[PATCH 12/20] Re: [2.6-BK-URL] NTFS 2.1.17 release
From: Anton Altaparmakov
Date: Mon Aug 23 2004 - 05:58:14 EST
This is patch 12/20 in the series. It contains the following ChangeSet:
<aia21@xxxxxxxxxx> (04/07/22 1.1815)
NTFS: Add fs/ntfs/attrib.[hc]::ntfs_find_vcn().
Signed-off-by: Anton Altaparmakov <aia21@xxxxxxxxxx>
Best regards,
Anton
--
Anton Altaparmakov <aia21 at cam.ac.uk> (replace at with @)
Unix Support, Computing Service, University of Cambridge, CB2 3QH, UK
Linux NTFS maintainer / IRC: #ntfs on irc.freenode.net
WWW: http://linux-ntfs.sf.net/, http://www-stu.christs.cam.ac.uk/~aia21/
===================================================================
diff -Nru a/fs/ntfs/ChangeLog b/fs/ntfs/ChangeLog
--- a/fs/ntfs/ChangeLog 2004-08-18 20:50:24 +01:00
+++ b/fs/ntfs/ChangeLog 2004-08-18 20:50:24 +01:00
@@ -25,6 +25,9 @@
- Implement bitmap modification code (fs/ntfs/bitmap.[hc]). This
includes functions to set/clear a single bit or a run of bits.
+ - Add fs/ntfs/attrib.[hc]::ntfs_find_vcn() which returns the locked
+ runlist element containing a particular vcn. It also takes care of
+ mapping any needed runlist fragments.
2.1.16 - Implement access time updates, file sync, async io, and read/writev.
@@ -448,7 +451,7 @@
cannot set any write related options when the driver is compiled
read-only.
- Optimize block resolution in fs/ntfs/aops.c::ntfs_read_block() to
- cache the current run list element. This should improve performance
+ cache the current runlist element. This should improve performance
when reading very large and/or very fragmented data.
2.0.16 - Convert access to $MFT/$BITMAP to attribute inode API.
@@ -496,9 +499,9 @@
- Change fs/ntfs/super.c::ntfs_statfs() to not rely on BKL by moving
the locking out of super.c::get_nr_free_mft_records() and taking and
dropping the mftbmp_lock rw_semaphore in ntfs_statfs() itself.
- - Bring attribute run list merging code (fs/ntfs/attrib.c) in sync with
+ - Bring attribute runlist merging code (fs/ntfs/attrib.c) in sync with
current userspace ntfs library code. This means that if a merge
- fails the original run lists are always left unmodified instead of
+ fails the original runlists are always left unmodified instead of
being silently corrupted.
- Misc typo fixes.
@@ -690,7 +693,7 @@
appropriately.
- Update to 2.5.9 kernel (preserving backwards compatibility) by
replacing all occurences of page->buffers with page_buffers(page).
- - Fix minor bugs in run list merging, also minor cleanup.
+ - Fix minor bugs in runlist merging, also minor cleanup.
- Updates to bootsector layout and mft mirror contents descriptions.
- Small bug fix in error detection in unistr.c and some cleanups.
- Grow name buffer allocations in unistr.c in aligned mutlipled of 64
@@ -713,12 +716,12 @@
initialized_size vs data_size (i.e. i_size). Done are
mft.c::ntfs_mft_readpage(), aops.c::end_buffer_read_index_async(),
and attrib.c::load_attribute_list().
- - Lock the run list in attrib.c::load_attribute_list() while using it.
+ - Lock the runlist in attrib.c::load_attribute_list() while using it.
- Fix memory leak in ntfs_file_read_compressed_block() and generally
clean up compress.c a little, removing some uncommented/unused debug
code.
- Tidy up dir.c a little bit.
- - Don't bother getting the run list in inode.c::ntfs_read_inode().
+ - Don't bother getting the runlist in inode.c::ntfs_read_inode().
- Merge mft.c::ntfs_mft_readpage() and aops.c::ntfs_index_readpage()
creating aops.c::ntfs_mst_readpage(), improving the handling of
holes and overflow in the process and implementing the correct
@@ -748,7 +751,7 @@
- Apply kludge in ntfs_read_inode(), setting i_nlink to 1 for
directories. Without this the "find" utility gets very upset which is
fair enough as Linux/Unix do not support directory hard links.
- - Further run list merging work. (Richard Russon)
+ - Further runlist merging work. (Richard Russon)
- Backwards compatibility for gcc-2.95. (Richard Russon)
- Update to kernel 2.5.5-pre1 and rediff the now tiny patch.
- Convert to new file system declaration using ->ntfs_get_sb() and
@@ -803,7 +806,7 @@
which is then referenced but not copied.
- Rename run_list structure to run_list_element and create a new
run_list structure containing a pointer to a run_list_element
- structure and a read/write semaphore. Adapt all users of run lists
+ structure and a read/write semaphore. Adapt all users of runlists
to new scheme and take and release the lock as needed. This fixes a
nasty race as the run_list changes even when inodes are locked for
reading and even when the inode isn't locked at all, so we really
@@ -834,7 +837,7 @@
- Cleanup mft.c and it's debug/error output in particular. Fix a minor
bug in mapping of extent inodes. Update all the comments to fit all
the recent code changes.
- - Modify vcn_to_lcn() to cope with entirely unmapped run lists.
+ - Modify vcn_to_lcn() to cope with entirely unmapped runlists.
- Cleanups in compress.c, mostly comments and folding help.
- Implement attrib.c::map_run_list() as a generic helper.
- Make compress.c::ntfs_file_read_compressed_block() use map_run_list()
@@ -860,11 +863,11 @@
pass in the upcase table and its length. These can be gotten from
ctx->ntfs_ino->vol->upcase{_len}. Update all callers.
- Cleanups in attrib.c.
- - Implement merging of run lists, attrib.c::merge_run_lists() and its
+ - Implement merging of runlists, attrib.c::merge_run_lists() and its
helpers. (Richard Russon)
- - Attribute lists part 2, attribute extents and multi part run lists:
+ - Attribute lists part 2, attribute extents and multi part runlists:
enable proper support for LCN_RL_NOT_MAPPED and automatic mapping of
- further run list parts via attrib.c::map_run_list().
+ further runlist parts via attrib.c::map_run_list().
- Tiny endianness bug fix in decompress_mapping_pairs().
tng-0.0.6 - Encrypted directories, bug fixes, cleanups, debugging enhancements.
@@ -896,7 +899,7 @@
support dollar signs in the names of variables/constants. Attribute
types now start with AT_ instead of $ and $I30 is now just I30.
- Cleanup ntfs_lookup() and add consistency check of sequence numbers.
- - Load complete run list for $MFT/$BITMAP during mount and cleanup
+ - Load complete runlist for $MFT/$BITMAP during mount and cleanup
access functions. This means we now cope with $MFT/$BITMAP being
spread accross several mft records.
- Disable modification of mft_zone_multiplier on remount. We can always
@@ -929,11 +932,11 @@
parameter list. Pass either READ or WRITE to this, each has the
obvious meaning.
- General cleanups to allow for easier folding in vi.
- - attrib.c::decompress_mapping_pairs() now accepts the old run list
+ - attrib.c::decompress_mapping_pairs() now accepts the old runlist
argument, and invokes attrib.c::merge_run_lists() to merge the old
- and the new run lists.
+ and the new runlists.
- Removed attrib.c::find_first_attr().
- - Implemented loading of attribute list and complete run list for $MFT.
+ - Implemented loading of attribute list and complete runlist for $MFT.
This means we now cope with $MFT being spread across several mft
records.
- Adapt to 2.5.2-pre9 and the changed create_empty_buffers() syntax.
@@ -971,7 +974,7 @@
tng-0.0.3 - Cleanups, enhancements, bug fixes.
- Work on attrib.c::decompress_mapping_pairs() to detect base extents
- and setup the run list appropriately using knowledge provided by the
+ and setup the runlist appropriately using knowledge provided by the
sizes in the base attribute record.
- Balance the get_/put_attr_search_ctx() calls so we don't leak memory
any more.
diff -Nru a/fs/ntfs/attrib.c b/fs/ntfs/attrib.c
--- a/fs/ntfs/attrib.c 2004-08-18 20:50:24 +01:00
+++ b/fs/ntfs/attrib.c 2004-08-18 20:50:24 +01:00
@@ -1051,6 +1051,107 @@
}
/**
+ * ntfs_find_vcn - find a vcn in the runlist described by an ntfs inode
+ * @ni: ntfs inode describing the runlist to search
+ * @vcn: vcn to find
+ * @need_write: if false, lock for reading and if true, lock for writing
+ *
+ * Find the virtual cluster number @vcn in the runlist described by the ntfs
+ * inode @ni and return the address of the runlist element containing the @vcn.
+ * The runlist is left locked and the caller has to unlock it. If @need_write
+ * is true, the runlist is locked for writing and if @need_write is false, the
+ * runlist is locked for reading. In the error case, the runlist is not left
+ * locked.
+ *
+ * Note you need to distinguish between the lcn of the returned runlist element
+ * being >= 0 and LCN_HOLE. In the later case you have to return zeroes on
+ * read and allocate clusters on write.
+ *
+ * Return the runlist element containing the @vcn on success and
+ * ERR_PTR(-errno) on error. You need to test the return value with IS_ERR()
+ * to decide if the return is success or failure and PTR_ERR() to get to the
+ * error code if IS_ERR() is true.
+ *
+ * The possible error return codes are:
+ * -ENOENT - No such vcn in the runlist, i.e. @vcn is out of bounds.
+ * -ENOMEM - Not enough memory to map runlist.
+ * -EIO - Critical error (runlist/file is corrupt, i/o error, etc).
+ *
+ * Locking: - The runlist must be unlocked on entry.
+ * - On failing return, the runlist is unlocked.
+ * - On successful return, the runlist is locked. If @need_write us
+ * true, it is locked for writing. Otherwise is is locked for
+ * reading.
+ */
+runlist_element *ntfs_find_vcn(ntfs_inode *ni, const VCN vcn,
+ const BOOL need_write)
+{
+ runlist_element *rl;
+ int err = 0;
+ BOOL is_retry = FALSE;
+
+ ntfs_debug("Entering for i_ino 0x%lx, vcn 0x%llx, lock for %sing.",
+ ni->mft_no, (unsigned long long)vcn,
+ !need_write ? "read" : "writ");
+ BUG_ON(!ni);
+ BUG_ON(!NInoNonResident(ni));
+ BUG_ON(vcn < 0);
+lock_retry_remap:
+ if (!need_write)
+ down_read(&ni->runlist.lock);
+ else
+ down_write(&ni->runlist.lock);
+ rl = ni->runlist.rl;
+ if (likely(rl && vcn >= rl[0].vcn)) {
+ while (likely(rl->length)) {
+ if (likely(vcn < rl[1].vcn)) {
+ if (likely(rl->lcn >= (LCN)LCN_HOLE)) {
+ ntfs_debug("Done.");
+ return rl;
+ }
+ break;
+ }
+ rl++;
+ }
+ switch (rl->lcn) {
+ case (LCN)LCN_RL_NOT_MAPPED:
+ break;
+ case (LCN)LCN_ENOENT:
+ err = -ENOENT;
+ break;
+ default:
+ err = -EIO;
+ break;
+ }
+ }
+ if (!need_write)
+ up_read(&ni->runlist.lock);
+ else
+ up_write(&ni->runlist.lock);
+ if (!err && !is_retry) {
+ /*
+ * The @vcn is in an unmapped region, map the runlist and
+ * retry.
+ */
+ err = ntfs_map_runlist(ni, vcn);
+ if (likely(!err)) {
+ is_retry = TRUE;
+ goto lock_retry_remap;
+ }
+ /*
+ * -EINVAL and -ENOENT coming from a failed mapping attempt are
+ * equivalent to i/o errors for us as they should not happen in
+ * our code paths.
+ */
+ if (err == -EINVAL || err == -ENOENT)
+ err = -EIO;
+ } else if (!err)
+ err = -EIO;
+ ntfs_error(ni->vol->sb, "Failed with error code %i.", err);
+ return ERR_PTR(err);
+}
+
+/**
* find_attr - find (next) attribute in mft record
* @type: attribute type to find
* @name: attribute name to find (optional, i.e. NULL means don't care)
diff -Nru a/fs/ntfs/attrib.h b/fs/ntfs/attrib.h
--- a/fs/ntfs/attrib.h 2004-08-18 20:50:24 +01:00
+++ b/fs/ntfs/attrib.h 2004-08-18 20:50:24 +01:00
@@ -78,6 +78,9 @@
extern LCN ntfs_vcn_to_lcn(const runlist_element *rl, const VCN vcn);
+extern runlist_element *ntfs_find_vcn(ntfs_inode *ni, const VCN vcn,
+ const BOOL need_write);
+
extern BOOL find_attr(const ATTR_TYPES type, const ntfschar *name,
const u32 name_len, const IGNORE_CASE_BOOL ic, const u8 *val,
const u32 val_len, attr_search_context *ctx);
-
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