#include <linux/security.h>
#include <linux/swapops.h>
#include <linux/mempolicy.h>
+#include <linux/namei.h>
#include <asm/uaccess.h>
#include <asm/div64.h>
#include <asm/pgtable.h>
/* This magic number is used in glibc for posix shared memory */
-#define TMPFS_MAGIC 0x01021994
#define ENTRIES_PER_PAGE (PAGE_CACHE_SIZE/sizeof(unsigned long))
#define ENTRIES_PER_PAGEPAGE (ENTRIES_PER_PAGE*ENTRIES_PER_PAGE)
}
static swp_entry_t *shmem_swp_map(struct page *page)
+{
+ return (swp_entry_t *)kmap_atomic(page, KM_USER1);
+}
+
+static inline void shmem_swp_balance_unmap(void)
{
/*
- * We have to avoid the unconditional inc_preempt_count()
- * in kmap_atomic(), since shmem_swp_unmap() will also be
- * applied to the low memory addresses within i_direct[].
- * PageHighMem and high_memory tests are good for all arches
- * and configs: highmem_start_page and FIXADDR_START are not.
+ * When passing a pointer to an i_direct entry, to code which
+ * also handles indirect entries and so will shmem_swp_unmap,
+ * we must arrange for the preempt count to remain in balance.
+ * What kmap_atomic of a lowmem page does depends on config
+ * and architecture, so pretend to kmap_atomic some lowmem page.
*/
- return PageHighMem(page)?
- (swp_entry_t *)kmap_atomic(page, KM_USER1):
- (swp_entry_t *)page_address(page);
+ (void) kmap_atomic(ZERO_PAGE(0), KM_USER1);
}
static inline void shmem_swp_unmap(swp_entry_t *entry)
{
- if (entry >= (swp_entry_t *)high_memory)
- kunmap_atomic(entry, KM_USER1);
+ kunmap_atomic(entry, KM_USER1);
}
static inline struct shmem_sb_info *SHMEM_SB(struct super_block *sb)
struct page **dir;
struct page *subdir;
- if (index < SHMEM_NR_DIRECT)
+ if (index < SHMEM_NR_DIRECT) {
+ shmem_swp_balance_unmap();
return info->i_direct+index;
+ }
if (!info->i_indirect) {
if (page) {
info->i_indirect = *page;
*page = NULL;
}
shmem_dir_unmap(dir);
-
- /*
- * With apologies... caller shmem_swp_alloc passes non-NULL
- * page (though perhaps NULL *page); and now we know that this
- * indirect page has been allocated, we can shortcut the final
- * kmap if we know it contains no swap entries, as is commonly
- * the case: return pointer to a 0 which doesn't need kmapping.
- */
- return (page && !subdir->nr_swapped)?
- (swp_entry_t *)&subdir->nr_swapped:
- shmem_swp_map(subdir) + offset;
+ return shmem_swp_map(subdir) + offset;
}
static void shmem_swp_set(struct shmem_inode_info *info, swp_entry_t *entry, unsigned long value)
struct shmem_sb_info *sbinfo = SHMEM_SB(inode->i_sb);
struct page *page = NULL;
swp_entry_t *entry;
- static const swp_entry_t unswapped = { 0 };
if (sgp != SGP_WRITE &&
((loff_t) index << PAGE_CACHE_SHIFT) >= i_size_read(inode))
while (!(entry = shmem_swp_entry(info, index, &page))) {
if (sgp == SGP_READ)
- return (swp_entry_t *) &unswapped;
+ return shmem_swp_map(ZERO_PAGE(0));
/*
* Test free_blocks against 1 not 0, since we have 1 data
* page (and perhaps indirect index pages) yet to allocate:
if (size > SHMEM_NR_DIRECT)
size = SHMEM_NR_DIRECT;
offset = shmem_find_swp(entry, ptr, ptr+size);
- if (offset >= 0)
+ if (offset >= 0) {
+ shmem_swp_balance_unmap();
goto found;
+ }
if (!info->i_indirect)
goto lost2;
/* we might be racing with shmem_truncate */
return err;
}
} else if (nonblock) {
- /*
- * If a nonlinear mapping then store the file page
- * offset in the pte.
- */
- if (pgoff != linear_page_index(vma, addr)) {
- err = install_file_pte(mm, vma, addr, pgoff, prot);
- if (err)
- return err;
- }
+ err = install_file_pte(mm, vma, addr, pgoff, prot);
+ if (err)
+ return err;
}
len -= PAGE_SIZE;
desc.written = 0;
desc.count = count;
- desc.buf = buf;
+ desc.arg.buf = buf;
desc.error = 0;
do_shmem_file_read(filp, ppos, &desc, file_read_actor);
}
static ssize_t shmem_file_sendfile(struct file *in_file, loff_t *ppos,
- size_t count, read_actor_t actor, void __user *target)
+ size_t count, read_actor_t actor, void *target)
{
read_descriptor_t desc;
desc.written = 0;
desc.count = count;
- desc.buf = target;
+ desc.arg.data = target;
desc.error = 0;
do_shmem_file_read(in_file, ppos, &desc, actor);
{
struct shmem_sb_info *sbinfo = SHMEM_SB(sb);
- buf->f_type = TMPFS_MAGIC;
+ buf->f_type = TMPFS_SUPER_MAGIC;
buf->f_bsize = PAGE_CACHE_SIZE;
spin_lock(&sbinfo->stat_lock);
buf->f_blocks = sbinfo->max_blocks;
return 0;
}
-static int shmem_readlink_inline(struct dentry *dentry, char __user *buffer, int buflen)
-{
- return vfs_readlink(dentry, buffer, buflen, (const char *)SHMEM_I(dentry->d_inode));
-}
-
static int shmem_follow_link_inline(struct dentry *dentry, struct nameidata *nd)
{
- return vfs_follow_link(nd, (const char *)SHMEM_I(dentry->d_inode));
+ nd_set_link(nd, (char *)SHMEM_I(dentry->d_inode));
+ return 0;
}
-static int shmem_readlink(struct dentry *dentry, char __user *buffer, int buflen)
+static int 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);
- if (res)
- return res;
- res = vfs_readlink(dentry, buffer, buflen, kmap(page));
- kunmap(page);
- mark_page_accessed(page);
- page_cache_release(page);
- return res;
+ nd_set_link(nd, res ? ERR_PTR(res) : kmap(page));
+ return 0;
}
-static int shmem_follow_link(struct dentry *dentry, struct nameidata *nd)
+static void shmem_put_link(struct dentry *dentry, struct nameidata *nd)
{
- struct page *page = NULL;
- int res = shmem_getpage(dentry->d_inode, 0, &page, SGP_READ, NULL);
- if (res)
- return res;
- res = vfs_follow_link(nd, kmap(page));
- kunmap(page);
- mark_page_accessed(page);
- page_cache_release(page);
- return res;
+ if (!IS_ERR(nd_get_link(nd))) {
+ struct page *page;
+
+ page = find_get_page(dentry->d_inode->i_mapping, 0);
+ if (!page)
+ BUG();
+ kunmap(page);
+ mark_page_accessed(page);
+ page_cache_release(page);
+ page_cache_release(page);
+ }
}
static struct inode_operations shmem_symlink_inline_operations = {
- .readlink = shmem_readlink_inline,
+ .readlink = generic_readlink,
.follow_link = shmem_follow_link_inline,
};
static struct inode_operations shmem_symlink_inode_operations = {
.truncate = shmem_truncate,
- .readlink = shmem_readlink,
+ .readlink = generic_readlink,
.follow_link = shmem_follow_link,
+ .put_link = shmem_put_link,
};
static int shmem_parse_options(char *options, int *mode, uid_t *uid, gid_t *gid, unsigned long *blocks, unsigned long *inodes)
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_magic = TMPFS_SUPER_MAGIC;
sb->s_op = &shmem_ops;
inode = shmem_get_inode(sb, S_IFDIR | mode, 0);
if (!inode)
git://git.onelab.eu / linux-2.6.git / blobdiff