From 680d794babebc74484c141448baa9b95b211cf5e Mon Sep 17 00:00:00 2001 From: "akpm@linux-foundation.org" Date: Fri, 8 Feb 2008 04:21:48 -0800 Subject: [PATCH] mount options: fix tmpfs Add .show_options super operation to tmpfs. Signed-off-by: Hugh Dickins Signed-off-by: Miklos Szeredi Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/shmem_fs.h | 5 +- mm/shmem.c | 196 ++++++++++++++++++++++++++------------- 2 files changed, 136 insertions(+), 65 deletions(-) diff --git a/include/linux/shmem_fs.h b/include/linux/shmem_fs.h index f3c51899117..8d5fb36ea04 100644 --- a/include/linux/shmem_fs.h +++ b/include/linux/shmem_fs.h @@ -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) diff --git a/mm/shmem.c b/mm/shmem.c index 85bed948faf..2f961a6dbf5 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -49,6 +49,7 @@ #include #include #include +#include #include #include @@ -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); @@ -1068,7 +1079,8 @@ redirty: } #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; @@ -1117,6 +1129,42 @@ out: 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) { @@ -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) { @@ -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 @@ -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; @@ -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", @@ -2170,24 +2226,20 @@ bad_val: 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 @@ -2195,23 +2247,42 @@ static int shmem_remount_fs(struct super_block *sb, int *flags, char *data) * 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) { @@ -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 /* @@ -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; @@ -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; @@ -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, -- 2.41.1