f2fs: fix to limit gc_pin_file_threshold

type of f2fs_inode.i_gc_failures, f2fs_inode_info.i_gc_failures, and
f2fs_sb_info.gc_pin_file_threshold is __le16, unsigned int, and u64,
so it will cause truncation during comparison and persistence.

Unifying variable of these three variables to unsigned short, and
add an upper boundary limitation for gc_pin_file_threshold.

Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

diff --git a/Documentation/ABI/testing/sysfs-fs-f2fs b/Documentation/ABI/testing/sysfs-fs-f2fs
index 1a4d83953379ec902c828af8f359003ff08955f0..cad6c3dc1f9c1f4f93c1b845865a605e66ca59d1 100644 (file)
--- a/Documentation/ABI/testing/sysfs-fs-f2fs
+++ b/Documentation/ABI/testing/sysfs-fs-f2fs
@@ -331,7 +331,7 @@ Date:               January 2018
 Contact:       Jaegeuk Kim <jaegeuk@kernel.org>
 Description:   This indicates how many GC can be failed for the pinned
                file. If it exceeds this, F2FS doesn't guarantee its pinning
-               state. 2048 trials is set by default.
+               state. 2048 trials is set by default, and 65535 as maximum.
 
 What:          /sys/fs/f2fs/<disk>/extension_list
 Date:          February 2018

diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index a4ebf3e91b68f3d9b03eedfbfb3ac0d452b19485..1352da2dfaa33f366ceeb377610bdcc03c3d0f15 100644 (file)
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -813,7 +813,7 @@ struct f2fs_inode_info {
        unsigned char i_dir_level;      /* use for dentry level for large dir */
        union {
                unsigned int i_current_depth;   /* only for directory depth */
-               unsigned int i_gc_failures;     /* for gc failure statistic */
+               unsigned short i_gc_failures;   /* for gc failure statistic */
        };
        unsigned int i_pino;            /* parent inode number */
        umode_t i_acl_mode;             /* keep file acl mode temporarily */
@@ -1673,7 +1673,7 @@ struct f2fs_sb_info {
        unsigned long long skipped_gc_rwsem;            /* FG_GC only */
 
        /* threshold for gc trials on pinned files */
-       u64 gc_pin_file_threshold;
+       unsigned short gc_pin_file_threshold;
        struct f2fs_rwsem pin_sem;
 
        /* maximum # of trials to find a victim segment for SSR and GC */

diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index 92aaa6986f993055abf193f357e89a41ba5fe6b1..72ce1a522fb26a8a2e0e793534a8cf291f1505f4 100644 (file)
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -3215,16 +3215,17 @@ int f2fs_pin_file_control(struct inode *inode, bool inc)
        struct f2fs_inode_info *fi = F2FS_I(inode);
        struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
 
-       /* Use i_gc_failures for normal file as a risk signal. */
-       if (inc)
-               f2fs_i_gc_failures_write(inode, fi->i_gc_failures + 1);
-
-       if (fi->i_gc_failures > sbi->gc_pin_file_threshold) {
+       if (fi->i_gc_failures >= sbi->gc_pin_file_threshold) {
                f2fs_warn(sbi, "%s: Enable GC = ino %lx after %x GC trials",
                          __func__, inode->i_ino, fi->i_gc_failures);
                clear_inode_flag(inode, FI_PIN_FILE);
                return -EAGAIN;
        }
+
+       /* Use i_gc_failures for normal file as a risk signal. */
+       if (inc)
+               f2fs_i_gc_failures_write(inode, fi->i_gc_failures + 1);
+
        return 0;
 }
 

diff --git a/fs/f2fs/gc.h b/fs/f2fs/gc.h
index 9c0d06c4d19a91f61757c4d9a5babbeb4a07729d..a8ea3301b815ad4f3cbce63775afc033fecf1642 100644 (file)
--- a/fs/f2fs/gc.h
+++ b/fs/f2fs/gc.h
@@ -26,6 +26,7 @@
 #define LIMIT_FREE_BLOCK       40 /* percentage over invalid + free space */
 
 #define DEF_GC_FAILED_PINNED_FILES     2048
+#define MAX_GC_FAILED_PINNED_FILES     USHRT_MAX
 
 /* Search max. number of dirty segments to select a victim segment */
 #define DEF_MAX_VICTIM_SEARCH 4096 /* covers 8GB */

diff --git a/fs/f2fs/sysfs.c b/fs/f2fs/sysfs.c
index a568ce96cf563130654333ccae5a69049050aae7..531fc58001095fff117f985170a85be5742bf974 100644 (file)
--- a/fs/f2fs/sysfs.c
+++ b/fs/f2fs/sysfs.c
@@ -675,6 +675,13 @@ out:
                return count;
        }
 
+       if (!strcmp(a->attr.name, "gc_pin_file_threshold")) {
+               if (t > MAX_GC_FAILED_PINNED_FILES)
+                       return -EINVAL;
+               sbi->gc_pin_file_threshold = t;
+               return count;
+       }
+
        if (!strcmp(a->attr.name, "gc_reclaimed_segments")) {
                if (t != 0)
                        return -EINVAL;