quota: Switch ->get_dqblk() and ->set_dqblk() to use bytes as space units

Currently ->get_dqblk() and ->set_dqblk() use struct fs_disk_quota which
tracks space limits and usage in 512-byte blocks. However VFS quotas
track usage in bytes (as some filesystems require that) and we need to
somehow pass this information. Upto now it wasn't a problem because we
didn't do any unit conversion (thus VFS quota routines happily stuck
number of bytes into d_bcount field of struct fd_disk_quota). Only if
you tried to use Q_XGETQUOTA or Q_XSETQLIM for VFS quotas (or Q_GETQUOTA
/ Q_SETQUOTA for XFS quotas), you got bogus results. Hardly anyone
tried this but reportedly some Samba users hit the problem in practice.
So when we want interfaces compatible we need to fix this.

We bite the bullet and define another quota structure used for passing
information from/to ->get_dqblk()/->set_dqblk. It's somewhat sad we have
to have more conversion routines in fs/quota/quota.c and another copying
of quota structure slows down getting of quota information by about 2%
but it seems cleaner than overloading e.g. units of d_bcount to bytes.

CC: stable@vger.kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>

1 files changed, 39 insertions, 44 deletions

diff --git a/fs/quota/dquot.c b/fs/quota/dquot.c
index 8f0acef3d184..69df5b239844 100644
--- a/fs/quota/dquot.c
+++ b/fs/quota/dquot.c
@@ -2396,30 +2396,25 @@ static inline qsize_t stoqb(qsize_t space)
 }
 
 /* Generic routine for getting common part of quota structure */
-static void do_get_dqblk(struct dquot *dquot, struct fs_disk_quota *di)
+static void do_get_dqblk(struct dquot *dquot, struct qc_dqblk *di)
 {
         struct mem_dqblk *dm = &dquot->dq_dqb;
 
         memset(di, 0, sizeof(*di));
-        di->d_version = FS_DQUOT_VERSION;
-        di->d_flags = dquot->dq_id.type == USRQUOTA ?
-                        FS_USER_QUOTA : FS_GROUP_QUOTA;
-        di->d_id = from_kqid_munged(current_user_ns(), dquot->dq_id);
-
         spin_lock(&dq_data_lock);
-        di->d_blk_hardlimit = stoqb(dm->dqb_bhardlimit);
-        di->d_blk_softlimit = stoqb(dm->dqb_bsoftlimit);
+        di->d_spc_hardlimit = dm->dqb_bhardlimit;
+        di->d_spc_softlimit = dm->dqb_bsoftlimit;
         di->d_ino_hardlimit = dm->dqb_ihardlimit;
         di->d_ino_softlimit = dm->dqb_isoftlimit;
-        di->d_bcount = dm->dqb_curspace + dm->dqb_rsvspace;
-        di->d_icount = dm->dqb_curinodes;
-        di->d_btimer = dm->dqb_btime;
-        di->d_itimer = dm->dqb_itime;
+        di->d_space = dm->dqb_curspace + dm->dqb_rsvspace;
+        di->d_ino_count = dm->dqb_curinodes;
+        di->d_spc_timer = dm->dqb_btime;
+        di->d_ino_timer = dm->dqb_itime;
         spin_unlock(&dq_data_lock);
 }
 
 int dquot_get_dqblk(struct super_block *sb, struct kqid qid,
-                    struct fs_disk_quota *di)
+                    struct qc_dqblk *di)
 {
         struct dquot *dquot;
 
@@ -2433,70 +2428,70 @@ int dquot_get_dqblk(struct super_block *sb, struct kqid qid,
 }
 EXPORT_SYMBOL(dquot_get_dqblk);
 
-#define VFS_FS_DQ_MASK \
-        (FS_DQ_BCOUNT | FS_DQ_BSOFT | FS_DQ_BHARD | \
-         FS_DQ_ICOUNT | FS_DQ_ISOFT | FS_DQ_IHARD | \
-         FS_DQ_BTIMER | FS_DQ_ITIMER)
+#define VFS_QC_MASK \
+        (QC_SPACE | QC_SPC_SOFT | QC_SPC_HARD | \
+         QC_INO_COUNT | QC_INO_SOFT | QC_INO_HARD | \
+         QC_SPC_TIMER | QC_INO_TIMER)
 
 /* Generic routine for setting common part of quota structure */
-static int do_set_dqblk(struct dquot *dquot, struct fs_disk_quota *di)
+static int do_set_dqblk(struct dquot *dquot, struct qc_dqblk *di)
 {
         struct mem_dqblk *dm = &dquot->dq_dqb;
         int check_blim = 0, check_ilim = 0;
         struct mem_dqinfo *dqi = &sb_dqopt(dquot->dq_sb)->info[dquot->dq_id.type];
 
-        if (di->d_fieldmask & ~VFS_FS_DQ_MASK)
+        if (di->d_fieldmask & ~VFS_QC_MASK)
                 return -EINVAL;
 
-        if (((di->d_fieldmask & FS_DQ_BSOFT) &&
-             (di->d_blk_softlimit > dqi->dqi_maxblimit)) ||
-            ((di->d_fieldmask & FS_DQ_BHARD) &&
-             (di->d_blk_hardlimit > dqi->dqi_maxblimit)) ||
-            ((di->d_fieldmask & FS_DQ_ISOFT) &&
+        if (((di->d_fieldmask & QC_SPC_SOFT) &&
+             stoqb(di->d_spc_softlimit) > dqi->dqi_maxblimit) ||
+            ((di->d_fieldmask & QC_SPC_HARD) &&
+             stoqb(di->d_spc_hardlimit) > dqi->dqi_maxblimit) ||
+            ((di->d_fieldmask & QC_INO_SOFT) &&
              (di->d_ino_softlimit > dqi->dqi_maxilimit)) ||
-            ((di->d_fieldmask & FS_DQ_IHARD) &&
+            ((di->d_fieldmask & QC_INO_HARD) &&
              (di->d_ino_hardlimit > dqi->dqi_maxilimit)))
                 return -ERANGE;
 
         spin_lock(&dq_data_lock);
-        if (di->d_fieldmask & FS_DQ_BCOUNT) {
-                dm->dqb_curspace = di->d_bcount - dm->dqb_rsvspace;
+        if (di->d_fieldmask & QC_SPACE) {
+                dm->dqb_curspace = di->d_space - dm->dqb_rsvspace;
                 check_blim = 1;
                 set_bit(DQ_LASTSET_B + QIF_SPACE_B, &dquot->dq_flags);
         }
 
-        if (di->d_fieldmask & FS_DQ_BSOFT)
-                dm->dqb_bsoftlimit = qbtos(di->d_blk_softlimit);
-        if (di->d_fieldmask & FS_DQ_BHARD)
-                dm->dqb_bhardlimit = qbtos(di->d_blk_hardlimit);
-        if (di->d_fieldmask & (FS_DQ_BSOFT | FS_DQ_BHARD)) {
+        if (di->d_fieldmask & QC_SPC_SOFT)
+                dm->dqb_bsoftlimit = di->d_spc_softlimit;
+        if (di->d_fieldmask & QC_SPC_HARD)
+                dm->dqb_bhardlimit = di->d_spc_hardlimit;
+        if (di->d_fieldmask & (QC_SPC_SOFT | QC_SPC_HARD)) {
                 check_blim = 1;
                 set_bit(DQ_LASTSET_B + QIF_BLIMITS_B, &dquot->dq_flags);
         }
 
-        if (di->d_fieldmask & FS_DQ_ICOUNT) {
-                dm->dqb_curinodes = di->d_icount;
+        if (di->d_fieldmask & QC_INO_COUNT) {
+                dm->dqb_curinodes = di->d_ino_count;
                 check_ilim = 1;
                 set_bit(DQ_LASTSET_B + QIF_INODES_B, &dquot->dq_flags);
         }
 
-        if (di->d_fieldmask & FS_DQ_ISOFT)
+        if (di->d_fieldmask & QC_INO_SOFT)
                 dm->dqb_isoftlimit = di->d_ino_softlimit;
-        if (di->d_fieldmask & FS_DQ_IHARD)
+        if (di->d_fieldmask & QC_INO_HARD)
                 dm->dqb_ihardlimit = di->d_ino_hardlimit;
-        if (di->d_fieldmask & (FS_DQ_ISOFT | FS_DQ_IHARD)) {
+        if (di->d_fieldmask & (QC_INO_SOFT | QC_INO_HARD)) {
                 check_ilim = 1;
                 set_bit(DQ_LASTSET_B + QIF_ILIMITS_B, &dquot->dq_flags);
         }
 
-        if (di->d_fieldmask & FS_DQ_BTIMER) {
-                dm->dqb_btime = di->d_btimer;
+        if (di->d_fieldmask & QC_SPC_TIMER) {
+                dm->dqb_btime = di->d_spc_timer;
                 check_blim = 1;
                 set_bit(DQ_LASTSET_B + QIF_BTIME_B, &dquot->dq_flags);
         }
 
-        if (di->d_fieldmask & FS_DQ_ITIMER) {
-                dm->dqb_itime = di->d_itimer;
+        if (di->d_fieldmask & QC_INO_TIMER) {
+                dm->dqb_itime = di->d_ino_timer;
                 check_ilim = 1;
                 set_bit(DQ_LASTSET_B + QIF_ITIME_B, &dquot->dq_flags);
         }
@@ -2506,7 +2501,7 @@ static int do_set_dqblk(struct dquot *dquot, struct fs_disk_quota *di)
                     dm->dqb_curspace < dm->dqb_bsoftlimit) {
                         dm->dqb_btime = 0;
                         clear_bit(DQ_BLKS_B, &dquot->dq_flags);
-                } else if (!(di->d_fieldmask & FS_DQ_BTIMER))
+                } else if (!(di->d_fieldmask & QC_SPC_TIMER))
                         /* Set grace only if user hasn't provided his own... */
                         dm->dqb_btime = get_seconds() + dqi->dqi_bgrace;
         }
@@ -2515,7 +2510,7 @@ static int do_set_dqblk(struct dquot *dquot, struct fs_disk_quota *di)
                     dm->dqb_curinodes < dm->dqb_isoftlimit) {
                         dm->dqb_itime = 0;
                         clear_bit(DQ_INODES_B, &dquot->dq_flags);
-                } else if (!(di->d_fieldmask & FS_DQ_ITIMER))
+                } else if (!(di->d_fieldmask & QC_INO_TIMER))
                         /* Set grace only if user hasn't provided his own... */
                         dm->dqb_itime = get_seconds() + dqi->dqi_igrace;
         }
@@ -2531,7 +2526,7 @@ static int do_set_dqblk(struct dquot *dquot, struct fs_disk_quota *di)
 }
 
 int dquot_set_dqblk(struct super_block *sb, struct kqid qid,
-                  struct fs_disk_quota *di)
+                  struct qc_dqblk *di)
 {
         struct dquot *dquot;
         int rc;