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ext4: use truncate_setsize() unconditionally 

In commit c8d46e41 (ext4: Add flag to files with blocks intentionally
past EOF), if the EOFBLOCKS_FL flag is set, we call ext4_truncate()
before calling vmtruncate().  This caused any allocated but unwritten
blocks created by calling fallocate() with the FALLOC_FL_KEEP_SIZE
flag to be dropped.  This was done to make to make sure that
EOFBLOCKS_FL would not be cleared while still leaving blocks past
i_size allocated.  This was not necessary, since ext4_truncate()
guarantees that blocks past i_size will be dropped, even in the case
where truncate() has increased i_size before calling ext4_truncate().

So fix this by removing the EOFBLOCKS_FL special case treatment in
ext4_setattr().  In addition, use truncate_setsize() followed by a
call to ext4_truncate() instead of using vmtruncate().  This is more
efficient since it skips the call to inode_newsize_ok(), which has
been checked already by inode_change_ok().  This is also in a win in
the case where EOFBLOCKS_FL is set since it avoids calling
ext4_truncate() twice.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
This commit is contained in:
Theodore Ts'o 2011-05-23 15:13:02 -04:00
parent 28e35e42fb
commit 072bd7ea74
1 changed files with 8 additions and 8 deletions
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16
fs/ext4/inode.c
View File

@ -5309,8 +5309,7 @@ int ext4_setattr(struct dentry *dentry, struct iattr *attr)
if (S_ISREG(inode->i_mode) &&
attr->ia_valid & ATTR_SIZE &&
(attr->ia_size < inode->i_size ||
(ext4_test_inode_flag(inode, EXT4_INODE_EOFBLOCKS)))) {
(attr->ia_size < inode->i_size)) {
handle_t *handle;
handle = ext4_journal_start(inode, 3);
@ -5344,14 +5343,15 @@ int ext4_setattr(struct dentry *dentry, struct iattr *attr)
goto err_out;
}
}
/* ext4_truncate will clear the flag */
if ((ext4_test_inode_flag(inode, EXT4_INODE_EOFBLOCKS)))
ext4_truncate(inode);
}
if ((attr->ia_valid & ATTR_SIZE) &&
attr->ia_size != i_size_read(inode))
rc = vmtruncate(inode, attr->ia_size);
if (attr->ia_valid & ATTR_SIZE) {
if (attr->ia_size != i_size_read(inode)) {
truncate_setsize(inode, attr->ia_size);
ext4_truncate(inode);
} else if (ext4_test_inode_flag(inode, EXT4_INODE_EOFBLOCKS))
ext4_truncate(inode);
}
if (!rc) {
setattr_copy(inode, attr);