Commit 2bfb4fff authored by Anton Altaparmakov's avatar Anton Altaparmakov
Browse files

NTFS: Add fs/ntfs/attrib.[hc]::ntfs_attr_make_non_resident().


Signed-off-by: default avatarAnton Altaparmakov <aia21@cantab.net>
parent c0c1cc0e
......@@ -97,6 +97,7 @@ ToDo/Notes:
whether someone else did not already do the work we wanted to do.
- Rename fs/ntfs/attrib.c::ntfs_find_vcn_nolock() to
ntfs_attr_find_vcn_nolock() and update all callers.
- Add fs/ntfs/attrib.[hc]::ntfs_attr_make_non_resident().
2.1.22 - Many bug and race fixes and error handling improvements.
......
......@@ -25,6 +25,8 @@
#include "attrib.h"
#include "debug.h"
#include "layout.h"
#include "lcnalloc.h"
#include "malloc.h"
#include "mft.h"
#include "ntfs.h"
#include "types.h"
......@@ -1226,6 +1228,304 @@ int ntfs_attr_record_resize(MFT_RECORD *m, ATTR_RECORD *a, u32 new_size)
return 0;
}
/**
* ntfs_attr_make_non_resident - convert a resident to a non-resident attribute
* @ni: ntfs inode describing the attribute to convert
*
* Convert the resident ntfs attribute described by the ntfs inode @ni to a
* non-resident one.
*
* Return 0 on success and -errno on error. The following error return codes
* are defined:
* -EPERM - The attribute is not allowed to be non-resident.
* -ENOMEM - Not enough memory.
* -ENOSPC - Not enough disk space.
* -EINVAL - Attribute not defined on the volume.
* -EIO - I/o error or other error.
*
* NOTE to self: No changes in the attribute list are required to move from
* a resident to a non-resident attribute.
*
* Locking: - The caller must hold i_sem on the inode.
*/
int ntfs_attr_make_non_resident(ntfs_inode *ni)
{
s64 new_size;
struct inode *vi = VFS_I(ni);
ntfs_volume *vol = ni->vol;
ntfs_inode *base_ni;
MFT_RECORD *m;
ATTR_RECORD *a;
ntfs_attr_search_ctx *ctx;
struct page *page;
runlist_element *rl;
u8 *kaddr;
unsigned long flags;
int mp_size, mp_ofs, name_ofs, arec_size, err, err2;
u32 attr_size;
u8 old_res_attr_flags;
/* Check that the attribute is allowed to be non-resident. */
err = ntfs_attr_can_be_non_resident(vol, ni->type);
if (unlikely(err)) {
if (err == -EPERM)
ntfs_debug("Attribute is not allowed to be "
"non-resident.");
else
ntfs_debug("Attribute not defined on the NTFS "
"volume!");
return err;
}
/*
* The size needs to be aligned to a cluster boundary for allocation
* purposes.
*/
new_size = (i_size_read(vi) + vol->cluster_size - 1) &
~(vol->cluster_size - 1);
if (new_size > 0) {
/*
* Will need the page later and since the page lock nests
* outside all ntfs locks, we need to get the page now.
*/
page = find_or_create_page(vi->i_mapping, 0,
mapping_gfp_mask(vi->i_mapping));
if (unlikely(!page))
return -ENOMEM;
/* Start by allocating clusters to hold the attribute value. */
rl = ntfs_cluster_alloc(vol, 0, new_size >>
vol->cluster_size_bits, -1, DATA_ZONE);
if (IS_ERR(rl)) {
err = PTR_ERR(rl);
ntfs_debug("Failed to allocate cluster%s, error code "
"%i.\n", (new_size >>
vol->cluster_size_bits) > 1 ? "s" : "",
err);
goto page_err_out;
}
} else {
rl = NULL;
page = NULL;
}
/* Determine the size of the mapping pairs array. */
mp_size = ntfs_get_size_for_mapping_pairs(vol, rl, 0);
if (unlikely(mp_size < 0)) {
err = mp_size;
ntfs_debug("Failed to get size for mapping pairs array, error "
"code %i.", err);
goto rl_err_out;
}
down_write(&ni->runlist.lock);
if (!NInoAttr(ni))
base_ni = ni;
else
base_ni = ni->ext.base_ntfs_ino;
m = map_mft_record(base_ni);
if (IS_ERR(m)) {
err = PTR_ERR(m);
m = NULL;
ctx = NULL;
goto err_out;
}
ctx = ntfs_attr_get_search_ctx(base_ni, m);
if (unlikely(!ctx)) {
err = -ENOMEM;
goto err_out;
}
err = ntfs_attr_lookup(ni->type, ni->name, ni->name_len,
CASE_SENSITIVE, 0, NULL, 0, ctx);
if (unlikely(err)) {
if (err == -ENOENT)
err = -EIO;
goto err_out;
}
m = ctx->mrec;
a = ctx->attr;
BUG_ON(NInoNonResident(ni));
BUG_ON(a->non_resident);
/*
* Calculate new offsets for the name and the mapping pairs array.
* We assume the attribute is not compressed or sparse.
*/
name_ofs = (offsetof(ATTR_REC,
data.non_resident.compressed_size) + 7) & ~7;
mp_ofs = (name_ofs + a->name_length * sizeof(ntfschar) + 7) & ~7;
/*
* Determine the size of the resident part of the now non-resident
* attribute record.
*/
arec_size = (mp_ofs + mp_size + 7) & ~7;
/*
* If the page is not uptodate bring it uptodate by copying from the
* attribute value.
*/
attr_size = le32_to_cpu(a->data.resident.value_length);
BUG_ON(attr_size != i_size_read(vi));
if (page && !PageUptodate(page)) {
kaddr = kmap_atomic(page, KM_USER0);
memcpy(kaddr, (u8*)a +
le16_to_cpu(a->data.resident.value_offset),
attr_size);
memset(kaddr + attr_size, 0, PAGE_CACHE_SIZE - attr_size);
kunmap_atomic(kaddr, KM_USER0);
flush_dcache_page(page);
SetPageUptodate(page);
}
/* Backup the attribute flag. */
old_res_attr_flags = a->data.resident.flags;
/* Resize the resident part of the attribute record. */
err = ntfs_attr_record_resize(m, a, arec_size);
if (unlikely(err))
goto err_out;
/* Setup the in-memory attribute structure to be non-resident. */
NInoSetNonResident(ni);
ni->runlist.rl = rl;
write_lock_irqsave(&ni->size_lock, flags);
ni->allocated_size = new_size;
write_unlock_irqrestore(&ni->size_lock, flags);
/*
* FIXME: For now just clear all of these as we do not support them
* when writing.
*/
NInoClearCompressed(ni);
NInoClearSparse(ni);
NInoClearEncrypted(ni);
/*
* Convert the resident part of the attribute record to describe a
* non-resident attribute.
*/
a->non_resident = 1;
/* Move the attribute name if it exists and update the offset. */
if (a->name_length)
memmove((u8*)a + name_ofs, (u8*)a + le16_to_cpu(a->name_offset),
a->name_length * sizeof(ntfschar));
a->name_offset = cpu_to_le16(name_ofs);
/* Update the flags to match the in-memory ones. */
a->flags &= cpu_to_le16(0xffff & ~le16_to_cpu(ATTR_IS_SPARSE |
ATTR_IS_ENCRYPTED | ATTR_COMPRESSION_MASK));
/* Setup the fields specific to non-resident attributes. */
a->data.non_resident.lowest_vcn = 0;
a->data.non_resident.highest_vcn = cpu_to_sle64((new_size - 1) >>
vol->cluster_size_bits);
a->data.non_resident.mapping_pairs_offset = cpu_to_le16(mp_ofs);
a->data.non_resident.compression_unit = 0;
memset(&a->data.non_resident.reserved, 0,
sizeof(a->data.non_resident.reserved));
a->data.non_resident.allocated_size = cpu_to_sle64(new_size);
a->data.non_resident.data_size =
a->data.non_resident.initialized_size =
cpu_to_sle64(attr_size);
/* Generate the mapping pairs array into the attribute record. */
err = ntfs_mapping_pairs_build(vol, (u8*)a + mp_ofs,
arec_size - mp_ofs, rl, 0, NULL);
if (unlikely(err)) {
ntfs_debug("Failed to build mapping pairs, error code %i.",
err);
goto undo_err_out;
}
/* Mark the mft record dirty, so it gets written back. */
flush_dcache_mft_record_page(ctx->ntfs_ino);
mark_mft_record_dirty(ctx->ntfs_ino);
ntfs_attr_put_search_ctx(ctx);
unmap_mft_record(base_ni);
up_write(&ni->runlist.lock);
if (page) {
set_page_dirty(page);
unlock_page(page);
page_cache_release(page);
}
ntfs_debug("Done.");
return 0;
undo_err_out:
/* Convert the attribute back into a resident attribute. */
a->non_resident = 0;
/* Move the attribute name if it exists and update the offset. */
name_ofs = (offsetof(ATTR_RECORD, data.resident.reserved) +
sizeof(a->data.resident.reserved) + 7) & ~7;
if (a->name_length)
memmove((u8*)a + name_ofs, (u8*)a + le16_to_cpu(a->name_offset),
a->name_length * sizeof(ntfschar));
mp_ofs = (name_ofs + a->name_length * sizeof(ntfschar) + 7) & ~7;
a->name_offset = cpu_to_le16(name_ofs);
arec_size = (mp_ofs + attr_size + 7) & ~7;
/* Resize the resident part of the attribute record. */
err2 = ntfs_attr_record_resize(m, a, arec_size);
if (unlikely(err2)) {
/*
* This cannot happen (well if memory corruption is at work it
* could happen in theory), but deal with it as well as we can.
* If the old size is too small, truncate the attribute,
* otherwise simply give it a larger allocated size.
* FIXME: Should check whether chkdsk complains when the
* allocated size is much bigger than the resident value size.
*/
arec_size = le32_to_cpu(a->length);
if ((mp_ofs + attr_size) > arec_size) {
err2 = attr_size;
attr_size = arec_size - mp_ofs;
ntfs_error(vol->sb, "Failed to undo partial resident "
"to non-resident attribute "
"conversion. Truncating inode 0x%lx, "
"attribute type 0x%x from %i bytes to "
"%i bytes to maintain metadata "
"consistency. THIS MEANS YOU ARE "
"LOSING %i BYTES DATA FROM THIS %s.",
vi->i_ino,
(unsigned)le32_to_cpu(ni->type),
err2, attr_size, err2 - attr_size,
((ni->type == AT_DATA) &&
!ni->name_len) ? "FILE": "ATTRIBUTE");
write_lock_irqsave(&ni->size_lock, flags);
ni->initialized_size = attr_size;
i_size_write(vi, attr_size);
write_unlock_irqrestore(&ni->size_lock, flags);
}
}
/* Setup the fields specific to resident attributes. */
a->data.resident.value_length = cpu_to_le32(attr_size);
a->data.resident.value_offset = cpu_to_le16(mp_ofs);
a->data.resident.flags = old_res_attr_flags;
memset(&a->data.resident.reserved, 0,
sizeof(a->data.resident.reserved));
/* Copy the data from the page back to the attribute value. */
if (page) {
kaddr = kmap_atomic(page, KM_USER0);
memcpy((u8*)a + mp_ofs, kaddr, attr_size);
kunmap_atomic(kaddr, KM_USER0);
}
/* Finally setup the ntfs inode appropriately. */
write_lock_irqsave(&ni->size_lock, flags);
ni->allocated_size = arec_size - mp_ofs;
write_unlock_irqrestore(&ni->size_lock, flags);
NInoClearNonResident(ni);
/* Mark the mft record dirty, so it gets written back. */
flush_dcache_mft_record_page(ctx->ntfs_ino);
mark_mft_record_dirty(ctx->ntfs_ino);
err_out:
if (ctx)
ntfs_attr_put_search_ctx(ctx);
if (m)
unmap_mft_record(base_ni);
ni->runlist.rl = NULL;
up_write(&ni->runlist.lock);
rl_err_out:
if (rl) {
if (ntfs_cluster_free_from_rl(vol, rl) < 0) {
ntfs_free(rl);
ntfs_error(vol->sb, "Failed to release allocated "
"cluster(s) in error code path. Run "
"chkdsk to recover the lost "
"cluster(s).");
NVolSetErrors(vol);
}
page_err_out:
unlock_page(page);
page_cache_release(page);
}
if (err == -EINVAL)
err = -EIO;
return err;
}
/**
* ntfs_attr_set - fill (a part of) an attribute with a byte
* @ni: ntfs inode describing the attribute to fill
......
......@@ -98,6 +98,8 @@ extern int ntfs_attr_can_be_resident(const ntfs_volume *vol,
extern int ntfs_attr_record_resize(MFT_RECORD *m, ATTR_RECORD *a, u32 new_size);
extern int ntfs_attr_make_non_resident(ntfs_inode *ni);
extern int ntfs_attr_set(ntfs_inode *ni, const s64 ofs, const s64 cnt,
const u8 val);
......
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