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author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /fs/nfs/symlink.c | |
download | linux-rt-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.gz |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'fs/nfs/symlink.c')
-rw-r--r-- | fs/nfs/symlink.c | 117 |
1 files changed, 117 insertions, 0 deletions
diff --git a/fs/nfs/symlink.c b/fs/nfs/symlink.c new file mode 100644 index 000000000000..35f106599144 --- /dev/null +++ b/fs/nfs/symlink.c @@ -0,0 +1,117 @@ +/* + * linux/fs/nfs/symlink.c + * + * Copyright (C) 1992 Rick Sladkey + * + * Optimization changes Copyright (C) 1994 Florian La Roche + * + * Jun 7 1999, cache symlink lookups in the page cache. -DaveM + * + * nfs symlink handling code + */ + +#define NFS_NEED_XDR_TYPES +#include <linux/time.h> +#include <linux/errno.h> +#include <linux/sunrpc/clnt.h> +#include <linux/nfs.h> +#include <linux/nfs2.h> +#include <linux/nfs_fs.h> +#include <linux/pagemap.h> +#include <linux/stat.h> +#include <linux/mm.h> +#include <linux/slab.h> +#include <linux/string.h> +#include <linux/smp_lock.h> +#include <linux/namei.h> + +/* Symlink caching in the page cache is even more simplistic + * and straight-forward than readdir caching. + * + * At the beginning of the page we store pointer to struct page in question, + * simplifying nfs_put_link() (if inode got invalidated we can't find the page + * to be freed via pagecache lookup). + * The NUL-terminated string follows immediately thereafter. + */ + +struct nfs_symlink { + struct page *page; + char body[0]; +}; + +static int nfs_symlink_filler(struct inode *inode, struct page *page) +{ + const unsigned int pgbase = offsetof(struct nfs_symlink, body); + const unsigned int pglen = PAGE_SIZE - pgbase; + int error; + + lock_kernel(); + error = NFS_PROTO(inode)->readlink(inode, page, pgbase, pglen); + unlock_kernel(); + if (error < 0) + goto error; + SetPageUptodate(page); + unlock_page(page); + return 0; + +error: + SetPageError(page); + unlock_page(page); + return -EIO; +} + +static int nfs_follow_link(struct dentry *dentry, struct nameidata *nd) +{ + struct inode *inode = dentry->d_inode; + struct page *page; + struct nfs_symlink *p; + void *err = ERR_PTR(nfs_revalidate_inode(NFS_SERVER(inode), inode)); + if (err) + goto read_failed; + page = read_cache_page(&inode->i_data, 0, + (filler_t *)nfs_symlink_filler, inode); + if (IS_ERR(page)) { + err = page; + goto read_failed; + } + if (!PageUptodate(page)) { + err = ERR_PTR(-EIO); + goto getlink_read_error; + } + p = kmap(page); + p->page = page; + nd_set_link(nd, p->body); + return 0; + +getlink_read_error: + page_cache_release(page); +read_failed: + nd_set_link(nd, err); + return 0; +} + +static void nfs_put_link(struct dentry *dentry, struct nameidata *nd) +{ + char *s = nd_get_link(nd); + if (!IS_ERR(s)) { + struct nfs_symlink *p; + struct page *page; + + p = container_of(s, struct nfs_symlink, body[0]); + page = p->page; + + kunmap(page); + page_cache_release(page); + } +} + +/* + * symlinks can't do much... + */ +struct inode_operations nfs_symlink_inode_operations = { + .readlink = generic_readlink, + .follow_link = nfs_follow_link, + .put_link = nfs_put_link, + .getattr = nfs_getattr, + .setattr = nfs_setattr, +}; |