[RFC] killing boilerplate checks in ->link/->mkdir/->rename

From: Al Viro
Date: Thu Feb 02 2012 - 16:24:20 EST


> Linux implementation of link(2) had exactly the same bug as that of v7 until
> 0.98.3 (for link(2)) and 0.99.1 (for mkdir(2), rename(2) - didn't exist as
> syscalls on v7, but had the same problem as soon as they made it in kernel
> at some point in BSD history). Note that limit for minixfs remained
> ridiculously low until '97 or so; for ext2 it was 32000 from the very
> beginning but note that e.g. ext had _not_ acquired fixes for link overflows
> on mkdir() at all - it had that hole all the way until removal in 2.1.26.
> Of course, there was a (completely useless) POSIX-mandated LINK_MAX, but
> since the actual limit depends on fs type, well... the checks remain
> in ->link()/->mkdir()/->rename() instances and IIRC I've caught a bunch of
> overflows in those circa 2.1.very_late.

FWIW, there's something we really should've done a long time ago: putting
that limit into sb->s_max_links. With 0 meaning "leave all checks to
->link/->mkdir/->rename". Something like the following would make a
reasonable start - just the conversion of obvious cases. As the next
step I'd probably initialize it as ~0U instead of 0 and let the filesystems
that want something trickier (reiserfs, ext4, gfs2, ocfs2) explicitly set
it to 0 in their foo_fill_super(). That would take care of a bunch of cases
where we forgot to do those checks (ubifs, hfsplus, jffs2, ramfs, etc.) and
it's probably a saner default anyway.

Comments? Boilerplate removal follows (22 files changed, 45 insertions(+),
120 deletions(-)), but it's *not* for immediate merge; it's really completely
untested.

diff --git a/fs/exofs/namei.c b/fs/exofs/namei.c
index 9dbf0c3..fc7161d 100644
--- a/fs/exofs/namei.c
+++ b/fs/exofs/namei.c
@@ -143,9 +143,6 @@ static int exofs_link(struct dentry *old_dentry, struct inode *dir,
{
struct inode *inode = old_dentry->d_inode;

- if (inode->i_nlink >= EXOFS_LINK_MAX)
- return -EMLINK;
-
inode->i_ctime = CURRENT_TIME;
inode_inc_link_count(inode);
ihold(inode);
@@ -156,10 +153,7 @@ static int exofs_link(struct dentry *old_dentry, struct inode *dir,
static int exofs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
{
struct inode *inode;
- int err = -EMLINK;
-
- if (dir->i_nlink >= EXOFS_LINK_MAX)
- goto out;
+ int err;

inode_inc_link_count(dir);

@@ -275,11 +269,6 @@ static int exofs_rename(struct inode *old_dir, struct dentry *old_dentry,
if (err)
goto out_dir;
} else {
- if (dir_de) {
- err = -EMLINK;
- if (new_dir->i_nlink >= EXOFS_LINK_MAX)
- goto out_dir;
- }
err = exofs_add_link(new_dentry, old_inode);
if (err)
goto out_dir;
diff --git a/fs/exofs/super.c b/fs/exofs/super.c
index d22cd16..6cafcad 100644
--- a/fs/exofs/super.c
+++ b/fs/exofs/super.c
@@ -754,6 +754,7 @@ static int exofs_fill_super(struct super_block *sb, void *data, int silent)
sb->s_blocksize = EXOFS_BLKSIZE;
sb->s_blocksize_bits = EXOFS_BLKSHIFT;
sb->s_maxbytes = MAX_LFS_FILESIZE;
+ sb->s_max_links = EXOFS_LINK_MAX;
atomic_set(&sbi->s_curr_pending, 0);
sb->s_bdev = NULL;
sb->s_dev = 0;
diff --git a/fs/ext2/namei.c b/fs/ext2/namei.c
index 0804198..dffb865 100644
--- a/fs/ext2/namei.c
+++ b/fs/ext2/namei.c
@@ -195,9 +195,6 @@ static int ext2_link (struct dentry * old_dentry, struct inode * dir,
struct inode *inode = old_dentry->d_inode;
int err;

- if (inode->i_nlink >= EXT2_LINK_MAX)
- return -EMLINK;
-
dquot_initialize(dir);

inode->i_ctime = CURRENT_TIME_SEC;
@@ -217,10 +214,7 @@ static int ext2_link (struct dentry * old_dentry, struct inode * dir,
static int ext2_mkdir(struct inode * dir, struct dentry * dentry, umode_t mode)
{
struct inode * inode;
- int err = -EMLINK;
-
- if (dir->i_nlink >= EXT2_LINK_MAX)
- goto out;
+ int err;

dquot_initialize(dir);

@@ -346,11 +340,6 @@ static int ext2_rename (struct inode * old_dir, struct dentry * old_dentry,
drop_nlink(new_inode);
inode_dec_link_count(new_inode);
} else {
- if (dir_de) {
- err = -EMLINK;
- if (new_dir->i_nlink >= EXT2_LINK_MAX)
- goto out_dir;
- }
err = ext2_add_link(new_dentry, old_inode);
if (err)
goto out_dir;
diff --git a/fs/ext2/super.c b/fs/ext2/super.c
index 0090595..9f6766a 100644
--- a/fs/ext2/super.c
+++ b/fs/ext2/super.c
@@ -919,6 +919,7 @@ static int ext2_fill_super(struct super_block *sb, void *data, int silent)
}

sb->s_maxbytes = ext2_max_size(sb->s_blocksize_bits);
+ sb->s_max_links = EXT2_LINK_MAX;

if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV) {
sbi->s_inode_size = EXT2_GOOD_OLD_INODE_SIZE;
diff --git a/fs/jfs/namei.c b/fs/jfs/namei.c
index 5f7c160..07c91ca 100644
--- a/fs/jfs/namei.c
+++ b/fs/jfs/namei.c
@@ -220,12 +220,6 @@ static int jfs_mkdir(struct inode *dip, struct dentry *dentry, umode_t mode)

dquot_initialize(dip);

- /* link count overflow on parent directory ? */
- if (dip->i_nlink == JFS_LINK_MAX) {
- rc = -EMLINK;
- goto out1;
- }
-
/*
* search parent directory for entry/freespace
* (dtSearch() returns parent directory page pinned)
@@ -806,9 +800,6 @@ static int jfs_link(struct dentry *old_dentry,
jfs_info("jfs_link: %s %s", old_dentry->d_name.name,
dentry->d_name.name);

- if (ip->i_nlink == JFS_LINK_MAX)
- return -EMLINK;
-
dquot_initialize(dir);

tid = txBegin(ip->i_sb, 0);
@@ -1138,10 +1129,6 @@ static int jfs_rename(struct inode *old_dir, struct dentry *old_dentry,
rc = -ENOTEMPTY;
goto out3;
}
- } else if ((new_dir != old_dir) &&
- (new_dir->i_nlink == JFS_LINK_MAX)) {
- rc = -EMLINK;
- goto out3;
}
} else if (new_ip) {
IWRITE_LOCK(new_ip, RDWRLOCK_NORMAL);
diff --git a/fs/jfs/super.c b/fs/jfs/super.c
index 682bca6..4661ad7 100644
--- a/fs/jfs/super.c
+++ b/fs/jfs/super.c
@@ -441,6 +441,7 @@ static int jfs_fill_super(struct super_block *sb, void *data, int silent)
return -ENOMEM;

sb->s_fs_info = sbi;
+ sb->s_max_links = JFS_LINK_MAX;
sbi->sb = sb;
sbi->uid = sbi->gid = sbi->umask = -1;

diff --git a/fs/logfs/dir.c b/fs/logfs/dir.c
index 3de7a32..4aea231 100644
--- a/fs/logfs/dir.c
+++ b/fs/logfs/dir.c
@@ -558,9 +558,6 @@ static int logfs_link(struct dentry *old_dentry, struct inode *dir,
{
struct inode *inode = old_dentry->d_inode;

- if (inode->i_nlink >= LOGFS_LINK_MAX)
- return -EMLINK;
-
inode->i_ctime = dir->i_ctime = dir->i_mtime = CURRENT_TIME;
ihold(inode);
inc_nlink(inode);
diff --git a/fs/logfs/super.c b/fs/logfs/super.c
index c9ee7f5..b1a491a 100644
--- a/fs/logfs/super.c
+++ b/fs/logfs/super.c
@@ -542,6 +542,7 @@ static struct dentry *logfs_get_sb_device(struct logfs_super *super,
* the filesystem incompatible with 32bit systems.
*/
sb->s_maxbytes = (1ull << 43) - 1;
+ sb->s_max_links = LOGFS_LINK_MAX;
sb->s_op = &logfs_super_operations;
sb->s_flags = flags | MS_NOATIME;

diff --git a/fs/minix/inode.c b/fs/minix/inode.c
index fa8b612..62c697c 100644
--- a/fs/minix/inode.c
+++ b/fs/minix/inode.c
@@ -190,24 +190,24 @@ static int minix_fill_super(struct super_block *s, void *data, int silent)
sbi->s_version = MINIX_V1;
sbi->s_dirsize = 16;
sbi->s_namelen = 14;
- sbi->s_link_max = MINIX_LINK_MAX;
+ s->s_max_links = MINIX_LINK_MAX;
} else if (s->s_magic == MINIX_SUPER_MAGIC2) {
sbi->s_version = MINIX_V1;
sbi->s_dirsize = 32;
sbi->s_namelen = 30;
- sbi->s_link_max = MINIX_LINK_MAX;
+ s->s_max_links = MINIX_LINK_MAX;
} else if (s->s_magic == MINIX2_SUPER_MAGIC) {
sbi->s_version = MINIX_V2;
sbi->s_nzones = ms->s_zones;
sbi->s_dirsize = 16;
sbi->s_namelen = 14;
- sbi->s_link_max = MINIX2_LINK_MAX;
+ s->s_max_links = MINIX2_LINK_MAX;
} else if (s->s_magic == MINIX2_SUPER_MAGIC2) {
sbi->s_version = MINIX_V2;
sbi->s_nzones = ms->s_zones;
sbi->s_dirsize = 32;
sbi->s_namelen = 30;
- sbi->s_link_max = MINIX2_LINK_MAX;
+ s->s_max_links = MINIX2_LINK_MAX;
} else if ( *(__u16 *)(bh->b_data + 24) == MINIX3_SUPER_MAGIC) {
m3s = (struct minix3_super_block *) bh->b_data;
s->s_magic = m3s->s_magic;
@@ -221,9 +221,9 @@ static int minix_fill_super(struct super_block *s, void *data, int silent)
sbi->s_dirsize = 64;
sbi->s_namelen = 60;
sbi->s_version = MINIX_V3;
- sbi->s_link_max = MINIX2_LINK_MAX;
sbi->s_mount_state = MINIX_VALID_FS;
sb_set_blocksize(s, m3s->s_blocksize);
+ s->s_max_links = MINIX2_LINK_MAX;
} else
goto out_no_fs;

diff --git a/fs/minix/minix.h b/fs/minix/minix.h
index c889ef0..1ebd118 100644
--- a/fs/minix/minix.h
+++ b/fs/minix/minix.h
@@ -34,7 +34,6 @@ struct minix_sb_info {
unsigned long s_max_size;
int s_dirsize;
int s_namelen;
- int s_link_max;
struct buffer_head ** s_imap;
struct buffer_head ** s_zmap;
struct buffer_head * s_sbh;
diff --git a/fs/minix/namei.c b/fs/minix/namei.c
index 2f76e38..2d0ee17 100644
--- a/fs/minix/namei.c
+++ b/fs/minix/namei.c
@@ -94,9 +94,6 @@ static int minix_link(struct dentry * old_dentry, struct inode * dir,
{
struct inode *inode = old_dentry->d_inode;

- if (inode->i_nlink >= minix_sb(inode->i_sb)->s_link_max)
- return -EMLINK;
-
inode->i_ctime = CURRENT_TIME_SEC;
inode_inc_link_count(inode);
ihold(inode);
@@ -106,10 +103,7 @@ static int minix_link(struct dentry * old_dentry, struct inode * dir,
static int minix_mkdir(struct inode * dir, struct dentry *dentry, umode_t mode)
{
struct inode * inode;
- int err = -EMLINK;
-
- if (dir->i_nlink >= minix_sb(dir->i_sb)->s_link_max)
- goto out;
+ int err;

inode_inc_link_count(dir);

@@ -181,7 +175,6 @@ static int minix_rmdir(struct inode * dir, struct dentry *dentry)
static int minix_rename(struct inode * old_dir, struct dentry *old_dentry,
struct inode * new_dir, struct dentry *new_dentry)
{
- struct minix_sb_info * info = minix_sb(old_dir->i_sb);
struct inode * old_inode = old_dentry->d_inode;
struct inode * new_inode = new_dentry->d_inode;
struct page * dir_page = NULL;
@@ -219,11 +212,6 @@ static int minix_rename(struct inode * old_dir, struct dentry *old_dentry,
drop_nlink(new_inode);
inode_dec_link_count(new_inode);
} else {
- if (dir_de) {
- err = -EMLINK;
- if (new_dir->i_nlink >= info->s_link_max)
- goto out_dir;
- }
err = minix_add_link(new_dentry, old_inode);
if (err)
goto out_dir;
diff --git a/fs/namei.c b/fs/namei.c
index 208c6aa..45f953c 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -2545,6 +2545,7 @@ SYSCALL_DEFINE3(mknod, const char __user *, filename, umode_t, mode, unsigned, d
int vfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
{
int error = may_create(dir, dentry);
+ unsigned max_links = dir->i_sb->s_max_links;

if (error)
return error;
@@ -2557,6 +2558,9 @@ int vfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
if (error)
return error;

+ if (max_links && dir->i_nlink >= max_links)
+ return -EMLINK;
+
error = dir->i_op->mkdir(dir, dentry, mode);
if (!error)
fsnotify_mkdir(dir, dentry);
@@ -2887,6 +2891,7 @@ SYSCALL_DEFINE2(symlink, const char __user *, oldname, const char __user *, newn
int vfs_link(struct dentry *old_dentry, struct inode *dir, struct dentry *new_dentry)
{
struct inode *inode = old_dentry->d_inode;
+ unsigned max_links = dir->i_sb->s_max_links;
int error;

if (!inode)
@@ -2917,6 +2922,8 @@ int vfs_link(struct dentry *old_dentry, struct inode *dir, struct dentry *new_de
/* Make sure we don't allow creating hardlink to an unlinked file */
if (inode->i_nlink == 0)
error = -ENOENT;
+ else if (max_links && inode->i_nlink >= max_links)
+ error = -EMLINK;
else
error = dir->i_op->link(old_dentry, dir, new_dentry);
mutex_unlock(&inode->i_mutex);
@@ -3026,6 +3033,7 @@ static int vfs_rename_dir(struct inode *old_dir, struct dentry *old_dentry,
{
int error = 0;
struct inode *target = new_dentry->d_inode;
+ unsigned max_links = new_dir->i_sb->s_max_links;

/*
* If we are going to change the parent - check write permissions,
@@ -3049,6 +3057,11 @@ static int vfs_rename_dir(struct inode *old_dir, struct dentry *old_dentry,
if (d_mountpoint(old_dentry) || d_mountpoint(new_dentry))
goto out;

+ error = -EMLINK;
+ if (max_links && !target && new_dir != old_dir &&
+ new_dir->i_nlink >= max_links)
+ goto out;
+
if (target)
shrink_dcache_parent(new_dentry);
error = old_dir->i_op->rename(old_dir, old_dentry, new_dir, new_dentry);
diff --git a/fs/nilfs2/namei.c b/fs/nilfs2/namei.c
index 1cd3f62..fce2bbe 100644
--- a/fs/nilfs2/namei.c
+++ b/fs/nilfs2/namei.c
@@ -193,9 +193,6 @@ static int nilfs_link(struct dentry *old_dentry, struct inode *dir,
struct nilfs_transaction_info ti;
int err;

- if (inode->i_nlink >= NILFS_LINK_MAX)
- return -EMLINK;
-
err = nilfs_transaction_begin(dir->i_sb, &ti, 1);
if (err)
return err;
@@ -219,9 +216,6 @@ static int nilfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
struct nilfs_transaction_info ti;
int err;

- if (dir->i_nlink >= NILFS_LINK_MAX)
- return -EMLINK;
-
err = nilfs_transaction_begin(dir->i_sb, &ti, 1);
if (err)
return err;
@@ -400,11 +394,6 @@ static int nilfs_rename(struct inode *old_dir, struct dentry *old_dentry,
drop_nlink(new_inode);
nilfs_mark_inode_dirty(new_inode);
} else {
- if (dir_de) {
- err = -EMLINK;
- if (new_dir->i_nlink >= NILFS_LINK_MAX)
- goto out_dir;
- }
err = nilfs_add_link(new_dentry, old_inode);
if (err)
goto out_dir;
diff --git a/fs/nilfs2/super.c b/fs/nilfs2/super.c
index 08e3d4f..1fc9ad3 100644
--- a/fs/nilfs2/super.c
+++ b/fs/nilfs2/super.c
@@ -1059,6 +1059,7 @@ nilfs_fill_super(struct super_block *sb, void *data, int silent)
sb->s_export_op = &nilfs_export_ops;
sb->s_root = NULL;
sb->s_time_gran = 1;
+ sb->s_max_links = NILFS_LINK_MAX;

bdi = sb->s_bdev->bd_inode->i_mapping->backing_dev_info;
sb->s_bdi = bdi ? : &default_backing_dev_info;
diff --git a/fs/sysv/namei.c b/fs/sysv/namei.c
index b217797..d7466e2 100644
--- a/fs/sysv/namei.c
+++ b/fs/sysv/namei.c
@@ -121,9 +121,6 @@ static int sysv_link(struct dentry * old_dentry, struct inode * dir,
{
struct inode *inode = old_dentry->d_inode;

- if (inode->i_nlink >= SYSV_SB(inode->i_sb)->s_link_max)
- return -EMLINK;
-
inode->i_ctime = CURRENT_TIME_SEC;
inode_inc_link_count(inode);
ihold(inode);
@@ -134,10 +131,8 @@ static int sysv_link(struct dentry * old_dentry, struct inode * dir,
static int sysv_mkdir(struct inode * dir, struct dentry *dentry, umode_t mode)
{
struct inode * inode;
- int err = -EMLINK;
+ int err;

- if (dir->i_nlink >= SYSV_SB(dir->i_sb)->s_link_max)
- goto out;
inode_inc_link_count(dir);

inode = sysv_new_inode(dir, S_IFDIR|mode);
@@ -251,11 +246,6 @@ static int sysv_rename(struct inode * old_dir, struct dentry * old_dentry,
drop_nlink(new_inode);
inode_dec_link_count(new_inode);
} else {
- if (dir_de) {
- err = -EMLINK;
- if (new_dir->i_nlink >= SYSV_SB(new_dir->i_sb)->s_link_max)
- goto out_dir;
- }
err = sysv_add_link(new_dentry, old_inode);
if (err)
goto out_dir;
diff --git a/fs/sysv/super.c b/fs/sysv/super.c
index f60c196..f467740 100644
--- a/fs/sysv/super.c
+++ b/fs/sysv/super.c
@@ -44,7 +44,7 @@ enum {
JAN_1_1980 = (10*365 + 2) * 24 * 60 * 60
};

-static void detected_xenix(struct sysv_sb_info *sbi)
+static void detected_xenix(struct sysv_sb_info *sbi, unsigned *max_links)
{
struct buffer_head *bh1 = sbi->s_bh1;
struct buffer_head *bh2 = sbi->s_bh2;
@@ -59,7 +59,7 @@ static void detected_xenix(struct sysv_sb_info *sbi)
sbd2 = (struct xenix_super_block *) (bh2->b_data - 512);
}

- sbi->s_link_max = XENIX_LINK_MAX;
+ *max_links = XENIX_LINK_MAX;
sbi->s_fic_size = XENIX_NICINOD;
sbi->s_flc_size = XENIX_NICFREE;
sbi->s_sbd1 = (char *)sbd1;
@@ -75,7 +75,7 @@ static void detected_xenix(struct sysv_sb_info *sbi)
sbi->s_nzones = fs32_to_cpu(sbi, sbd1->s_fsize);
}

-static void detected_sysv4(struct sysv_sb_info *sbi)
+static void detected_sysv4(struct sysv_sb_info *sbi, unsigned *max_links)
{
struct sysv4_super_block * sbd;
struct buffer_head *bh1 = sbi->s_bh1;
@@ -86,7 +86,7 @@ static void detected_sysv4(struct sysv_sb_info *sbi)
else
sbd = (struct sysv4_super_block *) bh2->b_data;

- sbi->s_link_max = SYSV_LINK_MAX;
+ *max_links = SYSV_LINK_MAX;
sbi->s_fic_size = SYSV_NICINOD;
sbi->s_flc_size = SYSV_NICFREE;
sbi->s_sbd1 = (char *)sbd;
@@ -103,7 +103,7 @@ static void detected_sysv4(struct sysv_sb_info *sbi)
sbi->s_nzones = fs32_to_cpu(sbi, sbd->s_fsize);
}

-static void detected_sysv2(struct sysv_sb_info *sbi)
+static void detected_sysv2(struct sysv_sb_info *sbi, unsigned *max_links)
{
struct sysv2_super_block *sbd;
struct buffer_head *bh1 = sbi->s_bh1;
@@ -114,7 +114,7 @@ static void detected_sysv2(struct sysv_sb_info *sbi)
else
sbd = (struct sysv2_super_block *) bh2->b_data;

- sbi->s_link_max = SYSV_LINK_MAX;
+ *max_links = SYSV_LINK_MAX;
sbi->s_fic_size = SYSV_NICINOD;
sbi->s_flc_size = SYSV_NICFREE;
sbi->s_sbd1 = (char *)sbd;
@@ -131,14 +131,14 @@ static void detected_sysv2(struct sysv_sb_info *sbi)
sbi->s_nzones = fs32_to_cpu(sbi, sbd->s_fsize);
}

-static void detected_coherent(struct sysv_sb_info *sbi)
+static void detected_coherent(struct sysv_sb_info *sbi, unsigned *max_links)
{
struct coh_super_block * sbd;
struct buffer_head *bh1 = sbi->s_bh1;

sbd = (struct coh_super_block *) bh1->b_data;

- sbi->s_link_max = COH_LINK_MAX;
+ *max_links = COH_LINK_MAX;
sbi->s_fic_size = COH_NICINOD;
sbi->s_flc_size = COH_NICFREE;
sbi->s_sbd1 = (char *)sbd;
@@ -154,12 +154,12 @@ static void detected_coherent(struct sysv_sb_info *sbi)
sbi->s_nzones = fs32_to_cpu(sbi, sbd->s_fsize);
}

-static void detected_v7(struct sysv_sb_info *sbi)
+static void detected_v7(struct sysv_sb_info *sbi, unsigned *max_links)
{
struct buffer_head *bh2 = sbi->s_bh2;
struct v7_super_block *sbd = (struct v7_super_block *)bh2->b_data;

- sbi->s_link_max = V7_LINK_MAX;
+ *max_links = V7_LINK_MAX;
sbi->s_fic_size = V7_NICINOD;
sbi->s_flc_size = V7_NICFREE;
sbi->s_sbd1 = (char *)sbd;
@@ -290,7 +290,7 @@ static char *flavour_names[] = {
[FSTYPE_AFS] = "AFS",
};

-static void (*flavour_setup[])(struct sysv_sb_info *) = {
+static void (*flavour_setup[])(struct sysv_sb_info *, unsigned *) = {
[FSTYPE_XENIX] = detected_xenix,
[FSTYPE_SYSV4] = detected_sysv4,
[FSTYPE_SYSV2] = detected_sysv2,
@@ -310,7 +310,7 @@ static int complete_read_super(struct super_block *sb, int silent, int size)

sbi->s_firstinodezone = 2;

- flavour_setup[sbi->s_type](sbi);
+ flavour_setup[sbi->s_type](sbi, &sb->s_max_links);

sbi->s_truncate = 1;
sbi->s_ndatazones = sbi->s_nzones - sbi->s_firstdatazone;
diff --git a/fs/sysv/sysv.h b/fs/sysv/sysv.h
index 0e4b821..11b0767 100644
--- a/fs/sysv/sysv.h
+++ b/fs/sysv/sysv.h
@@ -24,7 +24,6 @@ struct sysv_sb_info {
char s_bytesex; /* bytesex (le/be/pdp) */
char s_truncate; /* if 1: names > SYSV_NAMELEN chars are truncated */
/* if 0: they are disallowed (ENAMETOOLONG) */
- nlink_t s_link_max; /* max number of hard links to a file */
unsigned int s_inodes_per_block; /* number of inodes per block */
unsigned int s_inodes_per_block_1; /* inodes_per_block - 1 */
unsigned int s_inodes_per_block_bits; /* log2(inodes_per_block) */
diff --git a/fs/udf/namei.c b/fs/udf/namei.c
index 08bf46e..38de8f2 100644
--- a/fs/udf/namei.c
+++ b/fs/udf/namei.c
@@ -32,8 +32,6 @@
#include <linux/crc-itu-t.h>
#include <linux/exportfs.h>

-enum { UDF_MAX_LINKS = 0xffff };
-
static inline int udf_match(int len1, const unsigned char *name1, int len2,
const unsigned char *name2)
{
@@ -649,10 +647,6 @@ static int udf_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
struct udf_inode_info *dinfo = UDF_I(dir);
struct udf_inode_info *iinfo;

- err = -EMLINK;
- if (dir->i_nlink >= UDF_MAX_LINKS)
- goto out;
-
err = -EIO;
inode = udf_new_inode(dir, S_IFDIR | mode, &err);
if (!inode)
@@ -1032,9 +1026,6 @@ static int udf_link(struct dentry *old_dentry, struct inode *dir,
struct fileIdentDesc cfi, *fi;
int err;

- if (inode->i_nlink >= UDF_MAX_LINKS)
- return -EMLINK;
-
fi = udf_add_entry(dir, dentry, &fibh, &cfi, &err);
if (!fi) {
return err;
@@ -1126,10 +1117,6 @@ static int udf_rename(struct inode *old_dir, struct dentry *old_dentry,
if (udf_get_lb_pblock(old_inode->i_sb, &tloc, 0) !=
old_dir->i_ino)
goto end_rename;
-
- retval = -EMLINK;
- if (!new_inode && new_dir->i_nlink >= UDF_MAX_LINKS)
- goto end_rename;
}
if (!nfi) {
nfi = udf_add_entry(new_dir, new_dentry, &nfibh, &ncfi,
diff --git a/fs/udf/super.c b/fs/udf/super.c
index c09a84d..8d8b253 100644
--- a/fs/udf/super.c
+++ b/fs/udf/super.c
@@ -75,6 +75,8 @@

#define UDF_DEFAULT_BLOCKSIZE 2048

+enum { UDF_MAX_LINKS = 0xffff };
+
/* These are the "meat" - everything else is stuffing */
static int udf_fill_super(struct super_block *, void *, int);
static void udf_put_super(struct super_block *);
@@ -2042,6 +2044,7 @@ static int udf_fill_super(struct super_block *sb, void *options, int silent)
goto error_out;
}
sb->s_maxbytes = MAX_LFS_FILESIZE;
+ sb->s_max_links = UDF_MAX_LINKS;
return 0;

error_out:
diff --git a/fs/ufs/namei.c b/fs/ufs/namei.c
index 38cac19..a2281ca 100644
--- a/fs/ufs/namei.c
+++ b/fs/ufs/namei.c
@@ -166,10 +166,6 @@ static int ufs_link (struct dentry * old_dentry, struct inode * dir,
int error;

lock_ufs(dir->i_sb);
- if (inode->i_nlink >= UFS_LINK_MAX) {
- unlock_ufs(dir->i_sb);
- return -EMLINK;
- }

inode->i_ctime = CURRENT_TIME_SEC;
inode_inc_link_count(inode);
@@ -183,10 +179,7 @@ static int ufs_link (struct dentry * old_dentry, struct inode * dir,
static int ufs_mkdir(struct inode * dir, struct dentry * dentry, umode_t mode)
{
struct inode * inode;
- int err = -EMLINK;
-
- if (dir->i_nlink >= UFS_LINK_MAX)
- goto out;
+ int err;

lock_ufs(dir->i_sb);
inode_inc_link_count(dir);
@@ -305,11 +298,6 @@ static int ufs_rename(struct inode *old_dir, struct dentry *old_dentry,
drop_nlink(new_inode);
inode_dec_link_count(new_inode);
} else {
- if (dir_de) {
- err = -EMLINK;
- if (new_dir->i_nlink >= UFS_LINK_MAX)
- goto out_dir;
- }
err = ufs_add_link(new_dentry, old_inode);
if (err)
goto out_dir;
diff --git a/fs/ufs/super.c b/fs/ufs/super.c
index 5246ee3..ec25d09 100644
--- a/fs/ufs/super.c
+++ b/fs/ufs/super.c
@@ -1157,6 +1157,7 @@ magic_found:
"fast symlink size (%u)\n", uspi->s_maxsymlinklen);
uspi->s_maxsymlinklen = maxsymlen;
}
+ sb->s_max_links = UFS_LINK_MAX;

inode = ufs_iget(sb, UFS_ROOTINO);
if (IS_ERR(inode)) {
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 386da09..1e49554 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1459,6 +1459,7 @@ struct super_block {
u8 s_uuid[16]; /* UUID */

void *s_fs_info; /* Filesystem private info */
+ unsigned int s_max_links;
fmode_t s_mode;

/* Granularity of c/m/atime in ns.
--
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