Message ID | 20210901020955.1657340-4-yi.zhang@huawei.com |
---|---|
State | Accepted |
Headers | show |
Series | ext4: fix a inode checksum error | expand |
On Wed 01-09-21 10:09:55, Zhang Yi wrote: > In ext4_get_inode_loc(), we may skip IO and get an zero && uptodate > inode buffer when the inode monopolize an inode block for performance > reason. For most cases, ext4_mark_iloc_dirty() will fill the inode > buffer to make it fine, but we could miss this call if something bad > happened. Finally, __ext4_get_inode_loc_noinmem() may probably get an > empty inode buffer and trigger ext4 error. > > For example, if we remove a nonexistent xattr on inode A, > ext4_xattr_set_handle() will return ENODATA before invoking > ext4_mark_iloc_dirty(), it will left an uptodate but zero buffer. We > will get checksum error message in ext4_iget() when getting inode again. > > EXT4-fs error (device sda): ext4_lookup:1784: inode #131074: comm cat: iget: checksum invalid > > Even worse, if we allocate another inode B at the same inode block, it > will corrupt the inode A on disk when write back inode B. > > So this patch initialize the inode buffer by filling the in-mem inode > contents if we skip read I/O, ensure that the buffer is really uptodate. > > Signed-off-by: Zhang Yi <yi.zhang@huawei.com> Looks good. Feel free to add: Reviewed-by: Jan Kara <jack@suse.cz> Honza > --- > fs/ext4/inode.c | 24 ++++++++++++++---------- > 1 file changed, 14 insertions(+), 10 deletions(-) > > diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c > index 3c36e701e30e..a8388ec91f9f 100644 > --- a/fs/ext4/inode.c > +++ b/fs/ext4/inode.c > @@ -4441,12 +4441,12 @@ static int ext4_fill_raw_inode(struct inode *inode, struct ext4_inode *raw_inode > > /* > * ext4_get_inode_loc returns with an extra refcount against the inode's > - * underlying buffer_head on success. If 'in_mem' is true, we have all > - * data in memory that is needed to recreate the on-disk version of this > - * inode. > + * underlying buffer_head on success. If we pass 'inode' and it does not > + * have in-inode xattr, we have all inode data in memory that is needed > + * to recreate the on-disk version of this inode. > */ > static int __ext4_get_inode_loc(struct super_block *sb, unsigned long ino, > - struct ext4_iloc *iloc, int in_mem, > + struct inode *inode, struct ext4_iloc *iloc, > ext4_fsblk_t *ret_block) > { > struct ext4_group_desc *gdp; > @@ -4486,7 +4486,7 @@ static int __ext4_get_inode_loc(struct super_block *sb, unsigned long ino, > * is the only valid inode in the block, we need not read the > * block. > */ > - if (in_mem) { > + if (inode && !ext4_test_inode_state(inode, EXT4_STATE_XATTR)) { > struct buffer_head *bitmap_bh; > int i, start; > > @@ -4514,8 +4514,13 @@ static int __ext4_get_inode_loc(struct super_block *sb, unsigned long ino, > } > brelse(bitmap_bh); > if (i == start + inodes_per_block) { > + struct ext4_inode *raw_inode = > + (struct ext4_inode *) (bh->b_data + iloc->offset); > + > /* all other inodes are free, so skip I/O */ > memset(bh->b_data, 0, bh->b_size); > + if (!ext4_test_inode_state(inode, EXT4_STATE_NEW)) > + ext4_fill_raw_inode(inode, raw_inode); > set_buffer_uptodate(bh); > unlock_buffer(bh); > goto has_buffer; > @@ -4576,7 +4581,7 @@ static int __ext4_get_inode_loc_noinmem(struct inode *inode, > ext4_fsblk_t err_blk; > int ret; > > - ret = __ext4_get_inode_loc(inode->i_sb, inode->i_ino, iloc, 0, > + ret = __ext4_get_inode_loc(inode->i_sb, inode->i_ino, NULL, iloc, > &err_blk); > > if (ret == -EIO) > @@ -4591,9 +4596,8 @@ int ext4_get_inode_loc(struct inode *inode, struct ext4_iloc *iloc) > ext4_fsblk_t err_blk; > int ret; > > - /* We have all inode data except xattrs in memory here. */ > - ret = __ext4_get_inode_loc(inode->i_sb, inode->i_ino, iloc, > - !ext4_test_inode_state(inode, EXT4_STATE_XATTR), &err_blk); > + ret = __ext4_get_inode_loc(inode->i_sb, inode->i_ino, inode, iloc, > + &err_blk); > > if (ret == -EIO) > ext4_error_inode_block(inode, err_blk, EIO, > @@ -4606,7 +4610,7 @@ int ext4_get_inode_loc(struct inode *inode, struct ext4_iloc *iloc) > int ext4_get_fc_inode_loc(struct super_block *sb, unsigned long ino, > struct ext4_iloc *iloc) > { > - return __ext4_get_inode_loc(sb, ino, iloc, 0, NULL); > + return __ext4_get_inode_loc(sb, ino, NULL, iloc, NULL); > } > > static bool ext4_should_enable_dax(struct inode *inode) > -- > 2.31.1 >
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index 3c36e701e30e..a8388ec91f9f 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -4441,12 +4441,12 @@ static int ext4_fill_raw_inode(struct inode *inode, struct ext4_inode *raw_inode /* * ext4_get_inode_loc returns with an extra refcount against the inode's - * underlying buffer_head on success. If 'in_mem' is true, we have all - * data in memory that is needed to recreate the on-disk version of this - * inode. + * underlying buffer_head on success. If we pass 'inode' and it does not + * have in-inode xattr, we have all inode data in memory that is needed + * to recreate the on-disk version of this inode. */ static int __ext4_get_inode_loc(struct super_block *sb, unsigned long ino, - struct ext4_iloc *iloc, int in_mem, + struct inode *inode, struct ext4_iloc *iloc, ext4_fsblk_t *ret_block) { struct ext4_group_desc *gdp; @@ -4486,7 +4486,7 @@ static int __ext4_get_inode_loc(struct super_block *sb, unsigned long ino, * is the only valid inode in the block, we need not read the * block. */ - if (in_mem) { + if (inode && !ext4_test_inode_state(inode, EXT4_STATE_XATTR)) { struct buffer_head *bitmap_bh; int i, start; @@ -4514,8 +4514,13 @@ static int __ext4_get_inode_loc(struct super_block *sb, unsigned long ino, } brelse(bitmap_bh); if (i == start + inodes_per_block) { + struct ext4_inode *raw_inode = + (struct ext4_inode *) (bh->b_data + iloc->offset); + /* all other inodes are free, so skip I/O */ memset(bh->b_data, 0, bh->b_size); + if (!ext4_test_inode_state(inode, EXT4_STATE_NEW)) + ext4_fill_raw_inode(inode, raw_inode); set_buffer_uptodate(bh); unlock_buffer(bh); goto has_buffer; @@ -4576,7 +4581,7 @@ static int __ext4_get_inode_loc_noinmem(struct inode *inode, ext4_fsblk_t err_blk; int ret; - ret = __ext4_get_inode_loc(inode->i_sb, inode->i_ino, iloc, 0, + ret = __ext4_get_inode_loc(inode->i_sb, inode->i_ino, NULL, iloc, &err_blk); if (ret == -EIO) @@ -4591,9 +4596,8 @@ int ext4_get_inode_loc(struct inode *inode, struct ext4_iloc *iloc) ext4_fsblk_t err_blk; int ret; - /* We have all inode data except xattrs in memory here. */ - ret = __ext4_get_inode_loc(inode->i_sb, inode->i_ino, iloc, - !ext4_test_inode_state(inode, EXT4_STATE_XATTR), &err_blk); + ret = __ext4_get_inode_loc(inode->i_sb, inode->i_ino, inode, iloc, + &err_blk); if (ret == -EIO) ext4_error_inode_block(inode, err_blk, EIO, @@ -4606,7 +4610,7 @@ int ext4_get_inode_loc(struct inode *inode, struct ext4_iloc *iloc) int ext4_get_fc_inode_loc(struct super_block *sb, unsigned long ino, struct ext4_iloc *iloc) { - return __ext4_get_inode_loc(sb, ino, iloc, 0, NULL); + return __ext4_get_inode_loc(sb, ino, NULL, iloc, NULL); } static bool ext4_should_enable_dax(struct inode *inode)
In ext4_get_inode_loc(), we may skip IO and get an zero && uptodate inode buffer when the inode monopolize an inode block for performance reason. For most cases, ext4_mark_iloc_dirty() will fill the inode buffer to make it fine, but we could miss this call if something bad happened. Finally, __ext4_get_inode_loc_noinmem() may probably get an empty inode buffer and trigger ext4 error. For example, if we remove a nonexistent xattr on inode A, ext4_xattr_set_handle() will return ENODATA before invoking ext4_mark_iloc_dirty(), it will left an uptodate but zero buffer. We will get checksum error message in ext4_iget() when getting inode again. EXT4-fs error (device sda): ext4_lookup:1784: inode #131074: comm cat: iget: checksum invalid Even worse, if we allocate another inode B at the same inode block, it will corrupt the inode A on disk when write back inode B. So this patch initialize the inode buffer by filling the in-mem inode contents if we skip read I/O, ensure that the buffer is really uptodate. Signed-off-by: Zhang Yi <yi.zhang@huawei.com> --- fs/ext4/inode.c | 24 ++++++++++++++---------- 1 file changed, 14 insertions(+), 10 deletions(-)