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NTFS: Remove address space operations ->prepare_write and ->commit_write in

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preparation for the big rewrite of write(2) support in ntfs.

Signed-off-by: Anton Altaparmakov <aia21@cantab.net>
This commit is contained in:
Anton Altaparmakov 2005-10-11 14:59:40 +01:00
parent 29b8990513
commit 29f5f3c141
1 changed files with 0 additions and 827 deletions
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827
fs/ntfs/aops.c
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@ -1542,830 +1542,6 @@ static int ntfs_writepage(struct page *page, struct writeback_control *wbc)
return err;
}
/**
* ntfs_prepare_nonresident_write -
*
*/
static int ntfs_prepare_nonresident_write(struct page *page,
unsigned from, unsigned to)
{
VCN vcn;
LCN lcn;
s64 initialized_size;
loff_t i_size;
sector_t block, ablock, iblock;
struct inode *vi;
ntfs_inode *ni;
ntfs_volume *vol;
runlist_element *rl;
struct buffer_head *bh, *head, *wait[2], **wait_bh = wait;
unsigned long flags;
unsigned int vcn_ofs, block_start, block_end, blocksize;
int err;
BOOL is_retry;
unsigned char blocksize_bits;
vi = page->mapping->host;
ni = NTFS_I(vi);
vol = ni->vol;
ntfs_debug("Entering for inode 0x%lx, attribute type 0x%x, page index "
"0x%lx, from = %u, to = %u.", ni->mft_no, ni->type,
page->index, from, to);
BUG_ON(!NInoNonResident(ni));
blocksize_bits = vi->i_blkbits;
blocksize = 1 << blocksize_bits;
/*
* create_empty_buffers() will create uptodate/dirty buffers if the
* page is uptodate/dirty.
*/
if (!page_has_buffers(page))
create_empty_buffers(page, blocksize, 0);
bh = head = page_buffers(page);
if (unlikely(!bh))
return -ENOMEM;
/* The first block in the page. */
block = (s64)page->index << (PAGE_CACHE_SHIFT - blocksize_bits);
read_lock_irqsave(&ni->size_lock, flags);
/*
* The first out of bounds block for the allocated size. No need to
* round up as allocated_size is in multiples of cluster size and the
* minimum cluster size is 512 bytes, which is equal to the smallest
* blocksize.
*/
ablock = ni->allocated_size >> blocksize_bits;
i_size = i_size_read(vi);
initialized_size = ni->initialized_size;
read_unlock_irqrestore(&ni->size_lock, flags);
/* The last (fully or partially) initialized block. */
iblock = initialized_size >> blocksize_bits;
/* Loop through all the buffers in the page. */
block_start = 0;
rl = NULL;
err = 0;
do {
block_end = block_start + blocksize;
/*
* If buffer @bh is outside the write, just mark it uptodate
* if the page is uptodate and continue with the next buffer.
*/
if (block_end <= from || block_start >= to) {
if (PageUptodate(page)) {
if (!buffer_uptodate(bh))
set_buffer_uptodate(bh);
}
continue;
}
/*
* @bh is at least partially being written to.
* Make sure it is not marked as new.
*/
//if (buffer_new(bh))
// clear_buffer_new(bh);
if (block >= ablock) {
// TODO: block is above allocated_size, need to
// allocate it. Best done in one go to accommodate not
// only block but all above blocks up to and including:
// ((page->index << PAGE_CACHE_SHIFT) + to + blocksize
// - 1) >> blobksize_bits. Obviously will need to round
// up to next cluster boundary, too. This should be
// done with a helper function, so it can be reused.
ntfs_error(vol->sb, "Writing beyond allocated size "
"is not supported yet. Sorry.");
err = -EOPNOTSUPP;
goto err_out;
// Need to update ablock.
// Need to set_buffer_new() on all block bhs that are
// newly allocated.
}
/*
* Now we have enough allocated size to fulfill the whole
* request, i.e. block < ablock is true.
*/
if (unlikely((block >= iblock) &&
(initialized_size < i_size))) {
/*
* If this page is fully outside initialized size, zero
* out all pages between the current initialized size
* and the current page. Just use ntfs_readpage() to do
* the zeroing transparently.
*/
if (block > iblock) {
// TODO:
// For each page do:
// - read_cache_page()
// Again for each page do:
// - wait_on_page_locked()
// - Check (PageUptodate(page) &&
// !PageError(page))
// Update initialized size in the attribute and
// in the inode.
// Again, for each page do:
// __set_page_dirty_buffers();
// page_cache_release()
// We don't need to wait on the writes.
// Update iblock.
}
/*
* The current page straddles initialized size. Zero
* all non-uptodate buffers and set them uptodate (and
* dirty?). Note, there aren't any non-uptodate buffers
* if the page is uptodate.
* FIXME: For an uptodate page, the buffers may need to
* be written out because they were not initialized on
* disk before.
*/
if (!PageUptodate(page)) {
// TODO:
// Zero any non-uptodate buffers up to i_size.
// Set them uptodate and dirty.
}
// TODO:
// Update initialized size in the attribute and in the
// inode (up to i_size).
// Update iblock.
// FIXME: This is inefficient. Try to batch the two
// size changes to happen in one go.
ntfs_error(vol->sb, "Writing beyond initialized size "
"is not supported yet. Sorry.");
err = -EOPNOTSUPP;
goto err_out;
// Do NOT set_buffer_new() BUT DO clear buffer range
// outside write request range.
// set_buffer_uptodate() on complete buffers as well as
// set_buffer_dirty().
}
/* Need to map unmapped buffers. */
if (!buffer_mapped(bh)) {
/* Unmapped buffer. Need to map it. */
bh->b_bdev = vol->sb->s_bdev;
/* Convert block into corresponding vcn and offset. */
vcn = (VCN)block << blocksize_bits >>
vol->cluster_size_bits;
vcn_ofs = ((VCN)block << blocksize_bits) &
vol->cluster_size_mask;
is_retry = FALSE;
if (!rl) {
lock_retry_remap:
down_read(&ni->runlist.lock);
rl = ni->runlist.rl;
}
if (likely(rl != NULL)) {
/* Seek to element containing target vcn. */
while (rl->length && rl[1].vcn <= vcn)
rl++;
lcn = ntfs_rl_vcn_to_lcn(rl, vcn);
} else
lcn = LCN_RL_NOT_MAPPED;
if (unlikely(lcn < 0)) {
/*
* We extended the attribute allocation above.
* If we hit an ENOENT here it means that the
* allocation was insufficient which is a bug.
*/
BUG_ON(lcn == LCN_ENOENT);
/* It is a hole, need to instantiate it. */
if (lcn == LCN_HOLE) {
// TODO: Instantiate the hole.
// clear_buffer_new(bh);
// unmap_underlying_metadata(bh->b_bdev,
// bh->b_blocknr);
// For non-uptodate buffers, need to
// zero out the region outside the
// request in this bh or all bhs,
// depending on what we implemented
// above.
// Need to flush_dcache_page().
// Or could use set_buffer_new()
// instead?
ntfs_error(vol->sb, "Writing into "
"sparse regions is "
"not supported yet. "
"Sorry.");
err = -EOPNOTSUPP;
if (!rl)
up_read(&ni->runlist.lock);
goto err_out;
} else if (!is_retry &&
lcn == LCN_RL_NOT_MAPPED) {
is_retry = TRUE;
/*
* Attempt to map runlist, dropping
* lock for the duration.
*/
up_read(&ni->runlist.lock);
err = ntfs_map_runlist(ni, vcn);
if (likely(!err))
goto lock_retry_remap;
rl = NULL;
} else if (!rl)
up_read(&ni->runlist.lock);
/*
* Failed to map the buffer, even after
* retrying.
*/
if (!err)
err = -EIO;
bh->b_blocknr = -1;
ntfs_error(vol->sb, "Failed to write to inode "
"0x%lx, attribute type 0x%x, "
"vcn 0x%llx, offset 0x%x "
"because its location on disk "
"could not be determined%s "
"(error code %i).",
ni->mft_no, ni->type,
(unsigned long long)vcn,
vcn_ofs, is_retry ? " even "
"after retrying" : "", err);
goto err_out;
}
/* We now have a successful remap, i.e. lcn >= 0. */
/* Setup buffer head to correct block. */
bh->b_blocknr = ((lcn << vol->cluster_size_bits)
+ vcn_ofs) >> blocksize_bits;
set_buffer_mapped(bh);
// FIXME: Something analogous to this is needed for
// each newly allocated block, i.e. BH_New.
// FIXME: Might need to take this out of the
// if (!buffer_mapped(bh)) {}, depending on how we
// implement things during the allocated_size and
// initialized_size extension code above.
if (buffer_new(bh)) {
clear_buffer_new(bh);
unmap_underlying_metadata(bh->b_bdev,
bh->b_blocknr);
if (PageUptodate(page)) {
set_buffer_uptodate(bh);
continue;
}
/*
* Page is _not_ uptodate, zero surrounding
* region. NOTE: This is how we decide if to
* zero or not!
*/
if (block_end > to || block_start < from) {
void *kaddr;
kaddr = kmap_atomic(page, KM_USER0);
if (block_end > to)
memset(kaddr + to, 0,
block_end - to);
if (block_start < from)
memset(kaddr + block_start, 0,
from -
block_start);
flush_dcache_page(page);
kunmap_atomic(kaddr, KM_USER0);
}
continue;
}
}
/* @bh is mapped, set it uptodate if the page is uptodate. */
if (PageUptodate(page)) {
if (!buffer_uptodate(bh))
set_buffer_uptodate(bh);
continue;
}
/*
* The page is not uptodate. The buffer is mapped. If it is not
* uptodate, and it is only partially being written to, we need
* to read the buffer in before the write, i.e. right now.
*/
if (!buffer_uptodate(bh) &&
(block_start < from || block_end > to)) {
ll_rw_block(READ, 1, &bh);
*wait_bh++ = bh;
}
} while (block++, block_start = block_end,
(bh = bh->b_this_page) != head);
/* Release the lock if we took it. */
if (rl) {
up_read(&ni->runlist.lock);
rl = NULL;
}
/* If we issued read requests, let them complete. */
while (wait_bh > wait) {
wait_on_buffer(*--wait_bh);
if (!buffer_uptodate(*wait_bh))
return -EIO;
}
ntfs_debug("Done.");
return 0;
err_out:
/*
* Zero out any newly allocated blocks to avoid exposing stale data.
* If BH_New is set, we know that the block was newly allocated in the
* above loop.
* FIXME: What about initialized_size increments? Have we done all the
* required zeroing above? If not this error handling is broken, and
* in particular the if (block_end <= from) check is completely bogus.
*/
bh = head;
block_start = 0;
is_retry = FALSE;
do {
block_end = block_start + blocksize;
if (block_end <= from)
continue;
if (block_start >= to)
break;
if (buffer_new(bh)) {
void *kaddr;
clear_buffer_new(bh);
kaddr = kmap_atomic(page, KM_USER0);
memset(kaddr + block_start, 0, bh->b_size);
kunmap_atomic(kaddr, KM_USER0);
set_buffer_uptodate(bh);
mark_buffer_dirty(bh);
is_retry = TRUE;
}
} while (block_start = block_end, (bh = bh->b_this_page) != head);
if (is_retry)
flush_dcache_page(page);
if (rl)
up_read(&ni->runlist.lock);
return err;
}
/**
* ntfs_prepare_write - prepare a page for receiving data
*
* This is called from generic_file_write() with i_sem held on the inode
* (@page->mapping->host). The @page is locked but not kmap()ped. The source
* data has not yet been copied into the @page.
*
* Need to extend the attribute/fill in holes if necessary, create blocks and
* make partially overwritten blocks uptodate,
*
* i_size is not to be modified yet.
*
* Return 0 on success or -errno on error.
*
* Should be using block_prepare_write() [support for sparse files] or
* cont_prepare_write() [no support for sparse files]. Cannot do that due to
* ntfs specifics but can look at them for implementation guidance.
*
* Note: In the range, @from is inclusive and @to is exclusive, i.e. @from is
* the first byte in the page that will be written to and @to is the first byte
* after the last byte that will be written to.
*/
static int ntfs_prepare_write(struct file *file, struct page *page,
unsigned from, unsigned to)
{
s64 new_size;
loff_t i_size;
struct inode *vi = page->mapping->host;
ntfs_inode *base_ni = NULL, *ni = NTFS_I(vi);
ntfs_volume *vol = ni->vol;
ntfs_attr_search_ctx *ctx = NULL;
MFT_RECORD *m = NULL;
ATTR_RECORD *a;
u8 *kaddr;
u32 attr_len;
int err;
ntfs_debug("Entering for inode 0x%lx, attribute type 0x%x, page index "
"0x%lx, from = %u, to = %u.", vi->i_ino, ni->type,
page->index, from, to);
BUG_ON(!PageLocked(page));
BUG_ON(from > PAGE_CACHE_SIZE);
BUG_ON(to > PAGE_CACHE_SIZE);
BUG_ON(from > to);
BUG_ON(NInoMstProtected(ni));
/*
* If a previous ntfs_truncate() failed, repeat it and abort if it
* fails again.
*/
if (unlikely(NInoTruncateFailed(ni))) {
down_write(&vi->i_alloc_sem);
err = ntfs_truncate(vi);
up_write(&vi->i_alloc_sem);
if (err || NInoTruncateFailed(ni)) {
if (!err)
err = -EIO;
goto err_out;
}
}
/* If the attribute is not resident, deal with it elsewhere. */
if (NInoNonResident(ni)) {
/*
* Only unnamed $DATA attributes can be compressed, encrypted,
* and/or sparse.
*/
if (ni->type == AT_DATA && !ni->name_len) {
/* If file is encrypted, deny access, just like NT4. */
if (NInoEncrypted(ni)) {
ntfs_debug("Denying write access to encrypted "
"file.");
return -EACCES;
}
/* Compressed data streams are handled in compress.c. */
if (NInoCompressed(ni)) {
// TODO: Implement and replace this check with
// return ntfs_write_compressed_block(page);
ntfs_error(vi->i_sb, "Writing to compressed "
"files is not supported yet. "
"Sorry.");
return -EOPNOTSUPP;
}
// TODO: Implement and remove this check.
if (NInoSparse(ni)) {
ntfs_error(vi->i_sb, "Writing to sparse files "
"is not supported yet. Sorry.");
return -EOPNOTSUPP;
}
}
/* Normal data stream. */
return ntfs_prepare_nonresident_write(page, from, to);
}
/*
* Attribute is resident, implying it is not compressed, encrypted, or
* sparse.
*/
BUG_ON(page_has_buffers(page));
new_size = ((s64)page->index << PAGE_CACHE_SHIFT) + to;
/* If we do not need to resize the attribute allocation we are done. */
if (new_size <= i_size_read(vi))
goto done;
/* Map, pin, and lock the (base) mft record. */
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;
/* The total length of the attribute value. */
attr_len = le32_to_cpu(a->data.resident.value_length);
/* Fix an eventual previous failure of ntfs_commit_write(). */
i_size = i_size_read(vi);
if (unlikely(attr_len > i_size)) {
attr_len = i_size;
a->data.resident.value_length = cpu_to_le32(attr_len);
}
/* If we do not need to resize the attribute allocation we are done. */
if (new_size <= attr_len)
goto done_unm;
/* Check if new size is allowed in $AttrDef. */
err = ntfs_attr_size_bounds_check(vol, ni->type, new_size);
if (unlikely(err)) {
if (err == -ERANGE) {
ntfs_error(vol->sb, "Write would cause the inode "
"0x%lx to exceed the maximum size for "
"its attribute type (0x%x). Aborting "
"write.", vi->i_ino,
le32_to_cpu(ni->type));
} else {
ntfs_error(vol->sb, "Inode 0x%lx has unknown "
"attribute type 0x%x. Aborting "
"write.", vi->i_ino,
le32_to_cpu(ni->type));
err = -EIO;
}
goto err_out2;
}
/*
* Extend the attribute record to be able to store the new attribute
* size.
*/
if (new_size >= vol->mft_record_size || ntfs_attr_record_resize(m, a,
le16_to_cpu(a->data.resident.value_offset) +
new_size)) {
/* Not enough space in the mft record. */
ntfs_error(vol->sb, "Not enough space in the mft record for "
"the resized attribute value. This is not "
"supported yet. Aborting write.");
err = -EOPNOTSUPP;
goto err_out2;
}
/*
* We have enough space in the mft record to fit the write. This
* implies the attribute is smaller than the mft record and hence the
* attribute must be in a single page and hence page->index must be 0.
*/
BUG_ON(page->index);
/*
* If the beginning of the write is past the old size, enlarge the
* attribute value up to the beginning of the write and fill it with
* zeroes.
*/
if (from > attr_len) {
memset((u8*)a + le16_to_cpu(a->data.resident.value_offset) +
attr_len, 0, from - attr_len);
a->data.resident.value_length = cpu_to_le32(from);
/* Zero the corresponding area in the page as well. */
if (PageUptodate(page)) {
kaddr = kmap_atomic(page, KM_USER0);
memset(kaddr + attr_len, 0, from - attr_len);
kunmap_atomic(kaddr, KM_USER0);
flush_dcache_page(page);
}
}
flush_dcache_mft_record_page(ctx->ntfs_ino);
mark_mft_record_dirty(ctx->ntfs_ino);
done_unm:
ntfs_attr_put_search_ctx(ctx);
unmap_mft_record(base_ni);
/*
* Because resident attributes are handled by memcpy() to/from the
* corresponding MFT record, and because this form of i/o is byte
* aligned rather than block aligned, there is no need to bring the
* page uptodate here as in the non-resident case where we need to
* bring the buffers straddled by the write uptodate before
* generic_file_write() does the copying from userspace.
*
* We thus defer the uptodate bringing of the page region outside the
* region written to to ntfs_commit_write(), which makes the code
* simpler and saves one atomic kmap which is good.
*/
done:
ntfs_debug("Done.");
return 0;
err_out:
if (err == -ENOMEM)
ntfs_warning(vi->i_sb, "Error allocating memory required to "
"prepare the write.");
else {
ntfs_error(vi->i_sb, "Resident attribute prepare write failed "
"with error %i.", err);
NVolSetErrors(vol);
make_bad_inode(vi);
}
err_out2:
if (ctx)
ntfs_attr_put_search_ctx(ctx);
if (m)
unmap_mft_record(base_ni);
return err;
}
/**
* ntfs_commit_nonresident_write -
*
*/
static int ntfs_commit_nonresident_write(struct page *page,
unsigned from, unsigned to)
{
s64 pos = ((s64)page->index << PAGE_CACHE_SHIFT) + to;
struct inode *vi = page->mapping->host;
struct buffer_head *bh, *head;
unsigned int block_start, block_end, blocksize;
BOOL partial;
ntfs_debug("Entering for inode 0x%lx, attribute type 0x%x, page index "
"0x%lx, from = %u, to = %u.", vi->i_ino,
NTFS_I(vi)->type, page->index, from, to);
blocksize = 1 << vi->i_blkbits;
// FIXME: We need a whole slew of special cases in here for compressed
// files for example...
// For now, we know ntfs_prepare_write() would have failed so we can't
// get here in any of the cases which we have to special case, so we
// are just a ripped off, unrolled generic_commit_write().
bh = head = page_buffers(page);
block_start = 0;
partial = FALSE;
do {
block_end = block_start + blocksize;
if (block_end <= from || block_start >= to) {
if (!buffer_uptodate(bh))
partial = TRUE;
} else {
set_buffer_uptodate(bh);
mark_buffer_dirty(bh);
}
} while (block_start = block_end, (bh = bh->b_this_page) != head);
/*
* 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);
/*
* Not convinced about this at all. See disparity comment above. For
* now we know ntfs_prepare_write() would have failed in the write
* exceeds i_size case, so this will never trigger which is fine.
*/
if (pos > i_size_read(vi)) {
ntfs_error(vi->i_sb, "Writing beyond the existing file size is "
"not supported yet. Sorry.");
return -EOPNOTSUPP;
// vi->i_size = pos;
// mark_inode_dirty(vi);
}
ntfs_debug("Done.");
return 0;
}
/**
* ntfs_commit_write - commit the received data
*
* This is called from generic_file_write() with i_sem held on the inode
* (@page->mapping->host). The @page is locked but not kmap()ped. The source
* data has already been copied into the @page. ntfs_prepare_write() has been
* called before the data copied and it returned success so we can take the
* results of various BUG checks and some error handling for granted.
*
* Need to mark modified blocks dirty so they get written out later when
* ntfs_writepage() is invoked by the VM.
*
* Return 0 on success or -errno on error.
*
* Should be using generic_commit_write(). This marks buffers uptodate and
* dirty, sets the page uptodate if all buffers in the page are uptodate, and
* updates i_size if the end of io is beyond i_size. In that case, it also
* marks the inode dirty.
*
* Cannot use generic_commit_write() due to ntfs specialities but can look at
* it for implementation guidance.
*
* If things have gone as outlined in ntfs_prepare_write(), then we do not
* need to do any page content modifications here at all, except in the write
* to resident attribute case, where we need to do the uptodate bringing here
* which we combine with the copying into the mft record which means we save
* one atomic kmap.
*/
static int ntfs_commit_write(struct file *file, struct page *page,
unsigned from, unsigned to)
{
struct inode *vi = page->mapping->host;
ntfs_inode *base_ni, *ni = NTFS_I(vi);
char *kaddr, *kattr;
ntfs_attr_search_ctx *ctx;
MFT_RECORD *m;
ATTR_RECORD *a;
u32 attr_len;
int err;
ntfs_debug("Entering for inode 0x%lx, attribute type 0x%x, page index "
"0x%lx, from = %u, to = %u.", vi->i_ino, ni->type,
page->index, from, to);
/* If the attribute is not resident, deal with it elsewhere. */
if (NInoNonResident(ni)) {
/* Only unnamed $DATA attributes can be compressed/encrypted. */
if (ni->type == AT_DATA && !ni->name_len) {
/* Encrypted files need separate handling. */
if (NInoEncrypted(ni)) {
// We never get here at present!
BUG();
}
/* Compressed data streams are handled in compress.c. */
if (NInoCompressed(ni)) {
// TODO: Implement this!
// return ntfs_write_compressed_block(page);
// We never get here at present!
BUG();
}
}
/* Normal data stream. */
return ntfs_commit_nonresident_write(page, from, to);
}
/*
* Attribute is resident, implying it is not compressed, encrypted, or
* sparse.
*/
if (!NInoAttr(ni))
base_ni = ni;
else
base_ni = ni->ext.base_ntfs_ino;
/* Map, pin, and lock the mft record. */
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;
}
a = ctx->attr;
/* The total length of the attribute value. */
attr_len = le32_to_cpu(a->data.resident.value_length);
BUG_ON(from > attr_len);
kattr = (u8*)a + le16_to_cpu(a->data.resident.value_offset);
kaddr = kmap_atomic(page, KM_USER0);
/* Copy the received data from the page to the mft record. */
memcpy(kattr + from, kaddr + from, to - from);
/* Update the attribute length if necessary. */
if (to > attr_len) {
attr_len = to;
a->data.resident.value_length = cpu_to_le32(attr_len);
}
/*
* If the page is not uptodate, bring the out of bounds area(s)
* uptodate by copying data from the mft record to the page.
*/
if (!PageUptodate(page)) {
if (from > 0)
memcpy(kaddr, kattr, from);
if (to < attr_len)
memcpy(kaddr + to, kattr + to, attr_len - to);
/* Zero the region outside the end of the attribute value. */
if (attr_len < PAGE_CACHE_SIZE)
memset(kaddr + attr_len, 0, PAGE_CACHE_SIZE - attr_len);
/*
* The probability of not having done any of the above is
* extremely small, so we just flush unconditionally.
*/
flush_dcache_page(page);
SetPageUptodate(page);
}
kunmap_atomic(kaddr, KM_USER0);
/* Update i_size if necessary. */
if (i_size_read(vi) < attr_len) {
unsigned long flags;
write_lock_irqsave(&ni->size_lock, flags);
ni->allocated_size = ni->initialized_size = attr_len;
i_size_write(vi, attr_len);
write_unlock_irqrestore(&ni->size_lock, flags);
}
/* 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);
ntfs_debug("Done.");
return 0;
err_out:
if (err == -ENOMEM) {
ntfs_warning(vi->i_sb, "Error allocating memory required to "
"commit the write.");
if (PageUptodate(page)) {
ntfs_warning(vi->i_sb, "Page is uptodate, setting "
"dirty so the write will be retried "
"later on by the VM.");
/*
* Put the page on mapping->dirty_pages, but leave its
* buffers' dirty state as-is.
*/
__set_page_dirty_nobuffers(page);
err = 0;
} else
ntfs_error(vi->i_sb, "Page is not uptodate. Written "
"data has been lost.");
} else {
ntfs_error(vi->i_sb, "Resident attribute commit write failed "
"with error %i.", err);
NVolSetErrors(ni->vol);
make_bad_inode(vi);
}
if (ctx)
ntfs_attr_put_search_ctx(ctx);
if (m)
unmap_mft_record(base_ni);
return err;
}
#endif /* NTFS_RW */
/**
@ -2377,9 +1553,6 @@ struct address_space_operations ntfs_aops = {
disk request queue. */
#ifdef NTFS_RW
.writepage = ntfs_writepage, /* Write dirty page to disk. */
.prepare_write = ntfs_prepare_write, /* Prepare page and buffers
ready to receive data. */
.commit_write = ntfs_commit_write, /* Commit received data. */
#endif /* NTFS_RW */
};