On 1/16/25 06:16, Jaegeuk Kim via Linux-f2fs-devel wrote:
1. ioctl(fd1, F2FS_IOC_DONATE_RANGE, {0,3});
2. ioctl(fd2, F2FS_IOC_DONATE_RANGE, {1,2});
3. ioctl(fd3, F2FS_IOC_DONATE_RANGE, {3,1});
4. echo 3 > /sys/fs/f2fs/blk/donate_caches

will reclaim 3 page cache ranges, registered by #1, #2, and #3.

Signed-off-by: Jaegeuk Kim <jaeg...@kernel.org>
---
  Documentation/ABI/testing/sysfs-fs-f2fs |  7 +++++++
  fs/f2fs/f2fs.h                          |  2 ++
  fs/f2fs/shrinker.c                      | 27 +++++++++++++++++++++++++
  fs/f2fs/sysfs.c                         |  8 ++++++++
  4 files changed, 44 insertions(+)

diff --git a/Documentation/ABI/testing/sysfs-fs-f2fs 
b/Documentation/ABI/testing/sysfs-fs-f2fs
index 3e1630c70d8a..6f9d8b8889fd 100644
--- a/Documentation/ABI/testing/sysfs-fs-f2fs
+++ b/Documentation/ABI/testing/sysfs-fs-f2fs
@@ -828,3 +828,10 @@ Date:              November 2024
  Contact:      "Chao Yu" <c...@kernel.org>
  Description:  It controls max read extent count for per-inode, the value of 
threshold
                is 10240 by default.
+
+What:          /sys/fs/f2fs/<disk>/donate_caches
+Date:          December 2024
+Contact:       "Jaegeuk Kim" <jaeg...@kernel.org>
+Description:   It reclaims the certian file-backed pages registered by
+               ioctl(F2FS_IOC_DONATE_RANGE).
+               For example, writing N tries to drop N address spaces in LRU.
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 951fbc3f94c7..399ddd10a94f 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -1637,6 +1637,7 @@ struct f2fs_sb_info {
/* control donate caches */
        unsigned int donate_files;
+       unsigned int donate_caches;
/* basic filesystem units */
        unsigned int log_sectors_per_block;     /* log2 sectors per block */
@@ -4259,6 +4260,7 @@ unsigned long f2fs_shrink_count(struct shrinker *shrink,
                        struct shrink_control *sc);
  unsigned long f2fs_shrink_scan(struct shrinker *shrink,
                        struct shrink_control *sc);
+void f2fs_donate_caches(struct f2fs_sb_info *sbi);
  void f2fs_join_shrinker(struct f2fs_sb_info *sbi);
  void f2fs_leave_shrinker(struct f2fs_sb_info *sbi);
diff --git a/fs/f2fs/shrinker.c b/fs/f2fs/shrinker.c
index 83d6fb97dcae..22f62813910b 100644
--- a/fs/f2fs/shrinker.c
+++ b/fs/f2fs/shrinker.c
@@ -130,6 +130,33 @@ unsigned long f2fs_shrink_scan(struct shrinker *shrink,
        return freed;
  }
+void f2fs_donate_caches(struct f2fs_sb_info *sbi)
+{
+       struct inode *inode;
+       struct f2fs_inode_info *fi;
+       int nfiles = sbi->donate_caches;
+
+       while (nfiles--) {
+               spin_lock(&sbi->inode_lock[DONATE_INODE]);
+               if (list_empty(&sbi->inode_list[DONATE_INODE])) {
+                       spin_unlock(&sbi->inode_lock[DONATE_INODE]);
+                       break;
+               }
+               fi = list_first_entry(&sbi->inode_list[DONATE_INODE],
+                                       struct f2fs_inode_info, gdonate_list);
+               list_move_tail(&fi->gdonate_list, 
&sbi->inode_list[DONATE_INODE]);
+               inode = igrab(&fi->vfs_inode);
+               spin_unlock(&sbi->inode_lock[DONATE_INODE]);
+
+               if (!inode)
+                       continue;
+
+               invalidate_inode_pages2_range(inode->i_mapping,
+                                       fi->donate_start, fi->donate_end);

fi->donate_start and fi->donate_end can be updated in ioctl concurrently and become inconsistent here, is it fine?

Thanks,

+               iput(inode);
+       }
+}
+
  void f2fs_join_shrinker(struct f2fs_sb_info *sbi)
  {
        spin_lock(&f2fs_list_lock);
diff --git a/fs/f2fs/sysfs.c b/fs/f2fs/sysfs.c
index 6b99dc49f776..f81190fabdd3 100644
--- a/fs/f2fs/sysfs.c
+++ b/fs/f2fs/sysfs.c
@@ -811,6 +811,12 @@ static ssize_t __sbi_store(struct f2fs_attr *a,
                return count;
        }
+ if (!strcmp(a->attr.name, "donate_caches")) {
+               sbi->donate_caches = min(t, sbi->donate_files);
+               f2fs_donate_caches(sbi);
+               return count;
+       }
+
        *ui = (unsigned int)t;
return count;
@@ -1030,6 +1036,7 @@ F2FS_SBI_GENERAL_RW_ATTR(max_victim_search);
  F2FS_SBI_GENERAL_RW_ATTR(migration_granularity);
  F2FS_SBI_GENERAL_RW_ATTR(migration_window_granularity);
  F2FS_SBI_GENERAL_RW_ATTR(dir_level);
+F2FS_SBI_GENERAL_RW_ATTR(donate_caches);
  #ifdef CONFIG_F2FS_IOSTAT
  F2FS_SBI_GENERAL_RW_ATTR(iostat_enable);
  F2FS_SBI_GENERAL_RW_ATTR(iostat_period_ms);
@@ -1178,6 +1185,7 @@ static struct attribute *f2fs_attrs[] = {
        ATTR_LIST(migration_granularity),
        ATTR_LIST(migration_window_granularity),
        ATTR_LIST(dir_level),
+       ATTR_LIST(donate_caches),
        ATTR_LIST(ram_thresh),
        ATTR_LIST(ra_nid_pages),
        ATTR_LIST(dirty_nats_ratio),



_______________________________________________
Linux-f2fs-devel mailing list
Linux-f2fs-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel

Reply via email to