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authorLinus Torvalds <torvalds@linux-foundation.org>2023-08-28 21:04:18 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2023-08-28 21:04:18 +0300
commit511fb5bafed197ff76d9adf5448de67f1d0558ae (patch)
tree6683ae0e7b62caa9488040d71705768a306f37dd /fs/exfat
parentde16588a7737b12e63ec646d72b45befb2b1f8f7 (diff)
parentcd4284cfd3e11c7a49e4808f76f53284d47d04dd (diff)
downloadlinux-511fb5bafed197ff76d9adf5448de67f1d0558ae.tar.xz
Merge tag 'v6.6-vfs.super' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull superblock updates from Christian Brauner: "This contains the super rework that was ready for this cycle. The first part changes the order of how we open block devices and allocate superblocks, contains various cleanups, simplifications, and a new mechanism to wait on superblock state changes. This unblocks work to ultimately limit the number of writers to a block device. Jan has already scheduled follow-up work that will be ready for v6.7 and allows us to restrict the number of writers to a given block device. That series builds on this work right here. The second part contains filesystem freezing updates. Overview: The generic superblock changes are rougly organized as follows (ignoring additional minor cleanups): (1) Removal of the bd_super member from struct block_device. This was a very odd back pointer to struct super_block with unclear rules. For all relevant places we have other means to get the same information so just get rid of this. (2) Simplify rules for superblock cleanup. Roughly, everything that is allocated during fs_context initialization and that's stored in fs_context->s_fs_info needs to be cleaned up by the fs_context->free() implementation before the superblock allocation function has been called successfully. After sget_fc() returned fs_context->s_fs_info has been transferred to sb->s_fs_info at which point sb->kill_sb() if fully responsible for cleanup. Adhering to these rules means that cleanup of sb->s_fs_info in fill_super() is to be avoided as it's brittle and inconsistent. Cleanup shouldn't be duplicated between sb->put_super() as sb->put_super() is only called if sb->s_root has been set aka when the filesystem has been successfully born (SB_BORN). That complexity should be avoided. This also means that block devices are to be closed in sb->kill_sb() instead of sb->put_super(). More details in the lower section. (3) Make it possible to lookup or create a superblock before opening block devices There's a subtle dependency on (2) as some filesystems did rely on fill_super() to be called in order to correctly clean up sb->s_fs_info. All these filesystems have been fixed. (4) Switch most filesystem to follow the same logic as the generic mount code now does as outlined in (3). (5) Use the superblock as the holder of the block device. We can now easily go back from block device to owning superblock. (6) Export and extend the generic fs_holder_ops and use them as holder ops everywhere and remove the filesystem specific holder ops. (7) Call from the block layer up into the filesystem layer when the block device is removed, allowing to shut down the filesystem without risk of deadlocks. (8) Get rid of get_super(). We can now easily go back from the block device to owning superblock and can call up from the block layer into the filesystem layer when the device is removed. So no need to wade through all registered superblock to find the owning superblock anymore" Link: https://lore.kernel.org/lkml/20230824-prall-intakt-95dbffdee4a0@brauner/ * tag 'v6.6-vfs.super' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (47 commits) super: use higher-level helper for {freeze,thaw} super: wait until we passed kill super super: wait for nascent superblocks super: make locking naming consistent super: use locking helpers fs: simplify invalidate_inodes fs: remove get_super block: call into the file system for ioctl BLKFLSBUF block: call into the file system for bdev_mark_dead block: consolidate __invalidate_device and fsync_bdev block: drop the "busy inodes on changed media" log message dasd: also call __invalidate_device when setting the device offline amiflop: don't call fsync_bdev in FDFMTBEG floppy: call disk_force_media_change when changing the format block: simplify the disk_force_media_change interface nbd: call blk_mark_disk_dead in nbd_clear_sock_ioctl xfs use fs_holder_ops for the log and RT devices xfs: drop s_umount over opening the log and RT devices ext4: use fs_holder_ops for the log device ext4: drop s_umount over opening the log device ...
Diffstat (limited to 'fs/exfat')
-rw-r--r--fs/exfat/exfat_fs.h2
-rw-r--r--fs/exfat/super.c39
2 files changed, 20 insertions, 21 deletions
diff --git a/fs/exfat/exfat_fs.h b/fs/exfat/exfat_fs.h
index 729ada9e26e8..f55498e5c23d 100644
--- a/fs/exfat/exfat_fs.h
+++ b/fs/exfat/exfat_fs.h
@@ -273,8 +273,6 @@ struct exfat_sb_info {
spinlock_t inode_hash_lock;
struct hlist_head inode_hashtable[EXFAT_HASH_SIZE];
-
- struct rcu_head rcu;
};
#define EXFAT_CACHE_VALID 0
diff --git a/fs/exfat/super.c b/fs/exfat/super.c
index 8e0ca4b0fc8f..2778bd9b631e 100644
--- a/fs/exfat/super.c
+++ b/fs/exfat/super.c
@@ -31,16 +31,6 @@ static void exfat_free_iocharset(struct exfat_sb_info *sbi)
kfree(sbi->options.iocharset);
}
-static void exfat_delayed_free(struct rcu_head *p)
-{
- struct exfat_sb_info *sbi = container_of(p, struct exfat_sb_info, rcu);
-
- unload_nls(sbi->nls_io);
- exfat_free_iocharset(sbi);
- exfat_free_upcase_table(sbi);
- kfree(sbi);
-}
-
static void exfat_put_super(struct super_block *sb)
{
struct exfat_sb_info *sbi = EXFAT_SB(sb);
@@ -50,7 +40,8 @@ static void exfat_put_super(struct super_block *sb)
brelse(sbi->boot_bh);
mutex_unlock(&sbi->s_lock);
- call_rcu(&sbi->rcu, exfat_delayed_free);
+ unload_nls(sbi->nls_io);
+ exfat_free_upcase_table(sbi);
}
static int exfat_sync_fs(struct super_block *sb, int wait)
@@ -709,9 +700,6 @@ free_table:
check_nls_io:
unload_nls(sbi->nls_io);
- exfat_free_iocharset(sbi);
- sb->s_fs_info = NULL;
- kfree(sbi);
return err;
}
@@ -720,14 +708,18 @@ static int exfat_get_tree(struct fs_context *fc)
return get_tree_bdev(fc, exfat_fill_super);
}
+static void exfat_free_sbi(struct exfat_sb_info *sbi)
+{
+ exfat_free_iocharset(sbi);
+ kfree(sbi);
+}
+
static void exfat_free(struct fs_context *fc)
{
struct exfat_sb_info *sbi = fc->s_fs_info;
- if (sbi) {
- exfat_free_iocharset(sbi);
- kfree(sbi);
- }
+ if (sbi)
+ exfat_free_sbi(sbi);
}
static int exfat_reconfigure(struct fs_context *fc)
@@ -772,12 +764,21 @@ static int exfat_init_fs_context(struct fs_context *fc)
return 0;
}
+static void exfat_kill_sb(struct super_block *sb)
+{
+ struct exfat_sb_info *sbi = sb->s_fs_info;
+
+ kill_block_super(sb);
+ if (sbi)
+ exfat_free_sbi(sbi);
+}
+
static struct file_system_type exfat_fs_type = {
.owner = THIS_MODULE,
.name = "exfat",
.init_fs_context = exfat_init_fs_context,
.parameters = exfat_parameters,
- .kill_sb = kill_block_super,
+ .kill_sb = exfat_kill_sb,
.fs_flags = FS_REQUIRES_DEV,
};