Skip to content

Commit

Permalink
mount options: fix tmpfs
Browse files Browse the repository at this point in the history 
Add .show_options super operation to tmpfs.

Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
  • Loading branch information
akpm@linux-foundation.org authored and Linus Torvalds committed Feb 8, 2008
1 parent 90d09e1 commit 680d794
Show file tree
Hide file tree
Showing 2 changed files with 136 additions and 65 deletions.
5 changes: 4 additions & 1 deletion include/linux/shmem_fs.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -30,9 +30,12 @@ struct shmem_sb_info {
unsigned long free_blocks; /* How many are left for allocation */
unsigned long max_inodes; /* How many inodes are allowed */
unsigned long free_inodes; /* How many are left for allocation */
spinlock_t stat_lock; /* Serialize shmem_sb_info changes */
uid_t uid; /* Mount uid for root directory */
gid_t gid; /* Mount gid for root directory */
mode_t mode; /* Mount mode for root directory */
int policy; /* Default NUMA memory alloc policy */
nodemask_t policy_nodes; /* nodemask for preferred and bind */
spinlock_t stat_lock;
};

static inline struct shmem_inode_info *SHMEM_I(struct inode *inode)
Expand Down
196 changes: 132 additions & 64 deletions mm/shmem.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -49,6 +49,7 @@
#include <linux/ctype.h>
#include <linux/migrate.h>
#include <linux/highmem.h>
#include <linux/seq_file.h>

#include <asm/uaccess.h>
#include <asm/div64.h>
Expand Down Expand Up @@ -84,6 +85,16 @@ enum sgp_type {
SGP_WRITE, /* may exceed i_size, may allocate page */
};

static unsigned long shmem_default_max_blocks(void)
{
return totalram_pages / 2;
}

static unsigned long shmem_default_max_inodes(void)
{
return min(totalram_pages - totalhigh_pages, totalram_pages / 2);
}

static int shmem_getpage(struct inode *inode, unsigned long idx,
struct page **pagep, enum sgp_type sgp, int *type);

Expand Down Expand Up @@ -1068,7 +1079,8 @@ static int shmem_writepage(struct page *page, struct writeback_control *wbc)
}

#ifdef CONFIG_NUMA
static inline int shmem_parse_mpol(char *value, int *policy, nodemask_t *policy_nodes)
#ifdef CONFIG_TMPFS
static int shmem_parse_mpol(char *value, int *policy, nodemask_t *policy_nodes)
{
char *nodelist = strchr(value, ':');
int err = 1;
Expand Down Expand Up @@ -1117,6 +1129,42 @@ static inline int shmem_parse_mpol(char *value, int *policy, nodemask_t *policy_
return err;
}

static void shmem_show_mpol(struct seq_file *seq, int policy,
const nodemask_t policy_nodes)
{
char *policy_string;

switch (policy) {
case MPOL_PREFERRED:
policy_string = "prefer";
break;
case MPOL_BIND:
policy_string = "bind";
break;
case MPOL_INTERLEAVE:
policy_string = "interleave";
break;
default:
/* MPOL_DEFAULT */
return;
}

seq_printf(seq, ",mpol=%s", policy_string);

if (policy != MPOL_INTERLEAVE ||
!nodes_equal(policy_nodes, node_states[N_HIGH_MEMORY])) {
char buffer[64];
int len;

len = nodelist_scnprintf(buffer, sizeof(buffer), policy_nodes);
if (len < sizeof(buffer))
seq_printf(seq, ":%s", buffer);
else
seq_printf(seq, ":?");
}
}
#endif /* CONFIG_TMPFS */

static struct page *shmem_swapin(swp_entry_t entry, gfp_t gfp,
struct shmem_inode_info *info, unsigned long idx)
{
Expand Down Expand Up @@ -1148,13 +1196,20 @@ static struct page *shmem_alloc_page(gfp_t gfp,
mpol_free(pvma.vm_policy);
return page;
}
#else
#else /* !CONFIG_NUMA */
#ifdef CONFIG_TMPFS
static inline int shmem_parse_mpol(char *value, int *policy,
nodemask_t *policy_nodes)
{
return 1;
}

static inline void shmem_show_mpol(struct seq_file *seq, int policy,
const nodemask_t policy_nodes)
{
}
#endif /* CONFIG_TMPFS */

static inline struct page *shmem_swapin(swp_entry_t entry, gfp_t gfp,
struct shmem_inode_info *info, unsigned long idx)
{
Expand All @@ -1166,7 +1221,7 @@ static inline struct page *shmem_alloc_page(gfp_t gfp,
{
return alloc_page(gfp);
}
#endif
#endif /* CONFIG_NUMA */

/*
* shmem_getpage - either get the page from swap or allocate a new one
Expand Down Expand Up @@ -2077,9 +2132,8 @@ static const struct export_operations shmem_export_ops = {
.fh_to_dentry = shmem_fh_to_dentry,
};

static int shmem_parse_options(char *options, int *mode, uid_t *uid,
gid_t *gid, unsigned long *blocks, unsigned long *inodes,
int *policy, nodemask_t *policy_nodes)
static int shmem_parse_options(char *options, struct shmem_sb_info *sbinfo,
bool remount)
{
char *this_char, *value, *rest;

Expand Down Expand Up @@ -2122,35 +2176,37 @@ static int shmem_parse_options(char *options, int *mode, uid_t *uid,
}
if (*rest)
goto bad_val;
*blocks = DIV_ROUND_UP(size, PAGE_CACHE_SIZE);
sbinfo->max_blocks =
DIV_ROUND_UP(size, PAGE_CACHE_SIZE);
} else if (!strcmp(this_char,"nr_blocks")) {
*blocks = memparse(value,&rest);
sbinfo->max_blocks = memparse(value, &rest);
if (*rest)
goto bad_val;
} else if (!strcmp(this_char,"nr_inodes")) {
*inodes = memparse(value,&rest);
sbinfo->max_inodes = memparse(value, &rest);
if (*rest)
goto bad_val;
} else if (!strcmp(this_char,"mode")) {
if (!mode)
if (remount)
continue;
*mode = simple_strtoul(value,&rest,8);
sbinfo->mode = simple_strtoul(value, &rest, 8) & 07777;
if (*rest)
goto bad_val;
} else if (!strcmp(this_char,"uid")) {
if (!uid)
if (remount)
continue;
*uid = simple_strtoul(value,&rest,0);
sbinfo->uid = simple_strtoul(value, &rest, 0);
if (*rest)
goto bad_val;
} else if (!strcmp(this_char,"gid")) {
if (!gid)
if (remount)
continue;
*gid = simple_strtoul(value,&rest,0);
sbinfo->gid = simple_strtoul(value, &rest, 0);
if (*rest)
goto bad_val;
} else if (!strcmp(this_char,"mpol")) {
if (shmem_parse_mpol(value,policy,policy_nodes))
if (shmem_parse_mpol(value, &sbinfo->policy,
&sbinfo->policy_nodes))
goto bad_val;
} else {
printk(KERN_ERR "tmpfs: Bad mount option %s\n",
Expand All @@ -2170,48 +2226,63 @@ static int shmem_parse_options(char *options, int *mode, uid_t *uid,
static int shmem_remount_fs(struct super_block *sb, int *flags, char *data)
{
struct shmem_sb_info *sbinfo = SHMEM_SB(sb);
unsigned long max_blocks = sbinfo->max_blocks;
unsigned long max_inodes = sbinfo->max_inodes;
int policy = sbinfo->policy;
nodemask_t policy_nodes = sbinfo->policy_nodes;
struct shmem_sb_info config = *sbinfo;
unsigned long blocks;
unsigned long inodes;
int error = -EINVAL;

if (shmem_parse_options(data, NULL, NULL, NULL, &max_blocks,
&max_inodes, &policy, &policy_nodes))
if (shmem_parse_options(data, &config, true))
return error;

spin_lock(&sbinfo->stat_lock);
blocks = sbinfo->max_blocks - sbinfo->free_blocks;
inodes = sbinfo->max_inodes - sbinfo->free_inodes;
if (max_blocks < blocks)
if (config.max_blocks < blocks)
goto out;
if (max_inodes < inodes)
if (config.max_inodes < inodes)
goto out;
/*
* Those tests also disallow limited->unlimited while any are in
* use, so i_blocks will always be zero when max_blocks is zero;
* but we must separately disallow unlimited->limited, because
* in that case we have no record of how much is already in use.
*/
if (max_blocks && !sbinfo->max_blocks)
if (config.max_blocks && !sbinfo->max_blocks)
goto out;
if (max_inodes && !sbinfo->max_inodes)
if (config.max_inodes && !sbinfo->max_inodes)
goto out;

error = 0;
sbinfo->max_blocks = max_blocks;
sbinfo->free_blocks = max_blocks - blocks;
sbinfo->max_inodes = max_inodes;
sbinfo->free_inodes = max_inodes - inodes;
sbinfo->policy = policy;
sbinfo->policy_nodes = policy_nodes;
sbinfo->max_blocks = config.max_blocks;
sbinfo->free_blocks = config.max_blocks - blocks;
sbinfo->max_inodes = config.max_inodes;
sbinfo->free_inodes = config.max_inodes - inodes;
sbinfo->policy = config.policy;
sbinfo->policy_nodes = config.policy_nodes;
out:
spin_unlock(&sbinfo->stat_lock);
return error;
}
#endif

static int shmem_show_options(struct seq_file *seq, struct vfsmount *vfs)
{
struct shmem_sb_info *sbinfo = SHMEM_SB(vfs->mnt_sb);

if (sbinfo->max_blocks != shmem_default_max_blocks())
seq_printf(seq, ",size=%luk",
sbinfo->max_blocks << (PAGE_CACHE_SHIFT - 10));
if (sbinfo->max_inodes != shmem_default_max_inodes())
seq_printf(seq, ",nr_inodes=%lu", sbinfo->max_inodes);
if (sbinfo->mode != (S_IRWXUGO | S_ISVTX))
seq_printf(seq, ",mode=%03o", sbinfo->mode);
if (sbinfo->uid != 0)
seq_printf(seq, ",uid=%u", sbinfo->uid);
if (sbinfo->gid != 0)
seq_printf(seq, ",gid=%u", sbinfo->gid);
shmem_show_mpol(seq, sbinfo->policy, sbinfo->policy_nodes);
return 0;
}
#endif /* CONFIG_TMPFS */

static void shmem_put_super(struct super_block *sb)
{
Expand All @@ -2224,15 +2295,23 @@ static int shmem_fill_super(struct super_block *sb,
{
struct inode *inode;
struct dentry *root;
int mode = S_IRWXUGO | S_ISVTX;
uid_t uid = current->fsuid;
gid_t gid = current->fsgid;
int err = -ENOMEM;
struct shmem_sb_info *sbinfo;
unsigned long blocks = 0;
unsigned long inodes = 0;
int policy = MPOL_DEFAULT;
nodemask_t policy_nodes = node_states[N_HIGH_MEMORY];
int err = -ENOMEM;

/* Round up to L1_CACHE_BYTES to resist false sharing */
sbinfo = kmalloc(max((int)sizeof(struct shmem_sb_info),
L1_CACHE_BYTES), GFP_KERNEL);
if (!sbinfo)
return -ENOMEM;

sbinfo->max_blocks = 0;
sbinfo->max_inodes = 0;
sbinfo->mode = S_IRWXUGO | S_ISVTX;
sbinfo->uid = current->fsuid;
sbinfo->gid = current->fsgid;
sbinfo->policy = MPOL_DEFAULT;
sbinfo->policy_nodes = node_states[N_HIGH_MEMORY];
sb->s_fs_info = sbinfo;

#ifdef CONFIG_TMPFS
/*
Expand All @@ -2241,34 +2320,22 @@ static int shmem_fill_super(struct super_block *sb,
* but the internal instance is left unlimited.
*/
if (!(sb->s_flags & MS_NOUSER)) {
blocks = totalram_pages / 2;
inodes = totalram_pages - totalhigh_pages;
if (inodes > blocks)
inodes = blocks;
if (shmem_parse_options(data, &mode, &uid, &gid, &blocks,
&inodes, &policy, &policy_nodes))
return -EINVAL;
sbinfo->max_blocks = shmem_default_max_blocks();
sbinfo->max_inodes = shmem_default_max_inodes();
if (shmem_parse_options(data, sbinfo, false)) {
err = -EINVAL;
goto failed;
}
}
sb->s_export_op = &shmem_export_ops;
#else
sb->s_flags |= MS_NOUSER;
#endif

/* Round up to L1_CACHE_BYTES to resist false sharing */
sbinfo = kmalloc(max((int)sizeof(struct shmem_sb_info),
L1_CACHE_BYTES), GFP_KERNEL);
if (!sbinfo)
return -ENOMEM;

spin_lock_init(&sbinfo->stat_lock);
sbinfo->max_blocks = blocks;
sbinfo->free_blocks = blocks;
sbinfo->max_inodes = inodes;
sbinfo->free_inodes = inodes;
sbinfo->policy = policy;
sbinfo->policy_nodes = policy_nodes;
sbinfo->free_blocks = sbinfo->max_blocks;
sbinfo->free_inodes = sbinfo->max_inodes;

sb->s_fs_info = sbinfo;
sb->s_maxbytes = SHMEM_MAX_BYTES;
sb->s_blocksize = PAGE_CACHE_SIZE;
sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
Expand All @@ -2280,11 +2347,11 @@ static int shmem_fill_super(struct super_block *sb,
sb->s_flags |= MS_POSIXACL;
#endif

inode = shmem_get_inode(sb, S_IFDIR | mode, 0);
inode = shmem_get_inode(sb, S_IFDIR | sbinfo->mode, 0);
if (!inode)
goto failed;
inode->i_uid = uid;
inode->i_gid = gid;
inode->i_uid = sbinfo->uid;
inode->i_gid = sbinfo->gid;
root = d_alloc_root(inode);
if (!root)
goto failed_iput;
Expand Down Expand Up @@ -2420,6 +2487,7 @@ static const struct super_operations shmem_ops = {
#ifdef CONFIG_TMPFS
.statfs = shmem_statfs,
.remount_fs = shmem_remount_fs,
.show_options = shmem_show_options,
#endif
.delete_inode = shmem_delete_inode,
.drop_inode = generic_delete_inode,
Expand Down

0 comments on commit 680d794

Please sign in to comment.