lwn.git/fs/ext4/inline.c, branch docs-4.16

ext4: prevent data corruption with inline data + DAX

2017-10-12T15:52:34+00:00

If an inode has inline data it is currently prevented from using DAX by a check in ext4_set_inode_flags(). When the inode grows inline data via ext4_create_inline_data() or removes its inline data via ext4_destroy_inline_data_nolock(), the value of S_DAX can change. Currently these changes are unsafe because we don't hold off page faults and I/O, write back dirty radix tree entries and invalidate all mappings. There are also issues with mm-level races when changing the value of S_DAX, as well as issues with the VM_MIXEDMAP flag: https://www.spinics.net/lists/linux-xfs/msg09859.html The unsafe transition of S_DAX can reliably cause data corruption, as shown by the following fstest: https://patchwork.kernel.org/patch/9948381/ Fix this issue by preventing the DAX mount option from being used on filesystems that were created to support inline data. Inline data is an option given to mkfs.ext4. Signed-off-by: Ross Zwisler Signed-off-by: Theodore Ts'o Reviewed-by: Jan Kara CC: stable@vger.kernel.org

ext4: Add iomap support for inline data

2017-10-01T21:57:54+00:00

Report inline data as a IOMAP_F_DATA_INLINE mapping. This allows to use iomap_seek_hole and iomap_seek_data in ext4_llseek and makes switching to iomap_fiemap in ext4_fiemap easier. Signed-off-by: Andreas Gruenbacher Signed-off-by: Theodore Ts'o Reviewed-by: Jan Kara

ext4: xattr-in-inode support

2017-06-22T01:10:32+00:00

Large xattr support is implemented for EXT4_FEATURE_INCOMPAT_EA_INODE. If the size of an xattr value is larger than will fit in a single external block, then the xattr value will be saved into the body of an external xattr inode. The also helps support a larger number of xattr, since only the headers will be stored in the in-inode space or the single external block. The inode is referenced from the xattr header via "e_value_inum", which was formerly "e_value_block", but that field was never used. The e_value_size still contains the xattr size so that listing xattrs does not need to look up the inode if the data is not accessed. struct ext4_xattr_entry { __u8 e_name_len; /* length of name */ __u8 e_name_index; /* attribute name index */ __le16 e_value_offs; /* offset in disk block of value */ __le32 e_value_inum; /* inode in which value is stored */ __le32 e_value_size; /* size of attribute value */ __le32 e_hash; /* hash value of name and value */ char e_name[0]; /* attribute name */ }; The xattr inode is marked with the EXT4_EA_INODE_FL flag and also holds a back-reference to the owning inode in its i_mtime field, allowing the ext4/e2fsck to verify the correct inode is accessed. [ Applied fix by Dan Carpenter to avoid freeing an ERR_PTR. ] Lustre-Jira: https://jira.hpdd.intel.com/browse/LU-80 Lustre-bugzilla: https://bugzilla.lustre.org/show_bug.cgi?id=4424 Signed-off-by: Kalpak Shah Signed-off-by: James Simmons Signed-off-by: Andreas Dilger Signed-off-by: Tahsin Erdogan Signed-off-by: Theodore Ts'o Signed-off-by: Dan Carpenter

ext4: remove unused d_name argument from ext4_search_dir() et al.

2017-05-24T22:10:49+00:00

Now that we are passing a struct ext4_filename, we do not need to pass around the original struct qstr too. Signed-off-by: Eric Biggers Signed-off-by: Theodore Ts'o Reviewed-by: Jan Kara

ext4: trim return value and 'dir' argument from ext4_insert_dentry()

2017-04-30T03:27:26+00:00

In the initial implementation of ext4 encryption, the filename was encrypted in ext4_insert_dentry(), which could fail and also required access to the 'dir' inode. Since then ext4 filename encryption has been changed to encrypt the filename earlier, so we can revert the additions to ext4_insert_dentry(). Signed-off-by: Eric Biggers Signed-off-by: Theodore Ts'o

ext4: mark inode dirty after converting inline directory

2017-03-15T18:52:02+00:00

If ext4_convert_inline_data() was called on a directory with inline data, the filesystem was left in an inconsistent state (as considered by e2fsck) because the file size was not increased to cover the new block. This happened because the inode was not marked dirty after i_disksize was updated. Fix this by marking the inode dirty at the end of ext4_finish_convert_inline_dir(). This bug was probably not noticed before because most users mark the inode dirty afterwards for other reasons. But if userspace executed FS_IOC_SET_ENCRYPTION_POLICY with invalid parameters, as exercised by 'kvm-xfstests -c adv generic/396', then the inode was never marked dirty after updating i_disksize. Cc: stable@vger.kernel.org # 3.10+ Fixes: 3c47d54170b6a678875566b1b8d6dcf57904e49b Signed-off-by: Eric Biggers Signed-off-by: Theodore Ts'o

ext4: add shutdown bit and check for it

2017-02-05T06:28:48+00:00

Add a shutdown bit that will cause ext4 processing to fail immediately with EIO. Signed-off-by: Theodore Ts'o

ext4: fix inline data error paths

2017-02-05T04:04:00+00:00

The write_end() function must always unlock the page and drop its ref count, even on an error. Signed-off-by: Theodore Ts'o Cc: stable@vger.kernel.org

ext4: propagate error values from ext4_inline_data_truncate()

2017-01-23T00:35:49+00:00

Signed-off-by: Theodore Ts'o

ext4: avoid calling ext4_mark_inode_dirty() under unneeded semaphores

2017-01-12T03:14:49+00:00

There is no need to call ext4_mark_inode_dirty while holding xattr_sem or i_data_sem, so where it's easy to avoid it, move it out from the critical region. Signed-off-by: Theodore Ts'o