ocfs2: Remove i_generation from inode lock names
OCFS2 puts inode meta data in the "lock value block" provided by the DLM. Typically, i_generation is encoded in the lock name so that a deleted inode on and a new one in the same block don't share the same lvb. Unfortunately, that scheme means that the read in ocfs2_read_locked_inode() is potentially thrown away as soon as the meta data lock is taken - we cannot encode the lock name without first knowing i_generation, which requires a disk read. This patch encodes i_generation in the inode meta data lvb, and removes the value from the inode meta data lock name. This way, the read can be covered by a lock, and at the same time we can distinguish between an up to date and a stale LVB. This will help cold-cache stat(2) performance in particular. Since this patch changes the protocol version, we take the opportunity to do a minor re-organization of two of the LVB fields. Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
Este cometimento está contido em:
146
fs/ocfs2/inode.c
146
fs/ocfs2/inode.c
@@ -54,8 +54,6 @@
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#include "buffer_head_io.h"
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#define OCFS2_FI_FLAG_NOWAIT 0x1
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#define OCFS2_FI_FLAG_DELETE 0x2
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struct ocfs2_find_inode_args
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{
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u64 fi_blkno;
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@@ -109,7 +107,7 @@ struct inode *ocfs2_ilookup_for_vote(struct ocfs2_super *osb,
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return ilookup5(osb->sb, args.fi_ino, ocfs2_find_actor, &args);
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}
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struct inode *ocfs2_iget(struct ocfs2_super *osb, u64 blkno)
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struct inode *ocfs2_iget(struct ocfs2_super *osb, u64 blkno, int flags)
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{
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struct inode *inode = NULL;
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struct super_block *sb = osb->sb;
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@@ -127,7 +125,7 @@ struct inode *ocfs2_iget(struct ocfs2_super *osb, u64 blkno)
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}
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args.fi_blkno = blkno;
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args.fi_flags = 0;
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args.fi_flags = flags;
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args.fi_ino = ino_from_blkno(sb, blkno);
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inode = iget5_locked(sb, args.fi_ino, ocfs2_find_actor,
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@@ -297,15 +295,11 @@ int ocfs2_populate_inode(struct inode *inode, struct ocfs2_dinode *fe,
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OCFS2_I(inode)->ip_orphaned_slot = OCFS2_INVALID_SLOT;
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OCFS2_I(inode)->ip_attr = le32_to_cpu(fe->i_attr);
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if (create_ino)
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inode->i_ino = ino_from_blkno(inode->i_sb,
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le64_to_cpu(fe->i_blkno));
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mlog(0, "blkno = %llu, ino = %lu, create_ino = %s\n",
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(unsigned long long)fe->i_blkno, inode->i_ino, create_ino ? "true" : "false");
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inode->i_nlink = le16_to_cpu(fe->i_links_count);
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if (fe->i_flags & cpu_to_le32(OCFS2_SYSTEM_FL))
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OCFS2_I(inode)->ip_flags |= OCFS2_INODE_SYSTEM_FILE;
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if (fe->i_flags & cpu_to_le32(OCFS2_LOCAL_ALLOC_FL)) {
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OCFS2_I(inode)->ip_flags |= OCFS2_INODE_BITMAP;
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mlog(0, "local alloc inode: i_ino=%lu\n", inode->i_ino);
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@@ -343,12 +337,28 @@ int ocfs2_populate_inode(struct inode *inode, struct ocfs2_dinode *fe,
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break;
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}
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if (create_ino) {
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inode->i_ino = ino_from_blkno(inode->i_sb,
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le64_to_cpu(fe->i_blkno));
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/*
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* If we ever want to create system files from kernel,
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* the generation argument to
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* ocfs2_inode_lock_res_init() will have to change.
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*/
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BUG_ON(fe->i_flags & cpu_to_le32(OCFS2_SYSTEM_FL));
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ocfs2_inode_lock_res_init(&OCFS2_I(inode)->ip_meta_lockres,
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OCFS2_LOCK_TYPE_META, 0, inode);
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}
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ocfs2_inode_lock_res_init(&OCFS2_I(inode)->ip_rw_lockres,
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OCFS2_LOCK_TYPE_RW, inode);
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ocfs2_inode_lock_res_init(&OCFS2_I(inode)->ip_meta_lockres,
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OCFS2_LOCK_TYPE_META, inode);
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OCFS2_LOCK_TYPE_RW, inode->i_generation,
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inode);
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ocfs2_inode_lock_res_init(&OCFS2_I(inode)->ip_data_lockres,
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OCFS2_LOCK_TYPE_DATA, inode);
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OCFS2_LOCK_TYPE_DATA, inode->i_generation,
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inode);
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ocfs2_set_inode_flags(inode);
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inode->i_flags |= S_NOATIME;
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@@ -366,15 +376,15 @@ static int ocfs2_read_locked_inode(struct inode *inode,
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struct ocfs2_super *osb;
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struct ocfs2_dinode *fe;
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struct buffer_head *bh = NULL;
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int status;
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int sysfile = 0;
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int status, can_lock;
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u32 generation = 0;
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mlog_entry("(0x%p, 0x%p)\n", inode, args);
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status = -EINVAL;
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if (inode == NULL || inode->i_sb == NULL) {
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mlog(ML_ERROR, "bad inode\n");
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goto bail;
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return status;
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}
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sb = inode->i_sb;
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osb = OCFS2_SB(sb);
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@@ -382,50 +392,110 @@ static int ocfs2_read_locked_inode(struct inode *inode,
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if (!args) {
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mlog(ML_ERROR, "bad inode args\n");
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make_bad_inode(inode);
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goto bail;
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return status;
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}
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/* Read the FE off disk. This is safe because the kernel only
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* does one read_inode2 for a new inode, and if it doesn't
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* exist yet then nobody can be working on it! */
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status = ocfs2_read_block(osb, args->fi_blkno, &bh, 0, NULL);
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/*
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* To improve performance of cold-cache inode stats, we take
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* the cluster lock here if possible.
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*
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* Generally, OCFS2 never trusts the contents of an inode
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* unless it's holding a cluster lock, so taking it here isn't
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* a correctness issue as much as it is a performance
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* improvement.
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*
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* There are three times when taking the lock is not a good idea:
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*
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* 1) During startup, before we have initialized the DLM.
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*
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* 2) If we are reading certain system files which never get
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* cluster locks (local alloc, truncate log).
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*
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* 3) If the process doing the iget() is responsible for
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* orphan dir recovery. We're holding the orphan dir lock and
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* can get into a deadlock with another process on another
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* node in ->delete_inode().
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*
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* #1 and #2 can be simply solved by never taking the lock
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* here for system files (which are the only type we read
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* during mount). It's a heavier approach, but our main
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* concern is user-accesible files anyway.
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*
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* #3 works itself out because we'll eventually take the
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* cluster lock before trusting anything anyway.
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*/
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can_lock = !(args->fi_flags & OCFS2_FI_FLAG_SYSFILE)
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&& !(args->fi_flags & OCFS2_FI_FLAG_NOLOCK);
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/*
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* To maintain backwards compatibility with older versions of
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* ocfs2-tools, we still store the generation value for system
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* files. The only ones that actually matter to userspace are
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* the journals, but it's easier and inexpensive to just flag
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* all system files similarly.
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*/
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if (args->fi_flags & OCFS2_FI_FLAG_SYSFILE)
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generation = osb->fs_generation;
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ocfs2_inode_lock_res_init(&OCFS2_I(inode)->ip_meta_lockres,
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OCFS2_LOCK_TYPE_META,
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generation, inode);
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if (can_lock) {
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status = ocfs2_meta_lock(inode, NULL, NULL, 0);
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if (status) {
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make_bad_inode(inode);
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mlog_errno(status);
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return status;
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}
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}
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status = ocfs2_read_block(osb, args->fi_blkno, &bh, 0,
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can_lock ? inode : NULL);
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if (status < 0) {
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mlog_errno(status);
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make_bad_inode(inode);
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goto bail;
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}
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status = -EINVAL;
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fe = (struct ocfs2_dinode *) bh->b_data;
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if (!OCFS2_IS_VALID_DINODE(fe)) {
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mlog(ML_ERROR, "Invalid dinode #%llu: signature = %.*s\n",
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(unsigned long long)fe->i_blkno, 7, fe->i_signature);
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make_bad_inode(inode);
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goto bail;
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}
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if (fe->i_flags & cpu_to_le32(OCFS2_SYSTEM_FL))
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sysfile = 1;
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/*
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* This is a code bug. Right now the caller needs to
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* understand whether it is asking for a system file inode or
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* not so the proper lock names can be built.
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*/
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mlog_bug_on_msg(!!(fe->i_flags & cpu_to_le32(OCFS2_SYSTEM_FL)) !=
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!!(args->fi_flags & OCFS2_FI_FLAG_SYSFILE),
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"Inode %llu: system file state is ambigous\n",
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(unsigned long long)args->fi_blkno);
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if (S_ISCHR(le16_to_cpu(fe->i_mode)) ||
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S_ISBLK(le16_to_cpu(fe->i_mode)))
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inode->i_rdev = huge_decode_dev(le64_to_cpu(fe->id1.dev1.i_rdev));
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status = -EINVAL;
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if (ocfs2_populate_inode(inode, fe, 0) < 0) {
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mlog(ML_ERROR, "populate failed! i_blkno=%llu, i_ino=%lu\n",
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(unsigned long long)fe->i_blkno, inode->i_ino);
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make_bad_inode(inode);
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goto bail;
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}
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BUG_ON(args->fi_blkno != le64_to_cpu(fe->i_blkno));
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if (sysfile)
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OCFS2_I(inode)->ip_flags |= OCFS2_INODE_SYSTEM_FILE;
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status = 0;
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bail:
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if (can_lock)
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ocfs2_meta_unlock(inode, 0);
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if (status < 0)
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make_bad_inode(inode);
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if (args && bh)
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brelse(bh);
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@@ -898,9 +968,15 @@ void ocfs2_delete_inode(struct inode *inode)
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goto bail_unlock_inode;
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}
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/* Mark the inode as successfully deleted. This is important
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* for ocfs2_clear_inode as it will check this flag and skip
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* any checkpointing work */
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/*
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* Mark the inode as successfully deleted.
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*
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* This is important for ocfs2_clear_inode() as it will check
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* this flag and skip any checkpointing work
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*
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* ocfs2_stuff_meta_lvb() also uses this flag to invalidate
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* the LVB for other nodes.
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*/
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OCFS2_I(inode)->ip_flags |= OCFS2_INODE_DELETED;
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bail_unlock_inode:
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