diff options
author | Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp> | 2010-08-26 15:23:02 (GMT) |
---|---|---|
committer | Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp> | 2010-10-23 00:24:34 (GMT) |
commit | 8e656fd518784b49453f60c5f78b78703bc85cb2 (patch) | |
tree | 7adf4b71aba4bdf31dc05489a06933c48a0ea6f2 /fs/nilfs2/namei.c | |
parent | 4d8d9293dce503eb0e083e17a02a328d397e7f00 (diff) | |
download | linux-fsl-qoriq-8e656fd518784b49453f60c5f78b78703bc85cb2.tar.xz |
nilfs2: make snapshots in checkpoint tree exportable
The previous export operations cannot handle multiple versions of
a filesystem if they belong to the same sb instance.
This adds a new type of file handle and extends export operations so
that they can get the inode specified by a checkpoint number as well
as an inode number and a generation number.
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Diffstat (limited to 'fs/nilfs2/namei.c')
-rw-r--r-- | fs/nilfs2/namei.c | 137 |
1 files changed, 120 insertions, 17 deletions
diff --git a/fs/nilfs2/namei.c b/fs/nilfs2/namei.c index 1110d56..a65f465 100644 --- a/fs/nilfs2/namei.c +++ b/fs/nilfs2/namei.c @@ -40,7 +40,11 @@ #include <linux/pagemap.h> #include "nilfs.h" +#include "export.h" +#define NILFS_FID_SIZE_NON_CONNECTABLE \ + (offsetof(struct nilfs_fid, parent_gen) / 4) +#define NILFS_FID_SIZE_CONNECTABLE (sizeof(struct nilfs_fid) / 4) static inline int nilfs_add_nondir(struct dentry *dentry, struct inode *inode) { @@ -77,23 +81,6 @@ nilfs_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd) return d_splice_alias(inode, dentry); } -struct dentry *nilfs_get_parent(struct dentry *child) -{ - unsigned long ino; - struct inode *inode; - struct qstr dotdot = {.name = "..", .len = 2}; - - ino = nilfs_inode_by_name(child->d_inode, &dotdot); - if (!ino) - return ERR_PTR(-ENOENT); - - inode = nilfs_iget(child->d_inode->i_sb, - NILFS_I(child->d_inode)->i_root, ino); - if (IS_ERR(inode)) - return ERR_CAST(inode); - return d_obtain_alias(inode); -} - /* * By the time this is called, we already have created * the directory cache entry for the new file, but it @@ -469,6 +456,115 @@ out: return err; } +/* + * Export operations + */ +static struct dentry *nilfs_get_parent(struct dentry *child) +{ + unsigned long ino; + struct inode *inode; + struct qstr dotdot = {.name = "..", .len = 2}; + struct nilfs_root *root; + + ino = nilfs_inode_by_name(child->d_inode, &dotdot); + if (!ino) + return ERR_PTR(-ENOENT); + + root = NILFS_I(child->d_inode)->i_root; + + inode = nilfs_iget(child->d_inode->i_sb, root, ino); + if (IS_ERR(inode)) + return ERR_CAST(inode); + + return d_obtain_alias(inode); +} + +static struct dentry *nilfs_get_dentry(struct super_block *sb, u64 cno, + u64 ino, u32 gen) +{ + struct nilfs_root *root; + struct inode *inode; + + if (ino < NILFS_FIRST_INO(sb) && ino != NILFS_ROOT_INO) + return ERR_PTR(-ESTALE); + + root = nilfs_lookup_root(NILFS_SB(sb)->s_nilfs, cno); + if (!root) + return ERR_PTR(-ESTALE); + + inode = nilfs_iget(sb, root, ino); + nilfs_put_root(root); + + if (IS_ERR(inode)) + return ERR_CAST(inode); + if (gen && inode->i_generation != gen) { + iput(inode); + return ERR_PTR(-ESTALE); + } + return d_obtain_alias(inode); +} + +static struct dentry *nilfs_fh_to_dentry(struct super_block *sb, struct fid *fh, + int fh_len, int fh_type) +{ + struct nilfs_fid *fid = (struct nilfs_fid *)fh; + + if ((fh_len != NILFS_FID_SIZE_NON_CONNECTABLE && + fh_len != NILFS_FID_SIZE_CONNECTABLE) || + (fh_type != FILEID_NILFS_WITH_PARENT && + fh_type != FILEID_NILFS_WITHOUT_PARENT)) + return NULL; + + return nilfs_get_dentry(sb, fid->cno, fid->ino, fid->gen); +} + +static struct dentry *nilfs_fh_to_parent(struct super_block *sb, struct fid *fh, + int fh_len, int fh_type) +{ + struct nilfs_fid *fid = (struct nilfs_fid *)fh; + + if (fh_len != NILFS_FID_SIZE_CONNECTABLE || + fh_type != FILEID_NILFS_WITH_PARENT) + return NULL; + + return nilfs_get_dentry(sb, fid->cno, fid->parent_ino, fid->parent_gen); +} + +static int nilfs_encode_fh(struct dentry *dentry, __u32 *fh, int *lenp, + int connectable) +{ + struct nilfs_fid *fid = (struct nilfs_fid *)fh; + struct inode *inode = dentry->d_inode; + struct nilfs_root *root = NILFS_I(inode)->i_root; + int type; + + if (*lenp < NILFS_FID_SIZE_NON_CONNECTABLE || + (connectable && *lenp < NILFS_FID_SIZE_CONNECTABLE)) + return 255; + + fid->cno = root->cno; + fid->ino = inode->i_ino; + fid->gen = inode->i_generation; + + if (connectable && !S_ISDIR(inode->i_mode)) { + struct inode *parent; + + spin_lock(&dentry->d_lock); + parent = dentry->d_parent->d_inode; + fid->parent_ino = parent->i_ino; + fid->parent_gen = parent->i_generation; + spin_unlock(&dentry->d_lock); + + type = FILEID_NILFS_WITH_PARENT; + *lenp = NILFS_FID_SIZE_CONNECTABLE; + } else { + type = FILEID_NILFS_WITHOUT_PARENT; + *lenp = NILFS_FID_SIZE_NON_CONNECTABLE; + } + + return type; +} + const struct inode_operations nilfs_dir_inode_operations = { .create = nilfs_create, .lookup = nilfs_lookup, @@ -493,3 +589,10 @@ const struct inode_operations nilfs_symlink_inode_operations = { .follow_link = page_follow_link_light, .put_link = page_put_link, }; + +const struct export_operations nilfs_export_ops = { + .encode_fh = nilfs_encode_fh, + .fh_to_dentry = nilfs_fh_to_dentry, + .fh_to_parent = nilfs_fh_to_parent, + .get_parent = nilfs_get_parent, +}; |