diff options
Diffstat (limited to 'fs/afs/dir.c')
| -rw-r--r-- | fs/afs/dir.c | 122 |
1 files changed, 108 insertions, 14 deletions
diff --git a/fs/afs/dir.c b/fs/afs/dir.c index 23c7f395d718..ba2b458b36d1 100644 --- a/fs/afs/dir.c +++ b/fs/afs/dir.c @@ -17,10 +17,13 @@ #include <linux/pagemap.h> #include <linux/ctype.h> #include <linux/sched.h> +#include <linux/dns_resolver.h> #include "internal.h" static struct dentry *afs_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags); +static struct dentry *afs_dynroot_lookup(struct inode *dir, struct dentry *dentry, + unsigned int flags); static int afs_dir_open(struct inode *inode, struct file *file); static int afs_readdir(struct file *file, struct dir_context *ctx); static int afs_d_revalidate(struct dentry *dentry, unsigned int flags); @@ -64,6 +67,17 @@ const struct inode_operations afs_dir_inode_operations = { .listxattr = afs_listxattr, }; +const struct file_operations afs_dynroot_file_operations = { + .open = dcache_dir_open, + .release = dcache_dir_close, + .iterate_shared = dcache_readdir, + .llseek = dcache_dir_lseek, +}; + +const struct inode_operations afs_dynroot_inode_operations = { + .lookup = afs_dynroot_lookup, +}; + const struct dentry_operations afs_fs_dentry_operations = { .d_revalidate = afs_d_revalidate, .d_delete = afs_d_delete, @@ -468,25 +482,58 @@ static int afs_do_lookup(struct inode *dir, struct dentry *dentry, } /* + * Probe to see if a cell may exist. This prevents positive dentries from + * being created unnecessarily. + */ +static int afs_probe_cell_name(struct dentry *dentry) +{ + struct afs_cell *cell; + const char *name = dentry->d_name.name; + size_t len = dentry->d_name.len; + int ret; + + /* Names prefixed with a dot are R/W mounts. */ + if (name[0] == '.') { + if (len == 1) + return -EINVAL; + name++; + len--; + } + + cell = afs_lookup_cell_rcu(afs_d2net(dentry), name, len); + if (!IS_ERR(cell)) { + afs_put_cell(afs_d2net(dentry), cell); + return 0; + } + + ret = dns_query("afsdb", name, len, "ipv4", NULL, NULL); + if (ret == -ENODATA) + ret = -EDESTADDRREQ; + return ret; +} + +/* * Try to auto mount the mountpoint with pseudo directory, if the autocell * operation is setted. */ -static struct inode *afs_try_auto_mntpt( - int ret, struct dentry *dentry, struct inode *dir, struct key *key, - struct afs_fid *fid) +static struct inode *afs_try_auto_mntpt(struct dentry *dentry, + struct inode *dir, struct afs_fid *fid) { - const char *devname = dentry->d_name.name; struct afs_vnode *vnode = AFS_FS_I(dir); struct inode *inode; + int ret = -ENOENT; - _enter("%d, %p{%pd}, {%x:%u}, %p", - ret, dentry, dentry, vnode->fid.vid, vnode->fid.vnode, key); + _enter("%p{%pd}, {%x:%u}", + dentry, dentry, vnode->fid.vid, vnode->fid.vnode); + + if (!test_bit(AFS_VNODE_AUTOCELL, &vnode->flags)) + goto out; - if (ret != -ENOENT || - !test_bit(AFS_VNODE_AUTOCELL, &vnode->flags)) + ret = afs_probe_cell_name(dentry); + if (ret < 0) goto out; - inode = afs_iget_autocell(dir, devname, strlen(devname), key); + inode = afs_iget_pseudo_dir(dir->i_sb, false); if (IS_ERR(inode)) { ret = PTR_ERR(inode); goto out; @@ -545,13 +592,16 @@ static struct dentry *afs_lookup(struct inode *dir, struct dentry *dentry, ret = afs_do_lookup(dir, dentry, &fid, key); if (ret < 0) { - inode = afs_try_auto_mntpt(ret, dentry, dir, key, &fid); - if (!IS_ERR(inode)) { - key_put(key); - goto success; + if (ret == -ENOENT) { + inode = afs_try_auto_mntpt(dentry, dir, &fid); + if (!IS_ERR(inode)) { + key_put(key); + goto success; + } + + ret = PTR_ERR(inode); } - ret = PTR_ERR(inode); key_put(key); if (ret == -ENOENT) { d_add(dentry, NULL); @@ -583,12 +633,53 @@ success: } /* + * Look up an entry in a dynroot directory. + */ +static struct dentry *afs_dynroot_lookup(struct inode *dir, struct dentry *dentry, + unsigned int flags) +{ + struct afs_vnode *vnode; + struct afs_fid fid; + struct inode *inode; + int ret; + + vnode = AFS_FS_I(dir); + + _enter("%pd", dentry); + + ASSERTCMP(d_inode(dentry), ==, NULL); + + if (dentry->d_name.len >= AFSNAMEMAX) { + _leave(" = -ENAMETOOLONG"); + return ERR_PTR(-ENAMETOOLONG); + } + + inode = afs_try_auto_mntpt(dentry, dir, &fid); + if (IS_ERR(inode)) { + ret = PTR_ERR(inode); + if (ret == -ENOENT) { + d_add(dentry, NULL); + _leave(" = NULL [negative]"); + return NULL; + } + _leave(" = %d [do]", ret); + return ERR_PTR(ret); + } + + d_add(dentry, inode); + _leave(" = 0 { ino=%lu v=%u }", + d_inode(dentry)->i_ino, d_inode(dentry)->i_generation); + return NULL; +} + +/* * check that a dentry lookup hit has found a valid entry * - NOTE! the hit can be a negative hit too, so we can't assume we have an * inode */ static int afs_d_revalidate(struct dentry *dentry, unsigned int flags) { + struct afs_super_info *as = dentry->d_sb->s_fs_info; struct afs_vnode *vnode, *dir; struct afs_fid uninitialized_var(fid); struct dentry *parent; @@ -600,6 +691,9 @@ static int afs_d_revalidate(struct dentry *dentry, unsigned int flags) if (flags & LOOKUP_RCU) return -ECHILD; + if (as->dyn_root) + return 1; + if (d_really_is_positive(dentry)) { vnode = AFS_FS_I(d_inode(dentry)); _enter("{v={%x:%u} n=%pd fl=%lx},", |