minix: Fix data integrity writeout issues

Minix could fail to properly write out inode on fsync(2) due to races
with WB_SYNC_NONE writeback. Several racing fsyncs could also result in
some fsync returning earlier than all metadata buffers were properly
persisted. Furthermore DIRSYNC handling missed writing inode related
metadata.

Fix all these issues by using new .sync_inode_metadata method which
makes sure all inode related metadata is written to disk during any
WB_SYNC_ALL writeback.

Signed-off-by: Jan Kara <jack@suse.cz>
Link: https://patch.msgid.link/20260727104923.3828017-36-jack@suse.cz
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>

diff --git a/fs/minix/dir.c b/fs/minix/dir.c
index 361d26d87d2e2df980959dcb6a81847124df8a36..2ca16f849d5ac01832e5fe35cdf0d4f3c4ffe2c8 100644 (file)
--- a/fs/minix/dir.c
+++ b/fs/minix/dir.c
@@ -23,7 +23,7 @@ const struct file_operations minix_dir_operations = {
        .llseek         = generic_file_llseek,
        .read           = generic_read_dir,
        .iterate_shared = minix_readdir,
-       .fsync          = minix_fsync,
+       .fsync          = simple_fsync,
 };
 
 /*

diff --git a/fs/minix/file.c b/fs/minix/file.c
index 86e5943cd2ff74d755faaecb43aa9aef22c53329..02aabbdb5deaa06911d5881d959138328ddb872f 100644 (file)
--- a/fs/minix/file.c
+++ b/fs/minix/file.c
@@ -10,13 +10,6 @@
 #include <linux/buffer_head.h>
 #include "minix.h"
 
-int minix_fsync(struct file *file, loff_t start, loff_t end, int datasync)
-{
-       return mmb_fsync(file,
-                       &minix_i(file->f_mapping->host)->i_metadata_bhs,
-                       start, end, datasync);
-}
-
 /*
  * We have mostly NULLs here: the current defaults are OK for
  * the minix filesystem.
@@ -26,7 +19,7 @@ const struct file_operations minix_file_operations = {
        .read_iter      = generic_file_read_iter,
        .write_iter     = generic_file_write_iter,
        .mmap_prepare   = generic_file_mmap_prepare,
-       .fsync          = minix_fsync,
+       .fsync          = simple_fsync,
        .splice_read    = filemap_splice_read,
 };
 

diff --git a/fs/minix/inode.c b/fs/minix/inode.c
index c30cc590698d6f06002aab65f23545bb84b69d6a..daf83e4ff25c81362cc33d339f63fe6599b8f2c5 100644 (file)
--- a/fs/minix/inode.c
+++ b/fs/minix/inode.c
@@ -24,6 +24,8 @@
 
 static int minix_write_inode(struct inode *inode,
                struct writeback_control *wbc);
+static int minix_sync_inode_metadata(struct inode *inode,
+                                    struct writeback_control *wbc);
 static int minix_statfs(struct dentry *dentry, struct kstatfs *buf);
 
 void __minix_error_inode(struct inode *inode, const char *function,
@@ -128,6 +130,7 @@ static const struct super_operations minix_sops = {
        .alloc_inode    = minix_alloc_inode,
        .free_inode     = minix_free_in_core_inode,
        .write_inode    = minix_write_inode,
+       .sync_inode_metadata = minix_sync_inode_metadata,
        .evict_inode    = minix_evict_inode,
        .put_super      = minix_put_super,
        .statfs         = minix_statfs,
@@ -630,7 +633,7 @@ struct inode *minix_iget(struct super_block *sb, unsigned long ino)
 /*
  * The minix V1 function to synchronize an inode.
  */
-static struct buffer_head * V1_minix_update_inode(struct inode * inode)
+static int V1_minix_update_inode(struct inode * inode)
 {
        struct buffer_head * bh;
        struct minix_inode * raw_inode;
@@ -639,7 +642,7 @@ static struct buffer_head * V1_minix_update_inode(struct inode * inode)
 
        raw_inode = minix_V1_raw_inode(inode->i_sb, inode->i_ino, &bh);
        if (!raw_inode)
-               return NULL;
+               return -EIO;
        raw_inode->i_mode = inode->i_mode;
        raw_inode->i_uid = fs_high2lowuid(i_uid_read(inode));
        raw_inode->i_gid = fs_high2lowgid(i_gid_read(inode));
@@ -651,13 +654,15 @@ static struct buffer_head * V1_minix_update_inode(struct inode * inode)
        else for (i = 0; i < 9; i++)
                raw_inode->i_zone[i] = minix_inode->u.i1_data[i];
        mark_buffer_dirty(bh);
-       return bh;
+       brelse(bh);
+       set_inode_metadata_writeback(inode);
+       return 0;
 }
 
 /*
  * The minix V2 function to synchronize an inode.
  */
-static struct buffer_head * V2_minix_update_inode(struct inode * inode)
+static int V2_minix_update_inode(struct inode * inode)
 {
        struct buffer_head * bh;
        struct minix2_inode * raw_inode;
@@ -666,7 +671,7 @@ static struct buffer_head * V2_minix_update_inode(struct inode * inode)
 
        raw_inode = minix_V2_raw_inode(inode->i_sb, inode->i_ino, &bh);
        if (!raw_inode)
-               return NULL;
+               return -EIO;
        raw_inode->i_mode = inode->i_mode;
        raw_inode->i_uid = fs_high2lowuid(i_uid_read(inode));
        raw_inode->i_gid = fs_high2lowgid(i_gid_read(inode));
@@ -680,29 +685,42 @@ static struct buffer_head * V2_minix_update_inode(struct inode * inode)
        else for (i = 0; i < 10; i++)
                raw_inode->i_zone[i] = minix_inode->u.i2_data[i];
        mark_buffer_dirty(bh);
-       return bh;
+       brelse(bh);
+       set_inode_metadata_writeback(inode);
+       return 0;
 }
 
 static int minix_write_inode(struct inode *inode, struct writeback_control *wbc)
+{
+       if (INODE_VERSION(inode) == MINIX_V1)
+               return V1_minix_update_inode(inode);
+       return V2_minix_update_inode(inode);
+}
+
+static int minix_sync_inode_metadata(struct inode *inode,
+                                    struct writeback_control *wbc)
 {
        int err = 0;
        struct buffer_head *bh;
+       void *raw_inode;
 
        if (INODE_VERSION(inode) == MINIX_V1)
-               bh = V1_minix_update_inode(inode);
+               raw_inode = minix_V1_raw_inode(inode->i_sb, inode->i_ino, &bh);
        else
-               bh = V2_minix_update_inode(inode);
-       if (!bh)
+               raw_inode = minix_V2_raw_inode(inode->i_sb, inode->i_ino, &bh);
+       if (!raw_inode)
                return -EIO;
-       if (wbc->sync_mode == WB_SYNC_ALL && buffer_dirty(bh)) {
-               sync_dirty_buffer(bh);
-               if (buffer_req(bh) && !buffer_uptodate(bh)) {
-                       printk("IO error syncing minix inode [%s:%08llx]\n",
-                               inode->i_sb->s_id, inode->i_ino);
-                       err = -EIO;
-               }
+       err = mmb_sync(&minix_i(inode)->i_metadata_bhs);
+       if (err)
+               goto out;
+       sync_dirty_buffer(bh);
+       if (buffer_write_io_error(bh)) {
+               printk("IO error syncing minix inode [%s:%08llx]\n",
+                       inode->i_sb->s_id, inode->i_ino);
+               err = -EIO;
        }
-       brelse (bh);
+out:
+       brelse(bh);
        return err;
 }
 

diff --git a/fs/minix/minix.h b/fs/minix/minix.h
index 9e52d4302f0d2ea62225a4dcfe08ef1bef686687..78722ce22e1e19c6d5b45ac466e0adf44b5f9b72 100644 (file)
--- a/fs/minix/minix.h
+++ b/fs/minix/minix.h
@@ -59,7 +59,6 @@ int minix_getattr(struct mnt_idmap *, const struct path *,
                struct kstat *, u32, unsigned int);
 int minix_prepare_chunk(struct folio *folio, loff_t pos, unsigned len);
 struct mapping_metadata_bhs *minix_get_metadata_bhs(struct inode *inode);
-int minix_fsync(struct file *file, loff_t start, loff_t end, int datasync);
 
 extern void V1_minix_truncate(struct inode *);
 extern void V2_minix_truncate(struct inode *);