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ceph: record 'offset' for each entry of readdir result

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This is preparation for using hash value as dentry 'offset'

Signed-off-by: Yan, Zheng <zyan@redhat.com>
This commit is contained in:
Yan, Zheng
2016-04-28 15:17:40 +08:00
committed by Ilya Dryomov
parent 956d39d631
commit 8974eebd38
5 changed files with 59 additions and 29 deletions
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83
fs/ceph/dir.c
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@@ -277,12 +277,12 @@ static int ceph_readdir(struct file *file, struct dir_context *ctx)
struct ceph_fs_client *fsc = ceph_inode_to_client(inode);
struct ceph_mds_client *mdsc = fsc->mdsc;
unsigned frag = fpos_frag(ctx->pos);
int off = fpos_off(ctx->pos);
int i;
int err;
u32 ftype;
struct ceph_mds_reply_info_parsed *rinfo;
dout("readdir %p file %p frag %u off %u\n", inode, file, frag, off);
dout("readdir %p file %p pos %llx\n", inode, file, ctx->pos);
if (fi->flags & CEPH_F_ATEND)
return 0;
@@ -294,7 +294,6 @@ static int ceph_readdir(struct file *file, struct dir_context *ctx)
inode->i_mode >> 12))
return 0;
ctx->pos = 1;
off = 1;
}
if (ctx->pos == 1) {
ino_t ino = parent_ino(file->f_path.dentry);
@@ -304,7 +303,6 @@ static int ceph_readdir(struct file *file, struct dir_context *ctx)
inode->i_mode >> 12))
return 0;
ctx->pos = 2;
off = 2;
}
/* can we use the dcache? */
@@ -320,7 +318,6 @@ static int ceph_readdir(struct file *file, struct dir_context *ctx)
if (err != -EAGAIN)
return err;
frag = fpos_frag(ctx->pos);
off = fpos_off(ctx->pos);
} else {
spin_unlock(&ci->i_ceph_lock);
}
@@ -386,12 +383,12 @@ more:
rinfo = &req->r_reply_info;
if (le32_to_cpu(rinfo->dir_dir->frag) != frag) {
frag = le32_to_cpu(rinfo->dir_dir->frag);
off = req->r_readdir_offset;
fi->next_offset = off;
fi->next_offset = req->r_readdir_offset;
/* adjust ctx->pos to beginning of frag */
ctx->pos = ceph_make_fpos(frag, fi->next_offset);
}
fi->frag = frag;
fi->offset = fi->next_offset;
fi->last_readdir = req;
if (req->r_did_prepopulate) {
@@ -399,7 +396,8 @@ more:
if (fi->readdir_cache_idx < 0) {
/* preclude from marking dir ordered */
fi->dir_ordered_count = 0;
} else if (ceph_frag_is_leftmost(frag) && off == 2) {
} 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;
@@ -421,37 +419,54 @@ more:
struct ceph_mds_reply_dir_entry *rde =
rinfo->dir_entries + (rinfo->dir_nr-1);
err = note_last_dentry(fi, rde->name, rde->name_len,
fi->next_offset + rinfo->dir_nr);
fpos_off(rde->offset) + 1);
if (err)
return err;
}
}
rinfo = &fi->last_readdir->r_reply_info;
dout("readdir frag %x num %d off %d chunkoff %d\n", frag,
rinfo->dir_nr, off, fi->offset);
dout("readdir frag %x num %d pos %llx chunk first %llx\n",
frag, rinfo->dir_nr, ctx->pos,
rinfo->dir_nr ? rinfo->dir_entries[0].offset : 0LL);
ctx->pos = ceph_make_fpos(frag, off);
while (off >= fi->offset && off - fi->offset < rinfo->dir_nr) {
struct ceph_mds_reply_dir_entry *rde =
rinfo->dir_entries + (off - fi->offset);
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;
dout("readdir off %d (%d/%d) -> %lld '%.*s' %p\n",
off, off - fi->offset, rinfo->dir_nr, ctx->pos,
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;
}
off++;
ctx->pos++;
}
@@ -464,8 +479,7 @@ more:
/* more frags? */
if (!ceph_frag_is_rightmost(frag)) {
frag = ceph_frag_next(frag);
off = 2;
ctx->pos = ceph_make_fpos(frag, off);
ctx->pos = ceph_make_fpos(frag, 2);
dout("readdir next frag is %x\n", frag);
goto more;
}
@@ -497,7 +511,7 @@ more:
return 0;
}
static void reset_readdir(struct ceph_file_info *fi, unsigned frag)
static void reset_readdir(struct ceph_file_info *fi)
{
if (fi->last_readdir) {
ceph_mdsc_put_request(fi->last_readdir);
@@ -511,6 +525,23 @@ static void reset_readdir(struct ceph_file_info *fi, unsigned frag)
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;
if (new_pos == 0)
return true;
if (fpos_frag(new_pos) != fi->frag)
return true;
rinfo = fi->last_readdir ? &fi->last_readdir->r_reply_info : NULL;
if (!rinfo || !rinfo->dir_nr)
return true;
return new_pos < rinfo->dir_entries[0].offset;;
}
static loff_t ceph_dir_llseek(struct file *file, loff_t offset, int whence)
{
struct ceph_file_info *fi = file->private_data;
@@ -539,13 +570,9 @@ static loff_t ceph_dir_llseek(struct file *file, loff_t offset, int whence)
}
retval = offset;
if (offset == 0 ||
fpos_frag(offset) != fi->frag ||
fpos_off(offset) < fi->offset) {
/* discard buffered readdir content on seekdir(0), or
* seek to new frag, or seek prior to current chunk */
if (need_reset_readdir(fi, offset)) {
dout("dir_llseek dropping %p content\n", file);
reset_readdir(fi, fpos_frag(offset));
reset_readdir(fi);
} else if (fpos_cmp(offset, old_offset) > 0) {
/* reset dir_release_count if we did a forward seek */
fi->dir_release_count = 0;