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-rw-r--r--fs/btrfs/compression.c33
-rw-r--r--fs/btrfs/compression.h4
-rw-r--r--fs/btrfs/ctree.c14
-rw-r--r--fs/btrfs/locking.c24
-rw-r--r--fs/btrfs/locking.h2
-rw-r--r--fs/btrfs/lzo.c15
-rw-r--r--fs/btrfs/zlib.c20
7 files changed, 92 insertions, 20 deletions
diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c
index d3220d31d3c..dcd9be32ac5 100644
--- a/fs/btrfs/compression.c
+++ b/fs/btrfs/compression.c
@@ -1011,8 +1011,6 @@ int btrfs_decompress_buf2page(char *buf, unsigned long buf_start,
bytes = min(bytes, working_bytes);
kaddr = kmap_atomic(page_out);
memcpy(kaddr + *pg_offset, buf + buf_offset, bytes);
- if (*pg_index == (vcnt - 1) && *pg_offset == 0)
- memset(kaddr + bytes, 0, PAGE_CACHE_SIZE - bytes);
kunmap_atomic(kaddr);
flush_dcache_page(page_out);
@@ -1054,3 +1052,34 @@ int btrfs_decompress_buf2page(char *buf, unsigned long buf_start,
return 1;
}
+
+/*
+ * When uncompressing data, we need to make sure and zero any parts of
+ * the biovec that were not filled in by the decompression code. pg_index
+ * and pg_offset indicate the last page and the last offset of that page
+ * that have been filled in. This will zero everything remaining in the
+ * biovec.
+ */
+void btrfs_clear_biovec_end(struct bio_vec *bvec, int vcnt,
+ unsigned long pg_index,
+ unsigned long pg_offset)
+{
+ while (pg_index < vcnt) {
+ struct page *page = bvec[pg_index].bv_page;
+ unsigned long off = bvec[pg_index].bv_offset;
+ unsigned long len = bvec[pg_index].bv_len;
+
+ if (pg_offset < off)
+ pg_offset = off;
+ if (pg_offset < off + len) {
+ unsigned long bytes = off + len - pg_offset;
+ char *kaddr;
+
+ kaddr = kmap_atomic(page);
+ memset(kaddr + pg_offset, 0, bytes);
+ kunmap_atomic(kaddr);
+ }
+ pg_index++;
+ pg_offset = 0;
+ }
+}
diff --git a/fs/btrfs/compression.h b/fs/btrfs/compression.h
index 0c803b4fbf9..d181f70caae 100644
--- a/fs/btrfs/compression.h
+++ b/fs/btrfs/compression.h
@@ -45,7 +45,9 @@ int btrfs_submit_compressed_write(struct inode *inode, u64 start,
unsigned long nr_pages);
int btrfs_submit_compressed_read(struct inode *inode, struct bio *bio,
int mirror_num, unsigned long bio_flags);
-
+void btrfs_clear_biovec_end(struct bio_vec *bvec, int vcnt,
+ unsigned long pg_index,
+ unsigned long pg_offset);
struct btrfs_compress_op {
struct list_head *(*alloc_workspace)(void);
diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index 19bc6162fb8..150822ee0a0 100644
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -80,13 +80,6 @@ noinline void btrfs_clear_path_blocking(struct btrfs_path *p,
{
int i;
-#ifdef CONFIG_DEBUG_LOCK_ALLOC
- /* lockdep really cares that we take all of these spinlocks
- * in the right order. If any of the locks in the path are not
- * currently blocking, it is going to complain. So, make really
- * really sure by forcing the path to blocking before we clear
- * the path blocking.
- */
if (held) {
btrfs_set_lock_blocking_rw(held, held_rw);
if (held_rw == BTRFS_WRITE_LOCK)
@@ -95,7 +88,6 @@ noinline void btrfs_clear_path_blocking(struct btrfs_path *p,
held_rw = BTRFS_READ_LOCK_BLOCKING;
}
btrfs_set_path_blocking(p);
-#endif
for (i = BTRFS_MAX_LEVEL - 1; i >= 0; i--) {
if (p->nodes[i] && p->locks[i]) {
@@ -107,10 +99,8 @@ noinline void btrfs_clear_path_blocking(struct btrfs_path *p,
}
}
-#ifdef CONFIG_DEBUG_LOCK_ALLOC
if (held)
btrfs_clear_lock_blocking_rw(held, held_rw);
-#endif
}
/* this also releases the path */
@@ -2893,7 +2883,7 @@ cow_done:
}
p->locks[level] = BTRFS_WRITE_LOCK;
} else {
- err = btrfs_try_tree_read_lock(b);
+ err = btrfs_tree_read_lock_atomic(b);
if (!err) {
btrfs_set_path_blocking(p);
btrfs_tree_read_lock(b);
@@ -3025,7 +3015,7 @@ again:
}
level = btrfs_header_level(b);
- err = btrfs_try_tree_read_lock(b);
+ err = btrfs_tree_read_lock_atomic(b);
if (!err) {
btrfs_set_path_blocking(p);
btrfs_tree_read_lock(b);
diff --git a/fs/btrfs/locking.c b/fs/btrfs/locking.c
index 5665d214924..f8229ef1b46 100644
--- a/fs/btrfs/locking.c
+++ b/fs/btrfs/locking.c
@@ -128,6 +128,26 @@ again:
}
/*
+ * take a spinning read lock.
+ * returns 1 if we get the read lock and 0 if we don't
+ * this won't wait for blocking writers
+ */
+int btrfs_tree_read_lock_atomic(struct extent_buffer *eb)
+{
+ if (atomic_read(&eb->blocking_writers))
+ return 0;
+
+ read_lock(&eb->lock);
+ if (atomic_read(&eb->blocking_writers)) {
+ read_unlock(&eb->lock);
+ return 0;
+ }
+ atomic_inc(&eb->read_locks);
+ atomic_inc(&eb->spinning_readers);
+ return 1;
+}
+
+/*
* returns 1 if we get the read lock and 0 if we don't
* this won't wait for blocking writers
*/
@@ -158,9 +178,7 @@ int btrfs_try_tree_write_lock(struct extent_buffer *eb)
atomic_read(&eb->blocking_readers))
return 0;
- if (!write_trylock(&eb->lock))
- return 0;
-
+ write_lock(&eb->lock);
if (atomic_read(&eb->blocking_writers) ||
atomic_read(&eb->blocking_readers)) {
write_unlock(&eb->lock);
diff --git a/fs/btrfs/locking.h b/fs/btrfs/locking.h
index b81e0e9a489..c44a9d5f536 100644
--- a/fs/btrfs/locking.h
+++ b/fs/btrfs/locking.h
@@ -35,6 +35,8 @@ void btrfs_clear_lock_blocking_rw(struct extent_buffer *eb, int rw);
void btrfs_assert_tree_locked(struct extent_buffer *eb);
int btrfs_try_tree_read_lock(struct extent_buffer *eb);
int btrfs_try_tree_write_lock(struct extent_buffer *eb);
+int btrfs_tree_read_lock_atomic(struct extent_buffer *eb);
+
static inline void btrfs_tree_unlock_rw(struct extent_buffer *eb, int rw)
{
diff --git a/fs/btrfs/lzo.c b/fs/btrfs/lzo.c
index 78285f30909..617553cdb7d 100644
--- a/fs/btrfs/lzo.c
+++ b/fs/btrfs/lzo.c
@@ -373,6 +373,8 @@ cont:
}
done:
kunmap(pages_in[page_in_index]);
+ if (!ret)
+ btrfs_clear_biovec_end(bvec, vcnt, page_out_index, pg_offset);
return ret;
}
@@ -410,10 +412,23 @@ static int lzo_decompress(struct list_head *ws, unsigned char *data_in,
goto out;
}
+ /*
+ * the caller is already checking against PAGE_SIZE, but lets
+ * move this check closer to the memcpy/memset
+ */
+ destlen = min_t(unsigned long, destlen, PAGE_SIZE);
bytes = min_t(unsigned long, destlen, out_len - start_byte);
kaddr = kmap_atomic(dest_page);
memcpy(kaddr, workspace->buf + start_byte, bytes);
+
+ /*
+ * btrfs_getblock is doing a zero on the tail of the page too,
+ * but this will cover anything missing from the decompressed
+ * data.
+ */
+ if (bytes < destlen)
+ memset(kaddr+bytes, 0, destlen-bytes);
kunmap_atomic(kaddr);
out:
return ret;
diff --git a/fs/btrfs/zlib.c b/fs/btrfs/zlib.c
index 759fa4e2de8..fb22fd8d8fb 100644
--- a/fs/btrfs/zlib.c
+++ b/fs/btrfs/zlib.c
@@ -299,6 +299,8 @@ done:
zlib_inflateEnd(&workspace->strm);
if (data_in)
kunmap(pages_in[page_in_index]);
+ if (!ret)
+ btrfs_clear_biovec_end(bvec, vcnt, page_out_index, pg_offset);
return ret;
}
@@ -310,10 +312,14 @@ static int zlib_decompress(struct list_head *ws, unsigned char *data_in,
struct workspace *workspace = list_entry(ws, struct workspace, list);
int ret = 0;
int wbits = MAX_WBITS;
- unsigned long bytes_left = destlen;
+ unsigned long bytes_left;
unsigned long total_out = 0;
+ unsigned long pg_offset = 0;
char *kaddr;
+ destlen = min_t(unsigned long, destlen, PAGE_SIZE);
+ bytes_left = destlen;
+
workspace->strm.next_in = data_in;
workspace->strm.avail_in = srclen;
workspace->strm.total_in = 0;
@@ -341,7 +347,6 @@ static int zlib_decompress(struct list_head *ws, unsigned char *data_in,
unsigned long buf_start;
unsigned long buf_offset;
unsigned long bytes;
- unsigned long pg_offset = 0;
ret = zlib_inflate(&workspace->strm, Z_NO_FLUSH);
if (ret != Z_OK && ret != Z_STREAM_END)
@@ -384,6 +389,17 @@ next:
ret = 0;
zlib_inflateEnd(&workspace->strm);
+
+ /*
+ * this should only happen if zlib returned fewer bytes than we
+ * expected. btrfs_get_block is responsible for zeroing from the
+ * end of the inline extent (destlen) to the end of the page
+ */
+ if (pg_offset < destlen) {
+ kaddr = kmap_atomic(dest_page);
+ memset(kaddr + pg_offset, 0, destlen - pg_offset);
+ kunmap_atomic(kaddr);
+ }
return ret;
}
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2024-12-19 04:53:30 +0000