6.12-stable review patch. If anyone has any objections, please let me know.
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From: Gao Xiang hsiangkao@linux.alibaba.com
[ Upstream commit 6422cde1b0d5a31b206b263417c1c2b3c80fe82c ]
For many use cases (e.g. container images are just fetched from remote), performance will be impacted if underlay page cache is up-to-date but direct i/o flushes dirty pages first.
Instead, let's use buffered I/O by default to keep in sync with loop devices and add a (re)mount option to explicitly give a try to use direct I/O if supported by the underlying files.
The container startup time is improved as below: [workload] docker.io/library/workpress:latest unpack 1st run non-1st runs EROFS snapshotter buffered I/O file 4.586404265s 0.308s 0.198s EROFS snapshotter direct I/O file 4.581742849s 2.238s 0.222s EROFS snapshotter loop 4.596023152s 0.346s 0.201s Overlayfs snapshotter 5.382851037s 0.206s 0.214s
Fixes: fb176750266a ("erofs: add file-backed mount support") Cc: Derek McGowan derek@mcg.dev Reviewed-by: Chao Yu chao@kernel.org Signed-off-by: Gao Xiang hsiangkao@linux.alibaba.com Link: https://lore.kernel.org/r/20241212134336.2059899-1-hsiangkao@linux.alibaba.c... Signed-off-by: Sasha Levin sashal@kernel.org --- fs/erofs/fileio.c | 7 +++++-- fs/erofs/internal.h | 1 + fs/erofs/super.c | 23 +++++++++++++++-------- 3 files changed, 21 insertions(+), 10 deletions(-)
diff --git a/fs/erofs/fileio.c b/fs/erofs/fileio.c index a61b8faec651..33f8539dda4a 100644 --- a/fs/erofs/fileio.c +++ b/fs/erofs/fileio.c @@ -9,6 +9,7 @@ struct erofs_fileio_rq { struct bio_vec bvecs[BIO_MAX_VECS]; struct bio bio; struct kiocb iocb; + struct super_block *sb; };
struct erofs_fileio { @@ -52,8 +53,9 @@ static void erofs_fileio_rq_submit(struct erofs_fileio_rq *rq) rq->iocb.ki_pos = rq->bio.bi_iter.bi_sector << SECTOR_SHIFT; rq->iocb.ki_ioprio = get_current_ioprio(); rq->iocb.ki_complete = erofs_fileio_ki_complete; - rq->iocb.ki_flags = (rq->iocb.ki_filp->f_mode & FMODE_CAN_ODIRECT) ? - IOCB_DIRECT : 0; + if (test_opt(&EROFS_SB(rq->sb)->opt, DIRECT_IO) && + rq->iocb.ki_filp->f_mode & FMODE_CAN_ODIRECT) + rq->iocb.ki_flags = IOCB_DIRECT; iov_iter_bvec(&iter, ITER_DEST, rq->bvecs, rq->bio.bi_vcnt, rq->bio.bi_iter.bi_size); ret = vfs_iocb_iter_read(rq->iocb.ki_filp, &rq->iocb, &iter); @@ -68,6 +70,7 @@ static struct erofs_fileio_rq *erofs_fileio_rq_alloc(struct erofs_map_dev *mdev)
bio_init(&rq->bio, NULL, rq->bvecs, BIO_MAX_VECS, REQ_OP_READ); rq->iocb.ki_filp = mdev->m_dif->file; + rq->sb = mdev->m_sb; return rq; }
diff --git a/fs/erofs/internal.h b/fs/erofs/internal.h index 3108ece1d709..77e785a6dfa7 100644 --- a/fs/erofs/internal.h +++ b/fs/erofs/internal.h @@ -182,6 +182,7 @@ struct erofs_sb_info { #define EROFS_MOUNT_POSIX_ACL 0x00000020 #define EROFS_MOUNT_DAX_ALWAYS 0x00000040 #define EROFS_MOUNT_DAX_NEVER 0x00000080 +#define EROFS_MOUNT_DIRECT_IO 0x00000100
#define clear_opt(opt, option) ((opt)->mount_opt &= ~EROFS_MOUNT_##option) #define set_opt(opt, option) ((opt)->mount_opt |= EROFS_MOUNT_##option) diff --git a/fs/erofs/super.c b/fs/erofs/super.c index 60f7bd43a5a4..5b279977c9d5 100644 --- a/fs/erofs/super.c +++ b/fs/erofs/super.c @@ -379,14 +379,8 @@ static void erofs_default_options(struct erofs_sb_info *sbi) }
enum { - Opt_user_xattr, - Opt_acl, - Opt_cache_strategy, - Opt_dax, - Opt_dax_enum, - Opt_device, - Opt_fsid, - Opt_domain_id, + Opt_user_xattr, Opt_acl, Opt_cache_strategy, Opt_dax, Opt_dax_enum, + Opt_device, Opt_fsid, Opt_domain_id, Opt_directio, Opt_err };
@@ -413,6 +407,7 @@ static const struct fs_parameter_spec erofs_fs_parameters[] = { fsparam_string("device", Opt_device), fsparam_string("fsid", Opt_fsid), fsparam_string("domain_id", Opt_domain_id), + fsparam_flag_no("directio", Opt_directio), {} };
@@ -526,6 +521,16 @@ static int erofs_fc_parse_param(struct fs_context *fc, errorfc(fc, "%s option not supported", erofs_fs_parameters[opt].name); break; #endif + case Opt_directio: +#ifdef CONFIG_EROFS_FS_BACKED_BY_FILE + if (result.boolean) + set_opt(&sbi->opt, DIRECT_IO); + else + clear_opt(&sbi->opt, DIRECT_IO); +#else + errorfc(fc, "%s option not supported", erofs_fs_parameters[opt].name); +#endif + break; default: return -ENOPARAM; } @@ -963,6 +968,8 @@ static int erofs_show_options(struct seq_file *seq, struct dentry *root) seq_puts(seq, ",dax=always"); if (test_opt(opt, DAX_NEVER)) seq_puts(seq, ",dax=never"); + if (erofs_is_fileio_mode(sbi) && test_opt(opt, DIRECT_IO)) + seq_puts(seq, ",directio"); #ifdef CONFIG_EROFS_FS_ONDEMAND if (sbi->fsid) seq_printf(seq, ",fsid=%s", sbi->fsid);