From be6e8dc0ba84029997075a1ec77b4ddb863cbe15 Mon Sep 17 00:00:00 2001 From: Balaji Rao Date: Mon, 21 Jul 2008 02:01:56 +0530 Subject: NFS support for btrfs - v3 Date: Mon, 21 Jul 2008 02:01:56 +0530 Here's an implementation of NFS support for btrfs. It relies on the fixes which are going in to 2.6.28 for the NFS readdir/lookup deadlock. This uses the btrfs_iget helper introduced previously. [dwmw2: Tidy up a little, switch to d_obtain_alias() w/compat routine, change fh_type, store parent's root object ID where needed, fix some get_parent() and fs_to_dentry() bugs] Signed-off-by: Balaji Rao Signed-off-by: David Woodhouse Signed-off-by: Chris Mason --- fs/btrfs/export.c | 208 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 208 insertions(+) create mode 100644 fs/btrfs/export.c (limited to 'fs/btrfs/export.c') diff --git a/fs/btrfs/export.c b/fs/btrfs/export.c new file mode 100644 index 000000000000..797b4cbc3786 --- /dev/null +++ b/fs/btrfs/export.c @@ -0,0 +1,208 @@ +#include +#include +#include "ctree.h" +#include "disk-io.h" +#include "btrfs_inode.h" +#include "print-tree.h" +#include "export.h" +#include "compat.h" + +#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,28) +#define FILEID_BTRFS_WITHOUT_PARENT 0x4d +#define FILEID_BTRFS_WITH_PARENT 0x4e +#define FILEID_BTRFS_WITH_PARENT_ROOT 0x4f +#endif + +#define BTRFS_FID_SIZE_NON_CONNECTABLE (offsetof(struct btrfs_fid, parent_objectid)/4) +#define BTRFS_FID_SIZE_CONNECTABLE (offsetof(struct btrfs_fid, parent_root_objectid)/4) +#define BTRFS_FID_SIZE_CONNECTABLE_ROOT (sizeof(struct btrfs_fid)/4) + +static int btrfs_encode_fh(struct dentry *dentry, u32 *fh, int *max_len, + int connectable) +{ + struct btrfs_fid *fid = (struct btrfs_fid *)fh; + struct inode *inode = dentry->d_inode; + int len = *max_len; + int type; + + if ((len < BTRFS_FID_SIZE_NON_CONNECTABLE) || + (connectable && len < BTRFS_FID_SIZE_CONNECTABLE)) + return 255; + + len = BTRFS_FID_SIZE_NON_CONNECTABLE; + type = FILEID_BTRFS_WITHOUT_PARENT; + + fid->objectid = BTRFS_I(inode)->location.objectid; + fid->root_objectid = BTRFS_I(inode)->root->objectid; + fid->gen = inode->i_generation; + + if (connectable && !S_ISDIR(inode->i_mode)) { + struct inode *parent; + u64 parent_root_id; + + spin_lock(&dentry->d_lock); + + parent = dentry->d_parent->d_inode; + fid->parent_objectid = BTRFS_I(parent)->location.objectid; + fid->parent_gen = parent->i_generation; + parent_root_id = BTRFS_I(parent)->root->objectid; + + spin_unlock(&dentry->d_lock); + + if (parent_root_id != fid->root_objectid) { + fid->parent_root_objectid = parent_root_id; + len = BTRFS_FID_SIZE_CONNECTABLE_ROOT; + type = FILEID_BTRFS_WITH_PARENT_ROOT; + } else { + len = BTRFS_FID_SIZE_CONNECTABLE; + type = FILEID_BTRFS_WITH_PARENT; + } + } + + *max_len = len; + return type; +} + +static struct dentry *btrfs_get_dentry(struct super_block *sb, u64 objectid, + u64 root_objectid, u32 generation) +{ + struct btrfs_root *root; + struct inode *inode; + struct dentry *result; + struct btrfs_key key; + + key.objectid = objectid; + btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY); + key.offset = 0; + + root = btrfs_lookup_fs_root(btrfs_sb(sb)->fs_info, root_objectid); + inode = btrfs_iget(sb, &key, root, NULL); + if (IS_ERR(inode)) + return (void *)inode; + + if (generation != inode->i_generation) { + iput(inode); + return ERR_PTR(-ESTALE); + } + + result = d_obtain_alias(inode); + if (!result) + return ERR_PTR(-ENOMEM); + + return result; +} + +static struct dentry *btrfs_fh_to_parent(struct super_block *sb, struct fid *fh, + int fh_len, int fh_type) +{ + struct btrfs_fid *fid = (struct btrfs_fid *) fh; + u64 objectid, root_objectid; + u32 generation; + + if (fh_type == FILEID_BTRFS_WITH_PARENT) { + if (fh_len != BTRFS_FID_SIZE_CONNECTABLE) + return NULL; + root_objectid = fid->root_objectid; + } else if (fh_type == FILEID_BTRFS_WITH_PARENT_ROOT) { + if (fh_len != BTRFS_FID_SIZE_CONNECTABLE_ROOT) + return NULL; + root_objectid = fid->parent_root_objectid; + } else + return NULL; + + objectid = fid->parent_objectid; + generation = fid->parent_gen; + + return btrfs_get_dentry(sb, objectid, root_objectid, generation); +} + +static struct dentry *btrfs_fh_to_dentry(struct super_block *sb, struct fid *fh, + int fh_len, int fh_type) +{ + struct btrfs_fid *fid = (struct btrfs_fid *) fh; + u64 objectid, root_objectid; + u32 generation; + + if ((fh_type != FILEID_BTRFS_WITH_PARENT || + fh_len != BTRFS_FID_SIZE_CONNECTABLE) && + (fh_type != FILEID_BTRFS_WITH_PARENT_ROOT || + fh_len != BTRFS_FID_SIZE_CONNECTABLE_ROOT) && + (fh_type != FILEID_BTRFS_WITHOUT_PARENT || + fh_len != BTRFS_FID_SIZE_NON_CONNECTABLE)) + return NULL; + + objectid = fid->objectid; + root_objectid = fid->root_objectid; + generation = fid->gen; + + return btrfs_get_dentry(sb, objectid, root_objectid, generation); +} + +static struct dentry *btrfs_get_parent(struct dentry *child) +{ + struct inode *dir = child->d_inode; + struct inode *inode; + struct dentry *parent; + struct btrfs_root *root = BTRFS_I(dir)->root; + struct btrfs_key key; + struct btrfs_path *path; + struct extent_buffer *leaf; + u32 nritems; + int slot; + u64 objectid; + int ret; + + path = btrfs_alloc_path(); + + key.objectid = dir->i_ino; + btrfs_set_key_type(&key, BTRFS_INODE_REF_KEY); + key.offset = 0; + ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); + BUG_ON(ret == 0); + ret = 0; + + leaf = path->nodes[0]; + slot = path->slots[0]; + nritems = btrfs_header_nritems(leaf); + if (slot >= nritems) { + ret = btrfs_next_leaf(root, path); + if (ret) { + btrfs_free_path(path); + goto out; + } + leaf = path->nodes[0]; + slot = path->slots[0]; + } + + btrfs_free_path(path); + + btrfs_item_key_to_cpu(leaf, &key, slot); + if (key.objectid != dir->i_ino || key.type != BTRFS_INODE_REF_KEY) + goto out; + + objectid = key.offset; + + /* Build a new key for the inode item */ + key.objectid = objectid; + btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY); + key.offset = 0; + + inode = btrfs_iget(root->fs_info->sb, &key, root, NULL); + + parent = d_obtain_alias(inode); + if (!parent) + parent = ERR_PTR(-ENOMEM); + + return parent; + +out: + btrfs_free_path(path); + return ERR_PTR(-EINVAL); +} + +const struct export_operations btrfs_export_ops = { + .encode_fh = btrfs_encode_fh, + .fh_to_dentry = btrfs_fh_to_dentry, + .fh_to_parent = btrfs_fh_to_parent, + .get_parent = btrfs_get_parent, +}; -- cgit v1.2.3 From 87acb4ef9b2991e1c453b78d71bce2ef994ef1ff Mon Sep 17 00:00:00 2001 From: David Woodhouse Date: Mon, 18 Aug 2008 22:50:22 +0100 Subject: Simplify btrfs_get_parent(), fix use-after-free bug Date: Mon, 18 Aug 2008 22:50:22 +0100 Signed-off-by: David Woodhouse Signed-off-by: Chris Mason --- fs/btrfs/export.c | 26 +++++++++++--------------- 1 file changed, 11 insertions(+), 15 deletions(-) (limited to 'fs/btrfs/export.c') diff --git a/fs/btrfs/export.c b/fs/btrfs/export.c index 797b4cbc3786..a913b9befe68 100644 --- a/fs/btrfs/export.c +++ b/fs/btrfs/export.c @@ -147,7 +147,6 @@ static struct dentry *btrfs_get_parent(struct dentry *child) struct btrfs_key key; struct btrfs_path *path; struct extent_buffer *leaf; - u32 nritems; int slot; u64 objectid; int ret; @@ -156,27 +155,24 @@ static struct dentry *btrfs_get_parent(struct dentry *child) key.objectid = dir->i_ino; btrfs_set_key_type(&key, BTRFS_INODE_REF_KEY); - key.offset = 0; - ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); - BUG_ON(ret == 0); - ret = 0; + key.offset = (u64)-1; + ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); leaf = path->nodes[0]; slot = path->slots[0]; - nritems = btrfs_header_nritems(leaf); - if (slot >= nritems) { - ret = btrfs_next_leaf(root, path); - if (ret) { - btrfs_free_path(path); - goto out; - } - leaf = path->nodes[0]; - slot = path->slots[0]; + if (ret < 0 || slot == 0) { + btrfs_free_path(path); + goto out; } + /* btrfs_search_slot() returns the slot where we'd want to insert + an INODE_REF_KEY for parent inode #0xFFFFFFFFFFFFFFFF. The _real_ + one, telling us what the parent inode _actually_ is, will be in + the slot _before_ the one that btrfs_search_slot() returns. */ + slot--; + btrfs_item_key_to_cpu(leaf, &key, slot); btrfs_free_path(path); - btrfs_item_key_to_cpu(leaf, &key, slot); if (key.objectid != dir->i_ino || key.type != BTRFS_INODE_REF_KEY) goto out; -- cgit v1.2.3 From 2d4d9fbd6efa858dfa009518fca1ab85a73fd848 Mon Sep 17 00:00:00 2001 From: David Woodhouse Date: Tue, 19 Aug 2008 22:20:17 +0100 Subject: Btrfs: Fix NFS exporting of subvol roots. Date: Tue, 19 Aug 2008 22:20:17 +0100 btrfs_lookup_fs_root() only finds subvol roots which have already been seen and put into the cache. For btrfs_get_dentry() we actually have to go to the medium -- so use btrfs_read_fs_root_no_name() instead. In btrfs_get_parent(), notice when we've hit the root of the subvolume and return the real root instead. Signed-off-by: David Woodhouse Signed-off-by: Chris Mason --- fs/btrfs/export.c | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-) (limited to 'fs/btrfs/export.c') diff --git a/fs/btrfs/export.c b/fs/btrfs/export.c index a913b9befe68..36cbc6872fd0 100644 --- a/fs/btrfs/export.c +++ b/fs/btrfs/export.c @@ -71,11 +71,18 @@ static struct dentry *btrfs_get_dentry(struct super_block *sb, u64 objectid, struct dentry *result; struct btrfs_key key; + key.objectid = root_objectid; + btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY); + key.offset = (u64)-1; + + root = btrfs_read_fs_root_no_name(btrfs_sb(sb)->fs_info, &key); + if (IS_ERR(root)) + return ERR_CAST(root); + key.objectid = objectid; btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY); key.offset = 0; - root = btrfs_lookup_fs_root(btrfs_sb(sb)->fs_info, root_objectid); inode = btrfs_iget(sb, &key, root, NULL); if (IS_ERR(inode)) return (void *)inode; @@ -178,6 +185,10 @@ static struct dentry *btrfs_get_parent(struct dentry *child) objectid = key.offset; + /* If we are already at the root of a subvol, return the real root */ + if (objectid == dir->i_ino) + return dget(dir->i_sb->s_root); + /* Build a new key for the inode item */ key.objectid = objectid; btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY); -- cgit v1.2.3 From d54a83901055bb0bffca64fa09fce4d897274870 Mon Sep 17 00:00:00 2001 From: David Woodhouse Date: Tue, 19 Aug 2008 22:33:04 +0100 Subject: Clean up btrfs_get_parent() a little more, fix a free-after-free bug Date: Tue, 19 Aug 2008 22:33:04 +0100 Signed-off-by: David Woodhouse Signed-off-by: Chris Mason --- fs/btrfs/export.c | 31 ++++++++++++++++++------------- 1 file changed, 18 insertions(+), 13 deletions(-) (limited to 'fs/btrfs/export.c') diff --git a/fs/btrfs/export.c b/fs/btrfs/export.c index 36cbc6872fd0..292b0b24c302 100644 --- a/fs/btrfs/export.c +++ b/fs/btrfs/export.c @@ -165,23 +165,32 @@ static struct dentry *btrfs_get_parent(struct dentry *child) key.offset = (u64)-1; ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); + if (ret < 0) { + /* Error */ + btrfs_free_path(path); + return ERR_PTR(ret); + } leaf = path->nodes[0]; slot = path->slots[0]; - if (ret < 0 || slot == 0) { - btrfs_free_path(path); - goto out; + if (ret) { + /* btrfs_search_slot() returns the slot where we'd want to + insert a backref for parent inode #0xFFFFFFFFFFFFFFFF. + The _real_ backref, telling us what the parent inode + _actually_ is, will be in the slot _before_ the one + that btrfs_search_slot() returns. */ + if (!slot) { + /* Unless there is _no_ key in the tree before... */ + btrfs_free_path(path); + return ERR_PTR(-EIO); + } + slot--; } - /* btrfs_search_slot() returns the slot where we'd want to insert - an INODE_REF_KEY for parent inode #0xFFFFFFFFFFFFFFFF. The _real_ - one, telling us what the parent inode _actually_ is, will be in - the slot _before_ the one that btrfs_search_slot() returns. */ - slot--; btrfs_item_key_to_cpu(leaf, &key, slot); btrfs_free_path(path); if (key.objectid != dir->i_ino || key.type != BTRFS_INODE_REF_KEY) - goto out; + return ERR_PTR(-EINVAL); objectid = key.offset; @@ -201,10 +210,6 @@ static struct dentry *btrfs_get_parent(struct dentry *child) parent = ERR_PTR(-ENOMEM); return parent; - -out: - btrfs_free_path(path); - return ERR_PTR(-EINVAL); } const struct export_operations btrfs_export_ops = { -- cgit v1.2.3 From 50ec891cc54fb865c4c40c45845e60123e0e66ca Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Fri, 5 Sep 2008 16:43:20 -0400 Subject: Btrfs: cleanup d_obtain_alias useage d_obtain_alias is intended as a tailcall that can pass in errors encoded in the inode pointer if needed, so use it that way instead of duplicating the error handling. Signed-off-by: Christoph Hellwig Signed-off-by: Chris Mason --- fs/btrfs/export.c | 17 ++--------------- 1 file changed, 2 insertions(+), 15 deletions(-) (limited to 'fs/btrfs/export.c') diff --git a/fs/btrfs/export.c b/fs/btrfs/export.c index 292b0b24c302..2b357a6d2407 100644 --- a/fs/btrfs/export.c +++ b/fs/btrfs/export.c @@ -68,7 +68,6 @@ static struct dentry *btrfs_get_dentry(struct super_block *sb, u64 objectid, { struct btrfs_root *root; struct inode *inode; - struct dentry *result; struct btrfs_key key; key.objectid = root_objectid; @@ -92,11 +91,7 @@ static struct dentry *btrfs_get_dentry(struct super_block *sb, u64 objectid, return ERR_PTR(-ESTALE); } - result = d_obtain_alias(inode); - if (!result) - return ERR_PTR(-ENOMEM); - - return result; + return d_obtain_alias(inode); } static struct dentry *btrfs_fh_to_parent(struct super_block *sb, struct fid *fh, @@ -148,8 +143,6 @@ static struct dentry *btrfs_fh_to_dentry(struct super_block *sb, struct fid *fh, static struct dentry *btrfs_get_parent(struct dentry *child) { struct inode *dir = child->d_inode; - struct inode *inode; - struct dentry *parent; struct btrfs_root *root = BTRFS_I(dir)->root; struct btrfs_key key; struct btrfs_path *path; @@ -203,13 +196,7 @@ static struct dentry *btrfs_get_parent(struct dentry *child) btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY); key.offset = 0; - inode = btrfs_iget(root->fs_info->sb, &key, root, NULL); - - parent = d_obtain_alias(inode); - if (!parent) - parent = ERR_PTR(-ENOMEM); - - return parent; + return d_obtain_alias(btrfs_iget(root->fs_info->sb, &key, root, NULL)); } const struct export_operations btrfs_export_ops = { -- cgit v1.2.3 From 2b1f55b0f0d0d1a66470ef4ea2696cd5dd741a12 Mon Sep 17 00:00:00 2001 From: Chris Mason Date: Wed, 24 Sep 2008 11:48:04 -0400 Subject: Remove Btrfs compat code for older kernels Btrfs had compatibility code for kernels back to 2.6.18. These have been removed, and will be maintained in a separate backport git tree from now on. Signed-off-by: Chris Mason --- fs/btrfs/export.c | 6 ------ 1 file changed, 6 deletions(-) (limited to 'fs/btrfs/export.c') diff --git a/fs/btrfs/export.c b/fs/btrfs/export.c index 2b357a6d2407..48b82cd7583c 100644 --- a/fs/btrfs/export.c +++ b/fs/btrfs/export.c @@ -7,12 +7,6 @@ #include "export.h" #include "compat.h" -#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,28) -#define FILEID_BTRFS_WITHOUT_PARENT 0x4d -#define FILEID_BTRFS_WITH_PARENT 0x4e -#define FILEID_BTRFS_WITH_PARENT_ROOT 0x4f -#endif - #define BTRFS_FID_SIZE_NON_CONNECTABLE (offsetof(struct btrfs_fid, parent_objectid)/4) #define BTRFS_FID_SIZE_CONNECTABLE (offsetof(struct btrfs_fid, parent_root_objectid)/4) #define BTRFS_FID_SIZE_CONNECTABLE_ROOT (sizeof(struct btrfs_fid)/4) -- cgit v1.2.3 From d397712bcc6a759a560fd247e6053ecae091f958 Mon Sep 17 00:00:00 2001 From: Chris Mason Date: Mon, 5 Jan 2009 21:25:51 -0500 Subject: Btrfs: Fix checkpatch.pl warnings There were many, most are fixed now. struct-funcs.c generates some warnings but these are bogus. Signed-off-by: Chris Mason --- fs/btrfs/export.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) (limited to 'fs/btrfs/export.c') diff --git a/fs/btrfs/export.c b/fs/btrfs/export.c index 48b82cd7583c..85315d2c90de 100644 --- a/fs/btrfs/export.c +++ b/fs/btrfs/export.c @@ -7,9 +7,11 @@ #include "export.h" #include "compat.h" -#define BTRFS_FID_SIZE_NON_CONNECTABLE (offsetof(struct btrfs_fid, parent_objectid)/4) -#define BTRFS_FID_SIZE_CONNECTABLE (offsetof(struct btrfs_fid, parent_root_objectid)/4) -#define BTRFS_FID_SIZE_CONNECTABLE_ROOT (sizeof(struct btrfs_fid)/4) +#define BTRFS_FID_SIZE_NON_CONNECTABLE (offsetof(struct btrfs_fid, \ + parent_objectid) / 4) +#define BTRFS_FID_SIZE_CONNECTABLE (offsetof(struct btrfs_fid, \ + parent_root_objectid) / 4) +#define BTRFS_FID_SIZE_CONNECTABLE_ROOT (sizeof(struct btrfs_fid) / 4) static int btrfs_encode_fh(struct dentry *dentry, u32 *fh, int *max_len, int connectable) -- cgit v1.2.3