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author | David Sterba <dsterba@suse.com> | 2017-02-14 21:30:39 +0300 |
---|---|---|
committer | David Sterba <dsterba@suse.com> | 2017-02-28 16:26:35 +0300 |
commit | ff7638665c9a82894cabd18d26a9f8957f280f55 (patch) | |
tree | e7edeb798742e45df9e2966b2fb8c30e31a607a2 | |
parent | 4d3a800ebb1299944408f3b40b5b6b996477fba2 (diff) | |
download | linux-ff7638665c9a82894cabd18d26a9f8957f280f55.tar.xz |
btrfs: export compression buffer limits in a header
Move the buffer limit definitions out of compress_file_range.
Reviewed-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.com>
-rw-r--r-- | fs/btrfs/compression.h | 15 | ||||
-rw-r--r-- | fs/btrfs/inode.c | 10 |
2 files changed, 15 insertions, 10 deletions
diff --git a/fs/btrfs/compression.h b/fs/btrfs/compression.h index cfcec709c61b..619e64c27444 100644 --- a/fs/btrfs/compression.h +++ b/fs/btrfs/compression.h @@ -19,6 +19,21 @@ #ifndef __BTRFS_COMPRESSION_ #define __BTRFS_COMPRESSION_ +/* + * We want to make sure that amount of RAM required to uncompress an extent is + * reasonable, so we limit the total size in ram of a compressed extent to + * 128k. This is a crucial number because it also controls how easily we can + * spread reads across cpus for decompression. + * + * We also want to make sure the amount of IO required to do a random read is + * reasonably small, so we limit the size of a compressed extent to 128k. + */ + +/* Maximum length of compressed data stored on disk */ +#define BTRFS_MAX_COMPRESSED (SZ_128K) +/* Maximum size of data before compression */ +#define BTRFS_MAX_UNCOMPRESSED (SZ_128K) + void btrfs_init_compress(void); void btrfs_exit_compress(void); diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index 83bbe1e31869..77fb24b94a9e 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -471,16 +471,6 @@ again: (start > 0 || end + 1 < BTRFS_I(inode)->disk_i_size)) goto cleanup_and_bail_uncompressed; - /* we want to make sure that amount of ram required to uncompress - * an extent is reasonable, so we limit the total size in ram - * of a compressed extent to 128k. This is a crucial number - * because it also controls how easily we can spread reads across - * cpus for decompression. - * - * We also want to make sure the amount of IO required to do - * a random read is reasonably small, so we limit the size of - * a compressed extent to 128k. - */ total_compressed = min(total_compressed, max_uncompressed); num_bytes = ALIGN(end - start + 1, blocksize); num_bytes = max(blocksize, num_bytes); |