/* dir.c: AFS filesystem directory handling * * Copyright (C) 2002 Red Hat, Inc. All Rights Reserved. * Written by David Howells (dhowells@redhat.com) * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation; either version * 2 of the License, or (at your option) any later version. */ #include #include #include #include #include #include #include #include #include #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); static int afs_d_delete(const struct dentry *dentry); static void afs_d_release(struct dentry *dentry); static int afs_lookup_one_filldir(struct dir_context *ctx, const char *name, int nlen, loff_t fpos, u64 ino, unsigned dtype); static int afs_lookup_filldir(struct dir_context *ctx, const char *name, int nlen, loff_t fpos, u64 ino, unsigned dtype); static int afs_create(struct inode *dir, struct dentry *dentry, umode_t mode, bool excl); static int afs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode); static int afs_rmdir(struct inode *dir, struct dentry *dentry); static int afs_unlink(struct inode *dir, struct dentry *dentry); static int afs_link(struct dentry *from, struct inode *dir, struct dentry *dentry); static int afs_symlink(struct inode *dir, struct dentry *dentry, const char *content); static int afs_rename(struct inode *old_dir, struct dentry *old_dentry, struct inode *new_dir, struct dentry *new_dentry, unsigned int flags); const struct file_operations afs_dir_file_operations = { .open = afs_dir_open, .release = afs_release, .iterate_shared = afs_readdir, .lock = afs_lock, .llseek = generic_file_llseek, }; const struct inode_operations afs_dir_inode_operations = { .create = afs_create, .lookup = afs_lookup, .link = afs_link, .unlink = afs_unlink, .symlink = afs_symlink, .mkdir = afs_mkdir, .rmdir = afs_rmdir, .rename = afs_rename, .permission = afs_permission, .getattr = afs_getattr, .setattr = afs_setattr, .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, .d_release = afs_d_release, .d_automount = afs_d_automount, }; #define AFS_DIR_HASHTBL_SIZE 128 #define AFS_DIR_DIRENT_SIZE 32 #define AFS_DIRENT_PER_BLOCK 64 union afs_dirent { struct { uint8_t valid; uint8_t unused[1]; __be16 hash_next; __be32 vnode; __be32 unique; uint8_t name[16]; uint8_t overflow[4]; /* if any char of the name (inc * NUL) reaches here, consume * the next dirent too */ } u; uint8_t extended_name[32]; }; /* AFS directory page header (one at the beginning of every 2048-byte chunk) */ struct afs_dir_pagehdr { __be16 npages; __be16 magic; #define AFS_DIR_MAGIC htons(1234) uint8_t nentries; uint8_t bitmap[8]; uint8_t pad[19]; }; /* directory block layout */ union afs_dir_block { struct afs_dir_pagehdr pagehdr; struct { struct afs_dir_pagehdr pagehdr; uint8_t alloc_ctrs[128]; /* dir hash table */ uint16_t hashtable[AFS_DIR_HASHTBL_SIZE]; } hdr; union afs_dirent dirents[AFS_DIRENT_PER_BLOCK]; }; /* layout on a linux VM page */ struct afs_dir_page { union afs_dir_block blocks[PAGE_SIZE / sizeof(union afs_dir_block)]; }; struct afs_lookup_one_cookie { struct dir_context ctx; struct qstr name; bool found; struct afs_fid fid; }; struct afs_lookup_cookie { struct dir_context ctx; struct qstr name; bool found; bool one_only; unsigned short nr_fids; struct afs_file_status *statuses; struct afs_callback *callbacks; struct afs_fid fids[50]; }; /* * check that a directory page is valid */ bool afs_dir_check_page(struct inode *dir, struct page *page) { struct afs_dir_page *dbuf; struct afs_vnode *vnode = AFS_FS_I(dir); loff_t latter, i_size, off; int tmp, qty; #if 0 /* check the page count */ qty = desc.size / sizeof(dbuf->blocks[0]); if (qty == 0) goto error; if (page->index == 0 && qty != ntohs(dbuf->blocks[0].pagehdr.npages)) { printk("kAFS: %s(%lu): wrong number of dir blocks %d!=%hu\n", __func__, dir->i_ino, qty, ntohs(dbuf->blocks[0].pagehdr.npages)); goto error; } #endif /* Determine how many magic numbers there should be in this page, but * we must take care because the directory may change size under us. */ off = page_offset(page); i_size = i_size_read(dir); if (i_size <= off) goto checked; latter = i_size - off; if (latter >= PAGE_SIZE) qty = PAGE_SIZE; else qty = latter; qty /= sizeof(union afs_dir_block); /* check them */ dbuf = page_address(page); for (tmp = 0; tmp < qty; tmp++) { if (dbuf->blocks[tmp].pagehdr.magic != AFS_DIR_MAGIC) { printk("kAFS: %s(%lx): bad magic %d/%d is %04hx\n", __func__, dir->i_ino, tmp, qty, ntohs(dbuf->blocks[tmp].pagehdr.magic)); trace_afs_dir_check_failed(vnode, off, i_size); goto error; } } checked: SetPageChecked(page); return true; error: SetPageError(page); return false; } /* * discard a page cached in the pagecache */ static inline void afs_dir_put_page(struct page *page) { kunmap(page); unlock_page(page); put_page(page); } /* * get a page into the pagecache */ static struct page *afs_dir_get_page(struct inode *dir, unsigned long index, struct key *key) { struct page *page; _enter("{%lu},%lu", dir->i_ino, index); page = read_cache_page(dir->i_mapping, index, afs_page_filler, key); if (!IS_ERR(page)) { lock_page(page); kmap(page); if (unlikely(!PageChecked(page))) { if (PageError(page)) goto fail; } } return page; fail: afs_dir_put_page(page); _leave(" = -EIO"); return ERR_PTR(-EIO); } /* * open an AFS directory file */ static int afs_dir_open(struct inode *inode, struct file *file) { _enter("{%lu}", inode->i_ino); BUILD_BUG_ON(sizeof(union afs_dir_block) != 2048); BUILD_BUG_ON(sizeof(union afs_dirent) != 32); if (test_bit(AFS_VNODE_DELETED, &AFS_FS_I(inode)->flags)) return -ENOENT; return afs_open(inode, file); } /* * deal with one block in an AFS directory */ static int afs_dir_iterate_block(struct dir_context *ctx, union afs_dir_block *block, unsigned blkoff) { union afs_dirent *dire; unsigned offset, next, curr; size_t nlen; int tmp; _enter("%u,%x,%p,,",(unsigned)ctx->pos,blkoff,block); curr = (ctx->pos - blkoff) / sizeof(union afs_dirent); /* walk through the block, an entry at a time */ for (offset = AFS_DIRENT_PER_BLOCK - block->pagehdr.nentries; offset < AFS_DIRENT_PER_BLOCK; offset = next ) { next = offset + 1; /* skip entries marked unused in the bitmap */ if (!(block->pagehdr.bitmap[offset / 8] & (1 << (offset % 8)))) { _debug("ENT[%zu.%u]: unused", blkoff / sizeof(union afs_dir_block), offset); if (offset >= curr) ctx->pos = blkoff + next * sizeof(union afs_dirent); continue; } /* got a valid entry */ dire = &block->dirents[offset]; nlen = strnlen(dire->u.name, sizeof(*block) - offset * sizeof(union afs_dirent)); _debug("ENT[%zu.%u]: %s %zu \"%s\"", blkoff / sizeof(union afs_dir_block), offset, (offset < curr ? "skip" : "fill"), nlen, dire->u.name); /* work out where the next possible entry is */ for (tmp = nlen; tmp > 15; tmp -= sizeof(union afs_dirent)) { if (next >= AFS_DIRENT_PER_BLOCK) { _debug("ENT[%zu.%u]:" " %u travelled beyond end dir block" " (len %u/%zu)", blkoff / sizeof(union afs_dir_block), offset, next, tmp, nlen); return -EIO; } if (!(block->pagehdr.bitmap[next / 8] & (1 << (next % 8)))) { _debug("ENT[%zu.%u]:" " %u unmarked extension (len %u/%zu)", blkoff / sizeof(union afs_dir_block), offset, next, tmp, nlen); return -EIO; } _debug("ENT[%zu.%u]: ext %u/%zu", blkoff / sizeof(union afs_dir_block), next, tmp, nlen); next++; } /* skip if starts before the current position */ if (offset < curr) continue; /* found the next entry */ if (!dir_emit(ctx, dire->u.name, nlen, ntohl(dire->u.vnode), (ctx->actor == afs_lookup_filldir || ctx->actor == afs_lookup_one_filldir)? ntohl(dire->u.unique) : DT_UNKNOWN)) { _leave(" = 0 [full]"); return 0; } ctx->pos = blkoff + next * sizeof(union afs_dirent); } _leave(" = 1 [more]"); return 1; } /* * iterate through the data blob that lists the contents of an AFS directory */ static int afs_dir_iterate(struct inode *dir, struct dir_context *ctx, struct key *key) { union afs_dir_block *dblock; struct afs_dir_page *dbuf; struct page *page; unsigned blkoff, limit; int ret; _enter("{%lu},%u,,", dir->i_ino, (unsigned)ctx->pos); if (test_bit(AFS_VNODE_DELETED, &AFS_FS_I(dir)->flags)) { _leave(" = -ESTALE"); return -ESTALE; } /* round the file position up to the next entry boundary */ ctx->pos += sizeof(union afs_dirent) - 1; ctx->pos &= ~(sizeof(union afs_dirent) - 1); /* walk through the blocks in sequence */ ret = 0; while (ctx->pos < dir->i_size) { blkoff = ctx->pos & ~(sizeof(union afs_dir_block) - 1); /* fetch the appropriate page from the directory */ page = afs_dir_get_page(dir, blkoff / PAGE_SIZE, key); if (IS_ERR(page)) { ret = PTR_ERR(page); break; } limit = blkoff & ~(PAGE_SIZE - 1); dbuf = page_address(page); /* deal with the individual blocks stashed on this page */ do { dblock = &dbuf->blocks[(blkoff % PAGE_SIZE) / sizeof(union afs_dir_block)]; ret = afs_dir_iterate_block(ctx, dblock, blkoff); if (ret != 1) { afs_dir_put_page(page); goto out; } blkoff += sizeof(union afs_dir_block); } while (ctx->pos < dir->i_size && blkoff < limit); afs_dir_put_page(page); ret = 0; } out: _leave(" = %d", ret); return ret; } /* * read an AFS directory */ static int afs_readdir(struct file *file, struct dir_context *ctx) { return afs_dir_iterate(file_inode(file), ctx, afs_file_key(file)); } /* * Search the directory for a single name * - if afs_dir_iterate_block() spots this function, it'll pass the FID * uniquifier through dtype */ static int afs_lookup_one_filldir(struct dir_context *ctx, const char *name, int nlen, loff_t fpos, u64 ino, unsigned dtype) { struct afs_lookup_one_cookie *cookie = container_of(ctx, struct afs_lookup_one_cookie, ctx); _enter("{%s,%u},%s,%u,,%llu,%u", cookie->name.name, cookie->name.len, name, nlen, (unsigned long long) ino, dtype); /* insanity checks first */ BUILD_BUG_ON(sizeof(union afs_dir_block) != 2048); BUILD_BUG_ON(sizeof(union afs_dirent) != 32); if (cookie->name.len != nlen || memcmp(cookie->name.name, name, nlen) != 0) { _leave(" = 0 [no]"); return 0; } cookie->fid.vnode = ino; cookie->fid.unique = dtype; cookie->found = 1; _leave(" = -1 [found]"); return -1; } /* * Do a lookup of a single name in a directory * - just returns the FID the dentry name maps to if found */ static int afs_do_lookup_one(struct inode *dir, struct dentry *dentry, struct afs_fid *fid, struct key *key) { struct afs_super_info *as = dir->i_sb->s_fs_info; struct afs_lookup_one_cookie cookie = { .ctx.actor = afs_lookup_one_filldir, .name = dentry->d_name, .fid.vid = as->volume->vid }; int ret; _enter("{%lu},%p{%pd},", dir->i_ino, dentry, dentry); /* search the directory */ ret = afs_dir_iterate(dir, &cookie.ctx, key); if (ret < 0) { _leave(" = %d [iter]", ret); return ret; } ret = -ENOENT; if (!cookie.found) { _leave(" = -ENOENT [not found]"); return -ENOENT; } *fid = cookie.fid; _leave(" = 0 { vn=%u u=%u }", fid->vnode, fid->unique); return 0; } /* * search the directory for a name * - if afs_dir_iterate_block() spots this function, it'll pass the FID * uniquifier through dtype */ static int afs_lookup_filldir(struct dir_context *ctx, const char *name, int nlen, loff_t fpos, u64 ino, unsigned dtype) { struct afs_lookup_cookie *cookie = container_of(ctx, struct afs_lookup_cookie, ctx); int ret; _enter("{%s,%u},%s,%u,,%llu,%u", cookie->name.name, cookie->name.len, name, nlen, (unsigned long long) ino, dtype); /* insanity checks first */ BUILD_BUG_ON(sizeof(union afs_dir_block) != 2048); BUILD_BUG_ON(sizeof(union afs_dirent) != 32); if (cookie->found) { if (cookie->nr_fids < 50) { cookie->fids[cookie->nr_fids].vnode = ino; cookie->fids[cookie->nr_fids].unique = dtype; cookie->nr_fids++; } } else if (cookie->name.len == nlen && memcmp(cookie->name.name, name, nlen) == 0) { cookie->fids[0].vnode = ino; cookie->fids[0].unique = dtype; cookie->found = 1; if (cookie->one_only) return -1; } ret = cookie->nr_fids >= 50 ? -1 : 0; _leave(" = %d", ret); return ret; } /* * Do a lookup in a directory. We make use of bulk lookup to query a slew of * files in one go and create inodes for them. The inode of the file we were * asked for is returned. */ static struct inode *afs_do_lookup(struct inode *dir, struct dentry *dentry, struct key *key) { struct afs_lookup_cookie *cookie; struct afs_cb_interest *cbi = NULL; struct afs_super_info *as = dir->i_sb->s_fs_info; struct afs_iget_data data; struct afs_fs_cursor fc; struct afs_vnode *dvnode = AFS_FS_I(dir); struct inode *inode = NULL; int ret, i; _enter("{%lu},%p{%pd},", dir->i_ino, dentry, dentry); cookie = kzalloc(sizeof(struct afs_lookup_cookie), GFP_KERNEL); if (!cookie) return ERR_PTR(-ENOMEM); cookie->ctx.actor = afs_lookup_filldir; cookie->name = dentry->d_name; cookie->nr_fids = 1; /* slot 0 is saved for the fid we actually want */ read_seqlock_excl(&dvnode->cb_lock); if (dvnode->cb_interest && dvnode->cb_interest->server && test_bit(AFS_SERVER_FL_NO_IBULK, &dvnode->cb_interest->server->flags)) cookie->one_only = true; read_sequnlock_excl(&dvnode->cb_lock); for (i = 0; i < 50; i++) cookie->fids[i].vid = as->volume->vid; /* search the directory */ ret = afs_dir_iterate(dir, &cookie->ctx, key); if (ret < 0) { inode = ERR_PTR(ret); goto out; } inode = ERR_PTR(-ENOENT); if (!cookie->found) goto out; /* Check to see if we already have an inode for the primary fid. */ data.volume = dvnode->volume; data.fid = cookie->fids[0]; inode = ilookup5(dir->i_sb, cookie->fids[0].vnode, afs_iget5_test, &data); if (inode) goto out; /* Need space for examining all the selected files */ inode = ERR_PTR(-ENOMEM); cookie->statuses = kcalloc(cookie->nr_fids, sizeof(struct afs_file_status), GFP_KERNEL); if (!cookie->statuses) goto out; cookie->callbacks = kcalloc(cookie->nr_fids, sizeof(struct afs_callback), GFP_KERNEL); if (!cookie->callbacks) goto out_s; /* Try FS.InlineBulkStatus first. Abort codes for the individual * lookups contained therein are stored in the reply without aborting * the whole operation. */ if (cookie->one_only) goto no_inline_bulk_status; inode = ERR_PTR(-ERESTARTSYS); if (afs_begin_vnode_operation(&fc, dvnode, key)) { while (afs_select_fileserver(&fc)) { if (test_bit(AFS_SERVER_FL_NO_IBULK, &fc.cbi->server->flags)) { fc.ac.abort_code = RX_INVALID_OPERATION; fc.ac.error = -ECONNABORTED; break; } afs_fs_inline_bulk_status(&fc, afs_v2net(dvnode), cookie->fids, cookie->statuses, cookie->callbacks, cookie->nr_fids, NULL); } if (fc.ac.error == 0) cbi = afs_get_cb_interest(fc.cbi); if (fc.ac.abort_code == RX_INVALID_OPERATION) set_bit(AFS_SERVER_FL_NO_IBULK, &fc.cbi->server->flags); inode = ERR_PTR(afs_end_vnode_operation(&fc)); } if (!IS_ERR(inode)) goto success; if (fc.ac.abort_code != RX_INVALID_OPERATION) goto out_c; no_inline_bulk_status: /* We could try FS.BulkStatus next, but this aborts the entire op if * any of the lookups fails - so, for the moment, revert to * FS.FetchStatus for just the primary fid. */ cookie->nr_fids = 1; inode = ERR_PTR(-ERESTARTSYS); if (afs_begin_vnode_operation(&fc, dvnode, key)) { while (afs_select_fileserver(&fc)) { afs_fs_fetch_status(&fc, afs_v2net(dvnode), cookie->fids, cookie->statuses, cookie->callbacks, NULL); } if (fc.ac.error == 0) cbi = afs_get_cb_interest(fc.cbi); inode = ERR_PTR(afs_end_vnode_operation(&fc)); } if (IS_ERR(inode)) goto out_c; for (i = 0; i < cookie->nr_fids; i++) cookie->statuses[i].abort_code = 0; success: /* Turn all the files into inodes and save the first one - which is the * one we actually want. */ if (cookie->statuses[0].abort_code != 0) inode = ERR_PTR(afs_abort_to_error(cookie->statuses[0].abort_code)); for (i = 0; i < cookie->nr_fids; i++) { struct inode *ti; if (cookie->statuses[i].abort_code != 0) continue; ti = afs_iget(dir->i_sb, key, &cookie->fids[i], &cookie->statuses[i], &cookie->callbacks[i], cbi); if (i == 0) { inode = ti; } else { if (!IS_ERR(ti)) iput(ti); } } out_c: afs_put_cb_interest(afs_v2net(dvnode), cbi); kfree(cookie->callbacks); out_s: kfree(cookie->statuses); out: kfree(cookie); return inode; } /* * 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(struct dentry *dentry, struct inode *dir) { struct afs_vnode *vnode = AFS_FS_I(dir); struct inode *inode; int ret = -ENOENT; _enter("%p{%pd}, {%x:%u}", dentry, dentry, vnode->fid.vid, vnode->fid.vnode); if (!test_bit(AFS_VNODE_AUTOCELL, &vnode->flags)) goto out; ret = afs_probe_cell_name(dentry); if (ret < 0) goto out; inode = afs_iget_pseudo_dir(dir->i_sb, false); if (IS_ERR(inode)) { ret = PTR_ERR(inode); goto out; } _leave("= %p", inode); return inode; out: _leave("= %d", ret); return ERR_PTR(ret); } /* * Look up an entry in a directory with @sys substitution. */ static struct dentry *afs_lookup_atsys(struct inode *dir, struct dentry *dentry, struct key *key) { struct afs_sysnames *subs; struct afs_net *net = afs_i2net(dir); struct dentry *ret; char *buf, *p, *name; int len, i; _enter(""); ret = ERR_PTR(-ENOMEM); p = buf = kmalloc(AFSNAMEMAX, GFP_KERNEL); if (!buf) goto out_p; if (dentry->d_name.len > 4) { memcpy(p, dentry->d_name.name, dentry->d_name.len - 4); p += dentry->d_name.len - 4; } /* There is an ordered list of substitutes that we have to try. */ read_lock(&net->sysnames_lock); subs = net->sysnames; refcount_inc(&subs->usage); read_unlock(&net->sysnames_lock); for (i = 0; i < subs->nr; i++) { name = subs->subs[i]; len = dentry->d_name.len - 4 + strlen(name); if (len >= AFSNAMEMAX) { ret = ERR_PTR(-ENAMETOOLONG); goto out_s; } strcpy(p, name); ret = lookup_one_len(buf, dentry->d_parent, len); if (IS_ERR(ret) || d_is_positive(ret)) goto out_s; dput(ret); } /* We don't want to d_add() the @sys dentry here as we don't want to * the cached dentry to hide changes to the sysnames list. */ ret = NULL; out_s: afs_put_sysnames(subs); kfree(buf); out_p: key_put(key); return ret; } /* * look up an entry in a directory */ static struct dentry *afs_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags) { struct afs_vnode *dvnode = AFS_FS_I(dir); struct inode *inode; struct key *key; int ret; _enter("{%x:%u},%p{%pd},", dvnode->fid.vid, dvnode->fid.vnode, dentry, dentry); ASSERTCMP(d_inode(dentry), ==, NULL); if (dentry->d_name.len >= AFSNAMEMAX) { _leave(" = -ENAMETOOLONG"); return ERR_PTR(-ENAMETOOLONG); } if (test_bit(AFS_VNODE_DELETED, &dvnode->flags)) { _leave(" = -ESTALE"); return ERR_PTR(-ESTALE); } key = afs_request_key(dvnode->volume->cell); if (IS_ERR(key)) { _leave(" = %ld [key]", PTR_ERR(key)); return ERR_CAST(key); } ret = afs_validate(dvnode, key); if (ret < 0) { key_put(key); _leave(" = %d [val]", ret); return ERR_PTR(ret); } if (dentry->d_name.len >= 4 && dentry->d_name.name[dentry->d_name.len - 4] == '@' && dentry->d_name.name[dentry->d_name.len - 3] == 's' && dentry->d_name.name[dentry->d_name.len - 2] == 'y' && dentry->d_name.name[dentry->d_name.len - 1] == 's') return afs_lookup_atsys(dir, dentry, key); inode = afs_do_lookup(dir, dentry, key); if (IS_ERR(inode)) { ret = PTR_ERR(inode); if (ret == -ENOENT) { inode = afs_try_auto_mntpt(dentry, dir); if (!IS_ERR(inode)) { key_put(key); goto success; } ret = PTR_ERR(inode); } key_put(key); if (ret == -ENOENT) { d_add(dentry, NULL); _leave(" = NULL [negative]"); return NULL; } _leave(" = %d [do]", ret); return ERR_PTR(ret); } dentry->d_fsdata = (void *)(unsigned long)dvnode->status.data_version; /* instantiate the dentry */ key_put(key); if (IS_ERR(inode)) { _leave(" = %ld", PTR_ERR(inode)); return ERR_CAST(inode); } success: d_add(dentry, inode); _leave(" = 0 { ino=%lu v=%u }", d_inode(dentry)->i_ino, d_inode(dentry)->i_generation); return NULL; } /* * 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 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); 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; struct inode *inode; struct key *key; void *dir_version; int ret; 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},", vnode->fid.vid, vnode->fid.vnode, dentry, vnode->flags); } else { _enter("{neg n=%pd}", dentry); } key = afs_request_key(AFS_FS_S(dentry->d_sb)->volume->cell); if (IS_ERR(key)) key = NULL; if (d_really_is_positive(dentry)) { inode = d_inode(dentry); if (inode) { vnode = AFS_FS_I(inode); afs_validate(vnode, key); if (test_bit(AFS_VNODE_DELETED, &vnode->flags)) goto out_bad; } } /* lock down the parent dentry so we can peer at it */ parent = dget_parent(dentry); dir = AFS_FS_I(d_inode(parent)); /* validate the parent directory */ afs_validate(dir, key); if (test_bit(AFS_VNODE_DELETED, &dir->flags)) { _debug("%pd: parent dir deleted", dentry); goto out_bad_parent; } dir_version = (void *) (unsigned long) dir->status.data_version; if (dentry->d_fsdata == dir_version) goto out_valid; /* the dir contents are unchanged */ _debug("dir modified"); /* search the directory for this vnode */ ret = afs_do_lookup_one(&dir->vfs_inode, dentry, &fid, key); switch (ret) { case 0: /* the filename maps to something */ if (d_really_is_negative(dentry)) goto out_bad_parent; inode = d_inode(dentry); if (is_bad_inode(inode)) { printk("kAFS: afs_d_revalidate: %pd2 has bad inode\n", dentry); goto out_bad_parent; } vnode = AFS_FS_I(inode); /* if the vnode ID has changed, then the dirent points to a * different file */ if (fid.vnode != vnode->fid.vnode) { _debug("%pd: dirent changed [%u != %u]", dentry, fid.vnode, vnode->fid.vnode); goto not_found; } /* if the vnode ID uniqifier has changed, then the file has * been deleted and replaced, and the original vnode ID has * been reused */ if (fid.unique != vnode->fid.unique) { _debug("%pd: file deleted (uq %u -> %u I:%u)", dentry, fid.unique, vnode->fid.unique, vnode->vfs_inode.i_generation); write_seqlock(&vnode->cb_lock); set_bit(AFS_VNODE_DELETED, &vnode->flags); write_sequnlock(&vnode->cb_lock); goto not_found; } goto out_valid; case -ENOENT: /* the filename is unknown */ _debug("%pd: dirent not found", dentry); if (d_really_is_positive(dentry)) goto not_found; goto out_valid; default: _debug("failed to iterate dir %pd: %d", parent, ret); goto out_bad_parent; } out_valid: dentry->d_fsdata = dir_version; dput(parent); key_put(key); _leave(" = 1 [valid]"); return 1; /* the dirent, if it exists, now points to a different vnode */ not_found: spin_lock(&dentry->d_lock); dentry->d_flags |= DCACHE_NFSFS_RENAMED; spin_unlock(&dentry->d_lock); out_bad_parent: _debug("dropping dentry %pd2", dentry); dput(parent); out_bad: key_put(key); _leave(" = 0 [bad]"); return 0; } /* * allow the VFS to enquire as to whether a dentry should be unhashed (mustn't * sleep) * - called from dput() when d_count is going to 0. * - return 1 to request dentry be unhashed, 0 otherwise */ static int afs_d_delete(const struct dentry *dentry) { _enter("%pd", dentry); if (dentry->d_flags & DCACHE_NFSFS_RENAMED) goto zap; if (d_really_is_positive(dentry) && (test_bit(AFS_VNODE_DELETED, &AFS_FS_I(d_inode(dentry))->flags) || test_bit(AFS_VNODE_PSEUDODIR, &AFS_FS_I(d_inode(dentry))->flags))) goto zap; _leave(" = 0 [keep]"); return 0; zap: _leave(" = 1 [zap]"); return 1; } /* * handle dentry release */ static void afs_d_release(struct dentry *dentry) { _enter("%pd", dentry); } /* * Create a new inode for create/mkdir/symlink */ static void afs_vnode_new_inode(struct afs_fs_cursor *fc, struct dentry *new_dentry, struct afs_fid *newfid, struct afs_file_status *newstatus, struct afs_callback *newcb) { struct inode *inode; if (fc->ac.error < 0) return; d_drop(new_dentry); inode = afs_iget(fc->vnode->vfs_inode.i_sb, fc->key, newfid, newstatus, newcb, fc->cbi); if (IS_ERR(inode)) { /* ENOMEM or EINTR at a really inconvenient time - just abandon * the new directory on the server. */ fc->ac.error = PTR_ERR(inode); return; } d_add(new_dentry, inode); } /* * create a directory on an AFS filesystem */ static int afs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode) { struct afs_file_status newstatus; struct afs_fs_cursor fc; struct afs_callback newcb; struct afs_vnode *dvnode = AFS_FS_I(dir); struct afs_fid newfid; struct key *key; int ret; mode |= S_IFDIR; _enter("{%x:%u},{%pd},%ho", dvnode->fid.vid, dvnode->fid.vnode, dentry, mode); key = afs_request_key(dvnode->volume->cell); if (IS_ERR(key)) { ret = PTR_ERR(key); goto error; } ret = -ERESTARTSYS; if (afs_begin_vnode_operation(&fc, dvnode, key)) { while (afs_select_fileserver(&fc)) { fc.cb_break = dvnode->cb_break + dvnode->cb_s_break; afs_fs_create(&fc, dentry->d_name.name, mode, &newfid, &newstatus, &newcb); } afs_check_for_remote_deletion(&fc, fc.vnode); afs_vnode_commit_status(&fc, dvnode, fc.cb_break); afs_vnode_new_inode(&fc, dentry, &newfid, &newstatus, &newcb); ret = afs_end_vnode_operation(&fc); if (ret < 0) goto error_key; } else { goto error_key; } key_put(key); _leave(" = 0"); return 0; error_key: key_put(key); error: d_drop(dentry); _leave(" = %d", ret); return ret; } /* * Remove a subdir from a directory. */ static void afs_dir_remove_subdir(struct dentry *dentry) { if (d_really_is_positive(dentry)) { struct afs_vnode *vnode = AFS_FS_I(d_inode(dentry)); clear_nlink(&vnode->vfs_inode); set_bit(AFS_VNODE_DELETED, &vnode->flags); clear_bit(AFS_VNODE_CB_PROMISED, &vnode->flags); } } /* * remove a directory from an AFS filesystem */ static int afs_rmdir(struct inode *dir, struct dentry *dentry) { struct afs_fs_cursor fc; struct afs_vnode *dvnode = AFS_FS_I(dir); struct key *key; int ret; _enter("{%x:%u},{%pd}", dvnode->fid.vid, dvnode->fid.vnode, dentry); key = afs_request_key(dvnode->volume->cell); if (IS_ERR(key)) { ret = PTR_ERR(key); goto error; } ret = -ERESTARTSYS; if (afs_begin_vnode_operation(&fc, dvnode, key)) { while (afs_select_fileserver(&fc)) { fc.cb_break = dvnode->cb_break + dvnode->cb_s_break; afs_fs_remove(&fc, dentry->d_name.name, true); } afs_vnode_commit_status(&fc, dvnode, fc.cb_break); ret = afs_end_vnode_operation(&fc); if (ret == 0) afs_dir_remove_subdir(dentry); } key_put(key); error: return ret; } /* * Remove a link to a file or symlink from a directory. * * If the file was not deleted due to excess hard links, the fileserver will * break the callback promise on the file - if it had one - before it returns * to us, and if it was deleted, it won't * * However, if we didn't have a callback promise outstanding, or it was * outstanding on a different server, then it won't break it either... */ static int afs_dir_remove_link(struct dentry *dentry, struct key *key, unsigned long d_version_before, unsigned long d_version_after) { bool dir_valid; int ret = 0; /* There were no intervening changes on the server if the version * number we got back was incremented by exactly 1. */ dir_valid = (d_version_after == d_version_before + 1); if (d_really_is_positive(dentry)) { struct afs_vnode *vnode = AFS_FS_I(d_inode(dentry)); if (dir_valid) { drop_nlink(&vnode->vfs_inode); if (vnode->vfs_inode.i_nlink == 0) { set_bit(AFS_VNODE_DELETED, &vnode->flags); clear_bit(AFS_VNODE_CB_PROMISED, &vnode->flags); } ret = 0; } else { clear_bit(AFS_VNODE_CB_PROMISED, &vnode->flags); if (test_bit(AFS_VNODE_DELETED, &vnode->flags)) kdebug("AFS_VNODE_DELETED"); ret = afs_validate(vnode, key); if (ret == -ESTALE) ret = 0; } _debug("nlink %d [val %d]", vnode->vfs_inode.i_nlink, ret); } return ret; } /* * Remove a file or symlink from an AFS filesystem. */ static int afs_unlink(struct inode *dir, struct dentry *dentry) { struct afs_fs_cursor fc; struct afs_vnode *dvnode = AFS_FS_I(dir), *vnode; struct key *key; unsigned long d_version = (unsigned long)dentry->d_fsdata; int ret; _enter("{%x:%u},{%pd}", dvnode->fid.vid, dvnode->fid.vnode, dentry); if (dentry->d_name.len >= AFSNAMEMAX) return -ENAMETOOLONG; key = afs_request_key(dvnode->volume->cell); if (IS_ERR(key)) { ret = PTR_ERR(key); goto error; } /* Try to make sure we have a callback promise on the victim. */ if (d_really_is_positive(dentry)) { vnode = AFS_FS_I(d_inode(dentry)); ret = afs_validate(vnode, key); if (ret < 0) goto error_key; } ret = -ERESTARTSYS; if (afs_begin_vnode_operation(&fc, dvnode, key)) { while (afs_select_fileserver(&fc)) { fc.cb_break = dvnode->cb_break + dvnode->cb_s_break; afs_fs_remove(&fc, dentry->d_name.name, false); } afs_vnode_commit_status(&fc, dvnode, fc.cb_break); ret = afs_end_vnode_operation(&fc); if (ret == 0) ret = afs_dir_remove_link( dentry, key, d_version, (unsigned long)dvnode->status.data_version); } error_key: key_put(key); error: _leave(" = %d", ret); return ret; } /* * create a regular file on an AFS filesystem */ static int afs_create(struct inode *dir, struct dentry *dentry, umode_t mode, bool excl) { struct afs_fs_cursor fc; struct afs_file_status newstatus; struct afs_callback newcb; struct afs_vnode *dvnode = AFS_FS_I(dir); struct afs_fid newfid; struct key *key; int ret; mode |= S_IFREG; _enter("{%x:%u},{%pd},%ho,", dvnode->fid.vid, dvnode->fid.vnode, dentry, mode); ret = -ENAMETOOLONG; if (dentry->d_name.len >= AFSNAMEMAX) goto error; key = afs_request_key(dvnode->volume->cell); if (IS_ERR(key)) { ret = PTR_ERR(key); goto error; } ret = -ERESTARTSYS; if (afs_begin_vnode_operation(&fc, dvnode, key)) { while (afs_select_fileserver(&fc)) { fc.cb_break = dvnode->cb_break + dvnode->cb_s_break; afs_fs_create(&fc, dentry->d_name.name, mode, &newfid, &newstatus, &newcb); } afs_check_for_remote_deletion(&fc, fc.vnode); afs_vnode_commit_status(&fc, dvnode, fc.cb_break); afs_vnode_new_inode(&fc, dentry, &newfid, &newstatus, &newcb); ret = afs_end_vnode_operation(&fc); if (ret < 0) goto error_key; } else { goto error_key; } key_put(key); _leave(" = 0"); return 0; error_key: key_put(key); error: d_drop(dentry); _leave(" = %d", ret); return ret; } /* * create a hard link between files in an AFS filesystem */ static int afs_link(struct dentry *from, struct inode *dir, struct dentry *dentry) { struct afs_fs_cursor fc; struct afs_vnode *dvnode, *vnode; struct key *key; int ret; vnode = AFS_FS_I(d_inode(from)); dvnode = AFS_FS_I(dir); _enter("{%x:%u},{%x:%u},{%pd}", vnode->fid.vid, vnode->fid.vnode, dvnode->fid.vid, dvnode->fid.vnode, dentry); ret = -ENAMETOOLONG; if (dentry->d_name.len >= AFSNAMEMAX) goto error; key = afs_request_key(dvnode->volume->cell); if (IS_ERR(key)) { ret = PTR_ERR(key); goto error; } ret = -ERESTARTSYS; if (afs_begin_vnode_operation(&fc, dvnode, key)) { if (mutex_lock_interruptible_nested(&vnode->io_lock, 1) < 0) { afs_end_vnode_operation(&fc); goto error_key; } while (afs_select_fileserver(&fc)) { fc.cb_break = dvnode->cb_break + dvnode->cb_s_break; fc.cb_break_2 = vnode->cb_break + vnode->cb_s_break; afs_fs_link(&fc, vnode, dentry->d_name.name); } afs_vnode_commit_status(&fc, dvnode, fc.cb_break); afs_vnode_commit_status(&fc, vnode, fc.cb_break_2); ihold(&vnode->vfs_inode); d_instantiate(dentry, &vnode->vfs_inode); mutex_unlock(&vnode->io_lock); ret = afs_end_vnode_operation(&fc); if (ret < 0) goto error_key; } else { goto error_key; } key_put(key); _leave(" = 0"); return 0; error_key: key_put(key); error: d_drop(dentry); _leave(" = %d", ret); return ret; } /* * create a symlink in an AFS filesystem */ static int afs_symlink(struct inode *dir, struct dentry *dentry, const char *content) { struct afs_fs_cursor fc; struct afs_file_status newstatus; struct afs_vnode *dvnode = AFS_FS_I(dir); struct afs_fid newfid; struct key *key; int ret; _enter("{%x:%u},{%pd},%s", dvnode->fid.vid, dvnode->fid.vnode, dentry, content); ret = -ENAMETOOLONG; if (dentry->d_name.len >= AFSNAMEMAX) goto error; ret = -EINVAL; if (strlen(content) >= AFSPATHMAX) goto error; key = afs_request_key(dvnode->volume->cell); if (IS_ERR(key)) { ret = PTR_ERR(key); goto error; } ret = -ERESTARTSYS; if (afs_begin_vnode_operation(&fc, dvnode, key)) { while (afs_select_fileserver(&fc)) { fc.cb_break = dvnode->cb_break + dvnode->cb_s_break; afs_fs_symlink(&fc, dentry->d_name.name, content, &newfid, &newstatus); } afs_check_for_remote_deletion(&fc, fc.vnode); afs_vnode_commit_status(&fc, dvnode, fc.cb_break); afs_vnode_new_inode(&fc, dentry, &newfid, &newstatus, NULL); ret = afs_end_vnode_operation(&fc); if (ret < 0) goto error_key; } else { goto error_key; } key_put(key); _leave(" = 0"); return 0; error_key: key_put(key); error: d_drop(dentry); _leave(" = %d", ret); return ret; } /* * rename a file in an AFS filesystem and/or move it between directories */ static int afs_rename(struct inode *old_dir, struct dentry *old_dentry, struct inode *new_dir, struct dentry *new_dentry, unsigned int flags) { struct afs_fs_cursor fc; struct afs_vnode *orig_dvnode, *new_dvnode, *vnode; struct key *key; int ret; if (flags) return -EINVAL; vnode = AFS_FS_I(d_inode(old_dentry)); orig_dvnode = AFS_FS_I(old_dir); new_dvnode = AFS_FS_I(new_dir); _enter("{%x:%u},{%x:%u},{%x:%u},{%pd}", orig_dvnode->fid.vid, orig_dvnode->fid.vnode, vnode->fid.vid, vnode->fid.vnode, new_dvnode->fid.vid, new_dvnode->fid.vnode, new_dentry); key = afs_request_key(orig_dvnode->volume->cell); if (IS_ERR(key)) { ret = PTR_ERR(key); goto error; } ret = -ERESTARTSYS; if (afs_begin_vnode_operation(&fc, orig_dvnode, key)) { if (orig_dvnode != new_dvnode) { if (mutex_lock_interruptible_nested(&new_dvnode->io_lock, 1) < 0) { afs_end_vnode_operation(&fc); goto error_key; } } while (afs_select_fileserver(&fc)) { fc.cb_break = orig_dvnode->cb_break + orig_dvnode->cb_s_break; fc.cb_break_2 = new_dvnode->cb_break + new_dvnode->cb_s_break; afs_fs_rename(&fc, old_dentry->d_name.name, new_dvnode, new_dentry->d_name.name); } afs_vnode_commit_status(&fc, orig_dvnode, fc.cb_break); afs_vnode_commit_status(&fc, new_dvnode, fc.cb_break_2); if (orig_dvnode != new_dvnode) mutex_unlock(&new_dvnode->io_lock); ret = afs_end_vnode_operation(&fc); if (ret < 0) goto error_key; } error_key: key_put(key); error: _leave(" = %d", ret); return ret; }