From: Tahsin Erdogan Subject: [PATCH 11/28] ext4: clean up ext4_xattr_inode_get() Date: Wed, 31 May 2017 01:15:00 -0700 Message-ID: <20170531081517.11438-11-tahsin@google.com> References: <20170531081517.11438-1-tahsin@google.com> Cc: linux-kernel@vger.kernel.org, jfs-discussion@lists.sourceforge.net, linux-fsdevel@vger.kernel.org, ocfs2-devel@oss.oracle.com, reiserfs-devel@vger.kernel.org, Tahsin Erdogan To: Jan Kara , Theodore Ts'o , Andreas Dilger , Dave Kleikamp , Alexander Viro , Mark Fasheh , Joel Becker , Jens Axboe , Deepa Dinamani , Mike Christie , Fabian Frederick , linux-ext4@vger.kernel.org Return-path: In-Reply-To: <20170531081517.11438-1-tahsin@google.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-ext4.vger.kernel.org The input and output values of *size parameter are equal on successful return from ext4_xattr_inode_get(). On error return, the callers ignore the output value so there is no need to update it. Also check for NULL return from ext4_bread(). If the actual xattr inode size happens to be smaller than the expected size, ext4_bread() may return NULL which would indicate data corruption. Signed-off-by: Tahsin Erdogan --- fs/ext4/xattr.c | 35 +++++++++++++---------------------- 1 file changed, 13 insertions(+), 22 deletions(-) diff --git a/fs/ext4/xattr.c b/fs/ext4/xattr.c index d9477d01be9b..8e855fc2eb03 100644 --- a/fs/ext4/xattr.c +++ b/fs/ext4/xattr.c @@ -278,37 +278,28 @@ ext4_xattr_find_entry(struct ext4_xattr_entry **pentry, int name_index, /* * Read the EA value from an inode. */ -static int -ext4_xattr_inode_read(struct inode *ea_inode, void *buf, size_t *size) +static int ext4_xattr_inode_read(struct inode *ea_inode, void *buf, size_t size) { unsigned long block = 0; struct buffer_head *bh = NULL; - int blocksize; - size_t csize, ret_size = 0; - - if (*size == 0) - return 0; + int blocksize = ea_inode->i_sb->s_blocksize; + size_t csize, copied = 0; - blocksize = ea_inode->i_sb->s_blocksize; - - while (ret_size < *size) { - csize = (*size - ret_size) > blocksize ? blocksize : - *size - ret_size; + while (copied < size) { + csize = (size - copied) > blocksize ? blocksize : size - copied; bh = ext4_bread(NULL, ea_inode, block, 0); - if (IS_ERR(bh)) { - *size = ret_size; + if (IS_ERR(bh)) return PTR_ERR(bh); - } + if (!bh) + return -EFSCORRUPTED; + memcpy(buf, bh->b_data, csize); brelse(bh); buf += csize; block += 1; - ret_size += csize; + copied += csize; } - - *size = ret_size; - return 0; } @@ -360,7 +351,7 @@ static int ext4_xattr_inode_iget(struct inode *parent, unsigned long ea_ino, */ static int ext4_xattr_inode_get(struct inode *inode, unsigned long ea_ino, void *buffer, - size_t *size) + size_t size) { struct inode *ea_inode; int ret; @@ -417,7 +408,7 @@ ext4_xattr_block_get(struct inode *inode, int name_index, const char *name, if (entry->e_value_inum) { error = ext4_xattr_inode_get(inode, le32_to_cpu(entry->e_value_inum), - buffer, &size); + buffer, size); if (error) goto cleanup; } else { @@ -467,7 +458,7 @@ ext4_xattr_ibody_get(struct inode *inode, int name_index, const char *name, if (entry->e_value_inum) { error = ext4_xattr_inode_get(inode, le32_to_cpu(entry->e_value_inum), - buffer, &size); + buffer, size); if (error) goto cleanup; } else { -- 2.13.0.219.gdb65acc882-goog