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WSL2-Linux-Kernel
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WSL2-Linux-Kernel/fs/afs/dir.c

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53 KiB
C
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// SPDX-License-Identifier: GPL-2.0-or-later
/* dir.c: AFS filesystem directory handling
*
* Copyright (C) 2002, 2018 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
*/
#include <linux/kernel.h>
#include <linux/fs.h>
#include <linux/namei.h>
#include <linux/pagemap.h>
#include <linux/swap.h>
#include <linux/ctype.h>
#include <linux/sched.h>
#include <linux/task_io_accounting_ops.h>
#include "internal.h"
#include "afs_fs.h"
#include "xdr_fs.h"
static struct dentry *afs_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_iput(struct dentry *dentry, struct inode *inode);
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);
static int afs_dir_releasepage(struct page *page, gfp_t gfp_flags);
static void afs_dir_invalidatepage(struct page *page, unsigned int offset,
unsigned int length);
static int afs_dir_set_page_dirty(struct page *page)
{
BUG(); /* This should never happen. */
}
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 address_space_operations afs_dir_aops = {
.set_page_dirty = afs_dir_set_page_dirty,
.releasepage = afs_dir_releasepage,
.invalidatepage = afs_dir_invalidatepage,
};
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,
.d_iput = afs_d_iput,
};
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 inode **inodes;
struct afs_status_cb *statuses;
struct afs_fid fids[50];
};
/*
* check that a directory page is valid
*/
static bool afs_dir_check_page(struct afs_vnode *dvnode, struct page *page,
loff_t i_size)
{
struct afs_xdr_dir_page *dbuf;
loff_t latter, off;
int tmp, qty;
/* 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);
if (i_size <= off)
goto checked;
latter = i_size - off;
if (latter >= PAGE_SIZE)
qty = PAGE_SIZE;
else
qty = latter;
qty /= sizeof(union afs_xdr_dir_block);
/* check them */
dbuf = kmap(page);
for (tmp = 0; tmp < qty; tmp++) {
if (dbuf->blocks[tmp].hdr.magic != AFS_DIR_MAGIC) {
printk("kAFS: %s(%lx): bad magic %d/%d is %04hx\n",
__func__, dvnode->vfs_inode.i_ino, tmp, qty,
ntohs(dbuf->blocks[tmp].hdr.magic));
trace_afs_dir_check_failed(dvnode, off, i_size);
kunmap(page);
trace_afs_file_error(dvnode, -EIO, afs_file_error_dir_bad_magic);
goto error;
}
/* Make sure each block is NUL terminated so we can reasonably
* use string functions on it. The filenames in the page
* *should* be NUL-terminated anyway.
*/
((u8 *)&dbuf->blocks[tmp])[AFS_DIR_BLOCK_SIZE - 1] = 0;
}
kunmap(page);
checked:
afs_stat_v(dvnode, n_read_dir);
return true;
error:
return false;
}
/*
* Check the contents of a directory that we've just read.
*/
static bool afs_dir_check_pages(struct afs_vnode *dvnode, struct afs_read *req)
{
struct afs_xdr_dir_page *dbuf;
unsigned int i, j, qty = PAGE_SIZE / sizeof(union afs_xdr_dir_block);
for (i = 0; i < req->nr_pages; i++)
if (!afs_dir_check_page(dvnode, req->pages[i], req->actual_len))
goto bad;
return true;
bad:
pr_warn("DIR %llx:%llx f=%llx l=%llx al=%llx r=%llx\n",
dvnode->fid.vid, dvnode->fid.vnode,
req->file_size, req->len, req->actual_len, req->remain);
pr_warn("DIR %llx %x %x %x\n",
req->pos, req->index, req->nr_pages, req->offset);
for (i = 0; i < req->nr_pages; i++) {
dbuf = kmap(req->pages[i]);
for (j = 0; j < qty; j++) {
union afs_xdr_dir_block *block = &dbuf->blocks[j];
pr_warn("[%02x] %32phN\n", i * qty + j, block);
}
kunmap(req->pages[i]);
}
return false;
}
/*
* 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_xdr_dir_block) != 2048);
BUILD_BUG_ON(sizeof(union afs_xdr_dirent) != 32);
if (test_bit(AFS_VNODE_DELETED, &AFS_FS_I(inode)->flags))
return -ENOENT;
return afs_open(inode, file);
}
/*
* Read the directory into the pagecache in one go, scrubbing the previous
* contents. The list of pages is returned, pinning them so that they don't
* get reclaimed during the iteration.
*/
static struct afs_read *afs_read_dir(struct afs_vnode *dvnode, struct key *key)
__acquires(&dvnode->validate_lock)
{
struct afs_read *req;
loff_t i_size;
int nr_pages, nr_inline, i, n;
int ret = -ENOMEM;
retry:
i_size = i_size_read(&dvnode->vfs_inode);
if (i_size < 2048)
return ERR_PTR(afs_bad(dvnode, afs_file_error_dir_small));
if (i_size > 2048 * 1024) {
trace_afs_file_error(dvnode, -EFBIG, afs_file_error_dir_big);
return ERR_PTR(-EFBIG);
}
_enter("%llu", i_size);
/* Get a request record to hold the page list. We want to hold it
* inline if we can, but we don't want to make an order 1 allocation.
*/
nr_pages = (i_size + PAGE_SIZE - 1) / PAGE_SIZE;
nr_inline = nr_pages;
if (nr_inline > (PAGE_SIZE - sizeof(*req)) / sizeof(struct page *))
nr_inline = 0;
req = kzalloc(struct_size(req, array, nr_inline), GFP_KERNEL);
if (!req)
return ERR_PTR(-ENOMEM);
refcount_set(&req->usage, 1);
req->nr_pages = nr_pages;
req->actual_len = i_size; /* May change */
req->len = nr_pages * PAGE_SIZE; /* We can ask for more than there is */
req->data_version = dvnode->status.data_version; /* May change */
if (nr_inline > 0) {
req->pages = req->array;
} else {
req->pages = kcalloc(nr_pages, sizeof(struct page *),
GFP_KERNEL);
if (!req->pages)
goto error;
}
/* Get a list of all the pages that hold or will hold the directory
* content. We need to fill in any gaps that we might find where the
* memory reclaimer has been at work. If there are any gaps, we will
* need to reread the entire directory contents.
*/
i = 0;
do {
n = find_get_pages_contig(dvnode->vfs_inode.i_mapping, i,
req->nr_pages - i,
req->pages + i);
_debug("find %u at %u/%u", n, i, req->nr_pages);
if (n == 0) {
gfp_t gfp = dvnode->vfs_inode.i_mapping->gfp_mask;
if (test_and_clear_bit(AFS_VNODE_DIR_VALID, &dvnode->flags))
afs_stat_v(dvnode, n_inval);
ret = -ENOMEM;
req->pages[i] = __page_cache_alloc(gfp);
if (!req->pages[i])
goto error;
ret = add_to_page_cache_lru(req->pages[i],
dvnode->vfs_inode.i_mapping,
i, gfp);
if (ret < 0)
goto error;
set_page_private(req->pages[i], 1);
SetPagePrivate(req->pages[i]);
unlock_page(req->pages[i]);
i++;
} else {
i += n;
}
} while (i < req->nr_pages);
/* If we're going to reload, we need to lock all the pages to prevent
* races.
*/
ret = -ERESTARTSYS;
if (down_read_killable(&dvnode->validate_lock) < 0)
goto error;
if (test_bit(AFS_VNODE_DIR_VALID, &dvnode->flags))
goto success;
up_read(&dvnode->validate_lock);
if (down_write_killable(&dvnode->validate_lock) < 0)
goto error;
if (!test_bit(AFS_VNODE_DIR_VALID, &dvnode->flags)) {
trace_afs_reload_dir(dvnode);
ret = afs_fetch_data(dvnode, key, req);
if (ret < 0)
goto error_unlock;
task_io_account_read(PAGE_SIZE * req->nr_pages);
if (req->len < req->file_size)
goto content_has_grown;
/* Validate the data we just read. */
ret = -EIO;
if (!afs_dir_check_pages(dvnode, req))
goto error_unlock;
// TODO: Trim excess pages
set_bit(AFS_VNODE_DIR_VALID, &dvnode->flags);
}
downgrade_write(&dvnode->validate_lock);
success:
return req;
error_unlock:
up_write(&dvnode->validate_lock);
error:
afs_put_read(req);
_leave(" = %d", ret);
return ERR_PTR(ret);
content_has_grown:
up_write(&dvnode->validate_lock);
afs_put_read(req);
goto retry;
}
/*
* deal with one block in an AFS directory
*/
static int afs_dir_iterate_block(struct afs_vnode *dvnode,
struct dir_context *ctx,
union afs_xdr_dir_block *block,
unsigned blkoff)
{
union afs_xdr_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_xdr_dirent);
/* walk through the block, an entry at a time */
for (offset = (blkoff == 0 ? AFS_DIR_RESV_BLOCKS0 : AFS_DIR_RESV_BLOCKS);
offset < AFS_DIR_SLOTS_PER_BLOCK;
offset = next
) {
next = offset + 1;
/* skip entries marked unused in the bitmap */
if (!(block->hdr.bitmap[offset / 8] &
(1 << (offset % 8)))) {
_debug("ENT[%zu.%u]: unused",
blkoff / sizeof(union afs_xdr_dir_block), offset);
if (offset >= curr)
ctx->pos = blkoff +
next * sizeof(union afs_xdr_dirent);
continue;
}
/* got a valid entry */
dire = &block->dirents[offset];
nlen = strnlen(dire->u.name,
sizeof(*block) -
offset * sizeof(union afs_xdr_dirent));
_debug("ENT[%zu.%u]: %s %zu \"%s\"",
blkoff / sizeof(union afs_xdr_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_xdr_dirent)) {
if (next >= AFS_DIR_SLOTS_PER_BLOCK) {
_debug("ENT[%zu.%u]:"
" %u travelled beyond end dir block"
" (len %u/%zu)",
blkoff / sizeof(union afs_xdr_dir_block),
offset, next, tmp, nlen);
return afs_bad(dvnode, afs_file_error_dir_over_end);
}
if (!(block->hdr.bitmap[next / 8] &
(1 << (next % 8)))) {
_debug("ENT[%zu.%u]:"
" %u unmarked extension (len %u/%zu)",
blkoff / sizeof(union afs_xdr_dir_block),
offset, next, tmp, nlen);
return afs_bad(dvnode, afs_file_error_dir_unmarked_ext);
}
_debug("ENT[%zu.%u]: ext %u/%zu",
blkoff / sizeof(union afs_xdr_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_xdr_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, afs_dataversion_t *_dir_version)
{
struct afs_vnode *dvnode = AFS_FS_I(dir);
struct afs_xdr_dir_page *dbuf;
union afs_xdr_dir_block *dblock;
struct afs_read *req;
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;
}
req = afs_read_dir(dvnode, key);
if (IS_ERR(req))
return PTR_ERR(req);
*_dir_version = req->data_version;
/* round the file position up to the next entry boundary */
ctx->pos += sizeof(union afs_xdr_dirent) - 1;
ctx->pos &= ~(sizeof(union afs_xdr_dirent) - 1);
/* walk through the blocks in sequence */
ret = 0;
while (ctx->pos < req->actual_len) {
blkoff = ctx->pos & ~(sizeof(union afs_xdr_dir_block) - 1);
/* Fetch the appropriate page from the directory and re-add it
* to the LRU.
*/
page = req->pages[blkoff / PAGE_SIZE];
if (!page) {
ret = afs_bad(dvnode, afs_file_error_dir_missing_page);
break;
}
mark_page_accessed(page);
limit = blkoff & ~(PAGE_SIZE - 1);
dbuf = kmap(page);
/* deal with the individual blocks stashed on this page */
do {
dblock = &dbuf->blocks[(blkoff % PAGE_SIZE) /
sizeof(union afs_xdr_dir_block)];
ret = afs_dir_iterate_block(dvnode, ctx, dblock, blkoff);
if (ret != 1) {
kunmap(page);
goto out;
}
blkoff += sizeof(union afs_xdr_dir_block);
} while (ctx->pos < dir->i_size && blkoff < limit);
kunmap(page);
ret = 0;
}
out:
up_read(&dvnode->validate_lock);
afs_put_read(req);
_leave(" = %d", ret);
return ret;
}
/*
* read an AFS directory
*/
static int afs_readdir(struct file *file, struct dir_context *ctx)
{
afs_dataversion_t dir_version;
return afs_dir_iterate(file_inode(file), ctx, afs_file_key(file),
&dir_version);
}
/*
* 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_xdr_dir_block) != 2048);
BUILD_BUG_ON(sizeof(union afs_xdr_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,
afs_dataversion_t *_dir_version)
{
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, _dir_version);
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=%llu 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_xdr_dir_block) != 2048);
BUILD_BUG_ON(sizeof(union afs_xdr_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 *dcbi, *cbi = NULL;
struct afs_super_info *as = dir->i_sb->s_fs_info;
struct afs_status_cb *scb;
struct afs_iget_data iget_data;
struct afs_fs_cursor fc;
struct afs_server *server;
struct afs_vnode *dvnode = AFS_FS_I(dir), *vnode;
struct inode *inode = NULL, *ti;
afs_dataversion_t data_version = READ_ONCE(dvnode->status.data_version);
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);
dcbi = rcu_dereference_protected(dvnode->cb_interest,
lockdep_is_held(&dvnode->cb_lock.lock));
if (dcbi) {
server = dcbi->server;
if (server &&
test_bit(AFS_SERVER_FL_NO_IBULK, &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, &data_version);
if (ret < 0) {
inode = ERR_PTR(ret);
goto out;
}
dentry->d_fsdata = (void *)(unsigned long)data_version;
inode = ERR_PTR(-ENOENT);
if (!cookie->found)
goto out;
/* Check to see if we already have an inode for the primary fid. */
iget_data.fid = cookie->fids[0];
iget_data.volume = dvnode->volume;
iget_data.cb_v_break = dvnode->volume->cb_v_break;
iget_data.cb_s_break = 0;
inode = ilookup5(dir->i_sb, cookie->fids[0].vnode,
afs_iget5_test, &iget_data);
if (inode)
goto out;
/* Need space for examining all the selected files */
inode = ERR_PTR(-ENOMEM);
cookie->statuses = kvcalloc(cookie->nr_fids, sizeof(struct afs_status_cb),
GFP_KERNEL);
if (!cookie->statuses)
goto out;
cookie->inodes = kcalloc(cookie->nr_fids, sizeof(struct inode *),
GFP_KERNEL);
if (!cookie->inodes)
goto out_s;
for (i = 1; i < cookie->nr_fids; i++) {
scb = &cookie->statuses[i];
/* Find any inodes that already exist and get their
* callback counters.
*/
iget_data.fid = cookie->fids[i];
ti = ilookup5_nowait(dir->i_sb, iget_data.fid.vnode,
afs_iget5_test, &iget_data);
if (!IS_ERR_OR_NULL(ti)) {
vnode = AFS_FS_I(ti);
scb->cb_break = afs_calc_vnode_cb_break(vnode);
cookie->inodes[i] = ti;
}
}
/* 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, true)) {
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;
}
iget_data.cb_v_break = dvnode->volume->cb_v_break;
iget_data.cb_s_break = fc.cbi->server->cb_s_break;
afs_fs_inline_bulk_status(&fc,
afs_v2net(dvnode),
cookie->fids,
cookie->statuses,
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.
*/
inode = ERR_PTR(-ERESTARTSYS);
if (afs_begin_vnode_operation(&fc, dvnode, key, true)) {
while (afs_select_fileserver(&fc)) {
iget_data.cb_v_break = dvnode->volume->cb_v_break;
iget_data.cb_s_break = fc.cbi->server->cb_s_break;
scb = &cookie->statuses[0];
afs_fs_fetch_status(&fc,
afs_v2net(dvnode),
cookie->fids,
scb,
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;
success:
/* Turn all the files into inodes and save the first one - which is the
* one we actually want.
*/
scb = &cookie->statuses[0];
if (scb->status.abort_code != 0)
inode = ERR_PTR(afs_abort_to_error(scb->status.abort_code));
for (i = 0; i < cookie->nr_fids; i++) {
struct afs_status_cb *scb = &cookie->statuses[i];
if (!scb->have_status && !scb->have_error)
continue;
if (cookie->inodes[i]) {
struct afs_vnode *iv = AFS_FS_I(cookie->inodes[i]);
if (test_bit(AFS_VNODE_UNSET, &iv->flags))
continue;
afs_vnode_commit_status(&fc, iv,
scb->cb_break, NULL, scb);
continue;
}
if (scb->status.abort_code != 0)
continue;
iget_data.fid = cookie->fids[i];
ti = afs_iget(dir->i_sb, key, &iget_data, scb, cbi, dvnode);
if (!IS_ERR(ti))
afs_cache_permit(AFS_FS_I(ti), key,
0 /* Assume vnode->cb_break is 0 */ +
iget_data.cb_v_break,
scb);
if (i == 0) {
inode = ti;
} else {
if (!IS_ERR(ti))
iput(ti);
}
}
out_c:
afs_put_cb_interest(afs_v2net(dvnode), cbi);
if (cookie->inodes) {
for (i = 0; i < cookie->nr_fids; i++)
iput(cookie->inodes[i]);
kfree(cookie->inodes);
}
out_s:
kvfree(cookie->statuses);
out:
kfree(cookie);
return inode;
}
/*
* 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 afs_fid fid = {};
struct inode *inode;
struct dentry *d;
struct key *key;
int ret;
_enter("{%llx:%llu},%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);
afs_stat_v(dvnode, n_lookup);
inode = afs_do_lookup(dir, dentry, key);
key_put(key);
if (inode == ERR_PTR(-ENOENT))
inode = afs_try_auto_mntpt(dentry, dir);
if (!IS_ERR_OR_NULL(inode))
fid = AFS_FS_I(inode)->fid;
d = d_splice_alias(inode, dentry);
if (!IS_ERR_OR_NULL(d)) {
d->d_fsdata = dentry->d_fsdata;
trace_afs_lookup(dvnode, &d->d_name, &fid);
} else {
trace_afs_lookup(dvnode, &dentry->d_name, &fid);
}
return d;
}
/*
* Check the validity of a dentry under RCU conditions.
*/
static int afs_d_revalidate_rcu(struct dentry *dentry)
{
struct afs_vnode *dvnode, *vnode;
struct dentry *parent;
struct inode *dir, *inode;
long dir_version, de_version;
_enter("%p", dentry);
/* Check the parent directory is still valid first. */
parent = READ_ONCE(dentry->d_parent);
dir = d_inode_rcu(parent);
if (!dir)
return -ECHILD;
dvnode = AFS_FS_I(dir);
if (test_bit(AFS_VNODE_DELETED, &dvnode->flags))
return -ECHILD;
if (!afs_check_validity(dvnode))
return -ECHILD;
/* We only need to invalidate a dentry if the server's copy changed
* behind our back. If we made the change, it's no problem. Note that
* on a 32-bit system, we only have 32 bits in the dentry to store the
* version.
*/
dir_version = (long)READ_ONCE(dvnode->status.data_version);
de_version = (long)READ_ONCE(dentry->d_fsdata);
if (de_version != dir_version) {
dir_version = (long)READ_ONCE(dvnode->invalid_before);
if (de_version - dir_version < 0)
return -ECHILD;
}
/* Check to see if the vnode referred to by the dentry still
* has a callback.
*/
if (d_really_is_positive(dentry)) {
inode = d_inode_rcu(dentry);
if (inode) {
vnode = AFS_FS_I(inode);
if (!afs_check_validity(vnode))
return -ECHILD;
}
}
return 1; /* Still valid */
}
/*
* 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_vnode *vnode, *dir;
struct afs_fid uninitialized_var(fid);
struct dentry *parent;
struct inode *inode;
struct key *key;
afs_dataversion_t dir_version, invalid_before;
long de_version;
int ret;
if (flags & LOOKUP_RCU)
return afs_d_revalidate_rcu(dentry);
if (d_really_is_positive(dentry)) {
vnode = AFS_FS_I(d_inode(dentry));
_enter("{v={%llx:%llu} 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;
}
/* We only need to invalidate a dentry if the server's copy changed
* behind our back. If we made the change, it's no problem. Note that
* on a 32-bit system, we only have 32 bits in the dentry to store the
* version.
*/
dir_version = dir->status.data_version;
de_version = (long)dentry->d_fsdata;
if (de_version == (long)dir_version)
goto out_valid_noupdate;
invalid_before = dir->invalid_before;
if (de_version - (long)invalid_before >= 0)
goto out_valid;
_debug("dir modified");
afs_stat_v(dir, n_reval);
/* search the directory for this vnode */
ret = afs_do_lookup_one(&dir->vfs_inode, dentry, &fid, key, &dir_version);
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 [%llu != %llu]",
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 = (void *)(unsigned long)dir_version;
out_valid_noupdate:
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;
}
/*
* Clean up sillyrename files on dentry removal.
*/
static void afs_d_iput(struct dentry *dentry, struct inode *inode)
{
if (dentry->d_flags & DCACHE_NFSFS_RENAMED)
afs_silly_iput(dentry, inode);
iput(inode);
}
/*
* handle dentry release
*/
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_iget_data *new_data,
struct afs_status_cb *new_scb)
{
struct afs_vnode *vnode;
struct inode *inode;
if (fc->ac.error < 0)
return;
inode = afs_iget(fc->vnode->vfs_inode.i_sb, fc->key,
new_data, new_scb, fc->cbi, fc->vnode);
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;
}
vnode = AFS_FS_I(inode);
set_bit(AFS_VNODE_NEW_CONTENT, &vnode->flags);
if (fc->ac.error == 0)
afs_cache_permit(vnode, fc->key, vnode->cb_break, new_scb);
d_instantiate(new_dentry, inode);
}
static void afs_prep_for_new_inode(struct afs_fs_cursor *fc,
struct afs_iget_data *iget_data)
{
iget_data->volume = fc->vnode->volume;
iget_data->cb_v_break = fc->vnode->volume->cb_v_break;
iget_data->cb_s_break = fc->cbi->server->cb_s_break;
}
/*
* Note that a dentry got changed. We need to set d_fsdata to the data version
* number derived from the result of the operation. It doesn't matter if
* d_fsdata goes backwards as we'll just revalidate.
*/
static void afs_update_dentry_version(struct afs_fs_cursor *fc,
struct dentry *dentry,
struct afs_status_cb *scb)
{
if (fc->ac.error == 0)
dentry->d_fsdata =
(void *)(unsigned long)scb->status.data_version;
}
/*
* create a directory on an AFS filesystem
*/
static int afs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
{
struct afs_iget_data iget_data;
struct afs_status_cb *scb;
struct afs_fs_cursor fc;
struct afs_vnode *dvnode = AFS_FS_I(dir);
struct key *key;
afs_dataversion_t data_version;
int ret;
mode |= S_IFDIR;
_enter("{%llx:%llu},{%pd},%ho",
dvnode->fid.vid, dvnode->fid.vnode, dentry, mode);
ret = -ENOMEM;
scb = kcalloc(2, sizeof(struct afs_status_cb), GFP_KERNEL);
if (!scb)
goto error;
key = afs_request_key(dvnode->volume->cell);
if (IS_ERR(key)) {
ret = PTR_ERR(key);
goto error_scb;
}
ret = -ERESTARTSYS;
if (afs_begin_vnode_operation(&fc, dvnode, key, true)) {
data_version = dvnode->status.data_version + 1;
while (afs_select_fileserver(&fc)) {
fc.cb_break = afs_calc_vnode_cb_break(dvnode);
afs_prep_for_new_inode(&fc, &iget_data);
afs_fs_create(&fc, dentry->d_name.name, mode,
&scb[0], &iget_data.fid, &scb[1]);
}
afs_check_for_remote_deletion(&fc, dvnode);
afs_vnode_commit_status(&fc, dvnode, fc.cb_break,
&data_version, &scb[0]);
afs_update_dentry_version(&fc, dentry, &scb[0]);
afs_vnode_new_inode(&fc, dentry, &iget_data, &scb[1]);
ret = afs_end_vnode_operation(&fc);
if (ret < 0)
goto error_key;
} else {
goto error_key;
}
if (ret == 0) {
down_write(&dvnode->validate_lock);
if (test_bit(AFS_VNODE_DIR_VALID, &dvnode->flags) &&
dvnode->status.data_version == data_version)
afs_edit_dir_add(dvnode, &dentry->d_name, &iget_data.fid,
afs_edit_dir_for_create);
up_write(&dvnode->validate_lock);
}
key_put(key);
kfree(scb);
_leave(" = 0");
return 0;
error_key:
key_put(key);
error_scb:
kfree(scb);
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);
clear_bit(AFS_VNODE_DIR_VALID, &vnode->flags);
}
}
/*
* remove a directory from an AFS filesystem
*/
static int afs_rmdir(struct inode *dir, struct dentry *dentry)
{
struct afs_status_cb *scb;
struct afs_fs_cursor fc;
struct afs_vnode *dvnode = AFS_FS_I(dir), *vnode = NULL;
struct key *key;
afs_dataversion_t data_version;
int ret;
_enter("{%llx:%llu},{%pd}",
dvnode->fid.vid, dvnode->fid.vnode, dentry);
scb = kzalloc(sizeof(struct afs_status_cb), GFP_KERNEL);
if (!scb)
return -ENOMEM;
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;
}
if (vnode) {
ret = down_write_killable(&vnode->rmdir_lock);
if (ret < 0)
goto error_key;
}
ret = -ERESTARTSYS;
if (afs_begin_vnode_operation(&fc, dvnode, key, true)) {
data_version = dvnode->status.data_version + 1;
while (afs_select_fileserver(&fc)) {
fc.cb_break = afs_calc_vnode_cb_break(dvnode);
afs_fs_remove(&fc, vnode, dentry->d_name.name, true, scb);
}
afs_vnode_commit_status(&fc, dvnode, fc.cb_break,
&data_version, scb);
afs_update_dentry_version(&fc, dentry, scb);
ret = afs_end_vnode_operation(&fc);
if (ret == 0) {
afs_dir_remove_subdir(dentry);
down_write(&dvnode->validate_lock);
if (test_bit(AFS_VNODE_DIR_VALID, &dvnode->flags) &&
dvnode->status.data_version == data_version)
afs_edit_dir_remove(dvnode, &dentry->d_name,
afs_edit_dir_for_rmdir);
up_write(&dvnode->validate_lock);
}
}
if (vnode)
up_write(&vnode->rmdir_lock);
error_key:
key_put(key);
error:
kfree(scb);
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 afs_vnode *dvnode, struct dentry *dentry,
struct key *key)
{
int ret = 0;
if (d_really_is_positive(dentry)) {
struct afs_vnode *vnode = AFS_FS_I(d_inode(dentry));
if (test_bit(AFS_VNODE_DELETED, &vnode->flags)) {
/* Already done */
} else if (test_bit(AFS_VNODE_DIR_VALID, &dvnode->flags)) {
write_seqlock(&vnode->cb_lock);
drop_nlink(&vnode->vfs_inode);
if (vnode->vfs_inode.i_nlink == 0) {
set_bit(AFS_VNODE_DELETED, &vnode->flags);
__afs_break_callback(vnode, afs_cb_break_for_unlink);
}
write_sequnlock(&vnode->cb_lock);
ret = 0;
} else {
afs_break_callback(vnode, afs_cb_break_for_unlink);
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_status_cb *scb;
struct afs_vnode *dvnode = AFS_FS_I(dir);
struct afs_vnode *vnode = AFS_FS_I(d_inode(dentry));
struct key *key;
bool need_rehash = false;
int ret;
_enter("{%llx:%llu},{%pd}",
dvnode->fid.vid, dvnode->fid.vnode, dentry);
if (dentry->d_name.len >= AFSNAMEMAX)
return -ENAMETOOLONG;
ret = -ENOMEM;
scb = kcalloc(2, sizeof(struct afs_status_cb), GFP_KERNEL);
if (!scb)
goto error;
key = afs_request_key(dvnode->volume->cell);
if (IS_ERR(key)) {
ret = PTR_ERR(key);
goto error_scb;
}
/* Try to make sure we have a callback promise on the victim. */
ret = afs_validate(vnode, key);
if (ret < 0)
goto error_key;
spin_lock(&dentry->d_lock);
if (d_count(dentry) > 1) {
spin_unlock(&dentry->d_lock);
/* Start asynchronous writeout of the inode */
write_inode_now(d_inode(dentry), 0);
ret = afs_sillyrename(dvnode, vnode, dentry, key);
goto error_key;
}
if (!d_unhashed(dentry)) {
/* Prevent a race with RCU lookup. */
__d_drop(dentry);
need_rehash = true;
}
spin_unlock(&dentry->d_lock);
ret = -ERESTARTSYS;
if (afs_begin_vnode_operation(&fc, dvnode, key, true)) {
afs_dataversion_t data_version = dvnode->status.data_version + 1;
afs_dataversion_t data_version_2 = vnode->status.data_version;
while (afs_select_fileserver(&fc)) {
fc.cb_break = afs_calc_vnode_cb_break(dvnode);
fc.cb_break_2 = afs_calc_vnode_cb_break(vnode);
if (test_bit(AFS_SERVER_FL_IS_YFS, &fc.cbi->server->flags) &&
!test_bit(AFS_SERVER_FL_NO_RM2, &fc.cbi->server->flags)) {
yfs_fs_remove_file2(&fc, vnode, dentry->d_name.name,
&scb[0], &scb[1]);
if (fc.ac.error != -ECONNABORTED ||
fc.ac.abort_code != RXGEN_OPCODE)
continue;
set_bit(AFS_SERVER_FL_NO_RM2, &fc.cbi->server->flags);
}
afs_fs_remove(&fc, vnode, dentry->d_name.name, false, &scb[0]);
}
afs_vnode_commit_status(&fc, dvnode, fc.cb_break,
&data_version, &scb[0]);
afs_vnode_commit_status(&fc, vnode, fc.cb_break_2,
&data_version_2, &scb[1]);
afs_update_dentry_version(&fc, dentry, &scb[0]);
ret = afs_end_vnode_operation(&fc);
if (ret == 0 && !(scb[1].have_status || scb[1].have_error))
ret = afs_dir_remove_link(dvnode, dentry, key);
if (ret == 0) {
down_write(&dvnode->validate_lock);
if (test_bit(AFS_VNODE_DIR_VALID, &dvnode->flags) &&
dvnode->status.data_version == data_version)
afs_edit_dir_remove(dvnode, &dentry->d_name,
afs_edit_dir_for_unlink);
up_write(&dvnode->validate_lock);
}
}
if (need_rehash && ret < 0 && ret != -ENOENT)
d_rehash(dentry);
error_key:
key_put(key);
error_scb:
kfree(scb);
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_iget_data iget_data;
struct afs_fs_cursor fc;
struct afs_status_cb *scb;
struct afs_vnode *dvnode = AFS_FS_I(dir);
struct key *key;
afs_dataversion_t data_version;
int ret;
mode |= S_IFREG;
_enter("{%llx:%llu},{%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 = -ENOMEM;
scb = kcalloc(2, sizeof(struct afs_status_cb), GFP_KERNEL);
if (!scb)
goto error_scb;
ret = -ERESTARTSYS;
if (afs_begin_vnode_operation(&fc, dvnode, key, true)) {
data_version = dvnode->status.data_version + 1;
while (afs_select_fileserver(&fc)) {
fc.cb_break = afs_calc_vnode_cb_break(dvnode);
afs_prep_for_new_inode(&fc, &iget_data);
afs_fs_create(&fc, dentry->d_name.name, mode,
&scb[0], &iget_data.fid, &scb[1]);
}
afs_check_for_remote_deletion(&fc, dvnode);
afs_vnode_commit_status(&fc, dvnode, fc.cb_break,
&data_version, &scb[0]);
afs_update_dentry_version(&fc, dentry, &scb[0]);
afs_vnode_new_inode(&fc, dentry, &iget_data, &scb[1]);
ret = afs_end_vnode_operation(&fc);
if (ret < 0)
goto error_key;
} else {
goto error_key;
}
down_write(&dvnode->validate_lock);
if (test_bit(AFS_VNODE_DIR_VALID, &dvnode->flags) &&
dvnode->status.data_version == data_version)
afs_edit_dir_add(dvnode, &dentry->d_name, &iget_data.fid,
afs_edit_dir_for_create);
up_write(&dvnode->validate_lock);
kfree(scb);
key_put(key);
_leave(" = 0");
return 0;
error_scb:
kfree(scb);
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_status_cb *scb;
struct afs_vnode *dvnode = AFS_FS_I(dir);
struct afs_vnode *vnode = AFS_FS_I(d_inode(from));
struct key *key;
afs_dataversion_t data_version;
int ret;
_enter("{%llx:%llu},{%llx:%llu},{%pd}",
vnode->fid.vid, vnode->fid.vnode,
dvnode->fid.vid, dvnode->fid.vnode,
dentry);
ret = -ENAMETOOLONG;
if (dentry->d_name.len >= AFSNAMEMAX)
goto error;
ret = -ENOMEM;
scb = kcalloc(2, sizeof(struct afs_status_cb), GFP_KERNEL);
if (!scb)
goto error;
key = afs_request_key(dvnode->volume->cell);
if (IS_ERR(key)) {
ret = PTR_ERR(key);
goto error_scb;
}
ret = -ERESTARTSYS;
if (afs_begin_vnode_operation(&fc, dvnode, key, true)) {
data_version = dvnode->status.data_version + 1;
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 = afs_calc_vnode_cb_break(dvnode);
fc.cb_break_2 = afs_calc_vnode_cb_break(vnode);
afs_fs_link(&fc, vnode, dentry->d_name.name,
&scb[0], &scb[1]);
}
afs_vnode_commit_status(&fc, dvnode, fc.cb_break,
&data_version, &scb[0]);
afs_vnode_commit_status(&fc, vnode, fc.cb_break_2,
NULL, &scb[1]);
ihold(&vnode->vfs_inode);
afs_update_dentry_version(&fc, dentry, &scb[0]);
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;
}
down_write(&dvnode->validate_lock);
if (test_bit(AFS_VNODE_DIR_VALID, &dvnode->flags) &&
dvnode->status.data_version == data_version)
afs_edit_dir_add(dvnode, &dentry->d_name, &vnode->fid,
afs_edit_dir_for_link);
up_write(&dvnode->validate_lock);
key_put(key);
kfree(scb);
_leave(" = 0");
return 0;
error_key:
key_put(key);
error_scb:
kfree(scb);
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_iget_data iget_data;
struct afs_fs_cursor fc;
struct afs_status_cb *scb;
struct afs_vnode *dvnode = AFS_FS_I(dir);
struct key *key;
afs_dataversion_t data_version;
int ret;
_enter("{%llx:%llu},{%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;
ret = -ENOMEM;
scb = kcalloc(2, sizeof(struct afs_status_cb), GFP_KERNEL);
if (!scb)
goto error;
key = afs_request_key(dvnode->volume->cell);
if (IS_ERR(key)) {
ret = PTR_ERR(key);
goto error_scb;
}
ret = -ERESTARTSYS;
if (afs_begin_vnode_operation(&fc, dvnode, key, true)) {
data_version = dvnode->status.data_version + 1;
while (afs_select_fileserver(&fc)) {
fc.cb_break = afs_calc_vnode_cb_break(dvnode);
afs_prep_for_new_inode(&fc, &iget_data);
afs_fs_symlink(&fc, dentry->d_name.name, content,
&scb[0], &iget_data.fid, &scb[1]);
}
afs_check_for_remote_deletion(&fc, dvnode);
afs_vnode_commit_status(&fc, dvnode, fc.cb_break,
&data_version, &scb[0]);
afs_update_dentry_version(&fc, dentry, &scb[0]);
afs_vnode_new_inode(&fc, dentry, &iget_data, &scb[1]);
ret = afs_end_vnode_operation(&fc);
if (ret < 0)
goto error_key;
} else {
goto error_key;
}
down_write(&dvnode->validate_lock);
if (test_bit(AFS_VNODE_DIR_VALID, &dvnode->flags) &&
dvnode->status.data_version == data_version)
afs_edit_dir_add(dvnode, &dentry->d_name, &iget_data.fid,
afs_edit_dir_for_symlink);
up_write(&dvnode->validate_lock);
key_put(key);
kfree(scb);
_leave(" = 0");
return 0;
error_key:
key_put(key);
error_scb:
kfree(scb);
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_status_cb *scb;
struct afs_vnode *orig_dvnode, *new_dvnode, *vnode;
struct dentry *tmp = NULL, *rehash = NULL;
struct inode *new_inode;
struct key *key;
afs_dataversion_t orig_data_version;
afs_dataversion_t new_data_version;
bool new_negative = d_is_negative(new_dentry);
int ret;
if (flags)
return -EINVAL;
/* Don't allow silly-rename files be moved around. */
if (old_dentry->d_flags & DCACHE_NFSFS_RENAMED)
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("{%llx:%llu},{%llx:%llu},{%llx:%llu},{%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);
ret = -ENOMEM;
scb = kcalloc(2, sizeof(struct afs_status_cb), GFP_KERNEL);
if (!scb)
goto error;
key = afs_request_key(orig_dvnode->volume->cell);
if (IS_ERR(key)) {
ret = PTR_ERR(key);
goto error_scb;
}
/* For non-directories, check whether the target is busy and if so,
* make a copy of the dentry and then do a silly-rename. If the
* silly-rename succeeds, the copied dentry is hashed and becomes the
* new target.
*/
if (d_is_positive(new_dentry) && !d_is_dir(new_dentry)) {
/* To prevent any new references to the target during the
* rename, we unhash the dentry in advance.
*/
if (!d_unhashed(new_dentry)) {
d_drop(new_dentry);
rehash = new_dentry;
}
if (d_count(new_dentry) > 2) {
/* copy the target dentry's name */
ret = -ENOMEM;
tmp = d_alloc(new_dentry->d_parent,
&new_dentry->d_name);
if (!tmp)
goto error_rehash;
ret = afs_sillyrename(new_dvnode,
AFS_FS_I(d_inode(new_dentry)),
new_dentry, key);
if (ret)
goto error_rehash;
new_dentry = tmp;
rehash = NULL;
new_negative = true;
}
}
/* This bit is potentially nasty as there's a potential race with
* afs_d_revalidate{,_rcu}(). We have to change d_fsdata on the dentry
* to reflect it's new parent's new data_version after the op, but
* d_revalidate may see old_dentry between the op having taken place
* and the version being updated.
*
* So drop the old_dentry for now to make other threads go through
* lookup instead - which we hold a lock against.
*/
d_drop(old_dentry);
ret = -ERESTARTSYS;
if (afs_begin_vnode_operation(&fc, orig_dvnode, key, true)) {
orig_data_version = orig_dvnode->status.data_version + 1;
if (orig_dvnode != new_dvnode) {
if (mutex_lock_interruptible_nested(&new_dvnode->io_lock, 1) < 0) {
afs_end_vnode_operation(&fc);
goto error_rehash_old;
}
new_data_version = new_dvnode->status.data_version + 1;
} else {
new_data_version = orig_data_version;
}
while (afs_select_fileserver(&fc)) {
fc.cb_break = afs_calc_vnode_cb_break(orig_dvnode);
fc.cb_break_2 = afs_calc_vnode_cb_break(new_dvnode);
afs_fs_rename(&fc, old_dentry->d_name.name,
new_dvnode, new_dentry->d_name.name,
&scb[0], &scb[1]);
}
afs_vnode_commit_status(&fc, orig_dvnode, fc.cb_break,
&orig_data_version, &scb[0]);
if (new_dvnode != orig_dvnode) {
afs_vnode_commit_status(&fc, new_dvnode, fc.cb_break_2,
&new_data_version, &scb[1]);
mutex_unlock(&new_dvnode->io_lock);
}
ret = afs_end_vnode_operation(&fc);
if (ret < 0)
goto error_rehash_old;
}
if (ret == 0) {
if (rehash)
d_rehash(rehash);
down_write(&orig_dvnode->validate_lock);
if (test_bit(AFS_VNODE_DIR_VALID, &orig_dvnode->flags) &&
orig_dvnode->status.data_version == orig_data_version)
afs_edit_dir_remove(orig_dvnode, &old_dentry->d_name,
afs_edit_dir_for_rename_0);
if (orig_dvnode != new_dvnode) {
up_write(&orig_dvnode->validate_lock);
down_write(&new_dvnode->validate_lock);
}
if (test_bit(AFS_VNODE_DIR_VALID, &new_dvnode->flags) &&
orig_dvnode->status.data_version == new_data_version) {
if (!new_negative)
afs_edit_dir_remove(new_dvnode, &new_dentry->d_name,
afs_edit_dir_for_rename_1);
afs_edit_dir_add(new_dvnode, &new_dentry->d_name,
&vnode->fid, afs_edit_dir_for_rename_2);
}
new_inode = d_inode(new_dentry);
if (new_inode) {
spin_lock(&new_inode->i_lock);
if (new_inode->i_nlink > 0)
drop_nlink(new_inode);
spin_unlock(&new_inode->i_lock);
}
/* Now we can update d_fsdata on the dentries to reflect their
* new parent's data_version.
*
* Note that if we ever implement RENAME_EXCHANGE, we'll have
* to update both dentries with opposing dir versions.
*/
afs_update_dentry_version(&fc, old_dentry, &scb[1]);
afs_update_dentry_version(&fc, new_dentry, &scb[1]);
d_move(old_dentry, new_dentry);
up_write(&new_dvnode->validate_lock);
goto error_tmp;
}
error_rehash_old:
d_rehash(new_dentry);
error_rehash:
if (rehash)
d_rehash(rehash);
error_tmp:
if (tmp)
dput(tmp);
key_put(key);
error_scb:
kfree(scb);
error:
_leave(" = %d", ret);
return ret;
}
/*
* Release a directory page and clean up its private state if it's not busy
* - return true if the page can now be released, false if not
*/
static int afs_dir_releasepage(struct page *page, gfp_t gfp_flags)
{
struct afs_vnode *dvnode = AFS_FS_I(page->mapping->host);
_enter("{{%llx:%llu}[%lu]}", dvnode->fid.vid, dvnode->fid.vnode, page->index);
set_page_private(page, 0);
ClearPagePrivate(page);
/* The directory will need reloading. */
if (test_and_clear_bit(AFS_VNODE_DIR_VALID, &dvnode->flags))
afs_stat_v(dvnode, n_relpg);
return 1;
}
/*
* invalidate part or all of a page
* - release a page and clean up its private data if offset is 0 (indicating
* the entire page)
*/
static void afs_dir_invalidatepage(struct page *page, unsigned int offset,
unsigned int length)
{
struct afs_vnode *dvnode = AFS_FS_I(page->mapping->host);
_enter("{%lu},%u,%u", page->index, offset, length);
BUG_ON(!PageLocked(page));
/* The directory will need reloading. */
if (test_and_clear_bit(AFS_VNODE_DIR_VALID, &dvnode->flags))
afs_stat_v(dvnode, n_inval);
/* we clean up only if the entire page is being invalidated */
if (offset == 0 && length == PAGE_SIZE) {
set_page_private(page, 0);
ClearPagePrivate(page);
}
}
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