unimore/kernel-hacking-2024-linux-steffo
unimore/kernel-hacking-2024-linux-steffo
1
Fork 0
Code Pull requests 5 Wiki Activity

Btrfs: make uncache_state unconditional

Browse source 
The extent_io code can take cached pointers into the extent state trees,
and these can make lookups much faster in common operations.  The
caching only happens when specific bits are set that prevent merging
and splitting of the extent state.

A help function was added to uncache the state, and it was testing
the same set of conditionals.  This can leak in very strange corner
cases where the lock bit goes away unexpectedly.

The uncaching should be unconditional.  Once we have a ref on the
extent we should always give it up.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
This commit is contained in:
Chris Mason 2011-04-12 13:57:39 -04:00
parent 874d0d2633
commit 109b36a2bb
1 changed files with 3 additions and 5 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

8
fs/btrfs/extent_io.c
View file

@ -694,10 +694,8 @@ static void uncache_state(struct extent_state **cached_ptr)
{
if (cached_ptr && (*cached_ptr)) {
struct extent_state *state = *cached_ptr;
if (state->state & (EXTENT_IOBITS | EXTENT_BOUNDARY)) {
*cached_ptr = NULL;
free_extent_state(state);
}
*cached_ptr = NULL;
free_extent_state(state);
}
}
@ -1764,7 +1762,7 @@ static void end_bio_extent_readpage(struct bio *bio, int err)
spin_lock(&tree->lock);
state = find_first_extent_bit_state(tree, start, 0);
if (state) {
if (state && state->start == start) {
/*
* take a reference on the state, unlock will drop
* the ref