From: Eric Biggers <ebiggers@xxxxxxxxxx> Add support for STATX_IOALIGN to f2fs, so that I/O alignment information is exposed to userspace in a consistent and easy-to-use way. Signed-off-by: Eric Biggers <ebiggers@xxxxxxxxxx> --- fs/f2fs/file.c | 31 +++++++++++++++++++++++++++++++ 1 file changed, 31 insertions(+) diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c index c32f7722ba6b0..f89a190949c59 100644 --- a/fs/f2fs/file.c +++ b/fs/f2fs/file.c @@ -835,6 +835,21 @@ static bool f2fs_force_buffered_io(struct inode *inode) return false; } +/* Return the maximum value of io_opt across all the filesystem's devices. */ +static unsigned int f2fs_max_io_opt(struct inode *inode) +{ + struct f2fs_sb_info *sbi = F2FS_I_SB(inode); + int io_opt = 0; + int i; + + if (!f2fs_is_multi_device(sbi)) + return bdev_io_opt(sbi->sb->s_bdev); + + for (i = 0; i < sbi->s_ndevs; i++) + io_opt = max(io_opt, bdev_io_opt(FDEV(i).bdev)); + return io_opt; +} + int f2fs_getattr(struct user_namespace *mnt_userns, const struct path *path, struct kstat *stat, u32 request_mask, unsigned int query_flags) { @@ -851,6 +866,22 @@ int f2fs_getattr(struct user_namespace *mnt_userns, const struct path *path, stat->btime.tv_nsec = fi->i_crtime.tv_nsec; } + /* + * Return the I/O alignment information 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_IOALIGN) && S_ISREG(inode->i_mode)) { + unsigned int bsize = i_blocksize(inode); + + stat->result_mask |= STATX_IOALIGN; + if (!f2fs_force_buffered_io(inode)) { + stat->mem_align_dio = bsize; + stat->offset_align_dio = bsize; + } + stat->offset_align_optimal = max(f2fs_max_io_opt(inode), bsize); + } + flags = fi->i_flags; if (flags & F2FS_COMPR_FL) stat->attributes |= STATX_ATTR_COMPRESSED; -- 2.36.1