From: Daeho Jeong <[email protected]>
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 <[email protected]>
Signed-off-by: Jaegeuk Kim <[email protected]>
---
v3: changed a meaningless value to defined value
v2: fix minor style issues
---
Documentation/ABI/testing/sysfs-fs-f2fs | 6 +++++
fs/f2fs/f2fs.h | 5 +++++
fs/f2fs/file.c | 30 +++++++++++++++++++++++++
fs/f2fs/super.c | 1 +
fs/f2fs/sysfs.c | 10 +++++++++
5 files changed, 52 insertions(+)
diff --git a/Documentation/ABI/testing/sysfs-fs-f2fs b/Documentation/ABI/testing/sysfs-fs-f2fs
index 845c4be535b0..73211f77d11e 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" <[email protected]>
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" <[email protected]>
+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 8459b6d5a2f8..10a94ed839b1 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -1738,6 +1738,8 @@ 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 */
@@ -3992,6 +3994,9 @@ void f2fs_destroy_extent_cache(void);
/*
* sysfs.c
*/
+#define MIN_RA_MUL 2
+#define MAX_RA_MUL 256
+
int __init f2fs_init_sysfs(void);
void f2fs_exit_sysfs(void);
int f2fs_register_sysfs(struct f2fs_sb_info *sbi);
diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index b1cb5b50faac..1a631e6d3e9b 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 +4333,34 @@ 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)
+{
+ 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;
+ }
+
+ return generic_fadvise(filp, offset, len, advice);
+}
+
#ifdef CONFIG_COMPAT
struct compat_f2fs_gc_range {
u32 sync;
@@ -4460,4 +4489,5 @@ 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 72eb9d70969f..04aeb7c0df7d 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -3422,6 +3422,7 @@ 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 = MIN_RA_MUL;
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 b1725620c07d..f3a3aecbe111 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 >= MIN_RA_MUL && t <= MAX_RA_MUL)
+ 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,
--
2.32.0.554.ge1b32706d8-goog
On 2021/8/3 12:22, Daeho Jeong wrote:
> From: Daeho Jeong <[email protected]>
>
> 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 <[email protected]>
I guess you can add below tag directly in v3. :)
Reviewed-by: Chao Yu <[email protected]>
Thanks,