* 2000-2001 Christoph Rohland
* 2000-2001 SAP AG
* 2002 Red Hat Inc.
- * Copyright (C) 2002-2004 Hugh Dickins.
- * Copyright (C) 2002-2004 VERITAS Software Corporation.
+ * Copyright (C) 2002-2005 Hugh Dickins.
+ * Copyright (C) 2002-2005 VERITAS Software Corporation.
* Copyright (C) 2004 Andi Kleen, SuSE Labs
*
* Extended attribute support for tmpfs:
#include <linux/swapops.h>
#include <linux/mempolicy.h>
#include <linux/namei.h>
-#include <linux/xattr.h>
#include <asm/uaccess.h>
#include <asm/div64.h>
#include <asm/pgtable.h>
static struct file_operations shmem_file_operations;
static struct inode_operations shmem_inode_operations;
static struct inode_operations shmem_dir_inode_operations;
-static struct inode_operations shmem_special_inode_operations;
static struct vm_operations_struct shmem_vm_ops;
-static struct backing_dev_info shmem_backing_dev_info = {
+static struct backing_dev_info shmem_backing_dev_info __read_mostly = {
.ra_pages = 0, /* No readahead */
.capabilities = BDI_CAP_NO_ACCT_DIRTY | BDI_CAP_NO_WRITEBACK,
.unplug_io_fn = default_unplug_io_fn,
static void shmem_free_blocks(struct inode *inode, long pages)
{
struct shmem_sb_info *sbinfo = SHMEM_SB(inode->i_sb);
- if (sbinfo) {
+ if (sbinfo->max_blocks) {
spin_lock(&sbinfo->stat_lock);
sbinfo->free_blocks += pages;
inode->i_blocks -= pages*BLOCKS_PER_PAGE;
* page (and perhaps indirect index pages) yet to allocate:
* a waste to allocate index if we cannot allocate data.
*/
- if (sbinfo) {
+ if (sbinfo->max_blocks) {
spin_lock(&sbinfo->stat_lock);
if (sbinfo->free_blocks <= 1) {
spin_unlock(&sbinfo->stat_lock);
spin_unlock(&shmem_swaplist_lock);
}
}
- if (sbinfo) {
- BUG_ON(inode->i_blocks);
+ BUG_ON(inode->i_blocks);
+ if (sbinfo->max_inodes) {
spin_lock(&sbinfo->stat_lock);
sbinfo->free_inodes++;
spin_unlock(&sbinfo->stat_lock);
} else {
shmem_swp_unmap(entry);
sbinfo = SHMEM_SB(inode->i_sb);
- if (sbinfo) {
+ if (sbinfo->max_blocks) {
spin_lock(&sbinfo->stat_lock);
if (sbinfo->free_blocks == 0 ||
shmem_acct_block(info->flags)) {
err = shmem_getpage(inode, pgoff, &page, sgp, NULL);
if (err)
return err;
+ /* Page may still be null, but only if nonblock was set. */
if (page) {
mark_page_accessed(page);
err = install_page(mm, vma, addr, page, prot);
page_cache_release(page);
return err;
}
- } else if (nonblock) {
+ } else {
+ /* No page was found just because we can't read it in
+ * now (being here implies nonblock != 0), but the page
+ * may exist, so set the PTE to fault it in later. */
err = install_file_pte(mm, vma, addr, pgoff, prot);
if (err)
return err;
struct shmem_inode_info *info;
struct shmem_sb_info *sbinfo = SHMEM_SB(sb);
- if (sbinfo) {
+ if (sbinfo->max_inodes) {
spin_lock(&sbinfo->stat_lock);
if (!sbinfo->free_inodes) {
spin_unlock(&sbinfo->stat_lock);
switch (mode & S_IFMT) {
default:
- inode->i_op = &shmem_special_inode_operations;
init_special_inode(inode, mode, dev);
break;
case S_IFREG:
mpol_shared_policy_init(&info->policy);
break;
}
- } else if (sbinfo) {
+ } else if (sbinfo->max_inodes) {
spin_lock(&sbinfo->stat_lock);
sbinfo->free_inodes++;
spin_unlock(&sbinfo->stat_lock);
}
#ifdef CONFIG_TMPFS
-
-static int shmem_set_size(struct shmem_sb_info *sbinfo,
- unsigned long max_blocks, unsigned long max_inodes)
-{
- int error;
- unsigned long blocks, inodes;
-
- spin_lock(&sbinfo->stat_lock);
- blocks = sbinfo->max_blocks - sbinfo->free_blocks;
- inodes = sbinfo->max_inodes - sbinfo->free_inodes;
- error = -EINVAL;
- if (max_blocks < blocks)
- goto out;
- if (max_inodes < 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;
-out:
- spin_unlock(&sbinfo->stat_lock);
- return error;
-}
-
static struct inode_operations shmem_symlink_inode_operations;
static struct inode_operations shmem_symlink_inline_operations;
buf->f_type = TMPFS_MAGIC;
buf->f_bsize = PAGE_CACHE_SIZE;
buf->f_namelen = NAME_MAX;
- if (sbinfo) {
- spin_lock(&sbinfo->stat_lock);
+ spin_lock(&sbinfo->stat_lock);
+ if (sbinfo->max_blocks) {
buf->f_blocks = sbinfo->max_blocks;
buf->f_bavail = buf->f_bfree = sbinfo->free_blocks;
+ }
+ if (sbinfo->max_inodes) {
buf->f_files = sbinfo->max_inodes;
buf->f_ffree = sbinfo->free_inodes;
- spin_unlock(&sbinfo->stat_lock);
}
/* else leave those fields 0 like simple_statfs */
+ spin_unlock(&sbinfo->stat_lock);
return 0;
}
* but each new link needs a new dentry, pinning lowmem, and
* tmpfs dentries cannot be pruned until they are unlinked.
*/
- if (sbinfo) {
+ if (sbinfo->max_inodes) {
spin_lock(&sbinfo->stat_lock);
if (!sbinfo->free_inodes) {
spin_unlock(&sbinfo->stat_lock);
if (inode->i_nlink > 1 && !S_ISDIR(inode->i_mode)) {
struct shmem_sb_info *sbinfo = SHMEM_SB(inode->i_sb);
- if (sbinfo) {
+ if (sbinfo->max_inodes) {
spin_lock(&sbinfo->stat_lock);
sbinfo->free_inodes++;
spin_unlock(&sbinfo->stat_lock);
return 0;
}
-static int shmem_follow_link_inline(struct dentry *dentry, struct nameidata *nd)
+static void *shmem_follow_link_inline(struct dentry *dentry, struct nameidata *nd)
{
nd_set_link(nd, (char *)SHMEM_I(dentry->d_inode));
- return 0;
+ return NULL;
}
-static int shmem_follow_link(struct dentry *dentry, struct nameidata *nd)
+static void *shmem_follow_link(struct dentry *dentry, struct nameidata *nd)
{
struct page *page = NULL;
int res = shmem_getpage(dentry->d_inode, 0, &page, SGP_READ, NULL);
nd_set_link(nd, res ? ERR_PTR(res) : kmap(page));
- return 0;
+ return page;
}
-static void shmem_put_link(struct dentry *dentry, struct nameidata *nd)
+static void shmem_put_link(struct dentry *dentry, struct nameidata *nd, void *cookie)
{
if (!IS_ERR(nd_get_link(nd))) {
- struct page *page;
-
- page = find_get_page(dentry->d_inode->i_mapping, 0);
- if (!page)
- BUG();
+ struct page *page = cookie;
kunmap(page);
mark_page_accessed(page);
page_cache_release(page);
- page_cache_release(page);
}
}
static struct inode_operations shmem_symlink_inline_operations = {
.readlink = generic_readlink,
.follow_link = shmem_follow_link_inline,
-#ifdef CONFIG_TMPFS_XATTR
- .setxattr = generic_setxattr,
- .getxattr = generic_getxattr,
- .listxattr = generic_listxattr,
- .removexattr = generic_removexattr,
-#endif
};
static struct inode_operations shmem_symlink_inode_operations = {
.readlink = generic_readlink,
.follow_link = shmem_follow_link,
.put_link = shmem_put_link,
-#ifdef CONFIG_TMPFS_XATTR
- .setxattr = generic_setxattr,
- .getxattr = generic_getxattr,
- .listxattr = generic_listxattr,
- .removexattr = generic_removexattr,
-#endif
};
static int shmem_parse_options(char *options, int *mode, uid_t *uid, gid_t *gid, unsigned long *blocks, unsigned long *inodes)
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 = 0;
- unsigned long max_inodes = 0;
+ unsigned long max_blocks = sbinfo->max_blocks;
+ unsigned long max_inodes = sbinfo->max_inodes;
+ unsigned long blocks;
+ unsigned long inodes;
+ int error = -EINVAL;
+
+ if (shmem_parse_options(data, NULL, NULL, NULL,
+ &max_blocks, &max_inodes))
+ return error;
- if (sbinfo) {
- max_blocks = sbinfo->max_blocks;
- max_inodes = sbinfo->max_inodes;
- }
- if (shmem_parse_options(data, NULL, NULL, NULL, &max_blocks, &max_inodes))
- return -EINVAL;
- /* Keep it simple: disallow limited <-> unlimited remount */
- if ((max_blocks || max_inodes) == !sbinfo)
- return -EINVAL;
- /* But allow the pointless unlimited -> unlimited remount */
- if (!sbinfo)
- return 0;
- return shmem_set_size(sbinfo, max_blocks, max_inodes);
+ spin_lock(&sbinfo->stat_lock);
+ blocks = sbinfo->max_blocks - sbinfo->free_blocks;
+ inodes = sbinfo->max_inodes - sbinfo->free_inodes;
+ if (max_blocks < blocks)
+ goto out;
+ if (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)
+ goto out;
+ if (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;
+out:
+ spin_unlock(&sbinfo->stat_lock);
+ return error;
}
#endif
sb->s_fs_info = NULL;
}
-#ifdef CONFIG_TMPFS_XATTR
-static struct xattr_handler *shmem_xattr_handlers[];
-#else
-#define shmem_xattr_handlers NULL
-#endif
-
static int shmem_fill_super(struct super_block *sb,
void *data, int silent)
{
uid_t uid = current->fsuid;
gid_t gid = current->fsgid;
int err = -ENOMEM;
-
-#ifdef CONFIG_TMPFS
+ struct shmem_sb_info *sbinfo;
unsigned long blocks = 0;
unsigned long inodes = 0;
+#ifdef CONFIG_TMPFS
/*
* Per default we only allow half of the physical ram per
* tmpfs instance, limiting inodes to one per page of lowmem;
inodes = totalram_pages - totalhigh_pages;
if (inodes > blocks)
inodes = blocks;
-
- if (shmem_parse_options(data, &mode,
- &uid, &gid, &blocks, &inodes))
+ if (shmem_parse_options(data, &mode, &uid, &gid,
+ &blocks, &inodes))
return -EINVAL;
}
-
- if (blocks || inodes) {
- struct shmem_sb_info *sbinfo;
- sbinfo = kmalloc(sizeof(struct shmem_sb_info), GFP_KERNEL);
- if (!sbinfo)
- return -ENOMEM;
- sb->s_fs_info = sbinfo;
- spin_lock_init(&sbinfo->stat_lock);
- sbinfo->max_blocks = blocks;
- sbinfo->free_blocks = blocks;
- sbinfo->max_inodes = inodes;
- sbinfo->free_inodes = inodes;
- }
- sb->s_xattr = shmem_xattr_handlers;
#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;
+
+ sb->s_fs_info = sbinfo;
sb->s_maxbytes = SHMEM_MAX_BYTES;
sb->s_blocksize = PAGE_CACHE_SIZE;
sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
sb->s_magic = TMPFS_MAGIC;
sb->s_op = &shmem_ops;
+
inode = shmem_get_inode(sb, S_IFDIR | mode, 0);
if (!inode)
goto failed;
static struct inode_operations shmem_inode_operations = {
.truncate = shmem_truncate,
.setattr = shmem_notify_change,
-#ifdef CONFIG_TMPFS_XATTR
- .setxattr = generic_setxattr,
- .getxattr = generic_getxattr,
- .listxattr = generic_listxattr,
- .removexattr = generic_removexattr,
-#endif
};
static struct inode_operations shmem_dir_inode_operations = {
.rmdir = shmem_rmdir,
.mknod = shmem_mknod,
.rename = shmem_rename,
-#ifdef CONFIG_TMPFS_XATTR
- .setxattr = generic_setxattr,
- .getxattr = generic_getxattr,
- .listxattr = generic_listxattr,
- .removexattr = generic_removexattr,
-#endif
-#endif
-};
-
-static struct inode_operations shmem_special_inode_operations = {
-#ifdef CONFIG_TMPFS_XATTR
- .setxattr = generic_setxattr,
- .getxattr = generic_getxattr,
- .listxattr = generic_listxattr,
- .removexattr = generic_removexattr,
#endif
};
};
-#ifdef CONFIG_TMPFS_SECURITY
-
-static size_t shmem_xattr_security_list(struct inode *inode, char *list, size_t list_len,
- const char *name, size_t name_len)
-{
- return security_inode_listsecurity(inode, list, list_len);
-}
-
-static int shmem_xattr_security_get(struct inode *inode, const char *name, void *buffer, size_t size)
-{
- if (strcmp(name, "") == 0)
- return -EINVAL;
- return security_inode_getsecurity(inode, name, buffer, size);
-}
-
-static int shmem_xattr_security_set(struct inode *inode, const char *name, const void *value, size_t size, int flags)
-{
- if (strcmp(name, "") == 0)
- return -EINVAL;
- return security_inode_setsecurity(inode, name, value, size, flags);
-}
-
-static struct xattr_handler shmem_xattr_security_handler = {
- .prefix = XATTR_SECURITY_PREFIX,
- .list = shmem_xattr_security_list,
- .get = shmem_xattr_security_get,
- .set = shmem_xattr_security_set,
-};
-
-#endif /* CONFIG_TMPFS_SECURITY */
-
-#ifdef CONFIG_TMPFS_XATTR
-
-static struct xattr_handler *shmem_xattr_handlers[] = {
-#ifdef CONFIG_TMPFS_SECURITY
- &shmem_xattr_security_handler,
-#endif
- NULL
-};
-
-#endif /* CONFIG_TMPFS_XATTR */
-
static struct super_block *shmem_get_sb(struct file_system_type *fs_type,
int flags, const char *dev_name, void *data)
{
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