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SPDX-License-Identifier: GPL-2.0
diff --git a/include/linux/shmem_fs.h b/include/linux/shmem_fs.h
--- a/include/linux/shmem_fs.h
+++ b/include/linux/shmem_fs.h
@@ -27,10 +27,13 @@ struct shmem_inode_info {
};
struct shmem_sb_info {
+ struct mutex idr_lock;
+ bool idr_nouse;
+ struct idr idr; /* manages inode-number */
unsigned long max_blocks; /* How many blocks are allowed */
struct percpu_counter used_blocks; /* How many are allocated */
- unsigned long max_inodes; /* How many inodes are allowed */
- unsigned long free_inodes; /* How many are left for allocation */
+ int max_inodes; /* How many inodes are allowed */
+ int free_inodes; /* How many are left for allocation */
spinlock_t stat_lock; /* Serialize shmem_sb_info changes */
umode_t mode; /* Mount mode for root directory */
unsigned char huge; /* Whether to try for hugepages */
diff --git a/mm/shmem.c b/mm/shmem.c
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -110,7 +110,7 @@ struct shmem_falloc {
struct shmem_options {
unsigned long long blocks;
- unsigned long long inodes;
+ int inodes;
struct mempolicy *mpol;
kuid_t uid;
kgid_t gid;
@@ -128,11 +128,14 @@ static unsigned long shmem_default_max_blocks(void)
return totalram_pages() / 2;
}
-static unsigned long shmem_default_max_inodes(void)
+static int shmem_default_max_inodes(void)
{
unsigned long nr_pages = totalram_pages();
+ unsigned long ul;
- return min(nr_pages - totalhigh_pages(), nr_pages / 2);
+ ul = INT_MAX;
+ ul = min3(ul, nr_pages - totalhigh_pages(), nr_pages / 2);
+ return ul;
}
#endif
@@ -1100,6 +1103,11 @@ static void shmem_evict_inode(struct inode *inode)
simple_xattrs_free(&info->xattrs);
WARN_ON(inode->i_blocks);
+ if (!sbinfo->idr_nouse && inode->i_ino) {
+ mutex_lock(&sbinfo->idr_lock);
+ idr_remove(&sbinfo->idr, inode->i_ino);
+ mutex_unlock(&sbinfo->idr_lock);
+ }
shmem_free_inode(inode->i_sb);
clear_inode(inode);
}
@@ -2240,13 +2248,13 @@ static struct inode *shmem_get_inode(struct super_block *sb, const struct inode
struct inode *inode;
struct shmem_inode_info *info;
struct shmem_sb_info *sbinfo = SHMEM_SB(sb);
+ int ino;
if (shmem_reserve_inode(sb))
return NULL;
inode = new_inode(sb);
if (inode) {
- inode->i_ino = get_next_ino();
inode_init_owner(inode, dir, mode);
inode->i_blocks = 0;
inode->i_atime = inode->i_mtime = inode->i_ctime = current_time(inode);
@@ -2290,6 +2298,25 @@ static struct inode *shmem_get_inode(struct super_block *sb, const struct inode
break;
}
+ if (!sbinfo->idr_nouse) {
+ /* inum 0 and 1 are unused */
+ mutex_lock(&sbinfo->idr_lock);
+ ino = idr_alloc(&sbinfo->idr, inode, 2, INT_MAX,
+ GFP_NOFS);
+ if (ino > 0) {
+ inode->i_ino = ino;
+ mutex_unlock(&sbinfo->idr_lock);
+ __insert_inode_hash(inode, inode->i_ino);
+ } else {
+ inode->i_ino = 0;
+ mutex_unlock(&sbinfo->idr_lock);
+ iput(inode);
+ /* shmem_free_inode() will be called */
+ inode = NULL;
+ }
+ } else
+ inode->i_ino = get_next_ino();
+
lockdep_annotate_inode_mutex_key(inode);
} else
shmem_free_inode(sb);
@@ -3292,8 +3319,7 @@ static struct dentry *shmem_get_parent(struct dentry *child)
static int shmem_match(struct inode *ino, void *vfh)
{
__u32 *fh = vfh;
- __u64 inum = fh[2];
- inum = (inum << 32) | fh[1];
+ __u64 inum = fh[1];
return ino->i_ino == inum && fh[0] == ino->i_generation;
}
@@ -3313,14 +3339,11 @@ static struct dentry *shmem_fh_to_dentry(struct super_block *sb,
struct dentry *dentry = NULL;
u64 inum;
- if (fh_len < 3)
+ if (fh_len < 2)
return NULL;
- inum = fid->raw[2];
- inum = (inum << 32) | fid->raw[1];
-
- inode = ilookup5(sb, (unsigned long)(inum + fid->raw[0]),
- shmem_match, fid->raw);
+ inum = fid->raw[1];
+ inode = ilookup5(sb, inum, shmem_match, fid->raw);
if (inode) {
dentry = shmem_find_alias(inode);
iput(inode);
@@ -3332,30 +3355,15 @@ static struct dentry *shmem_fh_to_dentry(struct super_block *sb,
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static int shmem_encode_fh(struct inode *inode, __u32 *fh, int *len,
struct inode *parent)
{
- if (*len < 3) {
- *len = 3;
+ if (*len < 2) {
+ *len = 2;
return FILEID_INVALID;
}
- if (inode_unhashed(inode)) {
- /* Unfortunately insert_inode_hash is not idempotent,
- * so as we hash inodes here rather than at creation
- * time, we need a lock to ensure we only try
- * to do it once
- */
- static DEFINE_SPINLOCK(lock);
- spin_lock(&lock);
- if (inode_unhashed(inode))
- __insert_inode_hash(inode,
- inode->i_ino + inode->i_generation);
- spin_unlock(&lock);
- }
-
fh[0] = inode->i_generation;
fh[1] = inode->i_ino;
- fh[2] = ((__u64)inode->i_ino) >> 32;
- *len = 3;
+ *len = 2;
return 1;
}
@@ -3430,7 +3438,7 @@ static int shmem_parse_one(struct fs_context *fc, struct fs_parameter *param)
break;
case Opt_nr_inodes:
ctx->inodes = memparse(param->string, &rest);
- if (*rest)
+ if (*rest || ctx->inodes < 2)
goto bad_value;
ctx->seen |= SHMEM_SEEN_INODES;
break;
@@ -3528,7 +3536,7 @@ static int shmem_reconfigure(struct fs_context *fc)
{
struct shmem_options *ctx = fc->fs_private;
struct shmem_sb_info *sbinfo = SHMEM_SB(fc->root->d_sb);
- unsigned long inodes;
+ int inodes;
const char *err;
spin_lock(&sbinfo->stat_lock);
@@ -3587,7 +3595,7 @@ static int shmem_show_options(struct seq_file *seq, struct dentry *root)
seq_printf(seq, ",size=%luk",
sbinfo->max_blocks << (PAGE_SHIFT - 10));
if (sbinfo->max_inodes != shmem_default_max_inodes())
- seq_printf(seq, ",nr_inodes=%lu", sbinfo->max_inodes);
+ seq_printf(seq, ",nr_inodes=%d", sbinfo->max_inodes);
if (sbinfo->mode != (0777 | S_ISVTX))
seq_printf(seq, ",mode=%03ho", sbinfo->mode);
if (!uid_eq(sbinfo->uid, GLOBAL_ROOT_UID))
@@ -3611,6 +3619,8 @@ static void shmem_put_super(struct super_block *sb)
{
struct shmem_sb_info *sbinfo = SHMEM_SB(sb);
+ if (!sbinfo->idr_nouse)
+ idr_destroy(&sbinfo->idr);
percpu_counter_destroy(&sbinfo->used_blocks);
mpol_put(sbinfo->mpol);
kfree(sbinfo);
@@ -3651,6 +3661,8 @@ static int shmem_fill_super(struct super_block *sb, struct fs_context *fc)
#else
sb->s_flags |= SB_NOUSER;
#endif
+ mutex_init(&sbinfo->idr_lock);
+ idr_init(&sbinfo->idr);
sbinfo->max_blocks = ctx->blocks;
sbinfo->free_inodes = sbinfo->max_inodes = ctx->inodes;
sbinfo->uid = ctx->uid;
@@ -3762,6 +3774,15 @@ static void shmem_destroy_inodecache(void)
kmem_cache_destroy(shmem_inode_cachep);
}
+static __init void shmem_no_idr(struct super_block *sb)
+{
+ struct shmem_sb_info *sbinfo;
+
+ sbinfo = SHMEM_SB(sb);
+ sbinfo->idr_nouse = true;
+ idr_destroy(&sbinfo->idr);
+}
+
static const struct address_space_operations shmem_aops = {
.writepage = shmem_writepage,
.set_page_dirty = __set_page_dirty_no_writeback,
pr_err("Could not kern_mount tmpfs\n");
goto out1;
}
+ shmem_no_idr(shm_mnt->mnt_sb);
if (has_transparent_hugepage() && shmem_huge > SHMEM_HUGE_DENY)