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| author | Artem Bityutskiy <Artem.Bityutskiy@nokia.com> | 2008-11-01 14:20:50 +0200 |
|---|---|---|
| committer | Artem Bityutskiy <Artem.Bityutskiy@nokia.com> | 2008-12-03 13:13:59 +0200 |
| commit | a1dc080c27ec8ea7ca1c8a9b499362a71ebff792 (patch) | |
| tree | a41c931fb6f7c8bdc0c3481545892216921074eb | |
| parent | 062e4fee4400f283307cf8ac1b7931c939010229 (diff) | |
| download | linux-a1dc080c27ec8ea7ca1c8a9b499362a71ebff792.tar.bz2 | |
UBIFS: use bit-fields to store compression type
Save a 4 bytes of RAM per 'struct inode' by stroring inode
compression type in bit-filed, instead of using 'int'.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
| -rw-r--r-- | fs/ubifs/super.c | 8 | ||||
| -rw-r--r-- | fs/ubifs/ubifs.h | 6 |
2 files changed, 11 insertions, 3 deletions
diff --git a/fs/ubifs/super.c b/fs/ubifs/super.c index d80b2aef42b6..21b4103271ec 100644 --- a/fs/ubifs/super.c +++ b/fs/ubifs/super.c @@ -2021,6 +2021,14 @@ static int __init ubifs_init(void) BUILD_BUG_ON(UBIFS_REF_NODE_SZ != 64); /* + * We use 2 bit wide bit-fields to store compression type, which should + * be amended if more compressors are added. The bit-fields are: + * @compr_type in 'struct ubifs_inode' and @default_compr in + * 'struct ubifs_info'. + */ + BUILD_BUG_ON(UBIFS_COMPR_TYPES_CNT > 4); + + /* * We require that PAGE_CACHE_SIZE is greater-than-or-equal-to * UBIFS_BLOCK_SIZE. It is assumed that both are powers of 2. */ diff --git a/fs/ubifs/ubifs.h b/fs/ubifs/ubifs.h index 46b172560a06..4d76aba57ee1 100644 --- a/fs/ubifs/ubifs.h +++ b/fs/ubifs/ubifs.h @@ -386,12 +386,12 @@ struct ubifs_inode { unsigned int dirty:1; unsigned int xattr:1; unsigned int bulk_read:1; + unsigned int compr_type:2; struct mutex ui_mutex; spinlock_t ui_lock; loff_t synced_i_size; loff_t ui_size; int flags; - int compr_type; pgoff_t last_page_read; pgoff_t read_in_a_row; int data_len; @@ -946,6 +946,7 @@ struct ubifs_mount_opts { * @no_chk_data_crc: do not check CRCs when reading data nodes (except during * recovery) * @bulk_read: enable bulk-reads + * @default_compr: default compression algorithm (%UBIFS_COMPR_LZO, etc) * * @tnc_mutex: protects the Tree Node Cache (TNC), @zroot, @cnext, @enext, and * @calc_idx_sz @@ -986,7 +987,6 @@ struct ubifs_mount_opts { * @main_lebs: count of LEBs in the main area * @main_first: first LEB of the main area * @main_bytes: main area size in bytes - * @default_compr: default compression algorithm (%UBIFS_COMPR_LZO, etc) * * @key_hash_type: type of the key hash * @key_hash: direntry key hash function @@ -1196,6 +1196,7 @@ struct ubifs_info { unsigned int big_lpt:1; unsigned int no_chk_data_crc:1; unsigned int bulk_read:1; + unsigned int default_compr:2; struct mutex tnc_mutex; struct ubifs_zbranch zroot; @@ -1237,7 +1238,6 @@ struct ubifs_info { int main_lebs; int main_first; long long main_bytes; - int default_compr; uint8_t key_hash_type; uint32_t (*key_hash)(const char *str, int len); |