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Date: Mon, 7 Nov 2022 17:51:58 +0530
From: "Ritesh Harjani (IBM)" <ritesh.list@...il.com>
To: Theodore Ts'o <tytso@....edu>
Cc: linux-ext4@...r.kernel.org,
Harshad Shirwadkar <harshadshirwadkar@...il.com>,
Wang Shilong <wshilong@....com>,
Andreas Dilger <adilger.kernel@...ger.ca>,
Li Xi <lixi@....com>,
"Ritesh Harjani (IBM)" <ritesh.list@...il.com>
Subject: [RFCv1 70/72] e2fsck: Fix and simplify update_mmp in case of pfsck
This adds pass1_update_mmp_enter() & pass1_update_mmp_exit() routines
to update mmp block. This also fixes a data race reported by threadsan
because of reading and writing to mmp_update_thread variable.
Signed-off-by: Ritesh Harjani (IBM) <ritesh.list@...il.com>
---
e2fsck/pass1.c | 97 ++++++++++++++++++++++++++++++++------------------
1 file changed, 63 insertions(+), 34 deletions(-)
diff --git a/e2fsck/pass1.c b/e2fsck/pass1.c
index 4168a45d..2ff83fcb 100644
--- a/e2fsck/pass1.c
+++ b/e2fsck/pass1.c
@@ -1097,6 +1097,66 @@ out:
return 0;
}
+static void pass1_update_mmp_enter(e2fsck_t ctx, ext2_ino_t ino)
+{
+ ext2_filsys fs = ctx->fs;
+ e2fsck_t global_ctx = ctx->global_ctx ? ctx->global_ctx : ctx;
+ int check_mmp = 0;
+ int set_mmp = 0;
+
+#ifdef HAVE_PTHREAD
+ /* only one active thread could update mmp block. */
+ e2fsck_pass1_block_map_r_lock(ctx);
+ if (!global_ctx->mmp_update_thread)
+ set_mmp = 1;
+ if (global_ctx->mmp_update_thread == ctx->thread_info.et_thread_index + 1)
+ check_mmp = 1;
+ e2fsck_pass1_block_map_r_unlock(ctx);
+
+ if (!check_mmp && !set_mmp)
+ return;
+
+ if (set_mmp) {
+ e2fsck_pass1_block_map_w_lock(ctx);
+ if (!global_ctx->mmp_update_thread) {
+ global_ctx->mmp_update_thread =
+ ctx->thread_info.et_thread_index + 1;
+ check_mmp = 1;
+ }
+ e2fsck_pass1_block_map_w_unlock(ctx);
+ }
+#else
+ check_mmp = 1;
+#endif
+
+ if (check_mmp && (ino % (fs->super->s_inodes_per_group * 4) == 1)) {
+ if (e2fsck_mmp_update(fs))
+ fatal_error(ctx, 0);
+ }
+}
+
+static void pass1_update_mmp_exit(e2fsck_t ctx)
+{
+ ext2_filsys fs = ctx->fs;
+ e2fsck_t global_ctx = ctx->global_ctx ? ctx->global_ctx : ctx;
+ int set_mmp = 0;
+
+#ifdef HAVE_PTHREAD
+ e2fsck_pass1_block_map_r_lock(ctx);
+ if (global_ctx->mmp_update_thread == ctx->thread_info.et_thread_index + 1)
+ set_mmp = 1;
+ e2fsck_pass1_block_map_r_unlock(ctx);
+
+ if (!set_mmp)
+ return;
+
+ /* reset update_thread after this thread exit */
+ e2fsck_pass1_block_map_w_lock(ctx);
+ global_ctx->mmp_update_thread = 0;
+ e2fsck_pass1_block_map_w_unlock(ctx);
+#endif
+}
+
static void pass1_readahead(e2fsck_t ctx, dgrp_t *group, ext2_ino_t *next_ino)
{
ext2_ino_t inodes_in_group = 0, inodes_per_block, inodes_per_buffer;
@@ -1511,7 +1571,7 @@ void e2fsck_pass1_run(e2fsck_t ctx)
dgrp_t ra_group = 0;
struct ea_quota ea_ibody_quota;
struct process_inode_block *inodes_to_process;
- int process_inode_count, check_mmp;
+ int process_inode_count;
e2fsck_t global_ctx = ctx->global_ctx ? ctx->global_ctx : ctx;
init_resource_track(&rtrack, ctx->fs->io);
@@ -1675,33 +1735,8 @@ void e2fsck_pass1_run(e2fsck_t ctx)
#endif
while (1) {
- check_mmp = 0;
e2fsck_pass1_check_lock(ctx);
-#ifdef HAVE_PTHREAD
- if (!global_ctx->mmp_update_thread) {
- e2fsck_pass1_block_map_w_lock(ctx);
- if (!global_ctx->mmp_update_thread) {
- global_ctx->mmp_update_thread =
- ctx->thread_info.et_thread_index + 1;
- check_mmp = 1;
- }
- e2fsck_pass1_block_map_w_unlock(ctx);
- }
-
- /* only one active thread could update mmp block. */
- e2fsck_pass1_block_map_r_lock(ctx);
- if (global_ctx->mmp_update_thread ==
- ctx->thread_info.et_thread_index + 1)
- check_mmp = 1;
- e2fsck_pass1_block_map_r_unlock(ctx);
-#else
- check_mmp = 1;
-#endif
-
- if (check_mmp && (ino % (fs->super->s_inodes_per_group * 4) == 1)) {
- if (e2fsck_mmp_update(fs))
- fatal_error(ctx, 0);
- }
+ pass1_update_mmp_enter(ctx, ino);
old_op = ehandler_operation(eop_next_inode);
pctx.errcode = ext2fs_get_next_inode_full(scan, &ino,
inode, inode_size);
@@ -2458,13 +2493,7 @@ endit:
print_resource_track(ctx, _("Pass 1"), &rtrack, ctx->fs->io);
else
ctx->invalid_bitmaps++;
-#ifdef HAVE_PTHREAD
- /* reset update_thread after this thread exit */
- e2fsck_pass1_block_map_w_lock(ctx);
- if (check_mmp)
- global_ctx->mmp_update_thread = 0;
- e2fsck_pass1_block_map_w_unlock(ctx);
-#endif
+ pass1_update_mmp_exit(ctx);
}
#ifdef HAVE_PTHREAD
--
2.37.3
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