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dir.c
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#include <linux/ceph/ceph_debug.h>
#include <linux/spinlock.h>
#include <linux/fs_struct.h>
#include <linux/namei.h>
#include <linux/slab.h>
#include <linux/sched.h>
#include <linux/xattr.h>
#include "super.h"
#include "mds_client.h"
/*
* Directory operations: readdir, lookup, create, link, unlink,
* rename, etc.
*/
/*
* Ceph MDS operations are specified in terms of a base ino and
* relative path. Thus, the client can specify an operation on a
* specific inode (e.g., a getattr due to fstat(2)), or as a path
* relative to, say, the root directory.
*
* Normally, we limit ourselves to strict inode ops (no path component)
* or dentry operations (a single path component relative to an ino). The
* exception to this is open_root_dentry(), which will open the mount
* point by name.
*/
const struct dentry_operations ceph_dentry_ops;
/*
* Initialize ceph dentry state.
*/
static int ceph_d_init(struct dentry *dentry)
{
struct ceph_dentry_info *di;
di = kmem_cache_zalloc(ceph_dentry_cachep, GFP_KERNEL);
if (!di)
return -ENOMEM; /* oh well */
di->dentry = dentry;
di->lease_session = NULL;
di->time = jiffies;
dentry->d_fsdata = di;
ceph_dentry_lru_add(dentry);
return 0;
}
/*
* for f_pos for readdir:
* - hash order:
* (0xff << 52) | ((24 bits hash) << 28) |
* (the nth entry has hash collision);
* - frag+name order;
* ((frag value) << 28) | (the nth entry in frag);
*/
#define OFFSET_BITS 28
#define OFFSET_MASK ((1 << OFFSET_BITS) - 1)
#define HASH_ORDER (0xffull << (OFFSET_BITS + 24))
loff_t ceph_make_fpos(unsigned high, unsigned off, bool hash_order)
{
loff_t fpos = ((loff_t)high << 28) | (loff_t)off;
if (hash_order)
fpos |= HASH_ORDER;
return fpos;
}
static bool is_hash_order(loff_t p)
{
return (p & HASH_ORDER) == HASH_ORDER;
}
static unsigned fpos_frag(loff_t p)
{
return p >> OFFSET_BITS;
}
static unsigned fpos_hash(loff_t p)
{
return ceph_frag_value(fpos_frag(p));
}
static unsigned fpos_off(loff_t p)
{
return p & OFFSET_MASK;
}
static int fpos_cmp(loff_t l, loff_t r)
{
int v = ceph_frag_compare(fpos_frag(l), fpos_frag(r));
if (v)
return v;
return (int)(fpos_off(l) - fpos_off(r));
}
/*
* make note of the last dentry we read, so we can
* continue at the same lexicographical point,
* regardless of what dir changes take place on the
* server.
*/
static int note_last_dentry(struct ceph_file_info *fi, const char *name,
int len, unsigned next_offset)
{
char *buf = kmalloc(len+1, GFP_KERNEL);
if (!buf)
return -ENOMEM;
kfree(fi->last_name);
fi->last_name = buf;
memcpy(fi->last_name, name, len);
fi->last_name[len] = 0;
fi->next_offset = next_offset;
dout("note_last_dentry '%s'\n", fi->last_name);
return 0;
}
static struct dentry *
__dcache_find_get_entry(struct dentry *parent, u64 idx,
struct ceph_readdir_cache_control *cache_ctl)
{
struct inode *dir = d_inode(parent);
struct dentry *dentry;
unsigned idx_mask = (PAGE_SIZE / sizeof(struct dentry *)) - 1;
loff_t ptr_pos = idx * sizeof(struct dentry *);
pgoff_t ptr_pgoff = ptr_pos >> PAGE_SHIFT;
if (ptr_pos >= i_size_read(dir))
return NULL;
if (!cache_ctl->page || ptr_pgoff != page_index(cache_ctl->page)) {
ceph_readdir_cache_release(cache_ctl);
cache_ctl->page = find_lock_page(&dir->i_data, ptr_pgoff);
if (!cache_ctl->page) {
dout(" page %lu not found\n", ptr_pgoff);
return ERR_PTR(-EAGAIN);
}
/* reading/filling the cache are serialized by
i_mutex, no need to use page lock */
unlock_page(cache_ctl->page);
cache_ctl->dentries = kmap(cache_ctl->page);
}
cache_ctl->index = idx & idx_mask;
rcu_read_lock();
spin_lock(&parent->d_lock);
/* check i_size again here, because empty directory can be
* marked as complete while not holding the i_mutex. */
if (ceph_dir_is_complete_ordered(dir) && ptr_pos < i_size_read(dir))
dentry = cache_ctl->dentries[cache_ctl->index];
else
dentry = NULL;
spin_unlock(&parent->d_lock);
if (dentry && !lockref_get_not_dead(&dentry->d_lockref))
dentry = NULL;
rcu_read_unlock();
return dentry ? : ERR_PTR(-EAGAIN);
}
/*
* When possible, we try to satisfy a readdir by peeking at the
* dcache. We make this work by carefully ordering dentries on
* d_child when we initially get results back from the MDS, and
* falling back to a "normal" sync readdir if any dentries in the dir
* are dropped.
*
* Complete dir indicates that we have all dentries in the dir. It is
* defined IFF we hold CEPH_CAP_FILE_SHARED (which will be revoked by
* the MDS if/when the directory is modified).
*/
static int __dcache_readdir(struct file *file, struct dir_context *ctx,
u32 shared_gen)
{
struct ceph_file_info *fi = file->private_data;
struct dentry *parent = file->f_path.dentry;
struct inode *dir = d_inode(parent);
struct dentry *dentry, *last = NULL;
struct ceph_dentry_info *di;
struct ceph_readdir_cache_control cache_ctl = {};
u64 idx = 0;
int err = 0;
dout("__dcache_readdir %p v%u at %llx\n", dir, shared_gen, ctx->pos);
/* search start position */
if (ctx->pos > 2) {
u64 count = div_u64(i_size_read(dir), sizeof(struct dentry *));
while (count > 0) {
u64 step = count >> 1;
dentry = __dcache_find_get_entry(parent, idx + step,
&cache_ctl);
if (!dentry) {
/* use linar search */
idx = 0;
break;
}
if (IS_ERR(dentry)) {
err = PTR_ERR(dentry);
goto out;
}
di = ceph_dentry(dentry);
spin_lock(&dentry->d_lock);
if (fpos_cmp(di->offset, ctx->pos) < 0) {
idx += step + 1;
count -= step + 1;
} else {
count = step;
}
spin_unlock(&dentry->d_lock);
dput(dentry);
}
dout("__dcache_readdir %p cache idx %llu\n", dir, idx);
}
for (;;) {
bool emit_dentry = false;
dentry = __dcache_find_get_entry(parent, idx++, &cache_ctl);
if (!dentry) {
fi->flags |= CEPH_F_ATEND;
err = 0;
break;
}
if (IS_ERR(dentry)) {
err = PTR_ERR(dentry);
goto out;
}
di = ceph_dentry(dentry);
spin_lock(&dentry->d_lock);
if (di->lease_shared_gen == shared_gen &&
d_really_is_positive(dentry) &&
fpos_cmp(ctx->pos, di->offset) <= 0) {
emit_dentry = true;
}
spin_unlock(&dentry->d_lock);
if (emit_dentry) {
dout(" %llx dentry %p %pd %p\n", di->offset,
dentry, dentry, d_inode(dentry));
ctx->pos = di->offset;
if (!dir_emit(ctx, dentry->d_name.name,
dentry->d_name.len,
ceph_translate_ino(dentry->d_sb,
d_inode(dentry)->i_ino),
d_inode(dentry)->i_mode >> 12)) {
dput(dentry);
err = 0;
break;
}
ctx->pos++;
if (last)
dput(last);
last = dentry;
} else {
dput(dentry);
}
}
out:
ceph_readdir_cache_release(&cache_ctl);
if (last) {
int ret;
di = ceph_dentry(last);
ret = note_last_dentry(fi, last->d_name.name, last->d_name.len,
fpos_off(di->offset) + 1);
if (ret < 0)
err = ret;
dput(last);
/* last_name no longer match cache index */
if (fi->readdir_cache_idx >= 0) {
fi->readdir_cache_idx = -1;
fi->dir_release_count = 0;
}
}
return err;
}
static bool need_send_readdir(struct ceph_file_info *fi, loff_t pos)
{
if (!fi->last_readdir)
return true;
if (is_hash_order(pos))
return !ceph_frag_contains_value(fi->frag, fpos_hash(pos));
else
return fi->frag != fpos_frag(pos);
}
static int ceph_readdir(struct file *file, struct dir_context *ctx)
{
struct ceph_file_info *fi = file->private_data;
struct inode *inode = file_inode(file);
struct ceph_inode_info *ci = ceph_inode(inode);
struct ceph_fs_client *fsc = ceph_inode_to_client(inode);
struct ceph_mds_client *mdsc = fsc->mdsc;
int i;
int err;
unsigned frag = -1;
struct ceph_mds_reply_info_parsed *rinfo;
dout("readdir %p file %p pos %llx\n", inode, file, ctx->pos);
if (fi->flags & CEPH_F_ATEND)
return 0;
/* always start with . and .. */
if (ctx->pos == 0) {
dout("readdir off 0 -> '.'\n");
if (!dir_emit(ctx, ".", 1,
ceph_translate_ino(inode->i_sb, inode->i_ino),
inode->i_mode >> 12))
return 0;
ctx->pos = 1;
}
if (ctx->pos == 1) {
ino_t ino = parent_ino(file->f_path.dentry);
dout("readdir off 1 -> '..'\n");
if (!dir_emit(ctx, "..", 2,
ceph_translate_ino(inode->i_sb, ino),
inode->i_mode >> 12))
return 0;
ctx->pos = 2;
}
/* can we use the dcache? */
spin_lock(&ci->i_ceph_lock);
if (ceph_test_mount_opt(fsc, DCACHE) &&
!ceph_test_mount_opt(fsc, NOASYNCREADDIR) &&
ceph_snap(inode) != CEPH_SNAPDIR &&
__ceph_dir_is_complete_ordered(ci) &&
__ceph_caps_issued_mask(ci, CEPH_CAP_FILE_SHARED, 1)) {
u32 shared_gen = ci->i_shared_gen;
spin_unlock(&ci->i_ceph_lock);
err = __dcache_readdir(file, ctx, shared_gen);
if (err != -EAGAIN)
return err;
} else {
spin_unlock(&ci->i_ceph_lock);
}
/* proceed with a normal readdir */
more:
/* do we have the correct frag content buffered? */
if (need_send_readdir(fi, ctx->pos)) {
struct ceph_mds_request *req;
int op = ceph_snap(inode) == CEPH_SNAPDIR ?
CEPH_MDS_OP_LSSNAP : CEPH_MDS_OP_READDIR;
/* discard old result, if any */
if (fi->last_readdir) {
ceph_mdsc_put_request(fi->last_readdir);
fi->last_readdir = NULL;
}
if (is_hash_order(ctx->pos)) {
/* fragtree isn't always accurate. choose frag
* based on previous reply when possible. */
if (frag == (unsigned)-1)
frag = ceph_choose_frag(ci, fpos_hash(ctx->pos),
NULL, NULL);
} else {
frag = fpos_frag(ctx->pos);
}
dout("readdir fetching %llx.%llx frag %x offset '%s'\n",
ceph_vinop(inode), frag, fi->last_name);
req = ceph_mdsc_create_request(mdsc, op, USE_AUTH_MDS);
if (IS_ERR(req))
return PTR_ERR(req);
err = ceph_alloc_readdir_reply_buffer(req, inode);
if (err) {
ceph_mdsc_put_request(req);
return err;
}
/* hints to request -> mds selection code */
req->r_direct_mode = USE_AUTH_MDS;
if (op == CEPH_MDS_OP_READDIR) {
req->r_direct_hash = ceph_frag_value(frag);
__set_bit(CEPH_MDS_R_DIRECT_IS_HASH, &req->r_req_flags);
}
if (fi->last_name) {
req->r_path2 = kstrdup(fi->last_name, GFP_KERNEL);
if (!req->r_path2) {
ceph_mdsc_put_request(req);
return -ENOMEM;
}
} else if (is_hash_order(ctx->pos)) {
req->r_args.readdir.offset_hash =
cpu_to_le32(fpos_hash(ctx->pos));
}
req->r_dir_release_cnt = fi->dir_release_count;
req->r_dir_ordered_cnt = fi->dir_ordered_count;
req->r_readdir_cache_idx = fi->readdir_cache_idx;
req->r_readdir_offset = fi->next_offset;
req->r_args.readdir.frag = cpu_to_le32(frag);
req->r_args.readdir.flags =
cpu_to_le16(CEPH_READDIR_REPLY_BITFLAGS);
req->r_inode = inode;
ihold(inode);
req->r_dentry = dget(file->f_path.dentry);
err = ceph_mdsc_do_request(mdsc, NULL, req);
if (err < 0) {
ceph_mdsc_put_request(req);
return err;
}
dout("readdir got and parsed readdir result=%d on "
"frag %x, end=%d, complete=%d, hash_order=%d\n",
err, frag,
(int)req->r_reply_info.dir_end,
(int)req->r_reply_info.dir_complete,
(int)req->r_reply_info.hash_order);
rinfo = &req->r_reply_info;
if (le32_to_cpu(rinfo->dir_dir->frag) != frag) {
frag = le32_to_cpu(rinfo->dir_dir->frag);
if (!rinfo->hash_order) {
fi->next_offset = req->r_readdir_offset;
/* adjust ctx->pos to beginning of frag */
ctx->pos = ceph_make_fpos(frag,
fi->next_offset,
false);
}
}
fi->frag = frag;
fi->last_readdir = req;
if (test_bit(CEPH_MDS_R_DID_PREPOPULATE, &req->r_req_flags)) {
fi->readdir_cache_idx = req->r_readdir_cache_idx;
if (fi->readdir_cache_idx < 0) {
/* preclude from marking dir ordered */
fi->dir_ordered_count = 0;
} else if (ceph_frag_is_leftmost(frag) &&
fi->next_offset == 2) {
/* note dir version at start of readdir so
* we can tell if any dentries get dropped */
fi->dir_release_count = req->r_dir_release_cnt;
fi->dir_ordered_count = req->r_dir_ordered_cnt;
}
} else {
dout("readdir !did_prepopulate");
/* disable readdir cache */
fi->readdir_cache_idx = -1;
/* preclude from marking dir complete */
fi->dir_release_count = 0;
}
/* note next offset and last dentry name */
if (rinfo->dir_nr > 0) {
struct ceph_mds_reply_dir_entry *rde =
rinfo->dir_entries + (rinfo->dir_nr-1);
unsigned next_offset = req->r_reply_info.dir_end ?
2 : (fpos_off(rde->offset) + 1);
err = note_last_dentry(fi, rde->name, rde->name_len,
next_offset);
if (err)
return err;
} else if (req->r_reply_info.dir_end) {
fi->next_offset = 2;
/* keep last name */
}
}
rinfo = &fi->last_readdir->r_reply_info;
dout("readdir frag %x num %d pos %llx chunk first %llx\n",
fi->frag, rinfo->dir_nr, ctx->pos,
rinfo->dir_nr ? rinfo->dir_entries[0].offset : 0LL);
i = 0;
/* search start position */
if (rinfo->dir_nr > 0) {
int step, nr = rinfo->dir_nr;
while (nr > 0) {
step = nr >> 1;
if (rinfo->dir_entries[i + step].offset < ctx->pos) {
i += step + 1;
nr -= step + 1;
} else {
nr = step;
}
}
}
for (; i < rinfo->dir_nr; i++) {
struct ceph_mds_reply_dir_entry *rde = rinfo->dir_entries + i;
struct ceph_vino vino;
ino_t ino;
u32 ftype;
BUG_ON(rde->offset < ctx->pos);
ctx->pos = rde->offset;
dout("readdir (%d/%d) -> %llx '%.*s' %p\n",
i, rinfo->dir_nr, ctx->pos,
rde->name_len, rde->name, &rde->inode.in);
BUG_ON(!rde->inode.in);
ftype = le32_to_cpu(rde->inode.in->mode) >> 12;
vino.ino = le64_to_cpu(rde->inode.in->ino);
vino.snap = le64_to_cpu(rde->inode.in->snapid);
ino = ceph_vino_to_ino(vino);
if (!dir_emit(ctx, rde->name, rde->name_len,
ceph_translate_ino(inode->i_sb, ino), ftype)) {
dout("filldir stopping us...\n");
return 0;
}
ctx->pos++;
}
ceph_mdsc_put_request(fi->last_readdir);
fi->last_readdir = NULL;
if (fi->next_offset > 2) {
frag = fi->frag;
goto more;
}
/* more frags? */
if (!ceph_frag_is_rightmost(fi->frag)) {
frag = ceph_frag_next(fi->frag);
if (is_hash_order(ctx->pos)) {
loff_t new_pos = ceph_make_fpos(ceph_frag_value(frag),
fi->next_offset, true);
if (new_pos > ctx->pos)
ctx->pos = new_pos;
/* keep last_name */
} else {
ctx->pos = ceph_make_fpos(frag, fi->next_offset, false);
kfree(fi->last_name);
fi->last_name = NULL;
}
dout("readdir next frag is %x\n", frag);
goto more;
}
fi->flags |= CEPH_F_ATEND;
/*
* if dir_release_count still matches the dir, no dentries
* were released during the whole readdir, and we should have
* the complete dir contents in our cache.
*/
if (atomic64_read(&ci->i_release_count) == fi->dir_release_count) {
spin_lock(&ci->i_ceph_lock);
if (fi->dir_ordered_count == atomic64_read(&ci->i_ordered_count)) {
dout(" marking %p complete and ordered\n", inode);
/* use i_size to track number of entries in
* readdir cache */
BUG_ON(fi->readdir_cache_idx < 0);
i_size_write(inode, fi->readdir_cache_idx *
sizeof(struct dentry*));
} else {
dout(" marking %p complete\n", inode);
}
__ceph_dir_set_complete(ci, fi->dir_release_count,
fi->dir_ordered_count);
spin_unlock(&ci->i_ceph_lock);
}
dout("readdir %p file %p done.\n", inode, file);
return 0;
}
static void reset_readdir(struct ceph_file_info *fi)
{
if (fi->last_readdir) {
ceph_mdsc_put_request(fi->last_readdir);
fi->last_readdir = NULL;
}
kfree(fi->last_name);
fi->last_name = NULL;
fi->dir_release_count = 0;
fi->readdir_cache_idx = -1;
fi->next_offset = 2; /* compensate for . and .. */
fi->flags &= ~CEPH_F_ATEND;
}
/*
* discard buffered readdir content on seekdir(0), or seek to new frag,
* or seek prior to current chunk
*/
static bool need_reset_readdir(struct ceph_file_info *fi, loff_t new_pos)
{
struct ceph_mds_reply_info_parsed *rinfo;
loff_t chunk_offset;
if (new_pos == 0)
return true;
if (is_hash_order(new_pos)) {
/* no need to reset last_name for a forward seek when
* dentries are sotred in hash order */
} else if (fi->frag != fpos_frag(new_pos)) {
return true;
}
rinfo = fi->last_readdir ? &fi->last_readdir->r_reply_info : NULL;
if (!rinfo || !rinfo->dir_nr)
return true;
chunk_offset = rinfo->dir_entries[0].offset;
return new_pos < chunk_offset ||
is_hash_order(new_pos) != is_hash_order(chunk_offset);
}
static loff_t ceph_dir_llseek(struct file *file, loff_t offset, int whence)
{
struct ceph_file_info *fi = file->private_data;
struct inode *inode = file->f_mapping->host;
loff_t retval;
inode_lock(inode);
retval = -EINVAL;
switch (whence) {
case SEEK_CUR:
offset += file->f_pos;
case SEEK_SET:
break;
case SEEK_END:
retval = -EOPNOTSUPP;
default:
goto out;
}
if (offset >= 0) {
if (need_reset_readdir(fi, offset)) {
dout("dir_llseek dropping %p content\n", file);
reset_readdir(fi);
} else if (is_hash_order(offset) && offset > file->f_pos) {
/* for hash offset, we don't know if a forward seek
* is within same frag */
fi->dir_release_count = 0;
fi->readdir_cache_idx = -1;
}
if (offset != file->f_pos) {
file->f_pos = offset;
file->f_version = 0;
fi->flags &= ~CEPH_F_ATEND;
}
retval = offset;
}
out:
inode_unlock(inode);
return retval;
}
/*
* Handle lookups for the hidden .snap directory.
*/
int ceph_handle_snapdir(struct ceph_mds_request *req,
struct dentry *dentry, int err)
{
struct ceph_fs_client *fsc = ceph_sb_to_client(dentry->d_sb);
struct inode *parent = d_inode(dentry->d_parent); /* we hold i_mutex */
/* .snap dir? */
if (err == -ENOENT &&
ceph_snap(parent) == CEPH_NOSNAP &&
strcmp(dentry->d_name.name,
fsc->mount_options->snapdir_name) == 0) {
struct inode *inode = ceph_get_snapdir(parent);
dout("ENOENT on snapdir %p '%pd', linking to snapdir %p\n",
dentry, dentry, inode);
BUG_ON(!d_unhashed(dentry));
d_add(dentry, inode);
err = 0;
}
return err;
}
/*
* Figure out final result of a lookup/open request.
*
* Mainly, make sure we return the final req->r_dentry (if it already
* existed) in place of the original VFS-provided dentry when they
* differ.
*
* Gracefully handle the case where the MDS replies with -ENOENT and
* no trace (which it may do, at its discretion, e.g., if it doesn't
* care to issue a lease on the negative dentry).
*/
struct dentry *ceph_finish_lookup(struct ceph_mds_request *req,
struct dentry *dentry, int err)
{
if (err == -ENOENT) {
/* no trace? */
err = 0;
if (!req->r_reply_info.head->is_dentry) {
dout("ENOENT and no trace, dentry %p inode %p\n",
dentry, d_inode(dentry));
if (d_really_is_positive(dentry)) {
d_drop(dentry);
err = -ENOENT;
} else {
d_add(dentry, NULL);
}
}
}
if (err)
dentry = ERR_PTR(err);
else if (dentry != req->r_dentry)
dentry = dget(req->r_dentry); /* we got spliced */
else
dentry = NULL;
return dentry;
}
static bool is_root_ceph_dentry(struct inode *inode, struct dentry *dentry)
{
return ceph_ino(inode) == CEPH_INO_ROOT &&
strncmp(dentry->d_name.name, ".ceph", 5) == 0;
}
/*
* Look up a single dir entry. If there is a lookup intent, inform
* the MDS so that it gets our 'caps wanted' value in a single op.
*/
static struct dentry *ceph_lookup(struct inode *dir, struct dentry *dentry,
unsigned int flags)
{
struct ceph_fs_client *fsc = ceph_sb_to_client(dir->i_sb);
struct ceph_mds_client *mdsc = fsc->mdsc;
struct ceph_mds_request *req;
int op;
int mask;
int err;
dout("lookup %p dentry %p '%pd'\n",
dir, dentry, dentry);
if (dentry->d_name.len > NAME_MAX)
return ERR_PTR(-ENAMETOOLONG);
/* can we conclude ENOENT locally? */
if (d_really_is_negative(dentry)) {
struct ceph_inode_info *ci = ceph_inode(dir);
struct ceph_dentry_info *di = ceph_dentry(dentry);
spin_lock(&ci->i_ceph_lock);
dout(" dir %p flags are %d\n", dir, ci->i_ceph_flags);
if (strncmp(dentry->d_name.name,
fsc->mount_options->snapdir_name,
dentry->d_name.len) &&
!is_root_ceph_dentry(dir, dentry) &&
ceph_test_mount_opt(fsc, DCACHE) &&
__ceph_dir_is_complete(ci) &&
(__ceph_caps_issued_mask(ci, CEPH_CAP_FILE_SHARED, 1))) {
spin_unlock(&ci->i_ceph_lock);
dout(" dir %p complete, -ENOENT\n", dir);
d_add(dentry, NULL);
di->lease_shared_gen = ci->i_shared_gen;
return NULL;
}
spin_unlock(&ci->i_ceph_lock);
}
op = ceph_snap(dir) == CEPH_SNAPDIR ?
CEPH_MDS_OP_LOOKUPSNAP : CEPH_MDS_OP_LOOKUP;
req = ceph_mdsc_create_request(mdsc, op, USE_ANY_MDS);
if (IS_ERR(req))
return ERR_CAST(req);
req->r_dentry = dget(dentry);
req->r_num_caps = 2;
mask = CEPH_STAT_CAP_INODE | CEPH_CAP_AUTH_SHARED;
if (ceph_security_xattr_wanted(dir))
mask |= CEPH_CAP_XATTR_SHARED;
req->r_args.getattr.mask = cpu_to_le32(mask);
req->r_parent = dir;
set_bit(CEPH_MDS_R_PARENT_LOCKED, &req->r_req_flags);
err = ceph_mdsc_do_request(mdsc, NULL, req);
err = ceph_handle_snapdir(req, dentry, err);
dentry = ceph_finish_lookup(req, dentry, err);
ceph_mdsc_put_request(req); /* will dput(dentry) */
dout("lookup result=%p\n", dentry);
return dentry;
}
/*
* If we do a create but get no trace back from the MDS, follow up with
* a lookup (the VFS expects us to link up the provided dentry).
*/
int ceph_handle_notrace_create(struct inode *dir, struct dentry *dentry)
{
struct dentry *result = ceph_lookup(dir, dentry, 0);
if (result && !IS_ERR(result)) {
/*
* We created the item, then did a lookup, and found
* it was already linked to another inode we already
* had in our cache (and thus got spliced). To not
* confuse VFS (especially when inode is a directory),
* we don't link our dentry to that inode, return an
* error instead.
*
* This event should be rare and it happens only when
* we talk to old MDS. Recent MDS does not send traceless
* reply for request that creates new inode.
*/
d_drop(result);
return -ESTALE;
}
return PTR_ERR(result);
}
static int ceph_mknod(struct inode *dir, struct dentry *dentry,
umode_t mode, dev_t rdev)
{
struct ceph_fs_client *fsc = ceph_sb_to_client(dir->i_sb);
struct ceph_mds_client *mdsc = fsc->mdsc;
struct ceph_mds_request *req;
struct ceph_acls_info acls = {};
int err;
if (ceph_snap(dir) != CEPH_NOSNAP)
return -EROFS;
err = ceph_pre_init_acls(dir, &mode, &acls);
if (err < 0)
return err;
dout("mknod in dir %p dentry %p mode 0%ho rdev %d\n",
dir, dentry, mode, rdev);
req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_MKNOD, USE_AUTH_MDS);
if (IS_ERR(req)) {
err = PTR_ERR(req);
goto out;
}
req->r_dentry = dget(dentry);
req->r_num_caps = 2;
req->r_parent = dir;
set_bit(CEPH_MDS_R_PARENT_LOCKED, &req->r_req_flags);
req->r_args.mknod.mode = cpu_to_le32(mode);
req->r_args.mknod.rdev = cpu_to_le32(rdev);
req->r_dentry_drop = CEPH_CAP_FILE_SHARED;
req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
if (acls.pagelist) {
req->r_pagelist = acls.pagelist;
acls.pagelist = NULL;
}
err = ceph_mdsc_do_request(mdsc, dir, req);
if (!err && !req->r_reply_info.head->is_dentry)
err = ceph_handle_notrace_create(dir, dentry);
ceph_mdsc_put_request(req);
out:
if (!err)
ceph_init_inode_acls(d_inode(dentry), &acls);
else
d_drop(dentry);
ceph_release_acls_info(&acls);
return err;
}
static int ceph_create(struct inode *dir, struct dentry *dentry, umode_t mode,
bool excl)
{
return ceph_mknod(dir, dentry, mode, 0);
}
static int ceph_symlink(struct inode *dir, struct dentry *dentry,
const char *dest)
{
struct ceph_fs_client *fsc = ceph_sb_to_client(dir->i_sb);
struct ceph_mds_client *mdsc = fsc->mdsc;
struct ceph_mds_request *req;
int err;
if (ceph_snap(dir) != CEPH_NOSNAP)
return -EROFS;
dout("symlink in dir %p dentry %p to '%s'\n", dir, dentry, dest);
req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_SYMLINK, USE_AUTH_MDS);
if (IS_ERR(req)) {
err = PTR_ERR(req);
goto out;
}
req->r_path2 = kstrdup(dest, GFP_KERNEL);
if (!req->r_path2) {
err = -ENOMEM;
ceph_mdsc_put_request(req);
goto out;
}
req->r_parent = dir;
set_bit(CEPH_MDS_R_PARENT_LOCKED, &req->r_req_flags);
req->r_dentry = dget(dentry);
req->r_num_caps = 2;
req->r_dentry_drop = CEPH_CAP_FILE_SHARED;
req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
err = ceph_mdsc_do_request(mdsc, dir, req);
if (!err && !req->r_reply_info.head->is_dentry)
err = ceph_handle_notrace_create(dir, dentry);
ceph_mdsc_put_request(req);
out:
if (err)
d_drop(dentry);
return err;
}
static int ceph_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
{
struct ceph_fs_client *fsc = ceph_sb_to_client(dir->i_sb);
struct ceph_mds_client *mdsc = fsc->mdsc;
struct ceph_mds_request *req;
struct ceph_acls_info acls = {};
int err = -EROFS;
int op;
if (ceph_snap(dir) == CEPH_SNAPDIR) {
/* mkdir .snap/foo is a MKSNAP */
op = CEPH_MDS_OP_MKSNAP;
dout("mksnap dir %p snap '%pd' dn %p\n", dir,
dentry, dentry);
} else if (ceph_snap(dir) == CEPH_NOSNAP) {
dout("mkdir dir %p dn %p mode 0%ho\n", dir, dentry, mode);
op = CEPH_MDS_OP_MKDIR;
} else {
goto out;
}
mode |= S_IFDIR;
err = ceph_pre_init_acls(dir, &mode, &acls);
if (err < 0)
goto out;
req = ceph_mdsc_create_request(mdsc, op, USE_AUTH_MDS);
if (IS_ERR(req)) {
err = PTR_ERR(req);
goto out;
}
req->r_dentry = dget(dentry);
req->r_num_caps = 2;
req->r_parent = dir;
set_bit(CEPH_MDS_R_PARENT_LOCKED, &req->r_req_flags);
req->r_args.mkdir.mode = cpu_to_le32(mode);
req->r_dentry_drop = CEPH_CAP_FILE_SHARED;
req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
if (acls.pagelist) {
req->r_pagelist = acls.pagelist;
acls.pagelist = NULL;
}
err = ceph_mdsc_do_request(mdsc, dir, req);
if (!err &&
!req->r_reply_info.head->is_target &&
!req->r_reply_info.head->is_dentry)
err = ceph_handle_notrace_create(dir, dentry);
ceph_mdsc_put_request(req);
out:
if (!err)
ceph_init_inode_acls(d_inode(dentry), &acls);
else
d_drop(dentry);
ceph_release_acls_info(&acls);
return err;
}
static int ceph_link(struct dentry *old_dentry, struct inode *dir,
struct dentry *dentry)
{
struct ceph_fs_client *fsc = ceph_sb_to_client(dir->i_sb);
struct ceph_mds_client *mdsc = fsc->mdsc;
struct ceph_mds_request *req;
int err;
if (ceph_snap(dir) != CEPH_NOSNAP)
return -EROFS;
dout("link in dir %p old_dentry %p dentry %p\n", dir,
old_dentry, dentry);
req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_LINK, USE_AUTH_MDS);
if (IS_ERR(req)) {
d_drop(dentry);
return PTR_ERR(req);
}
req->r_dentry = dget(dentry);
req->r_num_caps = 2;
req->r_old_dentry = dget(old_dentry);
req->r_parent = dir;
set_bit(CEPH_MDS_R_PARENT_LOCKED, &req->r_req_flags);
req->r_dentry_drop = CEPH_CAP_FILE_SHARED;
req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
/* release LINK_SHARED on source inode (mds will lock it) */
req->r_old_inode_drop = CEPH_CAP_LINK_SHARED;
err = ceph_mdsc_do_request(mdsc, dir, req);
if (err) {
d_drop(dentry);
} else if (!req->r_reply_info.head->is_dentry) {
ihold(d_inode(old_dentry));
d_instantiate(dentry, d_inode(old_dentry));
}
ceph_mdsc_put_request(req);
return err;
}
/*
* For a soon-to-be unlinked file, drop the AUTH_RDCACHE caps. If it
* looks like the link count will hit 0, drop any other caps (other
* than PIN) we don't specifically want (due to the file still being