btrfs: use predefined limits for calculating maximum number of pages for compression

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

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 77fb24b94a9ebaf1ed75719ab9f15eebaee8134a..11a4eeadf662b29253d8915e382dc271b8c6335b 100644 (file)
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -432,8 +432,6 @@ static noinline void compress_file_range(struct inode *inode,
        unsigned long nr_pages;
        unsigned long total_compressed = 0;
        unsigned long total_in = 0;
-       unsigned long max_compressed = SZ_128K;
-       unsigned long max_uncompressed = SZ_128K;
        int i;
        int will_compress;
        int compress_type = fs_info->compress_type;
@@ -446,7 +444,9 @@ static noinline void compress_file_range(struct inode *inode,
 again:
        will_compress = 0;
        nr_pages = (end >> PAGE_SHIFT) - (start >> PAGE_SHIFT) + 1;
-       nr_pages = min_t(unsigned long, nr_pages, SZ_128K / PAGE_SIZE);
+       BUILD_BUG_ON((BTRFS_MAX_COMPRESSED % PAGE_SIZE) != 0);
+       nr_pages = min_t(unsigned long, nr_pages,
+                       BTRFS_MAX_COMPRESSED / PAGE_SIZE);
 
        /*
         * we don't want to send crud past the end of i_size through
@@ -471,7 +471,8 @@ again:
           (start > 0 || end + 1 < BTRFS_I(inode)->disk_i_size))
                goto cleanup_and_bail_uncompressed;
 
-       total_compressed = min(total_compressed, max_uncompressed);
+       total_compressed = min_t(unsigned long, total_compressed,
+                       BTRFS_MAX_UNCOMPRESSED);
        num_bytes = ALIGN(end - start + 1, blocksize);
        num_bytes = max(blocksize,  num_bytes);
        total_in = 0;
@@ -510,7 +511,7 @@ again:
                                           &nr_pages,
                                           &total_in,
                                           &total_compressed,
-                                          max_compressed);
+                                          BTRFS_MAX_COMPRESSED);
 
                if (!ret) {
                        unsigned long offset = total_compressed &