From 102a0743326a03cd1a1202ceda21e175b7d3575c Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Tue, 20 Feb 2024 01:20:52 +0000
Subject: [PATCH] add new system file
---
kernel/mm/shmem.c | 61 +++++++++++++++++++-----------
1 files changed, 39 insertions(+), 22 deletions(-)
diff --git a/kernel/mm/shmem.c b/kernel/mm/shmem.c
index 682a3e9..b812f26 100644
--- a/kernel/mm/shmem.c
+++ b/kernel/mm/shmem.c
@@ -285,10 +285,10 @@
ino_t ino;
if (!(sb->s_flags & SB_KERNMOUNT)) {
- raw_spin_lock(&sbinfo->stat_lock);
+ spin_lock(&sbinfo->stat_lock);
if (sbinfo->max_inodes) {
if (!sbinfo->free_inodes) {
- raw_spin_unlock(&sbinfo->stat_lock);
+ spin_unlock(&sbinfo->stat_lock);
return -ENOSPC;
}
sbinfo->free_inodes--;
@@ -311,7 +311,7 @@
}
*inop = ino;
}
- raw_spin_unlock(&sbinfo->stat_lock);
+ spin_unlock(&sbinfo->stat_lock);
} else if (inop) {
/*
* __shmem_file_setup, one of our callers, is lock-free: it
@@ -326,14 +326,13 @@
* to worry about things like glibc compatibility.
*/
ino_t *next_ino;
-
next_ino = per_cpu_ptr(sbinfo->ino_batch, get_cpu());
ino = *next_ino;
if (unlikely(ino % SHMEM_INO_BATCH == 0)) {
- raw_spin_lock(&sbinfo->stat_lock);
+ spin_lock(&sbinfo->stat_lock);
ino = sbinfo->next_ino;
sbinfo->next_ino += SHMEM_INO_BATCH;
- raw_spin_unlock(&sbinfo->stat_lock);
+ spin_unlock(&sbinfo->stat_lock);
if (unlikely(is_zero_ino(ino)))
ino++;
}
@@ -349,9 +348,9 @@
{
struct shmem_sb_info *sbinfo = SHMEM_SB(sb);
if (sbinfo->max_inodes) {
- raw_spin_lock(&sbinfo->stat_lock);
+ spin_lock(&sbinfo->stat_lock);
sbinfo->free_inodes++;
- raw_spin_unlock(&sbinfo->stat_lock);
+ spin_unlock(&sbinfo->stat_lock);
}
}
@@ -1493,10 +1492,10 @@
{
struct mempolicy *mpol = NULL;
if (sbinfo->mpol) {
- raw_spin_lock(&sbinfo->stat_lock); /* prevent replace/use races */
+ spin_lock(&sbinfo->stat_lock); /* prevent replace/use races */
mpol = sbinfo->mpol;
mpol_get(mpol);
- raw_spin_unlock(&sbinfo->stat_lock);
+ spin_unlock(&sbinfo->stat_lock);
}
return mpol;
}
@@ -3425,6 +3424,8 @@
unsigned long long size;
char *rest;
int opt;
+ kuid_t kuid;
+ kgid_t kgid;
opt = fs_parse(fc, shmem_fs_parameters, param, &result);
if (opt < 0)
@@ -3460,14 +3461,32 @@
ctx->mode = result.uint_32 & 07777;
break;
case Opt_uid:
- ctx->uid = make_kuid(current_user_ns(), result.uint_32);
- if (!uid_valid(ctx->uid))
+ kuid = make_kuid(current_user_ns(), result.uint_32);
+ if (!uid_valid(kuid))
goto bad_value;
+
+ /*
+ * The requested uid must be representable in the
+ * filesystem's idmapping.
+ */
+ if (!kuid_has_mapping(fc->user_ns, kuid))
+ goto bad_value;
+
+ ctx->uid = kuid;
break;
case Opt_gid:
- ctx->gid = make_kgid(current_user_ns(), result.uint_32);
- if (!gid_valid(ctx->gid))
+ kgid = make_kgid(current_user_ns(), result.uint_32);
+ if (!gid_valid(kgid))
goto bad_value;
+
+ /*
+ * The requested gid must be representable in the
+ * filesystem's idmapping.
+ */
+ if (!kgid_has_mapping(fc->user_ns, kgid))
+ goto bad_value;
+
+ ctx->gid = kgid;
break;
case Opt_huge:
ctx->huge = result.uint_32;
@@ -3563,10 +3582,9 @@
struct shmem_options *ctx = fc->fs_private;
struct shmem_sb_info *sbinfo = SHMEM_SB(fc->root->d_sb);
unsigned long inodes;
- struct mempolicy *mpol = NULL;
const char *err;
- raw_spin_lock(&sbinfo->stat_lock);
+ spin_lock(&sbinfo->stat_lock);
inodes = sbinfo->max_inodes - sbinfo->free_inodes;
if ((ctx->seen & SHMEM_SEEN_BLOCKS) && ctx->blocks) {
if (!sbinfo->max_blocks) {
@@ -3611,15 +3629,14 @@
* Preserve previous mempolicy unless mpol remount option was specified.
*/
if (ctx->mpol) {
- mpol = sbinfo->mpol;
+ mpol_put(sbinfo->mpol);
sbinfo->mpol = ctx->mpol; /* transfers initial ref */
ctx->mpol = NULL;
}
- raw_spin_unlock(&sbinfo->stat_lock);
- mpol_put(mpol);
+ spin_unlock(&sbinfo->stat_lock);
return 0;
out:
- raw_spin_unlock(&sbinfo->stat_lock);
+ spin_unlock(&sbinfo->stat_lock);
return invalfc(fc, "%s", err);
}
@@ -3736,7 +3753,7 @@
sbinfo->mpol = ctx->mpol;
ctx->mpol = NULL;
- raw_spin_lock_init(&sbinfo->stat_lock);
+ spin_lock_init(&sbinfo->stat_lock);
if (percpu_counter_init(&sbinfo->used_blocks, 0, GFP_KERNEL))
goto failed;
spin_lock_init(&sbinfo->shrinklist_lock);
@@ -4103,7 +4120,7 @@
.name = "tmpfs",
.init_fs_context = ramfs_init_fs_context,
.parameters = ramfs_fs_parameters,
- .kill_sb = kill_litter_super,
+ .kill_sb = ramfs_kill_sb,
.fs_flags = FS_USERNS_MOUNT,
};
--
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