Messages in this thread Patch in this message | | | From | Daeho Jeong <> | Subject | [PATCH] f2fs: add sysfs node to control ra_pages for fadvise seq file | Date | Thu, 22 Jul 2021 16:13:58 -0700 |
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From: Daeho Jeong <daehojeong@google.com>
fadvise() allows the user to expand the readahead window to double with POSIX_FADV_SEQUENTIAL, now. But, in some use cases, it is not that sufficient and we need to meet the need in a restricted way. We can control the multiplier value of bdi device readahead between 2 (default) and 256 for POSIX_FADV_SEQUENTIAL advise option.
Signed-off-by: Daeho Jeong <daehojeong@google.com> --- Documentation/ABI/testing/sysfs-fs-f2fs | 6 +++++ fs/f2fs/f2fs.h | 2 ++ fs/f2fs/file.c | 32 +++++++++++++++++++++++++ fs/f2fs/super.c | 1 + fs/f2fs/sysfs.c | 10 ++++++++ 5 files changed, 51 insertions(+)
diff --git a/Documentation/ABI/testing/sysfs-fs-f2fs b/Documentation/ABI/testing/sysfs-fs-f2fs index 3d1f853c6681..60f1f176374e 100644 --- a/Documentation/ABI/testing/sysfs-fs-f2fs +++ b/Documentation/ABI/testing/sysfs-fs-f2fs @@ -507,3 +507,9 @@ Date: July 2021 Contact: "Daeho Jeong" <daehojeong@google.com> Description: You can control for which gc mode the "gc_reclaimed_segments" node shows. Refer to the description of the modes in "gc_reclaimed_segments". + +What: /sys/fs/f2fs/<disk>/seq_file_ra_mul +Date: July 2021 +Contact: "Daeho Jeong" <daehojeong@google.com> +Description: You can control the multiplier value of bdi device readahead window size + between 2 (default) and 256 for POSIX_FADV_SEQUENTIAL advise option. diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h index 502e47936651..c59329dcb1f6 100644 --- a/fs/f2fs/f2fs.h +++ b/fs/f2fs/f2fs.h @@ -1733,6 +1733,8 @@ struct f2fs_sb_info { unsigned int gc_segment_mode; /* GC state for reclaimed segments */ unsigned int gc_reclaimed_segs[MAX_GC_MODE]; /* Reclaimed segs for each mode */ + unsigned long seq_file_ra_mul; /* multiplier for ra_pages of seq. files in fadvise */ + #ifdef CONFIG_F2FS_FS_COMPRESSION struct kmem_cache *page_array_slab; /* page array entry */ unsigned int page_array_slab_size; /* default page array slab size */ diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c index 6afd4562335f..f71c90236815 100644 --- a/fs/f2fs/file.c +++ b/fs/f2fs/file.c @@ -23,6 +23,7 @@ #include <linux/nls.h> #include <linux/sched/signal.h> #include <linux/fileattr.h> +#include <linux/fadvise.h> #include "f2fs.h" #include "node.h" @@ -4332,6 +4333,36 @@ static ssize_t f2fs_file_write_iter(struct kiocb *iocb, struct iov_iter *from) return ret; } +static int f2fs_file_fadvise(struct file *filp, loff_t offset, loff_t len, + int advice) +{ + int ret; + struct inode *inode; + struct address_space *mapping; + struct backing_dev_info *bdi; + + if (advice == POSIX_FADV_SEQUENTIAL) { + inode = file_inode(filp); + if (S_ISFIFO(inode->i_mode)) + return -ESPIPE; + + mapping = filp->f_mapping; + if (!mapping || len < 0) + return -EINVAL; + + bdi = inode_to_bdi(mapping->host); + filp->f_ra.ra_pages = bdi->ra_pages * F2FS_I_SB(inode)->seq_file_ra_mul; + spin_lock(&filp->f_lock); + filp->f_mode &= ~FMODE_RANDOM; + spin_unlock(&filp->f_lock); + return 0; + } + + ret = generic_fadvise(filp, offset, len, advice); + + return ret; +} + #ifdef CONFIG_COMPAT struct compat_f2fs_gc_range { u32 sync; @@ -4460,4 +4491,5 @@ const struct file_operations f2fs_file_operations = { #endif .splice_read = generic_file_splice_read, .splice_write = iter_file_splice_write, + .fadvise = f2fs_file_fadvise, }; diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c index 9089303f7f8c..ccb745807fe1 100644 --- a/fs/f2fs/super.c +++ b/fs/f2fs/super.c @@ -3312,6 +3312,7 @@ static void init_sb_info(struct f2fs_sb_info *sbi) sbi->next_victim_seg[FG_GC] = NULL_SEGNO; sbi->max_victim_search = DEF_MAX_VICTIM_SEARCH; sbi->migration_granularity = sbi->segs_per_sec; + sbi->seq_file_ra_mul = 2; sbi->dir_level = DEF_DIR_LEVEL; sbi->interval_time[CP_TIME] = DEF_CP_INTERVAL; diff --git a/fs/f2fs/sysfs.c b/fs/f2fs/sysfs.c index 15fe30d3aeb5..9a21be63436d 100644 --- a/fs/f2fs/sysfs.c +++ b/fs/f2fs/sysfs.c @@ -538,6 +538,14 @@ static ssize_t __sbi_store(struct f2fs_attr *a, return count; } + if (!strcmp(a->attr.name, "seq_file_ra_mul")) { + if (t >= 2 && t <= 256) + sbi->seq_file_ra_mul = t; + else + return -EINVAL; + return count; + } + *ui = (unsigned int)t; return count; @@ -763,6 +771,7 @@ F2FS_RW_ATTR(ATGC_INFO, atgc_management, atgc_candidate_count, max_candidate_cou F2FS_RW_ATTR(ATGC_INFO, atgc_management, atgc_age_weight, age_weight); F2FS_RW_ATTR(ATGC_INFO, atgc_management, atgc_age_threshold, age_threshold); +F2FS_RW_ATTR(F2FS_SBI, f2fs_sb_info, seq_file_ra_mul, seq_file_ra_mul); F2FS_RW_ATTR(F2FS_SBI, f2fs_sb_info, gc_segment_mode, gc_segment_mode); F2FS_RW_ATTR(F2FS_SBI, f2fs_sb_info, gc_reclaimed_segments, gc_reclaimed_segs); @@ -838,6 +847,7 @@ static struct attribute *f2fs_attrs[] = { ATTR_LIST(atgc_candidate_count), ATTR_LIST(atgc_age_weight), ATTR_LIST(atgc_age_threshold), + ATTR_LIST(seq_file_ra_mul), ATTR_LIST(gc_segment_mode), ATTR_LIST(gc_reclaimed_segments), NULL, -- 2.32.0.432.gabb21c7263-goog
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