From: Eric Biggers <ebiggers@xxxxxxxxxx> Add support for STATX_DIOALIGN to ext4, so that direct I/O alignment restrictions are exposed to userspace in a generic way. Signed-off-by: Eric Biggers <ebiggers@xxxxxxxxxx> --- fs/ext4/ext4.h | 1 + fs/ext4/file.c | 15 ++++----------- fs/ext4/inode.c | 29 +++++++++++++++++++++++++++++ 3 files changed, 34 insertions(+), 11 deletions(-) diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h index 75b8d81b24692..68e964394e917 100644 --- a/fs/ext4/ext4.h +++ b/fs/ext4/ext4.h @@ -2968,6 +2968,7 @@ extern struct inode *__ext4_iget(struct super_block *sb, unsigned long ino, extern int ext4_write_inode(struct inode *, struct writeback_control *); extern int ext4_setattr(struct user_namespace *, struct dentry *, struct iattr *); +extern u32 ext4_dio_alignment(struct inode *inode); extern int ext4_getattr(struct user_namespace *, const struct path *, struct kstat *, u32, unsigned int); extern void ext4_evict_inode(struct inode *); diff --git a/fs/ext4/file.c b/fs/ext4/file.c index 26d7426208970..ecede6b01b7f0 100644 --- a/fs/ext4/file.c +++ b/fs/ext4/file.c @@ -39,19 +39,12 @@ static bool ext4_dio_supported(struct kiocb *iocb, struct iov_iter *iter) { struct inode *inode = file_inode(iocb->ki_filp); + u32 dio_align = ext4_dio_alignment(inode); - if (IS_ENCRYPTED(inode)) { - if (!fscrypt_dio_supported(inode)) - return false; - if (!IS_ALIGNED(iocb->ki_pos | iov_iter_alignment(iter), - i_blocksize(inode))) - return false; - } - if (fsverity_active(inode)) - return false; - if (ext4_should_journal_data(inode)) + if (!dio_align) return false; - if (ext4_has_inline_data(inode)) + if (dio_align > bdev_logical_block_size(inode->i_sb->s_bdev) && + !IS_ALIGNED(iocb->ki_pos | iov_iter_alignment(iter), dio_align)) return false; return true; } diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index 3dce7d058985b..78180c98f3847 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -5536,6 +5536,22 @@ int ext4_setattr(struct user_namespace *mnt_userns, struct dentry *dentry, return error; } +u32 ext4_dio_alignment(struct inode *inode) +{ + if (fsverity_active(inode)) + return 0; + if (ext4_should_journal_data(inode)) + return 0; + if (ext4_has_inline_data(inode)) + return 0; + if (IS_ENCRYPTED(inode)) { + if (!fscrypt_dio_supported(inode)) + return 0; + return i_blocksize(inode); + } + return bdev_logical_block_size(inode->i_sb->s_bdev); +} + int ext4_getattr(struct user_namespace *mnt_userns, const struct path *path, struct kstat *stat, u32 request_mask, unsigned int query_flags) { @@ -5551,6 +5567,19 @@ int ext4_getattr(struct user_namespace *mnt_userns, const struct path *path, stat->btime.tv_nsec = ei->i_crtime.tv_nsec; } + /* + * Return the DIO alignment restrictions if requested. We only return + * this information when requested, since on encrypted files it might + * take a fair bit of work to get if the file wasn't opened recently. + */ + if ((request_mask & STATX_DIOALIGN) && S_ISREG(inode->i_mode)) { + u32 dio_align = ext4_dio_alignment(inode); + + stat->result_mask |= STATX_DIOALIGN; + stat->dio_mem_align = dio_align; + stat->dio_offset_align = dio_align; + } + flags = ei->i_flags & EXT4_FL_USER_VISIBLE; if (flags & EXT4_APPEND_FL) stat->attributes |= STATX_ATTR_APPEND; -- 2.36.1
![]() |