Commit 946929d8 authored by Anton Altaparmakov's avatar Anton Altaparmakov
Browse files

NTFS: Fixup the resident attribute resizing code in

      fs/ntfs/aops.c::ntfs_{prepare,commit}_write()() and re-enable it.
      It should be safe now.  (Famous last words...)
Signed-off-by: default avatarAnton Altaparmakov <>
parent 3834c3f2
......@@ -51,6 +51,11 @@ ToDo/Notes:
value afterwards when reading the size of the bitmap inode.
- Use i_size_{read,write}() in fs/ntfs/{aops.c,mft.c} and protect
access to the i_size and other size fields using the size_lock.
- Implement extension of resident files in the regular file write code
paths (fs/ntfs/aops.c::ntfs_{prepare,commit}_write()). At present
this only works until the data attribute becomes too big for the mft
record after which we abort the write returning -EOPNOTSUPP from
2.1.22 - Many bug and race fixes and error handling improvements.
......@@ -872,6 +872,7 @@ static int ntfs_write_mst_block(struct page *page,
if (likely(block < rec_block)) {
if (unlikely(block >= dblock)) {
......@@ -1830,6 +1831,7 @@ static int ntfs_prepare_write(struct file *file, struct page *page,
unsigned from, unsigned to)
s64 new_size;
unsigned long flags;
struct inode *vi = page->mapping->host;
ntfs_inode *base_ni = NULL, *ni = NTFS_I(vi);
ntfs_volume *vol = ni->vol;
......@@ -1903,12 +1905,6 @@ static int ntfs_prepare_write(struct file *file, struct page *page,
/* If we do not need to resize the attribute allocation we are done. */
if (new_size <= i_size_read(vi))
goto done;
// FIXME: We abort for now as this code is not safe.
ntfs_error(vi->i_sb, "Changing the file size is not supported yet. "
/* Map, pin, and lock the (base) mft record. */
if (!NInoAttr(ni))
base_ni = ni;
......@@ -1937,7 +1933,17 @@ static int ntfs_prepare_write(struct file *file, struct page *page,
a = ctx->attr;
/* The total length of the attribute value. */
attr_len = le32_to_cpu(a->data.resident.value_length);
BUG_ON(i_size_read(vi) != attr_len);
/* Fix an eventual previous failure of ntfs_commit_write(). */
read_lock_irqsave(&ni->size_lock, flags);
if (unlikely(ni->initialized_size < attr_len)) {
attr_len = ni->initialized_size;
a->data.resident.value_length = cpu_to_le32(attr_len);
BUG_ON(attr_len < i_size_read(vi));
read_unlock_irqrestore(&ni->size_lock, flags);
/* 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)) {
......@@ -1995,6 +2001,7 @@ static int ntfs_prepare_write(struct file *file, struct page *page,
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