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| author | Theodore Ts'o <tytso@mit.edu> | 2012-12-11 09:31:49 +0100 |
|---|---|---|
| committer | Theodore Ts'o <tytso@mit.edu> | 2012-12-11 09:31:49 +0100 |
| commit | bd9926e80330d43f15b710c2935fa41b792d56fd (patch) | |
| tree | ccc30335831784996b7435d10df39ee14e92afad /fs | |
| parent | ext4: ensure Inode flags consistency are checked at build time (diff) | |
| download | linux-bd9926e80330d43f15b710c2935fa41b792d56fd.tar.xz linux-bd9926e80330d43f15b710c2935fa41b792d56fd.zip | |
ext4: zero out inline data using memset() instead of empty_zero_page
Not all architectures (in particular, sparc64) have empty_zero_page.
So instead of copying from empty_zero_page, use memset to clear the
inline data by signalling to ext4_xattr_set_entry() via a magic
pointer value, EXT4_ZERO_ATTR_VALUE, which is defined by casting -1 to
a pointer.
This fixes a build failure on sparc64, and the memset() should be more
efficient than using memcpy() anyway.
Signed-off-by: Tao Ma <boyu.mt@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/ext4/inline.c | 2 | ||||
| -rw-r--r-- | fs/ext4/xattr.c | 22 | ||||
| -rw-r--r-- | fs/ext4/xattr.h | 1 |
3 files changed, 18 insertions, 7 deletions
diff --git a/fs/ext4/inline.c b/fs/ext4/inline.c index 53b2f65091dd..387c47c6cda9 100644 --- a/fs/ext4/inline.c +++ b/fs/ext4/inline.c @@ -268,7 +268,7 @@ static int ext4_create_inline_data(handle_t *handle, goto out; if (len > EXT4_MIN_INLINE_DATA_SIZE) { - value = (void *)empty_zero_page; + value = EXT4_ZERO_XATTR_VALUE; len -= EXT4_MIN_INLINE_DATA_SIZE; } else { value = ""; diff --git a/fs/ext4/xattr.c b/fs/ext4/xattr.c index 2251769a3c53..3a91ebc2b66f 100644 --- a/fs/ext4/xattr.c +++ b/fs/ext4/xattr.c @@ -628,9 +628,14 @@ ext4_xattr_set_entry(struct ext4_xattr_info *i, struct ext4_xattr_search *s) size. Just replace. */ s->here->e_value_size = cpu_to_le32(i->value_len); - memset(val + size - EXT4_XATTR_PAD, 0, - EXT4_XATTR_PAD); /* Clear pad bytes. */ - memcpy(val, i->value, i->value_len); + if (i->value == EXT4_ZERO_XATTR_VALUE) { + memset(val, 0, size); + } else { + /* Clear pad bytes first. */ + memset(val + size - EXT4_XATTR_PAD, 0, + EXT4_XATTR_PAD); + memcpy(val, i->value, i->value_len); + } return 0; } @@ -669,9 +674,14 @@ ext4_xattr_set_entry(struct ext4_xattr_info *i, struct ext4_xattr_search *s) size_t size = EXT4_XATTR_SIZE(i->value_len); void *val = s->base + min_offs - size; s->here->e_value_offs = cpu_to_le16(min_offs - size); - memset(val + size - EXT4_XATTR_PAD, 0, - EXT4_XATTR_PAD); /* Clear the pad bytes. */ - memcpy(val, i->value, i->value_len); + if (i->value == EXT4_ZERO_XATTR_VALUE) { + memset(val, 0, size); + } else { + /* Clear the pad bytes first. */ + memset(val + size - EXT4_XATTR_PAD, 0, + EXT4_XATTR_PAD); + memcpy(val, i->value, i->value_len); + } } } return 0; diff --git a/fs/ext4/xattr.h b/fs/ext4/xattr.h index 7b5513ed3b38..69eda787a96a 100644 --- a/fs/ext4/xattr.h +++ b/fs/ext4/xattr.h @@ -71,6 +71,7 @@ struct ext4_xattr_entry { #define BFIRST(bh) ENTRY(BHDR(bh)+1) #define IS_LAST_ENTRY(entry) (*(__u32 *)(entry) == 0) +#define EXT4_ZERO_XATTR_VALUE ((void *)-1) struct ext4_xattr_info { int name_index; |