD *a,
@ -1980,7 +1981,7 @@ int ntfs_resident_attr_value_resize(MFT_RECORD *m, ATTR_RECORD *a,
/* Calculate the new attribute length and mft record bytes used. */
new_alen = (le16_to_cpu(a->value_offset) + newsize + 7) & ~7;
/* If the actual attribute length has changed, move tihings around. */
/* If the actual attribute length has changed, move things around. */
if (new_alen != le32_to_cpu(a->length)) {
new_muse = le32_to_cpu(m->bytes_in_use) -
le32_to_cpu(a->length) + new_alen;
@ -1998,23 +1999,32 @@ int ntfs_resident_attr_value_resize(MFT_RECORD *m, ATTR_RECORD *a,
/* Adjust @a to reflect the new value size. */
a->length = cpu_to_le32(new_alen);
}
/*
* If we made the attribute value bigger, clear the area between the
* old size and @newsize.
*/
if (newsize > le32_to_cpu(a->value_length))
memset((u8*)a + le16_to_cpu(a->value_offset) +
le32_to_cpu(a->value_length), 0, newsize -
le32_to_cpu(a->value_length));
a->value_length = cpu_to_le32(newsize);
return 0;
}
/**
* ntfs_resident_attr_shrink - shrink a resident, open ntfs attribute
* @na: resident ntfs attribute to shrink
* ntfs_resident_attr_resize - resize a resident, open ntfs attribute
* @na: resident ntfs attribute to resize
* @newsize: new size (in bytes) to which to shrink the attribute
*
* Reduce the size of a resident, open ntfs attribute @na to @newsize bytes.
* Change the size of a resident, open ntfs attribute @na to @newsize bytes.
*
* On success return 0 and on error return -1 with errno set to the error code.
* The following error codes are defined:
* ENOTSUP - The desired resize is not implemented yet.
* ENOMEM - Not enough memory to complete operation.
* ERANGE - @newsize is not valid for the attribute type of @na.
*/
static int ntfs_resident_attr_shrink(ntfs_attr *na, const u32 newsize)
static int ntfs_resident_attr_resize(ntfs_attr *na, const s64 newsize)
{
ntfs_attr_search_ctx *ctx;
int err;
@ -2031,8 +2041,8 @@ static int ntfs_resident_attr_shrink(ntfs_attr *na, const u32 newsize)
goto put_err_out;
}
/*
* Check the attribute type and the corresponding minimum size
* against @newsize and fail if @newsize is too small.
* Check the attribute type and the corresponding minimum and maximum
* sizes against @newsize and fail if @newsize is out of bounds.
*/
if (ntfs_attr_size_bounds_check(na->ni->vol, na->type, newsize) < 0) {
err = errno;
@ -2044,15 +2054,43 @@ static int ntfs_resident_attr_shrink(ntfs_attr *na, const u32 newsize)
err = EIO;
goto put_err_out;
}
/* Perform the resize of the attribute record. */
if (ntfs_resident_attr_value_resize(ctx->mrec, ctx->attr, newsize)) {
err = errno;
goto put_err_out;
/*
* If @newsize is bigger than the mft record we need to make the
* attribute non-resident if the attribute type supports it. If it is
* smaller we can go ahead and attempt the resize.
*/
if (newsize < na->ni->vol->mft_record_size) {
/* Perform the resize of the attribute record. */
if (ntfs_resident_attr_value_resize(ctx->mrec, ctx->attr,
newsize)) {
err = errno;
if (err != ENOSPC)
goto put_err_out;
} else {
/* Update the ntfs attribute structure, too. */
na->allocated_size = na->data_size =
na->initialized_size = newsize;
if (NAttrCompressed(na) || NAttrSparse(na))
na->compressed_size = newsize;
goto resize_done;
}
}
/* Update the ntfs attribute structure, too. */
na->allocated_size = na->data_size = na->initialized_size = newsize;
if (NAttrCompressed(na) || NAttrSparse(na))
na->compressed_size = newsize;
/* There is not enough space in the mft record to perform the resize. */
// FIXME: Need to try to:
// - make the attribute non-resident if the attribute type allows
// - make other attributes non-resident to free up enough space
// - move the attribute to a new mft record
// Note that some of the above changes also require changes in the
// attribute list attribute (or even creation thereof) hence take
// care!!! Probably want to try to do things in the same order as
// above. Also take care that $MFT/$BITMAP _must_ be non-resident or
// windows ntfs driver causes a blue screen of death on mount attempt,
// i.e. usually at boot time which renders the machine not bootable.
err = ENOTSUP;
goto put_err_out;
resize_done:
/*
* Set the inode (and its base inode if it exists) dirty so it is
* written out later.
@ -2319,7 +2357,24 @@ put_err_out:
* @na: open ntfs attribute to resize
* @newsize: new size (in bytes) to which to resize the attribute
*
* Change the size of an open ntfs attribute @na to @newsize bytes.
* Change the size of an open ntfs attribute @na to @newsize bytes. If the
* attribute is made bigger and the attribute is resident the newly
* "allocated" space is cleared and if the attribute is non-resident the
* newly allocated space is marked as not initialised and no real allocation
* on disk is performed. FIXME: Do we have to create sparse runs or can we just
* leave the reunlist to finish below data_size, i.e. can we have
* allocated_size < data_size? I guess that what we can't and thus we will have
* to set the sparse bit of the attribute and create sparse runs to ensure that
* allocated_size is >= data_size. We don't need to clear the partial run at
* the end of the real allocation because we leave initialized_size low enough.
* FIXME: Do we want that? Alternatively, we leave initialized_size = data_size
* and do clear the partial run. The latter approach would be more inline with
* what windows would do, even though windows wouldn't even make the attribute
* sparse, it would just allocate clusters instead. TODO: Check what happens on
* WinXP and .NET. FIXME: Make sure to check what NT4 does with an NTFS1.2
* volume that has sparse files. I suspect it will blow up so we will need to
* perform allocations of clusters, like NT4 would do for NTFS1.2 while we can
* use sparse attributes on NTFS3.x.
*
* On success return 0 and on error return -1 with errno set to the error code.
* The following error codes are defined:
@ -2344,16 +2399,17 @@ int ntfs_attr_truncate(ntfs_attr *na, const s64 newsize)
return -1;
}
/*
* TODO: Implement making attributes bigger/filling in of uninitialized
* holes as well as handling of compressed attributes. (AIA)
* TODO: Implement making non-resident attributes bigger/filling in of
* uninitialized holes as well as handling of compressed attributes.
*/
if (newsize > na->initialized_size || NAttrCompressed(na)) {
if ((NAttrNonResident(na) && newsize > na->initialized_size) ||
NAttrCompressed(na)) {
errno = ENOTSUP;
return -1;
}
if (NAttrNonResident(na))
return ntfs_non_resident_attr_shrink(na, newsize);
return ntfs_resident_attr_shrink(na, (u32)newsize);
return ntfs_resident_attr_resize(na, newsize);
}