btrfs: derive maximum output size in the compression implementation

The value of max_out can be calculated from the parameters passed to the
compressors, which is number of pages and the page size, and we don't
have to needlessly pass it around.

Signed-off-by: David Sterba <dsterba@suse.com>

5 files changed, 9 insertions, 14 deletions

diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c
index 11dcda57e15c..c7721a6aa3bb 100644
--- a/fs/btrfs/compression.c
+++ b/fs/btrfs/compression.c
@@ -932,8 +932,7 @@ int btrfs_compress_pages(int type, struct address_space *mapping,
                          u64 start, struct page **pages,
                          unsigned long *out_pages,
                          unsigned long *total_in,
-                         unsigned long *total_out,
-                         unsigned long max_out)
+                         unsigned long *total_out)
 {
         struct list_head *workspace;
         int ret;
@@ -943,8 +942,7 @@ int btrfs_compress_pages(int type, struct address_space *mapping,
         ret = btrfs_compress_op[type-1]->compress_pages(workspace, mapping,
                                                       start, pages,
                                                       out_pages,
-                                                      total_in, total_out,
-                                                      max_out);
+                                                      total_in, total_out);
         free_workspace(type, workspace);
         return ret;
 }
diff --git a/fs/btrfs/compression.h b/fs/btrfs/compression.h
index 619e64c27444..39ec43ab8df1 100644
--- a/fs/btrfs/compression.h
+++ b/fs/btrfs/compression.h
@@ -41,8 +41,7 @@ int btrfs_compress_pages(int type, struct address_space *mapping,
                          u64 start, struct page **pages,
                          unsigned long *out_pages,
                          unsigned long *total_in,
-                         unsigned long *total_out,
-                         unsigned long max_out);
+                         unsigned long *total_out);
 int btrfs_decompress(int type, unsigned char *data_in, struct page *dest_page,
                      unsigned long start_byte, size_t srclen, size_t destlen);
 int btrfs_decompress_buf2page(const char *buf, unsigned long buf_start,
@@ -76,8 +75,7 @@ struct btrfs_compress_op {
                               struct page **pages,
                               unsigned long *out_pages,
                               unsigned long *total_in,
-                              unsigned long *total_out,
-                              unsigned long max_out);
+                              unsigned long *total_out);
 
         int (*decompress_bio)(struct list_head *workspace,
                                  struct page **pages_in,
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 11a4eeadf662..0d932b9594de 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -510,8 +510,7 @@ again:
                                            pages,
                                            &nr_pages,
                                            &total_in,
-                                           &total_compressed,
-                                           BTRFS_MAX_COMPRESSED);
+                                           &total_compressed);
 
                 if (!ret) {
                         unsigned long offset = total_compressed &
diff --git a/fs/btrfs/lzo.c b/fs/btrfs/lzo.c
index 0baf978fbcaf..f48c8c14dc14 100644
--- a/fs/btrfs/lzo.c
+++ b/fs/btrfs/lzo.c
@@ -90,8 +90,7 @@ static int lzo_compress_pages(struct list_head *ws,
                               struct page **pages,
                               unsigned long *out_pages,
                               unsigned long *total_in,
-                              unsigned long *total_out,
-                              unsigned long max_out)
+                              unsigned long *total_out)
 {
         struct workspace *workspace = list_entry(ws, struct workspace, list);
         int ret = 0;
@@ -103,6 +102,7 @@ static int lzo_compress_pages(struct list_head *ws,
         unsigned long bytes_left;
         unsigned long len = *total_out;
         unsigned long nr_dest_pages = *out_pages;
+        const unsigned long max_out = nr_dest_pages * PAGE_SIZE;
         size_t in_len;
         size_t out_len;
         char *buf;
diff --git a/fs/btrfs/zlib.c b/fs/btrfs/zlib.c
index e7f2020f8ee7..135b10823c6d 100644
--- a/fs/btrfs/zlib.c
+++ b/fs/btrfs/zlib.c
@@ -77,8 +77,7 @@ static int zlib_compress_pages(struct list_head *ws,
                                struct page **pages,
                                unsigned long *out_pages,
                                unsigned long *total_in,
-                               unsigned long *total_out,
-                               unsigned long max_out)
+                               unsigned long *total_out)
 {
         struct workspace *workspace = list_entry(ws, struct workspace, list);
         int ret;
@@ -90,6 +89,7 @@ static int zlib_compress_pages(struct list_head *ws,
         unsigned long bytes_left;
         unsigned long len = *total_out;
         unsigned long nr_dest_pages = *out_pages;
+        const unsigned long max_out = nr_dest_pages * PAGE_SIZE;
 
         *out_pages = 0;
         *total_out = 0;