Re: [PATCH] ntfs: remove unsupported quota handling

[Hyunchul Lee]

2026년 5월 17일 (일) 오후 12:44, DaeMyung Kang <charsyam@xxxxxxxxx>님이 작성:
>
> The ntfs driver does not implement quota accounting.  It creates
> new inodes with the NTFS 1.2 $STANDARD_INFORMATION layout and does
> not maintain the NTFS 3.x owner_id/quota_charged fields or the
> $Quota usage records that Windows would need for meaningful quota
> accounting.
>
> The only runtime quota path left in the driver is the remount-rw
> code that tries to mark $Quota/$Q out of date, plus the mount-time
> code that loads $Quota and its $Q index solely to support that
> marker.
>
> Since the driver does not maintain the per-file quota metadata,
> setting QUOTA_FLAG_OUT_OF_DATE does not make the quota state
> meaningful, and failures in this unsupported path can unnecessarily
> block remount-rw or force a mount read-only.
>
> Remove the quota marker, the $Quota/$Q loading state, and the
> unused quota volume flag.  Keep the on-disk quota layout definitions
> in layout.h so the documented NTFS structures remain available.
>
> Suggested-by: Hyunchul Lee <hyc.lee@xxxxxxxxx>
> Link: https://lore.kernel.org/all/CANFS6bYTzioqZjYt=51Kb9RdR3MKXaez_fh_WCLoym093VxFmg@xxxxxxxxxxxxxx/
> Signed-off-by: DaeMyung Kang <charsyam@xxxxxxxxx>

Looks good to me. Thank you for this patch.

Reviewed-by: Hyunchul Lee <hyc.lee@xxxxxxxxx>

> ---
> This is the standalone patch agreed in the discussion (see the Link:
> above): the earlier "$Quota view-index lookup" fix series is being
> dropped because the ntfs driver does not implement quota accounting, so
> the unsupported quota loading/marking path is removed instead of fixed.
>
> Tested:
> - Applied on 5d6919055dec (Linux 7.1-rc3).
> - Built with CONFIG_NTFS_FS=y.
> - Booted the patched kernel in QEMU with an mkfs.ntfs-created NTFS 3.1
>   image containing $Extend/$Quota.
> - Mounted the image read-only, remounted it read-write, created a
>   directory and file, read the file back, remounted read-only, unmounted,
>   mounted read-only again, and read the file back again.
> - Verified no remaining runtime quota references outside layout.h
>   definitions.
>
>  fs/ntfs/Makefile |   2 +-
>  fs/ntfs/quota.c  |  95 -----------------------------------------
>  fs/ntfs/quota.h  |  15 -------
>  fs/ntfs/super.c  | 109 +----------------------------------------------
>  fs/ntfs/volume.h |   7 ---
>  5 files changed, 2 insertions(+), 226 deletions(-)
>  delete mode 100644 fs/ntfs/quota.c
>  delete mode 100644 fs/ntfs/quota.h
>
> diff --git a/fs/ntfs/Makefile b/fs/ntfs/Makefile
> index 0ce4d9a9388a..e120c2e69862 100644
> --- a/fs/ntfs/Makefile
> +++ b/fs/ntfs/Makefile
> @@ -5,6 +5,6 @@ obj-$(CONFIG_NTFS_FS) += ntfs.o
>  ntfs-y := aops.o attrib.o collate.o dir.o file.o index.o inode.o \
>           mft.o mst.o namei.o runlist.o super.o unistr.o attrlist.o ea.o \
>           upcase.o bitmap.o lcnalloc.o logfile.o reparse.o compress.o \
> -         iomap.o debug.o sysctl.o quota.o object_id.o bdev-io.o
> +         iomap.o debug.o sysctl.o object_id.o bdev-io.o
>
>  ccflags-$(CONFIG_NTFS_DEBUG) += -DDEBUG
> diff --git a/fs/ntfs/quota.c b/fs/ntfs/quota.c
> deleted file mode 100644
> index b443243b58fb..000000000000
> --- a/fs/ntfs/quota.c
> +++ /dev/null
> @@ -1,95 +0,0 @@
> -// SPDX-License-Identifier: GPL-2.0-or-later
> -/*
> - * NTFS kernel quota ($Quota) handling.
> - *
> - * Copyright (c) 2004 Anton Altaparmakov
> - */
> -
> -#include "index.h"
> -#include "quota.h"
> -#include "debug.h"
> -#include "ntfs.h"
> -
> -/*
> - * ntfs_mark_quotas_out_of_date - mark the quotas out of date on an ntfs volume
> - * @vol:       ntfs volume on which to mark the quotas out of date
> - *
> - * Mark the quotas out of date on the ntfs volume @vol and return 'true' on
> - * success and 'false' on error.
> - */
> -bool ntfs_mark_quotas_out_of_date(struct ntfs_volume *vol)
> -{
> -       struct ntfs_index_context *ictx;
> -       struct quota_control_entry *qce;
> -       const __le32 qid = QUOTA_DEFAULTS_ID;
> -       int err;
> -
> -       ntfs_debug("Entering.");
> -       if (NVolQuotaOutOfDate(vol))
> -               goto done;
> -       if (!vol->quota_ino || !vol->quota_q_ino) {
> -               ntfs_error(vol->sb, "Quota inodes are not open.");
> -               return false;
> -       }
> -       inode_lock(vol->quota_q_ino);
> -       ictx = ntfs_index_ctx_get(NTFS_I(vol->quota_q_ino), I30, 4);
> -       if (!ictx) {
> -               ntfs_error(vol->sb, "Failed to get index context.");
> -               goto err_out;
> -       }
> -       err = ntfs_index_lookup(&qid, sizeof(qid), ictx);
> -       if (err) {
> -               if (err == -ENOENT)
> -                       ntfs_error(vol->sb, "Quota defaults entry is not present.");
> -               else
> -                       ntfs_error(vol->sb, "Lookup of quota defaults entry failed.");
> -               goto err_out;
> -       }
> -       if (ictx->data_len < offsetof(struct quota_control_entry, sid)) {
> -               ntfs_error(vol->sb, "Quota defaults entry size is invalid.  Run chkdsk.");
> -               goto err_out;
> -       }
> -       qce = (struct quota_control_entry *)ictx->data;
> -       if (le32_to_cpu(qce->version) != QUOTA_VERSION) {
> -               ntfs_error(vol->sb,
> -                       "Quota defaults entry version 0x%x is not supported.",
> -                       le32_to_cpu(qce->version));
> -               goto err_out;
> -       }
> -       ntfs_debug("Quota defaults flags = 0x%x.", le32_to_cpu(qce->flags));
> -       /* If quotas are already marked out of date, no need to do anything. */
> -       if (qce->flags & QUOTA_FLAG_OUT_OF_DATE)
> -               goto set_done;
> -       /*
> -        * If quota tracking is neither requested, nor enabled and there are no
> -        * pending deletes, no need to mark the quotas out of date.
> -        */
> -       if (!(qce->flags & (QUOTA_FLAG_TRACKING_ENABLED |
> -                       QUOTA_FLAG_TRACKING_REQUESTED |
> -                       QUOTA_FLAG_PENDING_DELETES)))
> -               goto set_done;
> -       /*
> -        * Set the QUOTA_FLAG_OUT_OF_DATE bit thus marking quotas out of date.
> -        * This is verified on WinXP to be sufficient to cause windows to
> -        * rescan the volume on boot and update all quota entries.
> -        */
> -       qce->flags |= QUOTA_FLAG_OUT_OF_DATE;
> -       /* Ensure the modified flags are written to disk. */
> -       ntfs_index_entry_mark_dirty(ictx);
> -set_done:
> -       ntfs_index_ctx_put(ictx);
> -       inode_unlock(vol->quota_q_ino);
> -       /*
> -        * We set the flag so we do not try to mark the quotas out of date
> -        * again on remount.
> -        */
> -       NVolSetQuotaOutOfDate(vol);
> -done:
> -       ntfs_debug("Done.");
> -       return true;
> -err_out:
> -       if (ictx)
> -               ntfs_index_ctx_put(ictx);
> -       inode_unlock(vol->quota_q_ino);
> -       return false;
> -}
> diff --git a/fs/ntfs/quota.h b/fs/ntfs/quota.h
> deleted file mode 100644
> index 4b7322661a32..000000000000
> --- a/fs/ntfs/quota.h
> +++ /dev/null
> @@ -1,15 +0,0 @@
> -/* SPDX-License-Identifier: GPL-2.0-or-later */
> -/*
> - * Defines for NTFS kernel quota ($Quota) handling.
> - *
> - * Copyright (c) 2004 Anton Altaparmakov
> - */
> -
> -#ifndef _LINUX_NTFS_QUOTA_H
> -#define _LINUX_NTFS_QUOTA_H
> -
> -#include "volume.h"
> -
> -bool ntfs_mark_quotas_out_of_date(struct ntfs_volume *vol);
> -
> -#endif /* _LINUX_NTFS_QUOTA_H */
> diff --git a/fs/ntfs/super.c b/fs/ntfs/super.c
> index 22dc7865eca7..a518dd1802f3 100644
> --- a/fs/ntfs/super.c
> +++ b/fs/ntfs/super.c
> @@ -17,7 +17,6 @@
>
>  #include "sysctl.h"
>  #include "logfile.h"
> -#include "quota.h"
>  #include "index.h"
>  #include "ntfs.h"
>  #include "ea.h"
> @@ -240,8 +239,7 @@ static int ntfs_reconfigure(struct fs_context *fc)
>          * flags are set.  Also, empty the logfile journal as it would become
>          * stale as soon as something is written to the volume and mark the
>          * volume dirty so that chkdsk is run if the volume is not umounted
> -        * cleanly.  Finally, mark the quotas out of date so Windows rescans
> -        * the volume on boot and updates them.
> +        * cleanly.
>          *
>          * When remounting read-only, mark the volume clean if no volume errors
>          * have occurred.
> @@ -274,12 +272,6 @@ static int ntfs_reconfigure(struct fs_context *fc)
>                         NVolSetErrors(vol);
>                         return -EROFS;
>                 }
> -               if (!ntfs_mark_quotas_out_of_date(vol)) {
> -                       ntfs_error(sb, "Failed to mark quotas out of date%s",
> -                                       es);
> -                       NVolSetErrors(vol);
> -                       return -EROFS;
> -               }
>         } else if (!sb_rdonly(sb) && (fc->sb_flags & SB_RDONLY)) {
>                 /* Remounting read-only. */
>                 if (!NVolErrors(vol)) {
> @@ -1154,73 +1146,6 @@ static int check_windows_hibernation_status(struct ntfs_volume *vol)
>         return ret;
>  }
>
> -/*
> - * load_and_init_quota - load and setup the quota file for a volume if present
> - * @vol:       ntfs super block describing device whose quota file to load
> - *
> - * Return 'true' on success or 'false' on error.  If $Quota is not present, we
> - * leave vol->quota_ino as NULL and return success.
> - */
> -static bool load_and_init_quota(struct ntfs_volume *vol)
> -{
> -       static const __le16 Quota[7] = { cpu_to_le16('$'),
> -                       cpu_to_le16('Q'), cpu_to_le16('u'),
> -                       cpu_to_le16('o'), cpu_to_le16('t'),
> -                       cpu_to_le16('a'), 0 };
> -       static __le16 Q[3] = { cpu_to_le16('$'),
> -                       cpu_to_le16('Q'), 0 };
> -       struct ntfs_name *name = NULL;
> -       u64 mref;
> -       struct inode *tmp_ino;
> -
> -       ntfs_debug("Entering.");
> -       /*
> -        * Find the inode number for the quota file by looking up the filename
> -        * $Quota in the extended system files directory $Extend.
> -        */
> -       inode_lock(vol->extend_ino);
> -       mref = ntfs_lookup_inode_by_name(NTFS_I(vol->extend_ino), Quota, 6,
> -                       &name);
> -       inode_unlock(vol->extend_ino);
> -       kfree(name);
> -       if (IS_ERR_MREF(mref)) {
> -               /*
> -                * If the file does not exist, quotas are disabled and have
> -                * never been enabled on this volume, just return success.
> -                */
> -               if (MREF_ERR(mref) == -ENOENT) {
> -                       ntfs_debug("$Quota not present.  Volume does not have quotas enabled.");
> -                       /*
> -                        * No need to try to set quotas out of date if they are
> -                        * not enabled.
> -                        */
> -                       NVolSetQuotaOutOfDate(vol);
> -                       return true;
> -               }
> -               /* A real error occurred. */
> -               ntfs_error(vol->sb, "Failed to find inode number for $Quota.");
> -               return false;
> -       }
> -       /* Get the inode. */
> -       tmp_ino = ntfs_iget(vol->sb, MREF(mref));
> -       if (IS_ERR(tmp_ino)) {
> -               if (!IS_ERR(tmp_ino))
> -                       iput(tmp_ino);
> -               ntfs_error(vol->sb, "Failed to load $Quota.");
> -               return false;
> -       }
> -       vol->quota_ino = tmp_ino;
> -       /* Get the $Q index allocation attribute. */
> -       tmp_ino = ntfs_index_iget(vol->quota_ino, Q, 2);
> -       if (IS_ERR(tmp_ino)) {
> -               ntfs_error(vol->sb, "Failed to load $Quota/$Q index.");
> -               return false;
> -       }
> -       vol->quota_q_ino = tmp_ino;
> -       ntfs_debug("Done.");
> -       return true;
> -}
> -
>  /*
>   * load_and_init_attrdef - load the attribute definitions table for a volume
>   * @vol:       ntfs super block describing device whose attrdef to load
> @@ -1638,18 +1563,6 @@ static bool load_system_files(struct ntfs_volume *vol)
>                 ntfs_error(sb, "Failed to load $Extend.");
>                 goto iput_sec_err_out;
>         }
> -       /* Find the quota file, load it if present, and set it up. */
> -       if (!load_and_init_quota(vol) &&
> -           vol->on_errors == ON_ERRORS_REMOUNT_RO) {
> -               static const char *es1 = "Failed to load $Quota";
> -               static const char *es2 = ".  Run chkdsk.";
> -
> -               sb->s_flags |= SB_RDONLY;
> -               ntfs_error(sb, "%s.  Mounting read-only%s", es1, es2);
> -               /* This will prevent a read-write remount. */
> -               NVolSetErrors(vol);
> -       }
> -
>         return true;
>
>  iput_sec_err_out:
> @@ -1747,10 +1660,6 @@ static void ntfs_put_super(struct super_block *sb)
>
>         /* NTFS 3.0+ specific. */
>         if (vol->major_ver >= 3) {
> -               if (vol->quota_q_ino)
> -                       ntfs_commit_inode(vol->quota_q_ino);
> -               if (vol->quota_ino)
> -                       ntfs_commit_inode(vol->quota_ino);
>                 if (vol->extend_ino)
>                         ntfs_commit_inode(vol->extend_ino);
>                 if (vol->secure_ino)
> @@ -1799,14 +1708,6 @@ static void ntfs_put_super(struct super_block *sb)
>
>         /* NTFS 3.0+ specific clean up. */
>         if (vol->major_ver >= 3) {
> -               if (vol->quota_q_ino) {
> -                       iput(vol->quota_q_ino);
> -                       vol->quota_q_ino = NULL;
> -               }
> -               if (vol->quota_ino) {
> -                       iput(vol->quota_ino);
> -                       vol->quota_ino = NULL;
> -               }
>                 if (vol->extend_ino) {
>                         iput(vol->extend_ino);
>                         vol->extend_ino = NULL;
> @@ -2455,14 +2356,6 @@ static int ntfs_fill_super(struct super_block *sb, struct fs_context *fc)
>         vol->vol_ino = NULL;
>         /* NTFS 3.0+ specific clean up. */
>         if (vol->major_ver >= 3) {
> -               if (vol->quota_q_ino) {
> -                       iput(vol->quota_q_ino);
> -                       vol->quota_q_ino = NULL;
> -               }
> -               if (vol->quota_ino) {
> -                       iput(vol->quota_ino);
> -                       vol->quota_ino = NULL;
> -               }
>                 if (vol->extend_ino) {
>                         iput(vol->extend_ino);
>                         vol->extend_ino = NULL;
> diff --git a/fs/ntfs/volume.h b/fs/ntfs/volume.h
> index af41427ec622..e13e1423b2a9 100644
> --- a/fs/ntfs/volume.h
> +++ b/fs/ntfs/volume.h
> @@ -76,8 +76,6 @@
>   * @root_ino: The VFS inode of the root directory.
>   * @secure_ino: The VFS inode of $Secure (NTFS3.0+ only, otherwise NULL).
>   * @extend_ino: The VFS inode of $Extend (NTFS3.0+ only, otherwise NULL).
> - * @quota_ino: The VFS inode of $Quota.
> - * @quota_q_ino: Attribute inode for $Quota/$Q.
>   * @nls_map: NLS (National Language Support) table.
>   * @nls_utf8: NLS table for UTF-8.
>   * @free_waitq: Wait queue for threads waiting for free clusters or MFT records.
> @@ -141,8 +139,6 @@ struct ntfs_volume {
>         struct inode *root_ino;
>         struct inode *secure_ino;
>         struct inode *extend_ino;
> -       struct inode *quota_ino;
> -       struct inode *quota_q_ino;
>         struct nls_table *nls_map;
>         bool nls_utf8;
>         wait_queue_head_t free_waitq;
> @@ -165,7 +161,6 @@ struct ntfs_volume {
>   *                             Otherwise be case insensitive but still
>   *                             create file names in POSIX namespace.
>   * NV_LogFileEmpty             LogFile journal is empty.
> - * NV_QuotaOutOfDate           Quota is out of date.
>   * NV_UsnJrnlStamped           UsnJrnl has been stamped.
>   * NV_ReadOnly                 Volume is mounted read-only.
>   * NV_Compression              Volume supports compression.
> @@ -186,7 +181,6 @@ enum {
>         NV_ShowSystemFiles,
>         NV_CaseSensitive,
>         NV_LogFileEmpty,
> -       NV_QuotaOutOfDate,
>         NV_UsnJrnlStamped,
>         NV_ReadOnly,
>         NV_Compression,
> @@ -223,7 +217,6 @@ DEFINE_NVOL_BIT_OPS(Errors)
>  DEFINE_NVOL_BIT_OPS(ShowSystemFiles)
>  DEFINE_NVOL_BIT_OPS(CaseSensitive)
>  DEFINE_NVOL_BIT_OPS(LogFileEmpty)
> -DEFINE_NVOL_BIT_OPS(QuotaOutOfDate)
>  DEFINE_NVOL_BIT_OPS(UsnJrnlStamped)
>  DEFINE_NVOL_BIT_OPS(ReadOnly)
>  DEFINE_NVOL_BIT_OPS(Compression)
>
> base-commit: 5d6919055dec134de3c40167a490f33c74c12581
> --
> 2.43.0
>


-- 
Thanks,
Hyunchul