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  1. 25 Apr, 2007 1 commit
    • David Woodhouse's avatar
      [JFFS2] Improve read_inode memory usage, v2. · df8e96f3
      David Woodhouse authored 
      We originally used to read every node and allocate a jffs2_tmp_dnode_info
structure for each, before processing them in (reverse) version order
and discarding the ones which are obsoleted by later nodes.

With huge logfiles, this behaviour caused memory problems. For example, a
file involved in OLPC trac #1292 has 1822391 nodes, and would cause the XO
machine to run out of memory during the first stage of read_inode().

Instead of just inserting nodes into a tree in version order as we find
them, we now put them into a tree in order of their offset within the
file, which allows us to immediately discard nodes which are completely
obsoleted.

We don't use a full tree with 'fragments' pointing to the real data
structure, as we do in the normal fragtree. We sort only on the start
address, and add an 'overlapped' flag to the tmp_dnode_info to indicate
that the node in question is (partially) overlapped by another.

When the scan is complete, we start at the end of the file, adding each
node to a real fragtree as before. Where the node is non-overlapped, we
just add it (it doesn't matter that it's not the latest version; there is
no overlap). When the node at the end of the tree _is_ overlapped, we sort
it and all its overlapping nodes into version order and then add them to
the fragtree in that order.

This 'early discard' reduces the peak allocation of tmp_dnode_info
structures from 1.8M to a mere 62872 (3.5%) in the degenerate case
referenced above.

This version of the patch also correctly rememembers the highest node
version# seen for an inode when it's scanned.
Signed-off-by: default avatarDavid Woodhouse <dwmw2@infradead.org>
      df8e96f3
  3. 23 Apr, 2007 2 commits
    • David Woodhouse's avatar
      [JFFS2] Improve failure mode if inode checking leaves unchecked space. · 44b998e1
      David Woodhouse authored 
      We should never find the unchecked size is non-zero after we've finished
checking all inodes. If it happens, used to BUG(), leaving the alloc_sem
held and deadlocking. Instead, just return -ENOSPC after complaining. The
GC thread will die, but read-only operation should be able to continue and
the file system should be unmountable.
Signed-off-by: default avatarDavid Woodhouse <dwmw2@infradead.org>
      44b998e1
    • David Woodhouse's avatar
      [JFFS2] Fix cross-endian build. · 566865a2
      David Woodhouse authored 
      When compiling a LE-capable JFFS2 on PowerPC, wbuf.c fails to compile:

fs/jffs2/wbuf.c:973: error: braced-group within expression allowed only inside a function
fs/jffs2/wbuf.c:973: error: initializer element is not constant
fs/jffs2/wbuf.c:973: error: (near initialization for ‘oob_cleanmarker.magic’)
fs/jffs2/wbuf.c:974: error: braced-group within expression allowed only inside a function
fs/jffs2/wbuf.c:974: error: initializer element is not constant
fs/jffs2/wbuf.c:974: error: (near initialization for ‘oob_cleanmarker.nodetype’)
fs/jffs2/wbuf.c:975: error: braced-group within expression allowed only inside a function
fs/jffs2/wbuf.c:976: error: initializer element is not constant
fs/jffs2/wbuf.c:976: error: (near initialization for ‘oob_cleanmarker.totlen’)

Provide constant_cpu_to_je{16,32} functions, and use them for initialising the
offending structure.
Signed-off-by: default avatarDavid Woodhouse <dwmw2@infradead.org>
      566865a2
  5. 22 Apr, 2007 1 commit
  7. 21 Apr, 2007 1 commit
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  11. 17 Apr, 2007 19 commits
  13. 02 Apr, 2007 3 commits
  15. 23 Mar, 2007 3 commits
  17. 10 Mar, 2007 8 commits
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