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| author | Theodore Ts'o <tytso@mit.edu> | 2011-01-10 18:18:25 +0100 |
|---|---|---|
| committer | Theodore Ts'o <tytso@mit.edu> | 2011-01-10 18:18:25 +0100 |
| commit | 353eb83c1422c6326eaab30ce044a179c6018169 (patch) | |
| tree | fd43e39b344de5ee43d82c90f0affda68a65f2df /fs/ext4/ext4.h | |
| parent | ext4: reorder ext4_inode_info structure elements to remove unneeded padding (diff) | |
| download | linux-353eb83c1422c6326eaab30ce044a179c6018169.tar.xz linux-353eb83c1422c6326eaab30ce044a179c6018169.zip | |
ext4: drop i_state_flags on architectures with 64-bit longs
We can store the dynamic inode state flags in the high bits of
EXT4_I(inode)->i_flags, and eliminate i_state_flags. This saves 8
bytes from the size of ext4_inode_info structure, which when
multiplied by the number of the number of in the inode cache, can save
a lot of memory.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Diffstat (limited to 'fs/ext4/ext4.h')
| -rw-r--r-- | fs/ext4/ext4.h | 28 |
1 files changed, 22 insertions, 6 deletions
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h index 50e3d24483fb..2fb531cfd48b 100644 --- a/fs/ext4/ext4.h +++ b/fs/ext4/ext4.h @@ -764,7 +764,9 @@ struct ext4_inode_info { */ ext4_group_t i_block_group; ext4_lblk_t i_dir_start_lookup; +#if (BITS_PER_LONG < 64) unsigned long i_state_flags; /* Dynamic state flags */ +#endif unsigned long i_flags; #ifdef CONFIG_EXT4_FS_XATTR @@ -1239,22 +1241,36 @@ enum { EXT4_STATE_DELALLOC_RESERVED, /* blks already reserved for delalloc */ }; -#define EXT4_INODE_BIT_FNS(name, field) \ +#define EXT4_INODE_BIT_FNS(name, field, offset) \ static inline int ext4_test_inode_##name(struct inode *inode, int bit) \ { \ - return test_bit(bit, &EXT4_I(inode)->i_##field); \ + return test_bit(bit + (offset), &EXT4_I(inode)->i_##field); \ } \ static inline void ext4_set_inode_##name(struct inode *inode, int bit) \ { \ - set_bit(bit, &EXT4_I(inode)->i_##field); \ + set_bit(bit + (offset), &EXT4_I(inode)->i_##field); \ } \ static inline void ext4_clear_inode_##name(struct inode *inode, int bit) \ { \ - clear_bit(bit, &EXT4_I(inode)->i_##field); \ + clear_bit(bit + (offset), &EXT4_I(inode)->i_##field); \ } -EXT4_INODE_BIT_FNS(flag, flags) -EXT4_INODE_BIT_FNS(state, state_flags) +EXT4_INODE_BIT_FNS(flag, flags, 0) +#if (BITS_PER_LONG < 64) +EXT4_INODE_BIT_FNS(state, state_flags, 0) + +static inline void ext4_clear_state_flags(struct ext4_inode_info *ei) +{ + (ei)->i_state_flags = 0; +} +#else +EXT4_INODE_BIT_FNS(state, flags, 32) + +static inline void ext4_clear_state_flags(struct ext4_inode_info *ei) +{ + /* We depend on the fact that callers will set i_flags */ +} +#endif #else /* Assume that user mode programs are passing in an ext4fs superblock, not * a kernel struct super_block. This will allow us to call the feature-test |