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authorNamjae Jeon <namjae.jeon@samsung.com>2014-12-12 16:57:26 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2014-12-13 12:42:51 -0800
commitc0ef0cc9d277f0f2a83b5a287a816b3916d9f026 (patch)
tree8dc88d4fc0de0bb485578ad6482044a0ecfdef2d /fs/fat
parentf441ada0040ed35572df517293b44a9998cc022d (diff)
downloadlinux-c0ef0cc9d277f0f2a83b5a287a816b3916d9f026.tar.bz2
fat: fix data past EOF resulting from fsx testsuite
When running FSX with direct I/O mode, fsx resulted in DATA past EOF issues. fsx ./file2 -Z -r 4096 -w 4096 ... .. truncating to largest ever: 0x907c fallocating to largest ever: 0x11137 truncating to largest ever: 0x2c6fe truncating to largest ever: 0x2cfdf fallocating to largest ever: 0x40000 Mapped Read: non-zero data past EOF (0x18628) page offset 0x629 is 0x2a4e ... .. The reason being, it is doing a truncate down, but the zeroing does not happen on the last block boundary when offset is not aligned. Even though it calls truncate_setsize()->truncate_inode_pages()-> truncate_inode_pages_range() and considers the partial zeroout but it retrieves the page using find_lock_page() - which only looks the page in the cache. So, zeroing out does not happen in case of direct IO. Make a truncate page based around block_truncate_page for FAT filesystem and invoke that helper to zerout in case the offset is not aligned with the blocksize. Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com> Signed-off-by: Amit Sahrawat <a.sahrawat@samsung.com> Acked-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs/fat')
-rw-r--r--fs/fat/fat.h1
-rw-r--r--fs/fat/file.c3
-rw-r--r--fs/fat/inode.c12
3 files changed, 16 insertions, 0 deletions
diff --git a/fs/fat/fat.h b/fs/fat/fat.h
index e0c4ba39a377..64e295e8ff38 100644
--- a/fs/fat/fat.h
+++ b/fs/fat/fat.h
@@ -370,6 +370,7 @@ extern int fat_file_fsync(struct file *file, loff_t start, loff_t end,
int datasync);
/* fat/inode.c */
+extern int fat_block_truncate_page(struct inode *inode, loff_t from);
extern void fat_attach(struct inode *inode, loff_t i_pos);
extern void fat_detach(struct inode *inode);
extern struct inode *fat_iget(struct super_block *sb, loff_t i_pos);
diff --git a/fs/fat/file.c b/fs/fat/file.c
index 85f79a89e747..8429c68e3057 100644
--- a/fs/fat/file.c
+++ b/fs/fat/file.c
@@ -443,6 +443,9 @@ int fat_setattr(struct dentry *dentry, struct iattr *attr)
}
if (attr->ia_valid & ATTR_SIZE) {
+ error = fat_block_truncate_page(inode, attr->ia_size);
+ if (error)
+ goto out;
down_write(&MSDOS_I(inode)->truncate_lock);
truncate_setsize(inode, attr->ia_size);
fat_truncate_blocks(inode, attr->ia_size);
diff --git a/fs/fat/inode.c b/fs/fat/inode.c
index 756aead10d96..7b41a2dcdd76 100644
--- a/fs/fat/inode.c
+++ b/fs/fat/inode.c
@@ -294,6 +294,18 @@ static sector_t _fat_bmap(struct address_space *mapping, sector_t block)
return blocknr;
}
+/*
+ * fat_block_truncate_page() zeroes out a mapping from file offset `from'
+ * up to the end of the block which corresponds to `from'.
+ * This is required during truncate to physically zeroout the tail end
+ * of that block so it doesn't yield old data if the file is later grown.
+ * Also, avoid causing failure from fsx for cases of "data past EOF"
+ */
+int fat_block_truncate_page(struct inode *inode, loff_t from)
+{
+ return block_truncate_page(inode->i_mapping, from, fat_get_block);
+}
+
static const struct address_space_operations fat_aops = {
.readpage = fat_readpage,
.readpages = fat_readpages,