[f2fs-dev] [PATCH 13/31] Remove unnecessary __attribute__((packed)) annotations

[Bart Van Assche <bvanassche@acm.org>]

Applying the __attribute__((packed)) annotation to members that do not
need it impacts performance negatively on architectures that do not
support efficient unaligned accesses (e.g. ARMv7). Hence minimize the
__attribute__((packed)) annotations.

See also CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS in the Linux kernel.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
---
 fsck/quotaio.c      |  2 +-
 fsck/quotaio_tree.h |  2 +-
 fsck/quotaio_v2.h   |  6 +++---
 fsck/xattr.h        |  2 +-
 include/f2fs_fs.h   | 52 ++++++++++++++++++++++-----------------------
 include/quota.h     |  9 +++-----
 tools/f2fscrypt.c   |  4 ++--
 7 files changed, 37 insertions(+), 40 deletions(-)

diff --git a/fsck/quotaio.c b/fsck/quotaio.c
index 52e962432c72..a3815b0c8835 100644
--- a/fsck/quotaio.c
+++ b/fsck/quotaio.c
@@ -31,7 +31,7 @@ static const char * const extensions[MAXQUOTAS] = {
 struct disk_dqheader {
 	__le32 dqh_magic;
 	__le32 dqh_version;
-} __attribute__ ((packed));
+};
 
 static_assert(sizeof(struct disk_dqheader) == 8, "");
 
diff --git a/fsck/quotaio_tree.h b/fsck/quotaio_tree.h
index b88c55c01d5c..8072c6e188fd 100644
--- a/fsck/quotaio_tree.h
+++ b/fsck/quotaio_tree.h
@@ -33,7 +33,7 @@ struct qt_disk_dqdbheader {
 	__le16 dqdh_entries; /* Number of valid entries in block */
 	__le16 dqdh_pad1;
 	__le32 dqdh_pad2;
-} __attribute__ ((packed));
+};
 
 static_assert(sizeof(struct qt_disk_dqdbheader) == 16, "");
 
diff --git a/fsck/quotaio_v2.h b/fsck/quotaio_v2.h
index a37300d78bd0..b054422f5a6e 100644
--- a/fsck/quotaio_v2.h
+++ b/fsck/quotaio_v2.h
@@ -18,7 +18,7 @@
 struct v2_disk_dqheader {
 	__le32 dqh_magic;	/* Magic number identifying file */
 	__le32 dqh_version;	/* File version */
-} __attribute__ ((packed));
+};
 
 static_assert(sizeof(struct v2_disk_dqheader) == 8, "");
 
@@ -36,7 +36,7 @@ struct v2_disk_dqinfo {
 	__le32 dqi_free_blk;	/* Number of first free block in the list */
 	__le32 dqi_free_entry;	/* Number of block with at least one
 					 * free entry */
-} __attribute__ ((packed));
+};
 
 static_assert(sizeof(struct v2_disk_dqinfo) == 24, "");
 
@@ -53,7 +53,7 @@ struct v2r1_disk_dqblk {
 	__le64 dqb_curspace;	/* current space occupied (in bytes) */
 	__le64 dqb_btime;	/* time limit for excessive disk use */
 	__le64 dqb_itime;	/* time limit for excessive inode use */
-} __attribute__ ((packed));
+};
 
 static_assert(sizeof(struct v2r1_disk_dqblk) == 72, "");
 
diff --git a/fsck/xattr.h b/fsck/xattr.h
index 5709a7df7adb..4e4b50d47bd7 100644
--- a/fsck/xattr.h
+++ b/fsck/xattr.h
@@ -45,7 +45,7 @@ struct fscrypt_context {
 	u8 flags;
 	u8 master_key_descriptor[FS_KEY_DESCRIPTOR_SIZE];
 	u8 nonce[FS_KEY_DERIVATION_NONCE_SIZE];
-} __attribute__((packed));
+};
 
 static_assert(sizeof(struct fscrypt_context) == 28, "");
 
diff --git a/include/f2fs_fs.h b/include/f2fs_fs.h
index cfd3b711f288..49438eb2e6f2 100644
--- a/include/f2fs_fs.h
+++ b/include/f2fs_fs.h
@@ -735,11 +735,10 @@ enum {
 /*
  * For superblock
  */
-#pragma pack(push, 1)
 struct f2fs_device {
 	__u8 path[MAX_PATH_LEN];
 	__le32 total_segments;
-} __attribute__((packed));
+};
 
 static_assert(sizeof(struct f2fs_device) == 68, "");
 
@@ -754,7 +753,8 @@ struct f2fs_super_block {
 	__le32 segs_per_sec;		/* # of segments per section */
 	__le32 secs_per_zone;		/* # of sections per zone */
 	__le32 checksum_offset;		/* checksum offset inside super block */
-	__le64 block_count;		/* total # of user blocks */
+	__le64 block_count __attribute__((packed));
+					/* total # of user blocks */
 	__le32 section_count;		/* total # of sections */
 	__le32 segment_count;		/* total # of segments */
 	__le32 segment_count_ckpt;	/* # of segments for checkpoint */
@@ -781,14 +781,14 @@ struct f2fs_super_block {
 	__le32 feature;			/* defined features */
 	__u8 encryption_level;		/* versioning level for encryption */
 	__u8 encrypt_pw_salt[16];	/* Salt used for string2key algorithm */
-	struct f2fs_device devs[MAX_DEVICES];	/* device list */
-	__le32 qf_ino[F2FS_MAX_QUOTAS];	/* quota inode numbers */
+	struct f2fs_device devs[MAX_DEVICES] __attribute__((packed));	/* device list */
+	__le32 qf_ino[F2FS_MAX_QUOTAS] __attribute__((packed));	/* quota inode numbers */
 	__u8 hot_ext_count;		/* # of hot file extension */
 	__le16  s_encoding;		/* Filename charset encoding */
 	__le16  s_encoding_flags;	/* Filename charset encoding flags */
 	__u8 reserved[306];		/* valid reserved region */
 	__le32 crc;			/* checksum of superblock */
-} __attribute__((packed));
+};
 
 static_assert(sizeof(struct f2fs_super_block) == 3072, "");
 
@@ -841,7 +841,7 @@ struct f2fs_checkpoint {
 
 	/* SIT and NAT version bitmap */
 	unsigned char sit_nat_version_bitmap[];
-} __attribute__((packed));
+};
 
 static_assert(sizeof(struct f2fs_checkpoint) == 192, "");
 
@@ -867,7 +867,7 @@ struct f2fs_orphan_block {
 	__le16 blk_count;	/* Number of orphan inode blocks in CP */
 	__le32 entry_count;	/* Total number of orphan nodes in current CP */
 	__le32 check_sum;	/* CRC32 for orphan inode block */
-} __attribute__((packed));
+};
 
 static_assert(sizeof(struct f2fs_orphan_block) == 4096, "");
 
@@ -878,7 +878,7 @@ struct f2fs_extent {
 	__le32 fofs;		/* start file offset of the extent */
 	__le32 blk_addr;	/* start block address of the extent */
 	__le32 len;		/* lengh of the extent */
-} __attribute__((packed));
+};
 
 static_assert(sizeof(struct f2fs_extent) == 12, "");
 
@@ -1005,7 +1005,7 @@ struct f2fs_inode {
 	__u8 i_name[F2FS_NAME_LEN];	/* file name for SPOR */
 	__u8 i_dir_level;		/* dentry_level for large dir */
 
-	struct f2fs_extent i_ext;	/* caching a largest extent */
+	struct f2fs_extent i_ext __attribute__((packed));	/* caching a largest extent */
 
 	union {
 		struct {
@@ -1025,19 +1025,21 @@ struct f2fs_inode {
 	};
 	__le32 i_nid[5];		/* direct(2), indirect(2),
 						double_indirect(1) node id */
-} __attribute__((packed));
+};
 
+static_assert(offsetof(struct f2fs_inode, i_extra_end) -
+	      offsetof(struct f2fs_inode, i_extra_isize) == 36, "");
 static_assert(sizeof(struct f2fs_inode) == 4072, "");
 
 struct direct_node {
 	__le32 addr[DEF_ADDRS_PER_BLOCK];	/* array of data block address */
-} __attribute__((packed));
+};
 
 static_assert(sizeof(struct direct_node) == 4072, "");
 
 struct indirect_node {
 	__le32 nid[NIDS_PER_BLOCK];	/* array of data block address */
-} __attribute__((packed));
+};
 
 static_assert(sizeof(struct indirect_node) == 4072, "");
 
@@ -1054,9 +1056,9 @@ struct node_footer {
 	__le32 nid;		/* node id */
 	__le32 ino;		/* inode nunmber */
 	__le32 flag;		/* include cold/fsync/dentry marks and offset */
-	__le64 cp_ver;		/* checkpoint version */
+	__le64 cp_ver __attribute__((packed));		/* checkpoint version */
 	__le32 next_blkaddr;	/* next node page block address */
-} __attribute__((packed));
+};
 
 static_assert(sizeof(struct node_footer) == 24, "");
 
@@ -1068,7 +1070,7 @@ struct f2fs_node {
 		struct indirect_node in;
 	};
 	struct node_footer footer;
-} __attribute__((packed));
+};
 
 static_assert(sizeof(struct f2fs_node) == 4096, "");
 
@@ -1090,7 +1092,7 @@ static_assert(sizeof(struct f2fs_nat_entry) == 9, "");
 
 struct f2fs_nat_block {
 	struct f2fs_nat_entry entries[NAT_ENTRY_PER_BLOCK];
-} __attribute__((packed));
+};
 
 static_assert(sizeof(struct f2fs_nat_block) == 4095, "");
 
@@ -1137,7 +1139,7 @@ static_assert(sizeof(struct f2fs_sit_entry) == 74, "");
 
 struct f2fs_sit_block {
 	struct f2fs_sit_entry entries[SIT_ENTRY_PER_BLOCK];
-} __attribute__((packed));
+};
 
 static_assert(sizeof(struct f2fs_sit_block) == 4070, "");
 
@@ -1181,8 +1183,8 @@ static_assert(sizeof(struct f2fs_summary) == 7, "");
 
 struct summary_footer {
 	unsigned char entry_type;	/* SUM_TYPE_XXX */
-	__le32 check_sum;		/* summary checksum */
-} __attribute__((packed));
+	__le32 check_sum __attribute__((packed)); /* summary checksum */
+};
 
 static_assert(sizeof(struct summary_footer) == 5, "");
 
@@ -1222,7 +1224,7 @@ static_assert(sizeof(struct nat_journal_entry) == 13, "");
 struct nat_journal {
 	struct nat_journal_entry entries[NAT_JOURNAL_ENTRIES];
 	__u8 reserved[NAT_JOURNAL_RESERVED];
-} __attribute__((packed));
+};
 
 static_assert(sizeof(struct nat_journal) == 505, "");
 
@@ -1236,7 +1238,7 @@ static_assert(sizeof(struct sit_journal_entry) == 78, "");
 struct sit_journal {
 	struct sit_journal_entry entries[SIT_JOURNAL_ENTRIES];
 	__u8 reserved[SIT_JOURNAL_RESERVED];
-} __attribute__((packed));
+};
 
 static_assert(sizeof(struct sit_journal) == 505, "");
 
@@ -1267,7 +1269,7 @@ struct f2fs_summary_block {
 	struct f2fs_summary entries[ENTRIES_IN_SUM];
 	struct f2fs_journal journal;
 	struct summary_footer footer;
-} __attribute__((packed));
+};
 
 static_assert(sizeof(struct f2fs_summary_block) == 4096, "");
 
@@ -1321,12 +1323,10 @@ struct f2fs_dentry_block {
 	__u8 reserved[SIZE_OF_RESERVED];
 	struct f2fs_dir_entry dentry[NR_DENTRY_IN_BLOCK];
 	__u8 filename[NR_DENTRY_IN_BLOCK][F2FS_SLOT_LEN];
-} __attribute__((packed));
+};
 
 static_assert(sizeof(struct f2fs_dentry_block) == 4096, "");
 
-#pragma pack(pop)
-
 /* for inline stuff */
 #define DEF_INLINE_RESERVED_SIZE	1
 
diff --git a/include/quota.h b/include/quota.h
index 5b7aaa891d28..f0eff71a9a26 100644
--- a/include/quota.h
+++ b/include/quota.h
@@ -44,11 +44,10 @@ enum quota_type {
 
 #define QT_TREEOFF	1	/* Offset of tree in file in blocks */
 
-#pragma pack(push, 1)
 struct v2_disk_dqheader {
 	uint32_t dqh_magic;	/* Magic number identifying file */
 	uint32_t dqh_version;	/* File version */
-} __attribute__ ((packed));
+};
 
 static_assert(sizeof(struct v2_disk_dqheader) == 8, "");
 
@@ -60,7 +59,7 @@ struct v2_disk_dqinfo {
 	uint32_t dqi_blocks;	/* Number of blocks in file */
 	uint32_t dqi_free_blk;	/* Number of first free block in the list */
 	uint32_t dqi_free_entry;	/* Number of block with at least one free entry */
-} __attribute__ ((packed));
+};
 
 static_assert(sizeof(struct v2_disk_dqinfo) == 24, "");
 
@@ -77,10 +76,8 @@ struct v2r1_disk_dqblk {
 	__le64 dqb_curspace;    /* current space occupied (in bytes) */
 	__le64 dqb_btime;       /* time limit for excessive disk use */
 	__le64 dqb_itime;       /* time limit for excessive inode use */
-} __attribute__ ((packed));
+};
 
 static_assert(sizeof(struct v2r1_disk_dqblk) == 72, "");
 
-#pragma pack(pop)
-
 #endif
diff --git a/tools/f2fscrypt.c b/tools/f2fscrypt.c
index 97624ba5e185..72bfb6467300 100644
--- a/tools/f2fscrypt.c
+++ b/tools/f2fscrypt.c
@@ -102,7 +102,7 @@ struct f2fs_fscrypt_policy {
 	__u8 filenames_encryption_mode;
 	__u8 flags;
 	__u8 master_key_descriptor[F2FS_KEY_DESCRIPTOR_SIZE];
-} __attribute__((packed));
+};
 
 static_assert(sizeof(struct f2fs_fscrypt_policy) == 12, "");
 
@@ -121,7 +121,7 @@ struct f2fs_encryption_key {
         __u32 mode;
         char raw[F2FS_MAX_KEY_SIZE];
         __u32 size;
-} __attribute__((__packed__));
+};
 
 static_assert(sizeof(struct f2fs_encryption_key) == 72, "");
 


_______________________________________________
Linux-f2fs-devel mailing list
Linux-f2fs-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel