summaryrefslogtreecommitdiffstats
path: root/fs/xfs/xfs_inode.c
diff options
context:
space:
mode:
authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
commit2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch)
tree848558de17fb3008cdf4d861b01ac7781903ce39 /fs/xfs/xfs_inode.c
parentInitial commit. (diff)
downloadlinux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz
linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip
Adding upstream version 6.1.76.upstream/6.1.76
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'fs/xfs/xfs_inode.c')
-rw-r--r--fs/xfs/xfs_inode.c3540
1 files changed, 3540 insertions, 0 deletions
diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c
new file mode 100644
index 000000000..aa303be11
--- /dev/null
+++ b/fs/xfs/xfs_inode.c
@@ -0,0 +1,3540 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2000-2006 Silicon Graphics, Inc.
+ * All Rights Reserved.
+ */
+#include <linux/iversion.h>
+
+#include "xfs.h"
+#include "xfs_fs.h"
+#include "xfs_shared.h"
+#include "xfs_format.h"
+#include "xfs_log_format.h"
+#include "xfs_trans_resv.h"
+#include "xfs_mount.h"
+#include "xfs_defer.h"
+#include "xfs_inode.h"
+#include "xfs_dir2.h"
+#include "xfs_attr.h"
+#include "xfs_trans_space.h"
+#include "xfs_trans.h"
+#include "xfs_buf_item.h"
+#include "xfs_inode_item.h"
+#include "xfs_iunlink_item.h"
+#include "xfs_ialloc.h"
+#include "xfs_bmap.h"
+#include "xfs_bmap_util.h"
+#include "xfs_errortag.h"
+#include "xfs_error.h"
+#include "xfs_quota.h"
+#include "xfs_filestream.h"
+#include "xfs_trace.h"
+#include "xfs_icache.h"
+#include "xfs_symlink.h"
+#include "xfs_trans_priv.h"
+#include "xfs_log.h"
+#include "xfs_bmap_btree.h"
+#include "xfs_reflink.h"
+#include "xfs_ag.h"
+#include "xfs_log_priv.h"
+
+struct kmem_cache *xfs_inode_cache;
+
+/*
+ * Used in xfs_itruncate_extents(). This is the maximum number of extents
+ * freed from a file in a single transaction.
+ */
+#define XFS_ITRUNC_MAX_EXTENTS 2
+
+STATIC int xfs_iunlink(struct xfs_trans *, struct xfs_inode *);
+STATIC int xfs_iunlink_remove(struct xfs_trans *tp, struct xfs_perag *pag,
+ struct xfs_inode *);
+
+/*
+ * helper function to extract extent size hint from inode
+ */
+xfs_extlen_t
+xfs_get_extsz_hint(
+ struct xfs_inode *ip)
+{
+ /*
+ * No point in aligning allocations if we need to COW to actually
+ * write to them.
+ */
+ if (xfs_is_always_cow_inode(ip))
+ return 0;
+ if ((ip->i_diflags & XFS_DIFLAG_EXTSIZE) && ip->i_extsize)
+ return ip->i_extsize;
+ if (XFS_IS_REALTIME_INODE(ip))
+ return ip->i_mount->m_sb.sb_rextsize;
+ return 0;
+}
+
+/*
+ * Helper function to extract CoW extent size hint from inode.
+ * Between the extent size hint and the CoW extent size hint, we
+ * return the greater of the two. If the value is zero (automatic),
+ * use the default size.
+ */
+xfs_extlen_t
+xfs_get_cowextsz_hint(
+ struct xfs_inode *ip)
+{
+ xfs_extlen_t a, b;
+
+ a = 0;
+ if (ip->i_diflags2 & XFS_DIFLAG2_COWEXTSIZE)
+ a = ip->i_cowextsize;
+ b = xfs_get_extsz_hint(ip);
+
+ a = max(a, b);
+ if (a == 0)
+ return XFS_DEFAULT_COWEXTSZ_HINT;
+ return a;
+}
+
+/*
+ * These two are wrapper routines around the xfs_ilock() routine used to
+ * centralize some grungy code. They are used in places that wish to lock the
+ * inode solely for reading the extents. The reason these places can't just
+ * call xfs_ilock(ip, XFS_ILOCK_SHARED) is that the inode lock also guards to
+ * bringing in of the extents from disk for a file in b-tree format. If the
+ * inode is in b-tree format, then we need to lock the inode exclusively until
+ * the extents are read in. Locking it exclusively all the time would limit
+ * our parallelism unnecessarily, though. What we do instead is check to see
+ * if the extents have been read in yet, and only lock the inode exclusively
+ * if they have not.
+ *
+ * The functions return a value which should be given to the corresponding
+ * xfs_iunlock() call.
+ */
+uint
+xfs_ilock_data_map_shared(
+ struct xfs_inode *ip)
+{
+ uint lock_mode = XFS_ILOCK_SHARED;
+
+ if (xfs_need_iread_extents(&ip->i_df))
+ lock_mode = XFS_ILOCK_EXCL;
+ xfs_ilock(ip, lock_mode);
+ return lock_mode;
+}
+
+uint
+xfs_ilock_attr_map_shared(
+ struct xfs_inode *ip)
+{
+ uint lock_mode = XFS_ILOCK_SHARED;
+
+ if (xfs_inode_has_attr_fork(ip) && xfs_need_iread_extents(&ip->i_af))
+ lock_mode = XFS_ILOCK_EXCL;
+ xfs_ilock(ip, lock_mode);
+ return lock_mode;
+}
+
+/*
+ * You can't set both SHARED and EXCL for the same lock,
+ * and only XFS_IOLOCK_SHARED, XFS_IOLOCK_EXCL, XFS_MMAPLOCK_SHARED,
+ * XFS_MMAPLOCK_EXCL, XFS_ILOCK_SHARED, XFS_ILOCK_EXCL are valid values
+ * to set in lock_flags.
+ */
+static inline void
+xfs_lock_flags_assert(
+ uint lock_flags)
+{
+ ASSERT((lock_flags & (XFS_IOLOCK_SHARED | XFS_IOLOCK_EXCL)) !=
+ (XFS_IOLOCK_SHARED | XFS_IOLOCK_EXCL));
+ ASSERT((lock_flags & (XFS_MMAPLOCK_SHARED | XFS_MMAPLOCK_EXCL)) !=
+ (XFS_MMAPLOCK_SHARED | XFS_MMAPLOCK_EXCL));
+ ASSERT((lock_flags & (XFS_ILOCK_SHARED | XFS_ILOCK_EXCL)) !=
+ (XFS_ILOCK_SHARED | XFS_ILOCK_EXCL));
+ ASSERT((lock_flags & ~(XFS_LOCK_MASK | XFS_LOCK_SUBCLASS_MASK)) == 0);
+ ASSERT(lock_flags != 0);
+}
+
+/*
+ * In addition to i_rwsem in the VFS inode, the xfs inode contains 2
+ * multi-reader locks: invalidate_lock and the i_lock. This routine allows
+ * various combinations of the locks to be obtained.
+ *
+ * The 3 locks should always be ordered so that the IO lock is obtained first,
+ * the mmap lock second and the ilock last in order to prevent deadlock.
+ *
+ * Basic locking order:
+ *
+ * i_rwsem -> invalidate_lock -> page_lock -> i_ilock
+ *
+ * mmap_lock locking order:
+ *
+ * i_rwsem -> page lock -> mmap_lock
+ * mmap_lock -> invalidate_lock -> page_lock
+ *
+ * The difference in mmap_lock locking order mean that we cannot hold the
+ * invalidate_lock over syscall based read(2)/write(2) based IO. These IO paths
+ * can fault in pages during copy in/out (for buffered IO) or require the
+ * mmap_lock in get_user_pages() to map the user pages into the kernel address
+ * space for direct IO. Similarly the i_rwsem cannot be taken inside a page
+ * fault because page faults already hold the mmap_lock.
+ *
+ * Hence to serialise fully against both syscall and mmap based IO, we need to
+ * take both the i_rwsem and the invalidate_lock. These locks should *only* be
+ * both taken in places where we need to invalidate the page cache in a race
+ * free manner (e.g. truncate, hole punch and other extent manipulation
+ * functions).
+ */
+void
+xfs_ilock(
+ xfs_inode_t *ip,
+ uint lock_flags)
+{
+ trace_xfs_ilock(ip, lock_flags, _RET_IP_);
+
+ xfs_lock_flags_assert(lock_flags);
+
+ if (lock_flags & XFS_IOLOCK_EXCL) {
+ down_write_nested(&VFS_I(ip)->i_rwsem,
+ XFS_IOLOCK_DEP(lock_flags));
+ } else if (lock_flags & XFS_IOLOCK_SHARED) {
+ down_read_nested(&VFS_I(ip)->i_rwsem,
+ XFS_IOLOCK_DEP(lock_flags));
+ }
+
+ if (lock_flags & XFS_MMAPLOCK_EXCL) {
+ down_write_nested(&VFS_I(ip)->i_mapping->invalidate_lock,
+ XFS_MMAPLOCK_DEP(lock_flags));
+ } else if (lock_flags & XFS_MMAPLOCK_SHARED) {
+ down_read_nested(&VFS_I(ip)->i_mapping->invalidate_lock,
+ XFS_MMAPLOCK_DEP(lock_flags));
+ }
+
+ if (lock_flags & XFS_ILOCK_EXCL)
+ mrupdate_nested(&ip->i_lock, XFS_ILOCK_DEP(lock_flags));
+ else if (lock_flags & XFS_ILOCK_SHARED)
+ mraccess_nested(&ip->i_lock, XFS_ILOCK_DEP(lock_flags));
+}
+
+/*
+ * This is just like xfs_ilock(), except that the caller
+ * is guaranteed not to sleep. It returns 1 if it gets
+ * the requested locks and 0 otherwise. If the IO lock is
+ * obtained but the inode lock cannot be, then the IO lock
+ * is dropped before returning.
+ *
+ * ip -- the inode being locked
+ * lock_flags -- this parameter indicates the inode's locks to be
+ * to be locked. See the comment for xfs_ilock() for a list
+ * of valid values.
+ */
+int
+xfs_ilock_nowait(
+ xfs_inode_t *ip,
+ uint lock_flags)
+{
+ trace_xfs_ilock_nowait(ip, lock_flags, _RET_IP_);
+
+ xfs_lock_flags_assert(lock_flags);
+
+ if (lock_flags & XFS_IOLOCK_EXCL) {
+ if (!down_write_trylock(&VFS_I(ip)->i_rwsem))
+ goto out;
+ } else if (lock_flags & XFS_IOLOCK_SHARED) {
+ if (!down_read_trylock(&VFS_I(ip)->i_rwsem))
+ goto out;
+ }
+
+ if (lock_flags & XFS_MMAPLOCK_EXCL) {
+ if (!down_write_trylock(&VFS_I(ip)->i_mapping->invalidate_lock))
+ goto out_undo_iolock;
+ } else if (lock_flags & XFS_MMAPLOCK_SHARED) {
+ if (!down_read_trylock(&VFS_I(ip)->i_mapping->invalidate_lock))
+ goto out_undo_iolock;
+ }
+
+ if (lock_flags & XFS_ILOCK_EXCL) {
+ if (!mrtryupdate(&ip->i_lock))
+ goto out_undo_mmaplock;
+ } else if (lock_flags & XFS_ILOCK_SHARED) {
+ if (!mrtryaccess(&ip->i_lock))
+ goto out_undo_mmaplock;
+ }
+ return 1;
+
+out_undo_mmaplock:
+ if (lock_flags & XFS_MMAPLOCK_EXCL)
+ up_write(&VFS_I(ip)->i_mapping->invalidate_lock);
+ else if (lock_flags & XFS_MMAPLOCK_SHARED)
+ up_read(&VFS_I(ip)->i_mapping->invalidate_lock);
+out_undo_iolock:
+ if (lock_flags & XFS_IOLOCK_EXCL)
+ up_write(&VFS_I(ip)->i_rwsem);
+ else if (lock_flags & XFS_IOLOCK_SHARED)
+ up_read(&VFS_I(ip)->i_rwsem);
+out:
+ return 0;
+}
+
+/*
+ * xfs_iunlock() is used to drop the inode locks acquired with
+ * xfs_ilock() and xfs_ilock_nowait(). The caller must pass
+ * in the flags given to xfs_ilock() or xfs_ilock_nowait() so
+ * that we know which locks to drop.
+ *
+ * ip -- the inode being unlocked
+ * lock_flags -- this parameter indicates the inode's locks to be
+ * to be unlocked. See the comment for xfs_ilock() for a list
+ * of valid values for this parameter.
+ *
+ */
+void
+xfs_iunlock(
+ xfs_inode_t *ip,
+ uint lock_flags)
+{
+ xfs_lock_flags_assert(lock_flags);
+
+ if (lock_flags & XFS_IOLOCK_EXCL)
+ up_write(&VFS_I(ip)->i_rwsem);
+ else if (lock_flags & XFS_IOLOCK_SHARED)
+ up_read(&VFS_I(ip)->i_rwsem);
+
+ if (lock_flags & XFS_MMAPLOCK_EXCL)
+ up_write(&VFS_I(ip)->i_mapping->invalidate_lock);
+ else if (lock_flags & XFS_MMAPLOCK_SHARED)
+ up_read(&VFS_I(ip)->i_mapping->invalidate_lock);
+
+ if (lock_flags & XFS_ILOCK_EXCL)
+ mrunlock_excl(&ip->i_lock);
+ else if (lock_flags & XFS_ILOCK_SHARED)
+ mrunlock_shared(&ip->i_lock);
+
+ trace_xfs_iunlock(ip, lock_flags, _RET_IP_);
+}
+
+/*
+ * give up write locks. the i/o lock cannot be held nested
+ * if it is being demoted.
+ */
+void
+xfs_ilock_demote(
+ xfs_inode_t *ip,
+ uint lock_flags)
+{
+ ASSERT(lock_flags & (XFS_IOLOCK_EXCL|XFS_MMAPLOCK_EXCL|XFS_ILOCK_EXCL));
+ ASSERT((lock_flags &
+ ~(XFS_IOLOCK_EXCL|XFS_MMAPLOCK_EXCL|XFS_ILOCK_EXCL)) == 0);
+
+ if (lock_flags & XFS_ILOCK_EXCL)
+ mrdemote(&ip->i_lock);
+ if (lock_flags & XFS_MMAPLOCK_EXCL)
+ downgrade_write(&VFS_I(ip)->i_mapping->invalidate_lock);
+ if (lock_flags & XFS_IOLOCK_EXCL)
+ downgrade_write(&VFS_I(ip)->i_rwsem);
+
+ trace_xfs_ilock_demote(ip, lock_flags, _RET_IP_);
+}
+
+#if defined(DEBUG) || defined(XFS_WARN)
+static inline bool
+__xfs_rwsem_islocked(
+ struct rw_semaphore *rwsem,
+ bool shared)
+{
+ if (!debug_locks)
+ return rwsem_is_locked(rwsem);
+
+ if (!shared)
+ return lockdep_is_held_type(rwsem, 0);
+
+ /*
+ * We are checking that the lock is held at least in shared
+ * mode but don't care that it might be held exclusively
+ * (i.e. shared | excl). Hence we check if the lock is held
+ * in any mode rather than an explicit shared mode.
+ */
+ return lockdep_is_held_type(rwsem, -1);
+}
+
+bool
+xfs_isilocked(
+ struct xfs_inode *ip,
+ uint lock_flags)
+{
+ if (lock_flags & (XFS_ILOCK_EXCL|XFS_ILOCK_SHARED)) {
+ if (!(lock_flags & XFS_ILOCK_SHARED))
+ return !!ip->i_lock.mr_writer;
+ return rwsem_is_locked(&ip->i_lock.mr_lock);
+ }
+
+ if (lock_flags & (XFS_MMAPLOCK_EXCL|XFS_MMAPLOCK_SHARED)) {
+ return __xfs_rwsem_islocked(&VFS_I(ip)->i_mapping->invalidate_lock,
+ (lock_flags & XFS_MMAPLOCK_SHARED));
+ }
+
+ if (lock_flags & (XFS_IOLOCK_EXCL | XFS_IOLOCK_SHARED)) {
+ return __xfs_rwsem_islocked(&VFS_I(ip)->i_rwsem,
+ (lock_flags & XFS_IOLOCK_SHARED));
+ }
+
+ ASSERT(0);
+ return false;
+}
+#endif
+
+/*
+ * xfs_lockdep_subclass_ok() is only used in an ASSERT, so is only called when
+ * DEBUG or XFS_WARN is set. And MAX_LOCKDEP_SUBCLASSES is then only defined
+ * when CONFIG_LOCKDEP is set. Hence the complex define below to avoid build
+ * errors and warnings.
+ */
+#if (defined(DEBUG) || defined(XFS_WARN)) && defined(CONFIG_LOCKDEP)
+static bool
+xfs_lockdep_subclass_ok(
+ int subclass)
+{
+ return subclass < MAX_LOCKDEP_SUBCLASSES;
+}
+#else
+#define xfs_lockdep_subclass_ok(subclass) (true)
+#endif
+
+/*
+ * Bump the subclass so xfs_lock_inodes() acquires each lock with a different
+ * value. This can be called for any type of inode lock combination, including
+ * parent locking. Care must be taken to ensure we don't overrun the subclass
+ * storage fields in the class mask we build.
+ */
+static inline uint
+xfs_lock_inumorder(
+ uint lock_mode,
+ uint subclass)
+{
+ uint class = 0;
+
+ ASSERT(!(lock_mode & (XFS_ILOCK_PARENT | XFS_ILOCK_RTBITMAP |
+ XFS_ILOCK_RTSUM)));
+ ASSERT(xfs_lockdep_subclass_ok(subclass));
+
+ if (lock_mode & (XFS_IOLOCK_SHARED|XFS_IOLOCK_EXCL)) {
+ ASSERT(subclass <= XFS_IOLOCK_MAX_SUBCLASS);
+ class += subclass << XFS_IOLOCK_SHIFT;
+ }
+
+ if (lock_mode & (XFS_MMAPLOCK_SHARED|XFS_MMAPLOCK_EXCL)) {
+ ASSERT(subclass <= XFS_MMAPLOCK_MAX_SUBCLASS);
+ class += subclass << XFS_MMAPLOCK_SHIFT;
+ }
+
+ if (lock_mode & (XFS_ILOCK_SHARED|XFS_ILOCK_EXCL)) {
+ ASSERT(subclass <= XFS_ILOCK_MAX_SUBCLASS);
+ class += subclass << XFS_ILOCK_SHIFT;
+ }
+
+ return (lock_mode & ~XFS_LOCK_SUBCLASS_MASK) | class;
+}
+
+/*
+ * The following routine will lock n inodes in exclusive mode. We assume the
+ * caller calls us with the inodes in i_ino order.
+ *
+ * We need to detect deadlock where an inode that we lock is in the AIL and we
+ * start waiting for another inode that is locked by a thread in a long running
+ * transaction (such as truncate). This can result in deadlock since the long
+ * running trans might need to wait for the inode we just locked in order to
+ * push the tail and free space in the log.
+ *
+ * xfs_lock_inodes() can only be used to lock one type of lock at a time -
+ * the iolock, the mmaplock or the ilock, but not more than one at a time. If we
+ * lock more than one at a time, lockdep will report false positives saying we
+ * have violated locking orders.
+ */
+static void
+xfs_lock_inodes(
+ struct xfs_inode **ips,
+ int inodes,
+ uint lock_mode)
+{
+ int attempts = 0;
+ uint i;
+ int j;
+ bool try_lock;
+ struct xfs_log_item *lp;
+
+ /*
+ * Currently supports between 2 and 5 inodes with exclusive locking. We
+ * support an arbitrary depth of locking here, but absolute limits on
+ * inodes depend on the type of locking and the limits placed by
+ * lockdep annotations in xfs_lock_inumorder. These are all checked by
+ * the asserts.
+ */
+ ASSERT(ips && inodes >= 2 && inodes <= 5);
+ ASSERT(lock_mode & (XFS_IOLOCK_EXCL | XFS_MMAPLOCK_EXCL |
+ XFS_ILOCK_EXCL));
+ ASSERT(!(lock_mode & (XFS_IOLOCK_SHARED | XFS_MMAPLOCK_SHARED |
+ XFS_ILOCK_SHARED)));
+ ASSERT(!(lock_mode & XFS_MMAPLOCK_EXCL) ||
+ inodes <= XFS_MMAPLOCK_MAX_SUBCLASS + 1);
+ ASSERT(!(lock_mode & XFS_ILOCK_EXCL) ||
+ inodes <= XFS_ILOCK_MAX_SUBCLASS + 1);
+
+ if (lock_mode & XFS_IOLOCK_EXCL) {
+ ASSERT(!(lock_mode & (XFS_MMAPLOCK_EXCL | XFS_ILOCK_EXCL)));
+ } else if (lock_mode & XFS_MMAPLOCK_EXCL)
+ ASSERT(!(lock_mode & XFS_ILOCK_EXCL));
+
+again:
+ try_lock = false;
+ i = 0;
+ for (; i < inodes; i++) {
+ ASSERT(ips[i]);
+
+ if (i && (ips[i] == ips[i - 1])) /* Already locked */
+ continue;
+
+ /*
+ * If try_lock is not set yet, make sure all locked inodes are
+ * not in the AIL. If any are, set try_lock to be used later.
+ */
+ if (!try_lock) {
+ for (j = (i - 1); j >= 0 && !try_lock; j--) {
+ lp = &ips[j]->i_itemp->ili_item;
+ if (lp && test_bit(XFS_LI_IN_AIL, &lp->li_flags))
+ try_lock = true;
+ }
+ }
+
+ /*
+ * If any of the previous locks we have locked is in the AIL,
+ * we must TRY to get the second and subsequent locks. If
+ * we can't get any, we must release all we have
+ * and try again.
+ */
+ if (!try_lock) {
+ xfs_ilock(ips[i], xfs_lock_inumorder(lock_mode, i));
+ continue;
+ }
+
+ /* try_lock means we have an inode locked that is in the AIL. */
+ ASSERT(i != 0);
+ if (xfs_ilock_nowait(ips[i], xfs_lock_inumorder(lock_mode, i)))
+ continue;
+
+ /*
+ * Unlock all previous guys and try again. xfs_iunlock will try
+ * to push the tail if the inode is in the AIL.
+ */
+ attempts++;
+ for (j = i - 1; j >= 0; j--) {
+ /*
+ * Check to see if we've already unlocked this one. Not
+ * the first one going back, and the inode ptr is the
+ * same.
+ */
+ if (j != (i - 1) && ips[j] == ips[j + 1])
+ continue;
+
+ xfs_iunlock(ips[j], lock_mode);
+ }
+
+ if ((attempts % 5) == 0) {
+ delay(1); /* Don't just spin the CPU */
+ }
+ goto again;
+ }
+}
+
+/*
+ * xfs_lock_two_inodes() can only be used to lock ilock. The iolock and
+ * mmaplock must be double-locked separately since we use i_rwsem and
+ * invalidate_lock for that. We now support taking one lock EXCL and the
+ * other SHARED.
+ */
+void
+xfs_lock_two_inodes(
+ struct xfs_inode *ip0,
+ uint ip0_mode,
+ struct xfs_inode *ip1,
+ uint ip1_mode)
+{
+ int attempts = 0;
+ struct xfs_log_item *lp;
+
+ ASSERT(hweight32(ip0_mode) == 1);
+ ASSERT(hweight32(ip1_mode) == 1);
+ ASSERT(!(ip0_mode & (XFS_IOLOCK_SHARED|XFS_IOLOCK_EXCL)));
+ ASSERT(!(ip1_mode & (XFS_IOLOCK_SHARED|XFS_IOLOCK_EXCL)));
+ ASSERT(!(ip0_mode & (XFS_MMAPLOCK_SHARED|XFS_MMAPLOCK_EXCL)));
+ ASSERT(!(ip1_mode & (XFS_MMAPLOCK_SHARED|XFS_MMAPLOCK_EXCL)));
+ ASSERT(ip0->i_ino != ip1->i_ino);
+
+ if (ip0->i_ino > ip1->i_ino) {
+ swap(ip0, ip1);
+ swap(ip0_mode, ip1_mode);
+ }
+
+ again:
+ xfs_ilock(ip0, xfs_lock_inumorder(ip0_mode, 0));
+
+ /*
+ * If the first lock we have locked is in the AIL, we must TRY to get
+ * the second lock. If we can't get it, we must release the first one
+ * and try again.
+ */
+ lp = &ip0->i_itemp->ili_item;
+ if (lp && test_bit(XFS_LI_IN_AIL, &lp->li_flags)) {
+ if (!xfs_ilock_nowait(ip1, xfs_lock_inumorder(ip1_mode, 1))) {
+ xfs_iunlock(ip0, ip0_mode);
+ if ((++attempts % 5) == 0)
+ delay(1); /* Don't just spin the CPU */
+ goto again;
+ }
+ } else {
+ xfs_ilock(ip1, xfs_lock_inumorder(ip1_mode, 1));
+ }
+}
+
+uint
+xfs_ip2xflags(
+ struct xfs_inode *ip)
+{
+ uint flags = 0;
+
+ if (ip->i_diflags & XFS_DIFLAG_ANY) {
+ if (ip->i_diflags & XFS_DIFLAG_REALTIME)
+ flags |= FS_XFLAG_REALTIME;
+ if (ip->i_diflags & XFS_DIFLAG_PREALLOC)
+ flags |= FS_XFLAG_PREALLOC;
+ if (ip->i_diflags & XFS_DIFLAG_IMMUTABLE)
+ flags |= FS_XFLAG_IMMUTABLE;
+ if (ip->i_diflags & XFS_DIFLAG_APPEND)
+ flags |= FS_XFLAG_APPEND;
+ if (ip->i_diflags & XFS_DIFLAG_SYNC)
+ flags |= FS_XFLAG_SYNC;
+ if (ip->i_diflags & XFS_DIFLAG_NOATIME)
+ flags |= FS_XFLAG_NOATIME;
+ if (ip->i_diflags & XFS_DIFLAG_NODUMP)
+ flags |= FS_XFLAG_NODUMP;
+ if (ip->i_diflags & XFS_DIFLAG_RTINHERIT)
+ flags |= FS_XFLAG_RTINHERIT;
+ if (ip->i_diflags & XFS_DIFLAG_PROJINHERIT)
+ flags |= FS_XFLAG_PROJINHERIT;
+ if (ip->i_diflags & XFS_DIFLAG_NOSYMLINKS)
+ flags |= FS_XFLAG_NOSYMLINKS;
+ if (ip->i_diflags & XFS_DIFLAG_EXTSIZE)
+ flags |= FS_XFLAG_EXTSIZE;
+ if (ip->i_diflags & XFS_DIFLAG_EXTSZINHERIT)
+ flags |= FS_XFLAG_EXTSZINHERIT;
+ if (ip->i_diflags & XFS_DIFLAG_NODEFRAG)
+ flags |= FS_XFLAG_NODEFRAG;
+ if (ip->i_diflags & XFS_DIFLAG_FILESTREAM)
+ flags |= FS_XFLAG_FILESTREAM;
+ }
+
+ if (ip->i_diflags2 & XFS_DIFLAG2_ANY) {
+ if (ip->i_diflags2 & XFS_DIFLAG2_DAX)
+ flags |= FS_XFLAG_DAX;
+ if (ip->i_diflags2 & XFS_DIFLAG2_COWEXTSIZE)
+ flags |= FS_XFLAG_COWEXTSIZE;
+ }
+
+ if (xfs_inode_has_attr_fork(ip))
+ flags |= FS_XFLAG_HASATTR;
+ return flags;
+}
+
+/*
+ * Lookups up an inode from "name". If ci_name is not NULL, then a CI match
+ * is allowed, otherwise it has to be an exact match. If a CI match is found,
+ * ci_name->name will point to a the actual name (caller must free) or
+ * will be set to NULL if an exact match is found.
+ */
+int
+xfs_lookup(
+ struct xfs_inode *dp,
+ const struct xfs_name *name,
+ struct xfs_inode **ipp,
+ struct xfs_name *ci_name)
+{
+ xfs_ino_t inum;
+ int error;
+
+ trace_xfs_lookup(dp, name);
+
+ if (xfs_is_shutdown(dp->i_mount))
+ return -EIO;
+
+ error = xfs_dir_lookup(NULL, dp, name, &inum, ci_name);
+ if (error)
+ goto out_unlock;
+
+ error = xfs_iget(dp->i_mount, NULL, inum, 0, 0, ipp);
+ if (error)
+ goto out_free_name;
+
+ return 0;
+
+out_free_name:
+ if (ci_name)
+ kmem_free(ci_name->name);
+out_unlock:
+ *ipp = NULL;
+ return error;
+}
+
+/* Propagate di_flags from a parent inode to a child inode. */
+static void
+xfs_inode_inherit_flags(
+ struct xfs_inode *ip,
+ const struct xfs_inode *pip)
+{
+ unsigned int di_flags = 0;
+ xfs_failaddr_t failaddr;
+ umode_t mode = VFS_I(ip)->i_mode;
+
+ if (S_ISDIR(mode)) {
+ if (pip->i_diflags & XFS_DIFLAG_RTINHERIT)
+ di_flags |= XFS_DIFLAG_RTINHERIT;
+ if (pip->i_diflags & XFS_DIFLAG_EXTSZINHERIT) {
+ di_flags |= XFS_DIFLAG_EXTSZINHERIT;
+ ip->i_extsize = pip->i_extsize;
+ }
+ if (pip->i_diflags & XFS_DIFLAG_PROJINHERIT)
+ di_flags |= XFS_DIFLAG_PROJINHERIT;
+ } else if (S_ISREG(mode)) {
+ if ((pip->i_diflags & XFS_DIFLAG_RTINHERIT) &&
+ xfs_has_realtime(ip->i_mount))
+ di_flags |= XFS_DIFLAG_REALTIME;
+ if (pip->i_diflags & XFS_DIFLAG_EXTSZINHERIT) {
+ di_flags |= XFS_DIFLAG_EXTSIZE;
+ ip->i_extsize = pip->i_extsize;
+ }
+ }
+ if ((pip->i_diflags & XFS_DIFLAG_NOATIME) &&
+ xfs_inherit_noatime)
+ di_flags |= XFS_DIFLAG_NOATIME;
+ if ((pip->i_diflags & XFS_DIFLAG_NODUMP) &&
+ xfs_inherit_nodump)
+ di_flags |= XFS_DIFLAG_NODUMP;
+ if ((pip->i_diflags & XFS_DIFLAG_SYNC) &&
+ xfs_inherit_sync)
+ di_flags |= XFS_DIFLAG_SYNC;
+ if ((pip->i_diflags & XFS_DIFLAG_NOSYMLINKS) &&
+ xfs_inherit_nosymlinks)
+ di_flags |= XFS_DIFLAG_NOSYMLINKS;
+ if ((pip->i_diflags & XFS_DIFLAG_NODEFRAG) &&
+ xfs_inherit_nodefrag)
+ di_flags |= XFS_DIFLAG_NODEFRAG;
+ if (pip->i_diflags & XFS_DIFLAG_FILESTREAM)
+ di_flags |= XFS_DIFLAG_FILESTREAM;
+
+ ip->i_diflags |= di_flags;
+
+ /*
+ * Inode verifiers on older kernels only check that the extent size
+ * hint is an integer multiple of the rt extent size on realtime files.
+ * They did not check the hint alignment on a directory with both
+ * rtinherit and extszinherit flags set. If the misaligned hint is
+ * propagated from a directory into a new realtime file, new file
+ * allocations will fail due to math errors in the rt allocator and/or
+ * trip the verifiers. Validate the hint settings in the new file so
+ * that we don't let broken hints propagate.
+ */
+ failaddr = xfs_inode_validate_extsize(ip->i_mount, ip->i_extsize,
+ VFS_I(ip)->i_mode, ip->i_diflags);
+ if (failaddr) {
+ ip->i_diflags &= ~(XFS_DIFLAG_EXTSIZE |
+ XFS_DIFLAG_EXTSZINHERIT);
+ ip->i_extsize = 0;
+ }
+}
+
+/* Propagate di_flags2 from a parent inode to a child inode. */
+static void
+xfs_inode_inherit_flags2(
+ struct xfs_inode *ip,
+ const struct xfs_inode *pip)
+{
+ xfs_failaddr_t failaddr;
+
+ if (pip->i_diflags2 & XFS_DIFLAG2_COWEXTSIZE) {
+ ip->i_diflags2 |= XFS_DIFLAG2_COWEXTSIZE;
+ ip->i_cowextsize = pip->i_cowextsize;
+ }
+ if (pip->i_diflags2 & XFS_DIFLAG2_DAX)
+ ip->i_diflags2 |= XFS_DIFLAG2_DAX;
+
+ /* Don't let invalid cowextsize hints propagate. */
+ failaddr = xfs_inode_validate_cowextsize(ip->i_mount, ip->i_cowextsize,
+ VFS_I(ip)->i_mode, ip->i_diflags, ip->i_diflags2);
+ if (failaddr) {
+ ip->i_diflags2 &= ~XFS_DIFLAG2_COWEXTSIZE;
+ ip->i_cowextsize = 0;
+ }
+}
+
+/*
+ * Initialise a newly allocated inode and return the in-core inode to the
+ * caller locked exclusively.
+ */
+int
+xfs_init_new_inode(
+ struct user_namespace *mnt_userns,
+ struct xfs_trans *tp,
+ struct xfs_inode *pip,
+ xfs_ino_t ino,
+ umode_t mode,
+ xfs_nlink_t nlink,
+ dev_t rdev,
+ prid_t prid,
+ bool init_xattrs,
+ struct xfs_inode **ipp)
+{
+ struct inode *dir = pip ? VFS_I(pip) : NULL;
+ struct xfs_mount *mp = tp->t_mountp;
+ struct xfs_inode *ip;
+ unsigned int flags;
+ int error;
+ struct timespec64 tv;
+ struct inode *inode;
+
+ /*
+ * Protect against obviously corrupt allocation btree records. Later
+ * xfs_iget checks will catch re-allocation of other active in-memory
+ * and on-disk inodes. If we don't catch reallocating the parent inode
+ * here we will deadlock in xfs_iget() so we have to do these checks
+ * first.
+ */
+ if ((pip && ino == pip->i_ino) || !xfs_verify_dir_ino(mp, ino)) {
+ xfs_alert(mp, "Allocated a known in-use inode 0x%llx!", ino);
+ return -EFSCORRUPTED;
+ }
+
+ /*
+ * Get the in-core inode with the lock held exclusively to prevent
+ * others from looking at until we're done.
+ */
+ error = xfs_iget(mp, tp, ino, XFS_IGET_CREATE, XFS_ILOCK_EXCL, &ip);
+ if (error)
+ return error;
+
+ ASSERT(ip != NULL);
+ inode = VFS_I(ip);
+ set_nlink(inode, nlink);
+ inode->i_rdev = rdev;
+ ip->i_projid = prid;
+
+ if (dir && !(dir->i_mode & S_ISGID) && xfs_has_grpid(mp)) {
+ inode_fsuid_set(inode, mnt_userns);
+ inode->i_gid = dir->i_gid;
+ inode->i_mode = mode;
+ } else {
+ inode_init_owner(mnt_userns, inode, dir, mode);
+ }
+
+ /*
+ * If the group ID of the new file does not match the effective group
+ * ID or one of the supplementary group IDs, the S_ISGID bit is cleared
+ * (and only if the irix_sgid_inherit compatibility variable is set).
+ */
+ if (irix_sgid_inherit && (inode->i_mode & S_ISGID) &&
+ !vfsgid_in_group_p(i_gid_into_vfsgid(mnt_userns, inode)))
+ inode->i_mode &= ~S_ISGID;
+
+ ip->i_disk_size = 0;
+ ip->i_df.if_nextents = 0;
+ ASSERT(ip->i_nblocks == 0);
+
+ tv = current_time(inode);
+ inode->i_mtime = tv;
+ inode->i_atime = tv;
+ inode->i_ctime = tv;
+
+ ip->i_extsize = 0;
+ ip->i_diflags = 0;
+
+ if (xfs_has_v3inodes(mp)) {
+ inode_set_iversion(inode, 1);
+ ip->i_cowextsize = 0;
+ ip->i_crtime = tv;
+ }
+
+ flags = XFS_ILOG_CORE;
+ switch (mode & S_IFMT) {
+ case S_IFIFO:
+ case S_IFCHR:
+ case S_IFBLK:
+ case S_IFSOCK:
+ ip->i_df.if_format = XFS_DINODE_FMT_DEV;
+ flags |= XFS_ILOG_DEV;
+ break;
+ case S_IFREG:
+ case S_IFDIR:
+ if (pip && (pip->i_diflags & XFS_DIFLAG_ANY))
+ xfs_inode_inherit_flags(ip, pip);
+ if (pip && (pip->i_diflags2 & XFS_DIFLAG2_ANY))
+ xfs_inode_inherit_flags2(ip, pip);
+ fallthrough;
+ case S_IFLNK:
+ ip->i_df.if_format = XFS_DINODE_FMT_EXTENTS;
+ ip->i_df.if_bytes = 0;
+ ip->i_df.if_u1.if_root = NULL;
+ break;
+ default:
+ ASSERT(0);
+ }
+
+ /*
+ * If we need to create attributes immediately after allocating the
+ * inode, initialise an empty attribute fork right now. We use the
+ * default fork offset for attributes here as we don't know exactly what
+ * size or how many attributes we might be adding. We can do this
+ * safely here because we know the data fork is completely empty and
+ * this saves us from needing to run a separate transaction to set the
+ * fork offset in the immediate future.
+ */
+ if (init_xattrs && xfs_has_attr(mp)) {
+ ip->i_forkoff = xfs_default_attroffset(ip) >> 3;
+ xfs_ifork_init_attr(ip, XFS_DINODE_FMT_EXTENTS, 0);
+ }
+
+ /*
+ * Log the new values stuffed into the inode.
+ */
+ xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
+ xfs_trans_log_inode(tp, ip, flags);
+
+ /* now that we have an i_mode we can setup the inode structure */
+ xfs_setup_inode(ip);
+
+ *ipp = ip;
+ return 0;
+}
+
+/*
+ * Decrement the link count on an inode & log the change. If this causes the
+ * link count to go to zero, move the inode to AGI unlinked list so that it can
+ * be freed when the last active reference goes away via xfs_inactive().
+ */
+static int /* error */
+xfs_droplink(
+ xfs_trans_t *tp,
+ xfs_inode_t *ip)
+{
+ xfs_trans_ichgtime(tp, ip, XFS_ICHGTIME_CHG);
+
+ drop_nlink(VFS_I(ip));
+ xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
+
+ if (VFS_I(ip)->i_nlink)
+ return 0;
+
+ return xfs_iunlink(tp, ip);
+}
+
+/*
+ * Increment the link count on an inode & log the change.
+ */
+static void
+xfs_bumplink(
+ xfs_trans_t *tp,
+ xfs_inode_t *ip)
+{
+ xfs_trans_ichgtime(tp, ip, XFS_ICHGTIME_CHG);
+
+ inc_nlink(VFS_I(ip));
+ xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
+}
+
+int
+xfs_create(
+ struct user_namespace *mnt_userns,
+ xfs_inode_t *dp,
+ struct xfs_name *name,
+ umode_t mode,
+ dev_t rdev,
+ bool init_xattrs,
+ xfs_inode_t **ipp)
+{
+ int is_dir = S_ISDIR(mode);
+ struct xfs_mount *mp = dp->i_mount;
+ struct xfs_inode *ip = NULL;
+ struct xfs_trans *tp = NULL;
+ int error;
+ bool unlock_dp_on_error = false;
+ prid_t prid;
+ struct xfs_dquot *udqp = NULL;
+ struct xfs_dquot *gdqp = NULL;
+ struct xfs_dquot *pdqp = NULL;
+ struct xfs_trans_res *tres;
+ uint resblks;
+ xfs_ino_t ino;
+
+ trace_xfs_create(dp, name);
+
+ if (xfs_is_shutdown(mp))
+ return -EIO;
+
+ prid = xfs_get_initial_prid(dp);
+
+ /*
+ * Make sure that we have allocated dquot(s) on disk.
+ */
+ error = xfs_qm_vop_dqalloc(dp, mapped_fsuid(mnt_userns, &init_user_ns),
+ mapped_fsgid(mnt_userns, &init_user_ns), prid,
+ XFS_QMOPT_QUOTALL | XFS_QMOPT_INHERIT,
+ &udqp, &gdqp, &pdqp);
+ if (error)
+ return error;
+
+ if (is_dir) {
+ resblks = XFS_MKDIR_SPACE_RES(mp, name->len);
+ tres = &M_RES(mp)->tr_mkdir;
+ } else {
+ resblks = XFS_CREATE_SPACE_RES(mp, name->len);
+ tres = &M_RES(mp)->tr_create;
+ }
+
+ /*
+ * Initially assume that the file does not exist and
+ * reserve the resources for that case. If that is not
+ * the case we'll drop the one we have and get a more
+ * appropriate transaction later.
+ */
+ error = xfs_trans_alloc_icreate(mp, tres, udqp, gdqp, pdqp, resblks,
+ &tp);
+ if (error == -ENOSPC) {
+ /* flush outstanding delalloc blocks and retry */
+ xfs_flush_inodes(mp);
+ error = xfs_trans_alloc_icreate(mp, tres, udqp, gdqp, pdqp,
+ resblks, &tp);
+ }
+ if (error)
+ goto out_release_dquots;
+
+ xfs_ilock(dp, XFS_ILOCK_EXCL | XFS_ILOCK_PARENT);
+ unlock_dp_on_error = true;
+
+ /*
+ * A newly created regular or special file just has one directory
+ * entry pointing to them, but a directory also the "." entry
+ * pointing to itself.
+ */
+ error = xfs_dialloc(&tp, dp->i_ino, mode, &ino);
+ if (!error)
+ error = xfs_init_new_inode(mnt_userns, tp, dp, ino, mode,
+ is_dir ? 2 : 1, rdev, prid, init_xattrs, &ip);
+ if (error)
+ goto out_trans_cancel;
+
+ /*
+ * Now we join the directory inode to the transaction. We do not do it
+ * earlier because xfs_dialloc might commit the previous transaction
+ * (and release all the locks). An error from here on will result in
+ * the transaction cancel unlocking dp so don't do it explicitly in the
+ * error path.
+ */
+ xfs_trans_ijoin(tp, dp, XFS_ILOCK_EXCL);
+ unlock_dp_on_error = false;
+
+ error = xfs_dir_createname(tp, dp, name, ip->i_ino,
+ resblks - XFS_IALLOC_SPACE_RES(mp));
+ if (error) {
+ ASSERT(error != -ENOSPC);
+ goto out_trans_cancel;
+ }
+ xfs_trans_ichgtime(tp, dp, XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);
+ xfs_trans_log_inode(tp, dp, XFS_ILOG_CORE);
+
+ if (is_dir) {
+ error = xfs_dir_init(tp, ip, dp);
+ if (error)
+ goto out_trans_cancel;
+
+ xfs_bumplink(tp, dp);
+ }
+
+ /*
+ * If this is a synchronous mount, make sure that the
+ * create transaction goes to disk before returning to
+ * the user.
+ */
+ if (xfs_has_wsync(mp) || xfs_has_dirsync(mp))
+ xfs_trans_set_sync(tp);
+
+ /*
+ * Attach the dquot(s) to the inodes and modify them incore.
+ * These ids of the inode couldn't have changed since the new
+ * inode has been locked ever since it was created.
+ */
+ xfs_qm_vop_create_dqattach(tp, ip, udqp, gdqp, pdqp);
+
+ error = xfs_trans_commit(tp);
+ if (error)
+ goto out_release_inode;
+
+ xfs_qm_dqrele(udqp);
+ xfs_qm_dqrele(gdqp);
+ xfs_qm_dqrele(pdqp);
+
+ *ipp = ip;
+ return 0;
+
+ out_trans_cancel:
+ xfs_trans_cancel(tp);
+ out_release_inode:
+ /*
+ * Wait until after the current transaction is aborted to finish the
+ * setup of the inode and release the inode. This prevents recursive
+ * transactions and deadlocks from xfs_inactive.
+ */
+ if (ip) {
+ xfs_finish_inode_setup(ip);
+ xfs_irele(ip);
+ }
+ out_release_dquots:
+ xfs_qm_dqrele(udqp);
+ xfs_qm_dqrele(gdqp);
+ xfs_qm_dqrele(pdqp);
+
+ if (unlock_dp_on_error)
+ xfs_iunlock(dp, XFS_ILOCK_EXCL);
+ return error;
+}
+
+int
+xfs_create_tmpfile(
+ struct user_namespace *mnt_userns,
+ struct xfs_inode *dp,
+ umode_t mode,
+ struct xfs_inode **ipp)
+{
+ struct xfs_mount *mp = dp->i_mount;
+ struct xfs_inode *ip = NULL;
+ struct xfs_trans *tp = NULL;
+ int error;
+ prid_t prid;
+ struct xfs_dquot *udqp = NULL;
+ struct xfs_dquot *gdqp = NULL;
+ struct xfs_dquot *pdqp = NULL;
+ struct xfs_trans_res *tres;
+ uint resblks;
+ xfs_ino_t ino;
+
+ if (xfs_is_shutdown(mp))
+ return -EIO;
+
+ prid = xfs_get_initial_prid(dp);
+
+ /*
+ * Make sure that we have allocated dquot(s) on disk.
+ */
+ error = xfs_qm_vop_dqalloc(dp, mapped_fsuid(mnt_userns, &init_user_ns),
+ mapped_fsgid(mnt_userns, &init_user_ns), prid,
+ XFS_QMOPT_QUOTALL | XFS_QMOPT_INHERIT,
+ &udqp, &gdqp, &pdqp);
+ if (error)
+ return error;
+
+ resblks = XFS_IALLOC_SPACE_RES(mp);
+ tres = &M_RES(mp)->tr_create_tmpfile;
+
+ error = xfs_trans_alloc_icreate(mp, tres, udqp, gdqp, pdqp, resblks,
+ &tp);
+ if (error)
+ goto out_release_dquots;
+
+ error = xfs_dialloc(&tp, dp->i_ino, mode, &ino);
+ if (!error)
+ error = xfs_init_new_inode(mnt_userns, tp, dp, ino, mode,
+ 0, 0, prid, false, &ip);
+ if (error)
+ goto out_trans_cancel;
+
+ if (xfs_has_wsync(mp))
+ xfs_trans_set_sync(tp);
+
+ /*
+ * Attach the dquot(s) to the inodes and modify them incore.
+ * These ids of the inode couldn't have changed since the new
+ * inode has been locked ever since it was created.
+ */
+ xfs_qm_vop_create_dqattach(tp, ip, udqp, gdqp, pdqp);
+
+ error = xfs_iunlink(tp, ip);
+ if (error)
+ goto out_trans_cancel;
+
+ error = xfs_trans_commit(tp);
+ if (error)
+ goto out_release_inode;
+
+ xfs_qm_dqrele(udqp);
+ xfs_qm_dqrele(gdqp);
+ xfs_qm_dqrele(pdqp);
+
+ *ipp = ip;
+ return 0;
+
+ out_trans_cancel:
+ xfs_trans_cancel(tp);
+ out_release_inode:
+ /*
+ * Wait until after the current transaction is aborted to finish the
+ * setup of the inode and release the inode. This prevents recursive
+ * transactions and deadlocks from xfs_inactive.
+ */
+ if (ip) {
+ xfs_finish_inode_setup(ip);
+ xfs_irele(ip);
+ }
+ out_release_dquots:
+ xfs_qm_dqrele(udqp);
+ xfs_qm_dqrele(gdqp);
+ xfs_qm_dqrele(pdqp);
+
+ return error;
+}
+
+int
+xfs_link(
+ xfs_inode_t *tdp,
+ xfs_inode_t *sip,
+ struct xfs_name *target_name)
+{
+ xfs_mount_t *mp = tdp->i_mount;
+ xfs_trans_t *tp;
+ int error, nospace_error = 0;
+ int resblks;
+
+ trace_xfs_link(tdp, target_name);
+
+ ASSERT(!S_ISDIR(VFS_I(sip)->i_mode));
+
+ if (xfs_is_shutdown(mp))
+ return -EIO;
+
+ error = xfs_qm_dqattach(sip);
+ if (error)
+ goto std_return;
+
+ error = xfs_qm_dqattach(tdp);
+ if (error)
+ goto std_return;
+
+ resblks = XFS_LINK_SPACE_RES(mp, target_name->len);
+ error = xfs_trans_alloc_dir(tdp, &M_RES(mp)->tr_link, sip, &resblks,
+ &tp, &nospace_error);
+ if (error)
+ goto std_return;
+
+ /*
+ * If we are using project inheritance, we only allow hard link
+ * creation in our tree when the project IDs are the same; else
+ * the tree quota mechanism could be circumvented.
+ */
+ if (unlikely((tdp->i_diflags & XFS_DIFLAG_PROJINHERIT) &&
+ tdp->i_projid != sip->i_projid)) {
+ error = -EXDEV;
+ goto error_return;
+ }
+
+ if (!resblks) {
+ error = xfs_dir_canenter(tp, tdp, target_name);
+ if (error)
+ goto error_return;
+ }
+
+ /*
+ * Handle initial link state of O_TMPFILE inode
+ */
+ if (VFS_I(sip)->i_nlink == 0) {
+ struct xfs_perag *pag;
+
+ pag = xfs_perag_get(mp, XFS_INO_TO_AGNO(mp, sip->i_ino));
+ error = xfs_iunlink_remove(tp, pag, sip);
+ xfs_perag_put(pag);
+ if (error)
+ goto error_return;
+ }
+
+ error = xfs_dir_createname(tp, tdp, target_name, sip->i_ino,
+ resblks);
+ if (error)
+ goto error_return;
+ xfs_trans_ichgtime(tp, tdp, XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);
+ xfs_trans_log_inode(tp, tdp, XFS_ILOG_CORE);
+
+ xfs_bumplink(tp, sip);
+
+ /*
+ * If this is a synchronous mount, make sure that the
+ * link transaction goes to disk before returning to
+ * the user.
+ */
+ if (xfs_has_wsync(mp) || xfs_has_dirsync(mp))
+ xfs_trans_set_sync(tp);
+
+ return xfs_trans_commit(tp);
+
+ error_return:
+ xfs_trans_cancel(tp);
+ std_return:
+ if (error == -ENOSPC && nospace_error)
+ error = nospace_error;
+ return error;
+}
+
+/* Clear the reflink flag and the cowblocks tag if possible. */
+static void
+xfs_itruncate_clear_reflink_flags(
+ struct xfs_inode *ip)
+{
+ struct xfs_ifork *dfork;
+ struct xfs_ifork *cfork;
+
+ if (!xfs_is_reflink_inode(ip))
+ return;
+ dfork = xfs_ifork_ptr(ip, XFS_DATA_FORK);
+ cfork = xfs_ifork_ptr(ip, XFS_COW_FORK);
+ if (dfork->if_bytes == 0 && cfork->if_bytes == 0)
+ ip->i_diflags2 &= ~XFS_DIFLAG2_REFLINK;
+ if (cfork->if_bytes == 0)
+ xfs_inode_clear_cowblocks_tag(ip);
+}
+
+/*
+ * Free up the underlying blocks past new_size. The new size must be smaller
+ * than the current size. This routine can be used both for the attribute and
+ * data fork, and does not modify the inode size, which is left to the caller.
+ *
+ * The transaction passed to this routine must have made a permanent log
+ * reservation of at least XFS_ITRUNCATE_LOG_RES. This routine may commit the
+ * given transaction and start new ones, so make sure everything involved in
+ * the transaction is tidy before calling here. Some transaction will be
+ * returned to the caller to be committed. The incoming transaction must
+ * already include the inode, and both inode locks must be held exclusively.
+ * The inode must also be "held" within the transaction. On return the inode
+ * will be "held" within the returned transaction. This routine does NOT
+ * require any disk space to be reserved for it within the transaction.
+ *
+ * If we get an error, we must return with the inode locked and linked into the
+ * current transaction. This keeps things simple for the higher level code,
+ * because it always knows that the inode is locked and held in the transaction
+ * that returns to it whether errors occur or not. We don't mark the inode
+ * dirty on error so that transactions can be easily aborted if possible.
+ */
+int
+xfs_itruncate_extents_flags(
+ struct xfs_trans **tpp,
+ struct xfs_inode *ip,
+ int whichfork,
+ xfs_fsize_t new_size,
+ int flags)
+{
+ struct xfs_mount *mp = ip->i_mount;
+ struct xfs_trans *tp = *tpp;
+ xfs_fileoff_t first_unmap_block;
+ xfs_filblks_t unmap_len;
+ int error = 0;
+
+ ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL));
+ ASSERT(!atomic_read(&VFS_I(ip)->i_count) ||
+ xfs_isilocked(ip, XFS_IOLOCK_EXCL));
+ ASSERT(new_size <= XFS_ISIZE(ip));
+ ASSERT(tp->t_flags & XFS_TRANS_PERM_LOG_RES);
+ ASSERT(ip->i_itemp != NULL);
+ ASSERT(ip->i_itemp->ili_lock_flags == 0);
+ ASSERT(!XFS_NOT_DQATTACHED(mp, ip));
+
+ trace_xfs_itruncate_extents_start(ip, new_size);
+
+ flags |= xfs_bmapi_aflag(whichfork);
+
+ /*
+ * Since it is possible for space to become allocated beyond
+ * the end of the file (in a crash where the space is allocated
+ * but the inode size is not yet updated), simply remove any
+ * blocks which show up between the new EOF and the maximum
+ * possible file size.
+ *
+ * We have to free all the blocks to the bmbt maximum offset, even if
+ * the page cache can't scale that far.
+ */
+ first_unmap_block = XFS_B_TO_FSB(mp, (xfs_ufsize_t)new_size);
+ if (!xfs_verify_fileoff(mp, first_unmap_block)) {
+ WARN_ON_ONCE(first_unmap_block > XFS_MAX_FILEOFF);
+ return 0;
+ }
+
+ unmap_len = XFS_MAX_FILEOFF - first_unmap_block + 1;
+ while (unmap_len > 0) {
+ ASSERT(tp->t_firstblock == NULLFSBLOCK);
+ error = __xfs_bunmapi(tp, ip, first_unmap_block, &unmap_len,
+ flags, XFS_ITRUNC_MAX_EXTENTS);
+ if (error)
+ goto out;
+
+ /* free the just unmapped extents */
+ error = xfs_defer_finish(&tp);
+ if (error)
+ goto out;
+ }
+
+ if (whichfork == XFS_DATA_FORK) {
+ /* Remove all pending CoW reservations. */
+ error = xfs_reflink_cancel_cow_blocks(ip, &tp,
+ first_unmap_block, XFS_MAX_FILEOFF, true);
+ if (error)
+ goto out;
+
+ xfs_itruncate_clear_reflink_flags(ip);
+ }
+
+ /*
+ * Always re-log the inode so that our permanent transaction can keep
+ * on rolling it forward in the log.
+ */
+ xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
+
+ trace_xfs_itruncate_extents_end(ip, new_size);
+
+out:
+ *tpp = tp;
+ return error;
+}
+
+int
+xfs_release(
+ xfs_inode_t *ip)
+{
+ xfs_mount_t *mp = ip->i_mount;
+ int error = 0;
+
+ if (!S_ISREG(VFS_I(ip)->i_mode) || (VFS_I(ip)->i_mode == 0))
+ return 0;
+
+ /* If this is a read-only mount, don't do this (would generate I/O) */
+ if (xfs_is_readonly(mp))
+ return 0;
+
+ if (!xfs_is_shutdown(mp)) {
+ int truncated;
+
+ /*
+ * If we previously truncated this file and removed old data
+ * in the process, we want to initiate "early" writeout on
+ * the last close. This is an attempt to combat the notorious
+ * NULL files problem which is particularly noticeable from a
+ * truncate down, buffered (re-)write (delalloc), followed by
+ * a crash. What we are effectively doing here is
+ * significantly reducing the time window where we'd otherwise
+ * be exposed to that problem.
+ */
+ truncated = xfs_iflags_test_and_clear(ip, XFS_ITRUNCATED);
+ if (truncated) {
+ xfs_iflags_clear(ip, XFS_IDIRTY_RELEASE);
+ if (ip->i_delayed_blks > 0) {
+ error = filemap_flush(VFS_I(ip)->i_mapping);
+ if (error)
+ return error;
+ }
+ }
+ }
+
+ if (VFS_I(ip)->i_nlink == 0)
+ return 0;
+
+ /*
+ * If we can't get the iolock just skip truncating the blocks past EOF
+ * because we could deadlock with the mmap_lock otherwise. We'll get
+ * another chance to drop them once the last reference to the inode is
+ * dropped, so we'll never leak blocks permanently.
+ */
+ if (!xfs_ilock_nowait(ip, XFS_IOLOCK_EXCL))
+ return 0;
+
+ if (xfs_can_free_eofblocks(ip, false)) {
+ /*
+ * Check if the inode is being opened, written and closed
+ * frequently and we have delayed allocation blocks outstanding
+ * (e.g. streaming writes from the NFS server), truncating the
+ * blocks past EOF will cause fragmentation to occur.
+ *
+ * In this case don't do the truncation, but we have to be
+ * careful how we detect this case. Blocks beyond EOF show up as
+ * i_delayed_blks even when the inode is clean, so we need to
+ * truncate them away first before checking for a dirty release.
+ * Hence on the first dirty close we will still remove the
+ * speculative allocation, but after that we will leave it in
+ * place.
+ */
+ if (xfs_iflags_test(ip, XFS_IDIRTY_RELEASE))
+ goto out_unlock;
+
+ error = xfs_free_eofblocks(ip);
+ if (error)
+ goto out_unlock;
+
+ /* delalloc blocks after truncation means it really is dirty */
+ if (ip->i_delayed_blks)
+ xfs_iflags_set(ip, XFS_IDIRTY_RELEASE);
+ }
+
+out_unlock:
+ xfs_iunlock(ip, XFS_IOLOCK_EXCL);
+ return error;
+}
+
+/*
+ * xfs_inactive_truncate
+ *
+ * Called to perform a truncate when an inode becomes unlinked.
+ */
+STATIC int
+xfs_inactive_truncate(
+ struct xfs_inode *ip)
+{
+ struct xfs_mount *mp = ip->i_mount;
+ struct xfs_trans *tp;
+ int error;
+
+ error = xfs_trans_alloc(mp, &M_RES(mp)->tr_itruncate, 0, 0, 0, &tp);
+ if (error) {
+ ASSERT(xfs_is_shutdown(mp));
+ return error;
+ }
+ xfs_ilock(ip, XFS_ILOCK_EXCL);
+ xfs_trans_ijoin(tp, ip, 0);
+
+ /*
+ * Log the inode size first to prevent stale data exposure in the event
+ * of a system crash before the truncate completes. See the related
+ * comment in xfs_vn_setattr_size() for details.
+ */
+ ip->i_disk_size = 0;
+ xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
+
+ error = xfs_itruncate_extents(&tp, ip, XFS_DATA_FORK, 0);
+ if (error)
+ goto error_trans_cancel;
+
+ ASSERT(ip->i_df.if_nextents == 0);
+
+ error = xfs_trans_commit(tp);
+ if (error)
+ goto error_unlock;
+
+ xfs_iunlock(ip, XFS_ILOCK_EXCL);
+ return 0;
+
+error_trans_cancel:
+ xfs_trans_cancel(tp);
+error_unlock:
+ xfs_iunlock(ip, XFS_ILOCK_EXCL);
+ return error;
+}
+
+/*
+ * xfs_inactive_ifree()
+ *
+ * Perform the inode free when an inode is unlinked.
+ */
+STATIC int
+xfs_inactive_ifree(
+ struct xfs_inode *ip)
+{
+ struct xfs_mount *mp = ip->i_mount;
+ struct xfs_trans *tp;
+ int error;
+
+ /*
+ * We try to use a per-AG reservation for any block needed by the finobt
+ * tree, but as the finobt feature predates the per-AG reservation
+ * support a degraded file system might not have enough space for the
+ * reservation at mount time. In that case try to dip into the reserved
+ * pool and pray.
+ *
+ * Send a warning if the reservation does happen to fail, as the inode
+ * now remains allocated and sits on the unlinked list until the fs is
+ * repaired.
+ */
+ if (unlikely(mp->m_finobt_nores)) {
+ error = xfs_trans_alloc(mp, &M_RES(mp)->tr_ifree,
+ XFS_IFREE_SPACE_RES(mp), 0, XFS_TRANS_RESERVE,
+ &tp);
+ } else {
+ error = xfs_trans_alloc(mp, &M_RES(mp)->tr_ifree, 0, 0, 0, &tp);
+ }
+ if (error) {
+ if (error == -ENOSPC) {
+ xfs_warn_ratelimited(mp,
+ "Failed to remove inode(s) from unlinked list. "
+ "Please free space, unmount and run xfs_repair.");
+ } else {
+ ASSERT(xfs_is_shutdown(mp));
+ }
+ return error;
+ }
+
+ /*
+ * We do not hold the inode locked across the entire rolling transaction
+ * here. We only need to hold it for the first transaction that
+ * xfs_ifree() builds, which may mark the inode XFS_ISTALE if the
+ * underlying cluster buffer is freed. Relogging an XFS_ISTALE inode
+ * here breaks the relationship between cluster buffer invalidation and
+ * stale inode invalidation on cluster buffer item journal commit
+ * completion, and can result in leaving dirty stale inodes hanging
+ * around in memory.
+ *
+ * We have no need for serialising this inode operation against other
+ * operations - we freed the inode and hence reallocation is required
+ * and that will serialise on reallocating the space the deferops need
+ * to free. Hence we can unlock the inode on the first commit of
+ * the transaction rather than roll it right through the deferops. This
+ * avoids relogging the XFS_ISTALE inode.
+ *
+ * We check that xfs_ifree() hasn't grown an internal transaction roll
+ * by asserting that the inode is still locked when it returns.
+ */
+ xfs_ilock(ip, XFS_ILOCK_EXCL);
+ xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
+
+ error = xfs_ifree(tp, ip);
+ ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL));
+ if (error) {
+ /*
+ * If we fail to free the inode, shut down. The cancel
+ * might do that, we need to make sure. Otherwise the
+ * inode might be lost for a long time or forever.
+ */
+ if (!xfs_is_shutdown(mp)) {
+ xfs_notice(mp, "%s: xfs_ifree returned error %d",
+ __func__, error);
+ xfs_force_shutdown(mp, SHUTDOWN_META_IO_ERROR);
+ }
+ xfs_trans_cancel(tp);
+ return error;
+ }
+
+ /*
+ * Credit the quota account(s). The inode is gone.
+ */
+ xfs_trans_mod_dquot_byino(tp, ip, XFS_TRANS_DQ_ICOUNT, -1);
+
+ /*
+ * Just ignore errors at this point. There is nothing we can do except
+ * to try to keep going. Make sure it's not a silent error.
+ */
+ error = xfs_trans_commit(tp);
+ if (error)
+ xfs_notice(mp, "%s: xfs_trans_commit returned error %d",
+ __func__, error);
+
+ return 0;
+}
+
+/*
+ * Returns true if we need to update the on-disk metadata before we can free
+ * the memory used by this inode. Updates include freeing post-eof
+ * preallocations; freeing COW staging extents; and marking the inode free in
+ * the inobt if it is on the unlinked list.
+ */
+bool
+xfs_inode_needs_inactive(
+ struct xfs_inode *ip)
+{
+ struct xfs_mount *mp = ip->i_mount;
+ struct xfs_ifork *cow_ifp = xfs_ifork_ptr(ip, XFS_COW_FORK);
+
+ /*
+ * If the inode is already free, then there can be nothing
+ * to clean up here.
+ */
+ if (VFS_I(ip)->i_mode == 0)
+ return false;
+
+ /* If this is a read-only mount, don't do this (would generate I/O) */
+ if (xfs_is_readonly(mp))
+ return false;
+
+ /* If the log isn't running, push inodes straight to reclaim. */
+ if (xfs_is_shutdown(mp) || xfs_has_norecovery(mp))
+ return false;
+
+ /* Metadata inodes require explicit resource cleanup. */
+ if (xfs_is_metadata_inode(ip))
+ return false;
+
+ /* Want to clean out the cow blocks if there are any. */
+ if (cow_ifp && cow_ifp->if_bytes > 0)
+ return true;
+
+ /* Unlinked files must be freed. */
+ if (VFS_I(ip)->i_nlink == 0)
+ return true;
+
+ /*
+ * This file isn't being freed, so check if there are post-eof blocks
+ * to free. @force is true because we are evicting an inode from the
+ * cache. Post-eof blocks must be freed, lest we end up with broken
+ * free space accounting.
+ *
+ * Note: don't bother with iolock here since lockdep complains about
+ * acquiring it in reclaim context. We have the only reference to the
+ * inode at this point anyways.
+ */
+ return xfs_can_free_eofblocks(ip, true);
+}
+
+/*
+ * xfs_inactive
+ *
+ * This is called when the vnode reference count for the vnode
+ * goes to zero. If the file has been unlinked, then it must
+ * now be truncated. Also, we clear all of the read-ahead state
+ * kept for the inode here since the file is now closed.
+ */
+void
+xfs_inactive(
+ xfs_inode_t *ip)
+{
+ struct xfs_mount *mp;
+ int error;
+ int truncate = 0;
+
+ /*
+ * If the inode is already free, then there can be nothing
+ * to clean up here.
+ */
+ if (VFS_I(ip)->i_mode == 0) {
+ ASSERT(ip->i_df.if_broot_bytes == 0);
+ goto out;
+ }
+
+ mp = ip->i_mount;
+ ASSERT(!xfs_iflags_test(ip, XFS_IRECOVERY));
+
+ /* If this is a read-only mount, don't do this (would generate I/O) */
+ if (xfs_is_readonly(mp))
+ goto out;
+
+ /* Metadata inodes require explicit resource cleanup. */
+ if (xfs_is_metadata_inode(ip))
+ goto out;
+
+ /* Try to clean out the cow blocks if there are any. */
+ if (xfs_inode_has_cow_data(ip))
+ xfs_reflink_cancel_cow_range(ip, 0, NULLFILEOFF, true);
+
+ if (VFS_I(ip)->i_nlink != 0) {
+ /*
+ * force is true because we are evicting an inode from the
+ * cache. Post-eof blocks must be freed, lest we end up with
+ * broken free space accounting.
+ *
+ * Note: don't bother with iolock here since lockdep complains
+ * about acquiring it in reclaim context. We have the only
+ * reference to the inode at this point anyways.
+ */
+ if (xfs_can_free_eofblocks(ip, true))
+ xfs_free_eofblocks(ip);
+
+ goto out;
+ }
+
+ if (S_ISREG(VFS_I(ip)->i_mode) &&
+ (ip->i_disk_size != 0 || XFS_ISIZE(ip) != 0 ||
+ ip->i_df.if_nextents > 0 || ip->i_delayed_blks > 0))
+ truncate = 1;
+
+ error = xfs_qm_dqattach(ip);
+ if (error)
+ goto out;
+
+ if (S_ISLNK(VFS_I(ip)->i_mode))
+ error = xfs_inactive_symlink(ip);
+ else if (truncate)
+ error = xfs_inactive_truncate(ip);
+ if (error)
+ goto out;
+
+ /*
+ * If there are attributes associated with the file then blow them away
+ * now. The code calls a routine that recursively deconstructs the
+ * attribute fork. If also blows away the in-core attribute fork.
+ */
+ if (xfs_inode_has_attr_fork(ip)) {
+ error = xfs_attr_inactive(ip);
+ if (error)
+ goto out;
+ }
+
+ ASSERT(ip->i_forkoff == 0);
+
+ /*
+ * Free the inode.
+ */
+ xfs_inactive_ifree(ip);
+
+out:
+ /*
+ * We're done making metadata updates for this inode, so we can release
+ * the attached dquots.
+ */
+ xfs_qm_dqdetach(ip);
+}
+
+/*
+ * In-Core Unlinked List Lookups
+ * =============================
+ *
+ * Every inode is supposed to be reachable from some other piece of metadata
+ * with the exception of the root directory. Inodes with a connection to a
+ * file descriptor but not linked from anywhere in the on-disk directory tree
+ * are collectively known as unlinked inodes, though the filesystem itself
+ * maintains links to these inodes so that on-disk metadata are consistent.
+ *
+ * XFS implements a per-AG on-disk hash table of unlinked inodes. The AGI
+ * header contains a number of buckets that point to an inode, and each inode
+ * record has a pointer to the next inode in the hash chain. This
+ * singly-linked list causes scaling problems in the iunlink remove function
+ * because we must walk that list to find the inode that points to the inode
+ * being removed from the unlinked hash bucket list.
+ *
+ * Hence we keep an in-memory double linked list to link each inode on an
+ * unlinked list. Because there are 64 unlinked lists per AGI, keeping pointer
+ * based lists would require having 64 list heads in the perag, one for each
+ * list. This is expensive in terms of memory (think millions of AGs) and cache
+ * misses on lookups. Instead, use the fact that inodes on the unlinked list
+ * must be referenced at the VFS level to keep them on the list and hence we
+ * have an existence guarantee for inodes on the unlinked list.
+ *
+ * Given we have an existence guarantee, we can use lockless inode cache lookups
+ * to resolve aginos to xfs inodes. This means we only need 8 bytes per inode
+ * for the double linked unlinked list, and we don't need any extra locking to
+ * keep the list safe as all manipulations are done under the AGI buffer lock.
+ * Keeping the list up to date does not require memory allocation, just finding
+ * the XFS inode and updating the next/prev unlinked list aginos.
+ */
+
+/*
+ * Find an inode on the unlinked list. This does not take references to the
+ * inode as we have existence guarantees by holding the AGI buffer lock and that
+ * only unlinked, referenced inodes can be on the unlinked inode list. If we
+ * don't find the inode in cache, then let the caller handle the situation.
+ */
+static struct xfs_inode *
+xfs_iunlink_lookup(
+ struct xfs_perag *pag,
+ xfs_agino_t agino)
+{
+ struct xfs_inode *ip;
+
+ rcu_read_lock();
+ ip = radix_tree_lookup(&pag->pag_ici_root, agino);
+
+ /*
+ * Inode not in memory or in RCU freeing limbo should not happen.
+ * Warn about this and let the caller handle the failure.
+ */
+ if (WARN_ON_ONCE(!ip || !ip->i_ino)) {
+ rcu_read_unlock();
+ return NULL;
+ }
+ ASSERT(!xfs_iflags_test(ip, XFS_IRECLAIMABLE | XFS_IRECLAIM));
+ rcu_read_unlock();
+ return ip;
+}
+
+/* Update the prev pointer of the next agino. */
+static int
+xfs_iunlink_update_backref(
+ struct xfs_perag *pag,
+ xfs_agino_t prev_agino,
+ xfs_agino_t next_agino)
+{
+ struct xfs_inode *ip;
+
+ /* No update necessary if we are at the end of the list. */
+ if (next_agino == NULLAGINO)
+ return 0;
+
+ ip = xfs_iunlink_lookup(pag, next_agino);
+ if (!ip)
+ return -EFSCORRUPTED;
+ ip->i_prev_unlinked = prev_agino;
+ return 0;
+}
+
+/*
+ * Point the AGI unlinked bucket at an inode and log the results. The caller
+ * is responsible for validating the old value.
+ */
+STATIC int
+xfs_iunlink_update_bucket(
+ struct xfs_trans *tp,
+ struct xfs_perag *pag,
+ struct xfs_buf *agibp,
+ unsigned int bucket_index,
+ xfs_agino_t new_agino)
+{
+ struct xfs_agi *agi = agibp->b_addr;
+ xfs_agino_t old_value;
+ int offset;
+
+ ASSERT(xfs_verify_agino_or_null(pag, new_agino));
+
+ old_value = be32_to_cpu(agi->agi_unlinked[bucket_index]);
+ trace_xfs_iunlink_update_bucket(tp->t_mountp, pag->pag_agno, bucket_index,
+ old_value, new_agino);
+
+ /*
+ * We should never find the head of the list already set to the value
+ * passed in because either we're adding or removing ourselves from the
+ * head of the list.
+ */
+ if (old_value == new_agino) {
+ xfs_buf_mark_corrupt(agibp);
+ return -EFSCORRUPTED;
+ }
+
+ agi->agi_unlinked[bucket_index] = cpu_to_be32(new_agino);
+ offset = offsetof(struct xfs_agi, agi_unlinked) +
+ (sizeof(xfs_agino_t) * bucket_index);
+ xfs_trans_log_buf(tp, agibp, offset, offset + sizeof(xfs_agino_t) - 1);
+ return 0;
+}
+
+static int
+xfs_iunlink_insert_inode(
+ struct xfs_trans *tp,
+ struct xfs_perag *pag,
+ struct xfs_buf *agibp,
+ struct xfs_inode *ip)
+{
+ struct xfs_mount *mp = tp->t_mountp;
+ struct xfs_agi *agi = agibp->b_addr;
+ xfs_agino_t next_agino;
+ xfs_agino_t agino = XFS_INO_TO_AGINO(mp, ip->i_ino);
+ short bucket_index = agino % XFS_AGI_UNLINKED_BUCKETS;
+ int error;
+
+ /*
+ * Get the index into the agi hash table for the list this inode will
+ * go on. Make sure the pointer isn't garbage and that this inode
+ * isn't already on the list.
+ */
+ next_agino = be32_to_cpu(agi->agi_unlinked[bucket_index]);
+ if (next_agino == agino ||
+ !xfs_verify_agino_or_null(pag, next_agino)) {
+ xfs_buf_mark_corrupt(agibp);
+ return -EFSCORRUPTED;
+ }
+
+ /*
+ * Update the prev pointer in the next inode to point back to this
+ * inode.
+ */
+ error = xfs_iunlink_update_backref(pag, agino, next_agino);
+ if (error)
+ return error;
+
+ if (next_agino != NULLAGINO) {
+ /*
+ * There is already another inode in the bucket, so point this
+ * inode to the current head of the list.
+ */
+ error = xfs_iunlink_log_inode(tp, ip, pag, next_agino);
+ if (error)
+ return error;
+ ip->i_next_unlinked = next_agino;
+ }
+
+ /* Point the head of the list to point to this inode. */
+ return xfs_iunlink_update_bucket(tp, pag, agibp, bucket_index, agino);
+}
+
+/*
+ * This is called when the inode's link count has gone to 0 or we are creating
+ * a tmpfile via O_TMPFILE. The inode @ip must have nlink == 0.
+ *
+ * We place the on-disk inode on a list in the AGI. It will be pulled from this
+ * list when the inode is freed.
+ */
+STATIC int
+xfs_iunlink(
+ struct xfs_trans *tp,
+ struct xfs_inode *ip)
+{
+ struct xfs_mount *mp = tp->t_mountp;
+ struct xfs_perag *pag;
+ struct xfs_buf *agibp;
+ int error;
+
+ ASSERT(VFS_I(ip)->i_nlink == 0);
+ ASSERT(VFS_I(ip)->i_mode != 0);
+ trace_xfs_iunlink(ip);
+
+ pag = xfs_perag_get(mp, XFS_INO_TO_AGNO(mp, ip->i_ino));
+
+ /* Get the agi buffer first. It ensures lock ordering on the list. */
+ error = xfs_read_agi(pag, tp, &agibp);
+ if (error)
+ goto out;
+
+ error = xfs_iunlink_insert_inode(tp, pag, agibp, ip);
+out:
+ xfs_perag_put(pag);
+ return error;
+}
+
+static int
+xfs_iunlink_remove_inode(
+ struct xfs_trans *tp,
+ struct xfs_perag *pag,
+ struct xfs_buf *agibp,
+ struct xfs_inode *ip)
+{
+ struct xfs_mount *mp = tp->t_mountp;
+ struct xfs_agi *agi = agibp->b_addr;
+ xfs_agino_t agino = XFS_INO_TO_AGINO(mp, ip->i_ino);
+ xfs_agino_t head_agino;
+ short bucket_index = agino % XFS_AGI_UNLINKED_BUCKETS;
+ int error;
+
+ trace_xfs_iunlink_remove(ip);
+
+ /*
+ * Get the index into the agi hash table for the list this inode will
+ * go on. Make sure the head pointer isn't garbage.
+ */
+ head_agino = be32_to_cpu(agi->agi_unlinked[bucket_index]);
+ if (!xfs_verify_agino(pag, head_agino)) {
+ XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp,
+ agi, sizeof(*agi));
+ return -EFSCORRUPTED;
+ }
+
+ /*
+ * Set our inode's next_unlinked pointer to NULL and then return
+ * the old pointer value so that we can update whatever was previous
+ * to us in the list to point to whatever was next in the list.
+ */
+ error = xfs_iunlink_log_inode(tp, ip, pag, NULLAGINO);
+ if (error)
+ return error;
+
+ /*
+ * Update the prev pointer in the next inode to point back to previous
+ * inode in the chain.
+ */
+ error = xfs_iunlink_update_backref(pag, ip->i_prev_unlinked,
+ ip->i_next_unlinked);
+ if (error)
+ return error;
+
+ if (head_agino != agino) {
+ struct xfs_inode *prev_ip;
+
+ prev_ip = xfs_iunlink_lookup(pag, ip->i_prev_unlinked);
+ if (!prev_ip)
+ return -EFSCORRUPTED;
+
+ error = xfs_iunlink_log_inode(tp, prev_ip, pag,
+ ip->i_next_unlinked);
+ prev_ip->i_next_unlinked = ip->i_next_unlinked;
+ } else {
+ /* Point the head of the list to the next unlinked inode. */
+ error = xfs_iunlink_update_bucket(tp, pag, agibp, bucket_index,
+ ip->i_next_unlinked);
+ }
+
+ ip->i_next_unlinked = NULLAGINO;
+ ip->i_prev_unlinked = NULLAGINO;
+ return error;
+}
+
+/*
+ * Pull the on-disk inode from the AGI unlinked list.
+ */
+STATIC int
+xfs_iunlink_remove(
+ struct xfs_trans *tp,
+ struct xfs_perag *pag,
+ struct xfs_inode *ip)
+{
+ struct xfs_buf *agibp;
+ int error;
+
+ trace_xfs_iunlink_remove(ip);
+
+ /* Get the agi buffer first. It ensures lock ordering on the list. */
+ error = xfs_read_agi(pag, tp, &agibp);
+ if (error)
+ return error;
+
+ return xfs_iunlink_remove_inode(tp, pag, agibp, ip);
+}
+
+/*
+ * Look up the inode number specified and if it is not already marked XFS_ISTALE
+ * mark it stale. We should only find clean inodes in this lookup that aren't
+ * already stale.
+ */
+static void
+xfs_ifree_mark_inode_stale(
+ struct xfs_perag *pag,
+ struct xfs_inode *free_ip,
+ xfs_ino_t inum)
+{
+ struct xfs_mount *mp = pag->pag_mount;
+ struct xfs_inode_log_item *iip;
+ struct xfs_inode *ip;
+
+retry:
+ rcu_read_lock();
+ ip = radix_tree_lookup(&pag->pag_ici_root, XFS_INO_TO_AGINO(mp, inum));
+
+ /* Inode not in memory, nothing to do */
+ if (!ip) {
+ rcu_read_unlock();
+ return;
+ }
+
+ /*
+ * because this is an RCU protected lookup, we could find a recently
+ * freed or even reallocated inode during the lookup. We need to check
+ * under the i_flags_lock for a valid inode here. Skip it if it is not
+ * valid, the wrong inode or stale.
+ */
+ spin_lock(&ip->i_flags_lock);
+ if (ip->i_ino != inum || __xfs_iflags_test(ip, XFS_ISTALE))
+ goto out_iflags_unlock;
+
+ /*
+ * Don't try to lock/unlock the current inode, but we _cannot_ skip the
+ * other inodes that we did not find in the list attached to the buffer
+ * and are not already marked stale. If we can't lock it, back off and
+ * retry.
+ */
+ if (ip != free_ip) {
+ if (!xfs_ilock_nowait(ip, XFS_ILOCK_EXCL)) {
+ spin_unlock(&ip->i_flags_lock);
+ rcu_read_unlock();
+ delay(1);
+ goto retry;
+ }
+ }
+ ip->i_flags |= XFS_ISTALE;
+
+ /*
+ * If the inode is flushing, it is already attached to the buffer. All
+ * we needed to do here is mark the inode stale so buffer IO completion
+ * will remove it from the AIL.
+ */
+ iip = ip->i_itemp;
+ if (__xfs_iflags_test(ip, XFS_IFLUSHING)) {
+ ASSERT(!list_empty(&iip->ili_item.li_bio_list));
+ ASSERT(iip->ili_last_fields);
+ goto out_iunlock;
+ }
+
+ /*
+ * Inodes not attached to the buffer can be released immediately.
+ * Everything else has to go through xfs_iflush_abort() on journal
+ * commit as the flock synchronises removal of the inode from the
+ * cluster buffer against inode reclaim.
+ */
+ if (!iip || list_empty(&iip->ili_item.li_bio_list))
+ goto out_iunlock;
+
+ __xfs_iflags_set(ip, XFS_IFLUSHING);
+ spin_unlock(&ip->i_flags_lock);
+ rcu_read_unlock();
+
+ /* we have a dirty inode in memory that has not yet been flushed. */
+ spin_lock(&iip->ili_lock);
+ iip->ili_last_fields = iip->ili_fields;
+ iip->ili_fields = 0;
+ iip->ili_fsync_fields = 0;
+ spin_unlock(&iip->ili_lock);
+ ASSERT(iip->ili_last_fields);
+
+ if (ip != free_ip)
+ xfs_iunlock(ip, XFS_ILOCK_EXCL);
+ return;
+
+out_iunlock:
+ if (ip != free_ip)
+ xfs_iunlock(ip, XFS_ILOCK_EXCL);
+out_iflags_unlock:
+ spin_unlock(&ip->i_flags_lock);
+ rcu_read_unlock();
+}
+
+/*
+ * A big issue when freeing the inode cluster is that we _cannot_ skip any
+ * inodes that are in memory - they all must be marked stale and attached to
+ * the cluster buffer.
+ */
+static int
+xfs_ifree_cluster(
+ struct xfs_trans *tp,
+ struct xfs_perag *pag,
+ struct xfs_inode *free_ip,
+ struct xfs_icluster *xic)
+{
+ struct xfs_mount *mp = free_ip->i_mount;
+ struct xfs_ino_geometry *igeo = M_IGEO(mp);
+ struct xfs_buf *bp;
+ xfs_daddr_t blkno;
+ xfs_ino_t inum = xic->first_ino;
+ int nbufs;
+ int i, j;
+ int ioffset;
+ int error;
+
+ nbufs = igeo->ialloc_blks / igeo->blocks_per_cluster;
+
+ for (j = 0; j < nbufs; j++, inum += igeo->inodes_per_cluster) {
+ /*
+ * The allocation bitmap tells us which inodes of the chunk were
+ * physically allocated. Skip the cluster if an inode falls into
+ * a sparse region.
+ */
+ ioffset = inum - xic->first_ino;
+ if ((xic->alloc & XFS_INOBT_MASK(ioffset)) == 0) {
+ ASSERT(ioffset % igeo->inodes_per_cluster == 0);
+ continue;
+ }
+
+ blkno = XFS_AGB_TO_DADDR(mp, XFS_INO_TO_AGNO(mp, inum),
+ XFS_INO_TO_AGBNO(mp, inum));
+
+ /*
+ * We obtain and lock the backing buffer first in the process
+ * here to ensure dirty inodes attached to the buffer remain in
+ * the flushing state while we mark them stale.
+ *
+ * If we scan the in-memory inodes first, then buffer IO can
+ * complete before we get a lock on it, and hence we may fail
+ * to mark all the active inodes on the buffer stale.
+ */
+ error = xfs_trans_get_buf(tp, mp->m_ddev_targp, blkno,
+ mp->m_bsize * igeo->blocks_per_cluster,
+ XBF_UNMAPPED, &bp);
+ if (error)
+ return error;
+
+ /*
+ * This buffer may not have been correctly initialised as we
+ * didn't read it from disk. That's not important because we are
+ * only using to mark the buffer as stale in the log, and to
+ * attach stale cached inodes on it. That means it will never be
+ * dispatched for IO. If it is, we want to know about it, and we
+ * want it to fail. We can acheive this by adding a write
+ * verifier to the buffer.
+ */
+ bp->b_ops = &xfs_inode_buf_ops;
+
+ /*
+ * Now we need to set all the cached clean inodes as XFS_ISTALE,
+ * too. This requires lookups, and will skip inodes that we've
+ * already marked XFS_ISTALE.
+ */
+ for (i = 0; i < igeo->inodes_per_cluster; i++)
+ xfs_ifree_mark_inode_stale(pag, free_ip, inum + i);
+
+ xfs_trans_stale_inode_buf(tp, bp);
+ xfs_trans_binval(tp, bp);
+ }
+ return 0;
+}
+
+/*
+ * This is called to return an inode to the inode free list. The inode should
+ * already be truncated to 0 length and have no pages associated with it. This
+ * routine also assumes that the inode is already a part of the transaction.
+ *
+ * The on-disk copy of the inode will have been added to the list of unlinked
+ * inodes in the AGI. We need to remove the inode from that list atomically with
+ * respect to freeing it here.
+ */
+int
+xfs_ifree(
+ struct xfs_trans *tp,
+ struct xfs_inode *ip)
+{
+ struct xfs_mount *mp = ip->i_mount;
+ struct xfs_perag *pag;
+ struct xfs_icluster xic = { 0 };
+ struct xfs_inode_log_item *iip = ip->i_itemp;
+ int error;
+
+ ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL));
+ ASSERT(VFS_I(ip)->i_nlink == 0);
+ ASSERT(ip->i_df.if_nextents == 0);
+ ASSERT(ip->i_disk_size == 0 || !S_ISREG(VFS_I(ip)->i_mode));
+ ASSERT(ip->i_nblocks == 0);
+
+ pag = xfs_perag_get(mp, XFS_INO_TO_AGNO(mp, ip->i_ino));
+
+ /*
+ * Free the inode first so that we guarantee that the AGI lock is going
+ * to be taken before we remove the inode from the unlinked list. This
+ * makes the AGI lock -> unlinked list modification order the same as
+ * used in O_TMPFILE creation.
+ */
+ error = xfs_difree(tp, pag, ip->i_ino, &xic);
+ if (error)
+ goto out;
+
+ error = xfs_iunlink_remove(tp, pag, ip);
+ if (error)
+ goto out;
+
+ /*
+ * Free any local-format data sitting around before we reset the
+ * data fork to extents format. Note that the attr fork data has
+ * already been freed by xfs_attr_inactive.
+ */
+ if (ip->i_df.if_format == XFS_DINODE_FMT_LOCAL) {
+ kmem_free(ip->i_df.if_u1.if_data);
+ ip->i_df.if_u1.if_data = NULL;
+ ip->i_df.if_bytes = 0;
+ }
+
+ VFS_I(ip)->i_mode = 0; /* mark incore inode as free */
+ ip->i_diflags = 0;
+ ip->i_diflags2 = mp->m_ino_geo.new_diflags2;
+ ip->i_forkoff = 0; /* mark the attr fork not in use */
+ ip->i_df.if_format = XFS_DINODE_FMT_EXTENTS;
+ if (xfs_iflags_test(ip, XFS_IPRESERVE_DM_FIELDS))
+ xfs_iflags_clear(ip, XFS_IPRESERVE_DM_FIELDS);
+
+ /* Don't attempt to replay owner changes for a deleted inode */
+ spin_lock(&iip->ili_lock);
+ iip->ili_fields &= ~(XFS_ILOG_AOWNER | XFS_ILOG_DOWNER);
+ spin_unlock(&iip->ili_lock);
+
+ /*
+ * Bump the generation count so no one will be confused
+ * by reincarnations of this inode.
+ */
+ VFS_I(ip)->i_generation++;
+ xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
+
+ if (xic.deleted)
+ error = xfs_ifree_cluster(tp, pag, ip, &xic);
+out:
+ xfs_perag_put(pag);
+ return error;
+}
+
+/*
+ * This is called to unpin an inode. The caller must have the inode locked
+ * in at least shared mode so that the buffer cannot be subsequently pinned
+ * once someone is waiting for it to be unpinned.
+ */
+static void
+xfs_iunpin(
+ struct xfs_inode *ip)
+{
+ ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL|XFS_ILOCK_SHARED));
+
+ trace_xfs_inode_unpin_nowait(ip, _RET_IP_);
+
+ /* Give the log a push to start the unpinning I/O */
+ xfs_log_force_seq(ip->i_mount, ip->i_itemp->ili_commit_seq, 0, NULL);
+
+}
+
+static void
+__xfs_iunpin_wait(
+ struct xfs_inode *ip)
+{
+ wait_queue_head_t *wq = bit_waitqueue(&ip->i_flags, __XFS_IPINNED_BIT);
+ DEFINE_WAIT_BIT(wait, &ip->i_flags, __XFS_IPINNED_BIT);
+
+ xfs_iunpin(ip);
+
+ do {
+ prepare_to_wait(wq, &wait.wq_entry, TASK_UNINTERRUPTIBLE);
+ if (xfs_ipincount(ip))
+ io_schedule();
+ } while (xfs_ipincount(ip));
+ finish_wait(wq, &wait.wq_entry);
+}
+
+void
+xfs_iunpin_wait(
+ struct xfs_inode *ip)
+{
+ if (xfs_ipincount(ip))
+ __xfs_iunpin_wait(ip);
+}
+
+/*
+ * Removing an inode from the namespace involves removing the directory entry
+ * and dropping the link count on the inode. Removing the directory entry can
+ * result in locking an AGF (directory blocks were freed) and removing a link
+ * count can result in placing the inode on an unlinked list which results in
+ * locking an AGI.
+ *
+ * The big problem here is that we have an ordering constraint on AGF and AGI
+ * locking - inode allocation locks the AGI, then can allocate a new extent for
+ * new inodes, locking the AGF after the AGI. Similarly, freeing the inode
+ * removes the inode from the unlinked list, requiring that we lock the AGI
+ * first, and then freeing the inode can result in an inode chunk being freed
+ * and hence freeing disk space requiring that we lock an AGF.
+ *
+ * Hence the ordering that is imposed by other parts of the code is AGI before
+ * AGF. This means we cannot remove the directory entry before we drop the inode
+ * reference count and put it on the unlinked list as this results in a lock
+ * order of AGF then AGI, and this can deadlock against inode allocation and
+ * freeing. Therefore we must drop the link counts before we remove the
+ * directory entry.
+ *
+ * This is still safe from a transactional point of view - it is not until we
+ * get to xfs_defer_finish() that we have the possibility of multiple
+ * transactions in this operation. Hence as long as we remove the directory
+ * entry and drop the link count in the first transaction of the remove
+ * operation, there are no transactional constraints on the ordering here.
+ */
+int
+xfs_remove(
+ xfs_inode_t *dp,
+ struct xfs_name *name,
+ xfs_inode_t *ip)
+{
+ xfs_mount_t *mp = dp->i_mount;
+ xfs_trans_t *tp = NULL;
+ int is_dir = S_ISDIR(VFS_I(ip)->i_mode);
+ int dontcare;
+ int error = 0;
+ uint resblks;
+
+ trace_xfs_remove(dp, name);
+
+ if (xfs_is_shutdown(mp))
+ return -EIO;
+
+ error = xfs_qm_dqattach(dp);
+ if (error)
+ goto std_return;
+
+ error = xfs_qm_dqattach(ip);
+ if (error)
+ goto std_return;
+
+ /*
+ * We try to get the real space reservation first, allowing for
+ * directory btree deletion(s) implying possible bmap insert(s). If we
+ * can't get the space reservation then we use 0 instead, and avoid the
+ * bmap btree insert(s) in the directory code by, if the bmap insert
+ * tries to happen, instead trimming the LAST block from the directory.
+ *
+ * Ignore EDQUOT and ENOSPC being returned via nospace_error because
+ * the directory code can handle a reservationless update and we don't
+ * want to prevent a user from trying to free space by deleting things.
+ */
+ resblks = XFS_REMOVE_SPACE_RES(mp);
+ error = xfs_trans_alloc_dir(dp, &M_RES(mp)->tr_remove, ip, &resblks,
+ &tp, &dontcare);
+ if (error) {
+ ASSERT(error != -ENOSPC);
+ goto std_return;
+ }
+
+ /*
+ * If we're removing a directory perform some additional validation.
+ */
+ if (is_dir) {
+ ASSERT(VFS_I(ip)->i_nlink >= 2);
+ if (VFS_I(ip)->i_nlink != 2) {
+ error = -ENOTEMPTY;
+ goto out_trans_cancel;
+ }
+ if (!xfs_dir_isempty(ip)) {
+ error = -ENOTEMPTY;
+ goto out_trans_cancel;
+ }
+
+ /* Drop the link from ip's "..". */
+ error = xfs_droplink(tp, dp);
+ if (error)
+ goto out_trans_cancel;
+
+ /* Drop the "." link from ip to self. */
+ error = xfs_droplink(tp, ip);
+ if (error)
+ goto out_trans_cancel;
+
+ /*
+ * Point the unlinked child directory's ".." entry to the root
+ * directory to eliminate back-references to inodes that may
+ * get freed before the child directory is closed. If the fs
+ * gets shrunk, this can lead to dirent inode validation errors.
+ */
+ if (dp->i_ino != tp->t_mountp->m_sb.sb_rootino) {
+ error = xfs_dir_replace(tp, ip, &xfs_name_dotdot,
+ tp->t_mountp->m_sb.sb_rootino, 0);
+ if (error)
+ return error;
+ }
+ } else {
+ /*
+ * When removing a non-directory we need to log the parent
+ * inode here. For a directory this is done implicitly
+ * by the xfs_droplink call for the ".." entry.
+ */
+ xfs_trans_log_inode(tp, dp, XFS_ILOG_CORE);
+ }
+ xfs_trans_ichgtime(tp, dp, XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);
+
+ /* Drop the link from dp to ip. */
+ error = xfs_droplink(tp, ip);
+ if (error)
+ goto out_trans_cancel;
+
+ error = xfs_dir_removename(tp, dp, name, ip->i_ino, resblks);
+ if (error) {
+ ASSERT(error != -ENOENT);
+ goto out_trans_cancel;
+ }
+
+ /*
+ * If this is a synchronous mount, make sure that the
+ * remove transaction goes to disk before returning to
+ * the user.
+ */
+ if (xfs_has_wsync(mp) || xfs_has_dirsync(mp))
+ xfs_trans_set_sync(tp);
+
+ error = xfs_trans_commit(tp);
+ if (error)
+ goto std_return;
+
+ if (is_dir && xfs_inode_is_filestream(ip))
+ xfs_filestream_deassociate(ip);
+
+ return 0;
+
+ out_trans_cancel:
+ xfs_trans_cancel(tp);
+ std_return:
+ return error;
+}
+
+/*
+ * Enter all inodes for a rename transaction into a sorted array.
+ */
+#define __XFS_SORT_INODES 5
+STATIC void
+xfs_sort_for_rename(
+ struct xfs_inode *dp1, /* in: old (source) directory inode */
+ struct xfs_inode *dp2, /* in: new (target) directory inode */
+ struct xfs_inode *ip1, /* in: inode of old entry */
+ struct xfs_inode *ip2, /* in: inode of new entry */
+ struct xfs_inode *wip, /* in: whiteout inode */
+ struct xfs_inode **i_tab,/* out: sorted array of inodes */
+ int *num_inodes) /* in/out: inodes in array */
+{
+ int i, j;
+
+ ASSERT(*num_inodes == __XFS_SORT_INODES);
+ memset(i_tab, 0, *num_inodes * sizeof(struct xfs_inode *));
+
+ /*
+ * i_tab contains a list of pointers to inodes. We initialize
+ * the table here & we'll sort it. We will then use it to
+ * order the acquisition of the inode locks.
+ *
+ * Note that the table may contain duplicates. e.g., dp1 == dp2.
+ */
+ i = 0;
+ i_tab[i++] = dp1;
+ i_tab[i++] = dp2;
+ i_tab[i++] = ip1;
+ if (ip2)
+ i_tab[i++] = ip2;
+ if (wip)
+ i_tab[i++] = wip;
+ *num_inodes = i;
+
+ /*
+ * Sort the elements via bubble sort. (Remember, there are at
+ * most 5 elements to sort, so this is adequate.)
+ */
+ for (i = 0; i < *num_inodes; i++) {
+ for (j = 1; j < *num_inodes; j++) {
+ if (i_tab[j]->i_ino < i_tab[j-1]->i_ino) {
+ struct xfs_inode *temp = i_tab[j];
+ i_tab[j] = i_tab[j-1];
+ i_tab[j-1] = temp;
+ }
+ }
+ }
+}
+
+static int
+xfs_finish_rename(
+ struct xfs_trans *tp)
+{
+ /*
+ * If this is a synchronous mount, make sure that the rename transaction
+ * goes to disk before returning to the user.
+ */
+ if (xfs_has_wsync(tp->t_mountp) || xfs_has_dirsync(tp->t_mountp))
+ xfs_trans_set_sync(tp);
+
+ return xfs_trans_commit(tp);
+}
+
+/*
+ * xfs_cross_rename()
+ *
+ * responsible for handling RENAME_EXCHANGE flag in renameat2() syscall
+ */
+STATIC int
+xfs_cross_rename(
+ struct xfs_trans *tp,
+ struct xfs_inode *dp1,
+ struct xfs_name *name1,
+ struct xfs_inode *ip1,
+ struct xfs_inode *dp2,
+ struct xfs_name *name2,
+ struct xfs_inode *ip2,
+ int spaceres)
+{
+ int error = 0;
+ int ip1_flags = 0;
+ int ip2_flags = 0;
+ int dp2_flags = 0;
+
+ /* Swap inode number for dirent in first parent */
+ error = xfs_dir_replace(tp, dp1, name1, ip2->i_ino, spaceres);
+ if (error)
+ goto out_trans_abort;
+
+ /* Swap inode number for dirent in second parent */
+ error = xfs_dir_replace(tp, dp2, name2, ip1->i_ino, spaceres);
+ if (error)
+ goto out_trans_abort;
+
+ /*
+ * If we're renaming one or more directories across different parents,
+ * update the respective ".." entries (and link counts) to match the new
+ * parents.
+ */
+ if (dp1 != dp2) {
+ dp2_flags = XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG;
+
+ if (S_ISDIR(VFS_I(ip2)->i_mode)) {
+ error = xfs_dir_replace(tp, ip2, &xfs_name_dotdot,
+ dp1->i_ino, spaceres);
+ if (error)
+ goto out_trans_abort;
+
+ /* transfer ip2 ".." reference to dp1 */
+ if (!S_ISDIR(VFS_I(ip1)->i_mode)) {
+ error = xfs_droplink(tp, dp2);
+ if (error)
+ goto out_trans_abort;
+ xfs_bumplink(tp, dp1);
+ }
+
+ /*
+ * Although ip1 isn't changed here, userspace needs
+ * to be warned about the change, so that applications
+ * relying on it (like backup ones), will properly
+ * notify the change
+ */
+ ip1_flags |= XFS_ICHGTIME_CHG;
+ ip2_flags |= XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG;
+ }
+
+ if (S_ISDIR(VFS_I(ip1)->i_mode)) {
+ error = xfs_dir_replace(tp, ip1, &xfs_name_dotdot,
+ dp2->i_ino, spaceres);
+ if (error)
+ goto out_trans_abort;
+
+ /* transfer ip1 ".." reference to dp2 */
+ if (!S_ISDIR(VFS_I(ip2)->i_mode)) {
+ error = xfs_droplink(tp, dp1);
+ if (error)
+ goto out_trans_abort;
+ xfs_bumplink(tp, dp2);
+ }
+
+ /*
+ * Although ip2 isn't changed here, userspace needs
+ * to be warned about the change, so that applications
+ * relying on it (like backup ones), will properly
+ * notify the change
+ */
+ ip1_flags |= XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG;
+ ip2_flags |= XFS_ICHGTIME_CHG;
+ }
+ }
+
+ if (ip1_flags) {
+ xfs_trans_ichgtime(tp, ip1, ip1_flags);
+ xfs_trans_log_inode(tp, ip1, XFS_ILOG_CORE);
+ }
+ if (ip2_flags) {
+ xfs_trans_ichgtime(tp, ip2, ip2_flags);
+ xfs_trans_log_inode(tp, ip2, XFS_ILOG_CORE);
+ }
+ if (dp2_flags) {
+ xfs_trans_ichgtime(tp, dp2, dp2_flags);
+ xfs_trans_log_inode(tp, dp2, XFS_ILOG_CORE);
+ }
+ xfs_trans_ichgtime(tp, dp1, XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);
+ xfs_trans_log_inode(tp, dp1, XFS_ILOG_CORE);
+ return xfs_finish_rename(tp);
+
+out_trans_abort:
+ xfs_trans_cancel(tp);
+ return error;
+}
+
+/*
+ * xfs_rename_alloc_whiteout()
+ *
+ * Return a referenced, unlinked, unlocked inode that can be used as a
+ * whiteout in a rename transaction. We use a tmpfile inode here so that if we
+ * crash between allocating the inode and linking it into the rename transaction
+ * recovery will free the inode and we won't leak it.
+ */
+static int
+xfs_rename_alloc_whiteout(
+ struct user_namespace *mnt_userns,
+ struct xfs_name *src_name,
+ struct xfs_inode *dp,
+ struct xfs_inode **wip)
+{
+ struct xfs_inode *tmpfile;
+ struct qstr name;
+ int error;
+
+ error = xfs_create_tmpfile(mnt_userns, dp, S_IFCHR | WHITEOUT_MODE,
+ &tmpfile);
+ if (error)
+ return error;
+
+ name.name = src_name->name;
+ name.len = src_name->len;
+ error = xfs_inode_init_security(VFS_I(tmpfile), VFS_I(dp), &name);
+ if (error) {
+ xfs_finish_inode_setup(tmpfile);
+ xfs_irele(tmpfile);
+ return error;
+ }
+
+ /*
+ * Prepare the tmpfile inode as if it were created through the VFS.
+ * Complete the inode setup and flag it as linkable. nlink is already
+ * zero, so we can skip the drop_nlink.
+ */
+ xfs_setup_iops(tmpfile);
+ xfs_finish_inode_setup(tmpfile);
+ VFS_I(tmpfile)->i_state |= I_LINKABLE;
+
+ *wip = tmpfile;
+ return 0;
+}
+
+/*
+ * xfs_rename
+ */
+int
+xfs_rename(
+ struct user_namespace *mnt_userns,
+ struct xfs_inode *src_dp,
+ struct xfs_name *src_name,
+ struct xfs_inode *src_ip,
+ struct xfs_inode *target_dp,
+ struct xfs_name *target_name,
+ struct xfs_inode *target_ip,
+ unsigned int flags)
+{
+ struct xfs_mount *mp = src_dp->i_mount;
+ struct xfs_trans *tp;
+ struct xfs_inode *wip = NULL; /* whiteout inode */
+ struct xfs_inode *inodes[__XFS_SORT_INODES];
+ int i;
+ int num_inodes = __XFS_SORT_INODES;
+ bool new_parent = (src_dp != target_dp);
+ bool src_is_directory = S_ISDIR(VFS_I(src_ip)->i_mode);
+ int spaceres;
+ bool retried = false;
+ int error, nospace_error = 0;
+
+ trace_xfs_rename(src_dp, target_dp, src_name, target_name);
+
+ if ((flags & RENAME_EXCHANGE) && !target_ip)
+ return -EINVAL;
+
+ /*
+ * If we are doing a whiteout operation, allocate the whiteout inode
+ * we will be placing at the target and ensure the type is set
+ * appropriately.
+ */
+ if (flags & RENAME_WHITEOUT) {
+ error = xfs_rename_alloc_whiteout(mnt_userns, src_name,
+ target_dp, &wip);
+ if (error)
+ return error;
+
+ /* setup target dirent info as whiteout */
+ src_name->type = XFS_DIR3_FT_CHRDEV;
+ }
+
+ xfs_sort_for_rename(src_dp, target_dp, src_ip, target_ip, wip,
+ inodes, &num_inodes);
+
+retry:
+ nospace_error = 0;
+ spaceres = XFS_RENAME_SPACE_RES(mp, target_name->len);
+ error = xfs_trans_alloc(mp, &M_RES(mp)->tr_rename, spaceres, 0, 0, &tp);
+ if (error == -ENOSPC) {
+ nospace_error = error;
+ spaceres = 0;
+ error = xfs_trans_alloc(mp, &M_RES(mp)->tr_rename, 0, 0, 0,
+ &tp);
+ }
+ if (error)
+ goto out_release_wip;
+
+ /*
+ * Attach the dquots to the inodes
+ */
+ error = xfs_qm_vop_rename_dqattach(inodes);
+ if (error)
+ goto out_trans_cancel;
+
+ /*
+ * Lock all the participating inodes. Depending upon whether
+ * the target_name exists in the target directory, and
+ * whether the target directory is the same as the source
+ * directory, we can lock from 2 to 5 inodes.
+ */
+ xfs_lock_inodes(inodes, num_inodes, XFS_ILOCK_EXCL);
+
+ /*
+ * Join all the inodes to the transaction. From this point on,
+ * we can rely on either trans_commit or trans_cancel to unlock
+ * them.
+ */
+ xfs_trans_ijoin(tp, src_dp, XFS_ILOCK_EXCL);
+ if (new_parent)
+ xfs_trans_ijoin(tp, target_dp, XFS_ILOCK_EXCL);
+ xfs_trans_ijoin(tp, src_ip, XFS_ILOCK_EXCL);
+ if (target_ip)
+ xfs_trans_ijoin(tp, target_ip, XFS_ILOCK_EXCL);
+ if (wip)
+ xfs_trans_ijoin(tp, wip, XFS_ILOCK_EXCL);
+
+ /*
+ * If we are using project inheritance, we only allow renames
+ * into our tree when the project IDs are the same; else the
+ * tree quota mechanism would be circumvented.
+ */
+ if (unlikely((target_dp->i_diflags & XFS_DIFLAG_PROJINHERIT) &&
+ target_dp->i_projid != src_ip->i_projid)) {
+ error = -EXDEV;
+ goto out_trans_cancel;
+ }
+
+ /* RENAME_EXCHANGE is unique from here on. */
+ if (flags & RENAME_EXCHANGE)
+ return xfs_cross_rename(tp, src_dp, src_name, src_ip,
+ target_dp, target_name, target_ip,
+ spaceres);
+
+ /*
+ * Try to reserve quota to handle an expansion of the target directory.
+ * We'll allow the rename to continue in reservationless mode if we hit
+ * a space usage constraint. If we trigger reservationless mode, save
+ * the errno if there isn't any free space in the target directory.
+ */
+ if (spaceres != 0) {
+ error = xfs_trans_reserve_quota_nblks(tp, target_dp, spaceres,
+ 0, false);
+ if (error == -EDQUOT || error == -ENOSPC) {
+ if (!retried) {
+ xfs_trans_cancel(tp);
+ xfs_blockgc_free_quota(target_dp, 0);
+ retried = true;
+ goto retry;
+ }
+
+ nospace_error = error;
+ spaceres = 0;
+ error = 0;
+ }
+ if (error)
+ goto out_trans_cancel;
+ }
+
+ /*
+ * Check for expected errors before we dirty the transaction
+ * so we can return an error without a transaction abort.
+ */
+ if (target_ip == NULL) {
+ /*
+ * If there's no space reservation, check the entry will
+ * fit before actually inserting it.
+ */
+ if (!spaceres) {
+ error = xfs_dir_canenter(tp, target_dp, target_name);
+ if (error)
+ goto out_trans_cancel;
+ }
+ } else {
+ /*
+ * If target exists and it's a directory, check that whether
+ * it can be destroyed.
+ */
+ if (S_ISDIR(VFS_I(target_ip)->i_mode) &&
+ (!xfs_dir_isempty(target_ip) ||
+ (VFS_I(target_ip)->i_nlink > 2))) {
+ error = -EEXIST;
+ goto out_trans_cancel;
+ }
+ }
+
+ /*
+ * Lock the AGI buffers we need to handle bumping the nlink of the
+ * whiteout inode off the unlinked list and to handle dropping the
+ * nlink of the target inode. Per locking order rules, do this in
+ * increasing AG order and before directory block allocation tries to
+ * grab AGFs because we grab AGIs before AGFs.
+ *
+ * The (vfs) caller must ensure that if src is a directory then
+ * target_ip is either null or an empty directory.
+ */
+ for (i = 0; i < num_inodes && inodes[i] != NULL; i++) {
+ if (inodes[i] == wip ||
+ (inodes[i] == target_ip &&
+ (VFS_I(target_ip)->i_nlink == 1 || src_is_directory))) {
+ struct xfs_perag *pag;
+ struct xfs_buf *bp;
+
+ pag = xfs_perag_get(mp,
+ XFS_INO_TO_AGNO(mp, inodes[i]->i_ino));
+ error = xfs_read_agi(pag, tp, &bp);
+ xfs_perag_put(pag);
+ if (error)
+ goto out_trans_cancel;
+ }
+ }
+
+ /*
+ * Directory entry creation below may acquire the AGF. Remove
+ * the whiteout from the unlinked list first to preserve correct
+ * AGI/AGF locking order. This dirties the transaction so failures
+ * after this point will abort and log recovery will clean up the
+ * mess.
+ *
+ * For whiteouts, we need to bump the link count on the whiteout
+ * inode. After this point, we have a real link, clear the tmpfile
+ * state flag from the inode so it doesn't accidentally get misused
+ * in future.
+ */
+ if (wip) {
+ struct xfs_perag *pag;
+
+ ASSERT(VFS_I(wip)->i_nlink == 0);
+
+ pag = xfs_perag_get(mp, XFS_INO_TO_AGNO(mp, wip->i_ino));
+ error = xfs_iunlink_remove(tp, pag, wip);
+ xfs_perag_put(pag);
+ if (error)
+ goto out_trans_cancel;
+
+ xfs_bumplink(tp, wip);
+ VFS_I(wip)->i_state &= ~I_LINKABLE;
+ }
+
+ /*
+ * Set up the target.
+ */
+ if (target_ip == NULL) {
+ /*
+ * If target does not exist and the rename crosses
+ * directories, adjust the target directory link count
+ * to account for the ".." reference from the new entry.
+ */
+ error = xfs_dir_createname(tp, target_dp, target_name,
+ src_ip->i_ino, spaceres);
+ if (error)
+ goto out_trans_cancel;
+
+ xfs_trans_ichgtime(tp, target_dp,
+ XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);
+
+ if (new_parent && src_is_directory) {
+ xfs_bumplink(tp, target_dp);
+ }
+ } else { /* target_ip != NULL */
+ /*
+ * Link the source inode under the target name.
+ * If the source inode is a directory and we are moving
+ * it across directories, its ".." entry will be
+ * inconsistent until we replace that down below.
+ *
+ * In case there is already an entry with the same
+ * name at the destination directory, remove it first.
+ */
+ error = xfs_dir_replace(tp, target_dp, target_name,
+ src_ip->i_ino, spaceres);
+ if (error)
+ goto out_trans_cancel;
+
+ xfs_trans_ichgtime(tp, target_dp,
+ XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);
+
+ /*
+ * Decrement the link count on the target since the target
+ * dir no longer points to it.
+ */
+ error = xfs_droplink(tp, target_ip);
+ if (error)
+ goto out_trans_cancel;
+
+ if (src_is_directory) {
+ /*
+ * Drop the link from the old "." entry.
+ */
+ error = xfs_droplink(tp, target_ip);
+ if (error)
+ goto out_trans_cancel;
+ }
+ } /* target_ip != NULL */
+
+ /*
+ * Remove the source.
+ */
+ if (new_parent && src_is_directory) {
+ /*
+ * Rewrite the ".." entry to point to the new
+ * directory.
+ */
+ error = xfs_dir_replace(tp, src_ip, &xfs_name_dotdot,
+ target_dp->i_ino, spaceres);
+ ASSERT(error != -EEXIST);
+ if (error)
+ goto out_trans_cancel;
+ }
+
+ /*
+ * We always want to hit the ctime on the source inode.
+ *
+ * This isn't strictly required by the standards since the source
+ * inode isn't really being changed, but old unix file systems did
+ * it and some incremental backup programs won't work without it.
+ */
+ xfs_trans_ichgtime(tp, src_ip, XFS_ICHGTIME_CHG);
+ xfs_trans_log_inode(tp, src_ip, XFS_ILOG_CORE);
+
+ /*
+ * Adjust the link count on src_dp. This is necessary when
+ * renaming a directory, either within one parent when
+ * the target existed, or across two parent directories.
+ */
+ if (src_is_directory && (new_parent || target_ip != NULL)) {
+
+ /*
+ * Decrement link count on src_directory since the
+ * entry that's moved no longer points to it.
+ */
+ error = xfs_droplink(tp, src_dp);
+ if (error)
+ goto out_trans_cancel;
+ }
+
+ /*
+ * For whiteouts, we only need to update the source dirent with the
+ * inode number of the whiteout inode rather than removing it
+ * altogether.
+ */
+ if (wip)
+ error = xfs_dir_replace(tp, src_dp, src_name, wip->i_ino,
+ spaceres);
+ else
+ error = xfs_dir_removename(tp, src_dp, src_name, src_ip->i_ino,
+ spaceres);
+
+ if (error)
+ goto out_trans_cancel;
+
+ xfs_trans_ichgtime(tp, src_dp, XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);
+ xfs_trans_log_inode(tp, src_dp, XFS_ILOG_CORE);
+ if (new_parent)
+ xfs_trans_log_inode(tp, target_dp, XFS_ILOG_CORE);
+
+ error = xfs_finish_rename(tp);
+ if (wip)
+ xfs_irele(wip);
+ return error;
+
+out_trans_cancel:
+ xfs_trans_cancel(tp);
+out_release_wip:
+ if (wip)
+ xfs_irele(wip);
+ if (error == -ENOSPC && nospace_error)
+ error = nospace_error;
+ return error;
+}
+
+static int
+xfs_iflush(
+ struct xfs_inode *ip,
+ struct xfs_buf *bp)
+{
+ struct xfs_inode_log_item *iip = ip->i_itemp;
+ struct xfs_dinode *dip;
+ struct xfs_mount *mp = ip->i_mount;
+ int error;
+
+ ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL|XFS_ILOCK_SHARED));
+ ASSERT(xfs_iflags_test(ip, XFS_IFLUSHING));
+ ASSERT(ip->i_df.if_format != XFS_DINODE_FMT_BTREE ||
+ ip->i_df.if_nextents > XFS_IFORK_MAXEXT(ip, XFS_DATA_FORK));
+ ASSERT(iip->ili_item.li_buf == bp);
+
+ dip = xfs_buf_offset(bp, ip->i_imap.im_boffset);
+
+ /*
+ * We don't flush the inode if any of the following checks fail, but we
+ * do still update the log item and attach to the backing buffer as if
+ * the flush happened. This is a formality to facilitate predictable
+ * error handling as the caller will shutdown and fail the buffer.
+ */
+ error = -EFSCORRUPTED;
+ if (XFS_TEST_ERROR(dip->di_magic != cpu_to_be16(XFS_DINODE_MAGIC),
+ mp, XFS_ERRTAG_IFLUSH_1)) {
+ xfs_alert_tag(mp, XFS_PTAG_IFLUSH,
+ "%s: Bad inode %llu magic number 0x%x, ptr "PTR_FMT,
+ __func__, ip->i_ino, be16_to_cpu(dip->di_magic), dip);
+ goto flush_out;
+ }
+ if (S_ISREG(VFS_I(ip)->i_mode)) {
+ if (XFS_TEST_ERROR(
+ ip->i_df.if_format != XFS_DINODE_FMT_EXTENTS &&
+ ip->i_df.if_format != XFS_DINODE_FMT_BTREE,
+ mp, XFS_ERRTAG_IFLUSH_3)) {
+ xfs_alert_tag(mp, XFS_PTAG_IFLUSH,
+ "%s: Bad regular inode %llu, ptr "PTR_FMT,
+ __func__, ip->i_ino, ip);
+ goto flush_out;
+ }
+ } else if (S_ISDIR(VFS_I(ip)->i_mode)) {
+ if (XFS_TEST_ERROR(
+ ip->i_df.if_format != XFS_DINODE_FMT_EXTENTS &&
+ ip->i_df.if_format != XFS_DINODE_FMT_BTREE &&
+ ip->i_df.if_format != XFS_DINODE_FMT_LOCAL,
+ mp, XFS_ERRTAG_IFLUSH_4)) {
+ xfs_alert_tag(mp, XFS_PTAG_IFLUSH,
+ "%s: Bad directory inode %llu, ptr "PTR_FMT,
+ __func__, ip->i_ino, ip);
+ goto flush_out;
+ }
+ }
+ if (XFS_TEST_ERROR(ip->i_df.if_nextents + xfs_ifork_nextents(&ip->i_af) >
+ ip->i_nblocks, mp, XFS_ERRTAG_IFLUSH_5)) {
+ xfs_alert_tag(mp, XFS_PTAG_IFLUSH,
+ "%s: detected corrupt incore inode %llu, "
+ "total extents = %llu nblocks = %lld, ptr "PTR_FMT,
+ __func__, ip->i_ino,
+ ip->i_df.if_nextents + xfs_ifork_nextents(&ip->i_af),
+ ip->i_nblocks, ip);
+ goto flush_out;
+ }
+ if (XFS_TEST_ERROR(ip->i_forkoff > mp->m_sb.sb_inodesize,
+ mp, XFS_ERRTAG_IFLUSH_6)) {
+ xfs_alert_tag(mp, XFS_PTAG_IFLUSH,
+ "%s: bad inode %llu, forkoff 0x%x, ptr "PTR_FMT,
+ __func__, ip->i_ino, ip->i_forkoff, ip);
+ goto flush_out;
+ }
+
+ /*
+ * Inode item log recovery for v2 inodes are dependent on the flushiter
+ * count for correct sequencing. We bump the flush iteration count so
+ * we can detect flushes which postdate a log record during recovery.
+ * This is redundant as we now log every change and hence this can't
+ * happen but we need to still do it to ensure backwards compatibility
+ * with old kernels that predate logging all inode changes.
+ */
+ if (!xfs_has_v3inodes(mp))
+ ip->i_flushiter++;
+
+ /*
+ * If there are inline format data / attr forks attached to this inode,
+ * make sure they are not corrupt.
+ */
+ if (ip->i_df.if_format == XFS_DINODE_FMT_LOCAL &&
+ xfs_ifork_verify_local_data(ip))
+ goto flush_out;
+ if (xfs_inode_has_attr_fork(ip) &&
+ ip->i_af.if_format == XFS_DINODE_FMT_LOCAL &&
+ xfs_ifork_verify_local_attr(ip))
+ goto flush_out;
+
+ /*
+ * Copy the dirty parts of the inode into the on-disk inode. We always
+ * copy out the core of the inode, because if the inode is dirty at all
+ * the core must be.
+ */
+ xfs_inode_to_disk(ip, dip, iip->ili_item.li_lsn);
+
+ /* Wrap, we never let the log put out DI_MAX_FLUSH */
+ if (!xfs_has_v3inodes(mp)) {
+ if (ip->i_flushiter == DI_MAX_FLUSH)
+ ip->i_flushiter = 0;
+ }
+
+ xfs_iflush_fork(ip, dip, iip, XFS_DATA_FORK);
+ if (xfs_inode_has_attr_fork(ip))
+ xfs_iflush_fork(ip, dip, iip, XFS_ATTR_FORK);
+
+ /*
+ * We've recorded everything logged in the inode, so we'd like to clear
+ * the ili_fields bits so we don't log and flush things unnecessarily.
+ * However, we can't stop logging all this information until the data
+ * we've copied into the disk buffer is written to disk. If we did we
+ * might overwrite the copy of the inode in the log with all the data
+ * after re-logging only part of it, and in the face of a crash we
+ * wouldn't have all the data we need to recover.
+ *
+ * What we do is move the bits to the ili_last_fields field. When
+ * logging the inode, these bits are moved back to the ili_fields field.
+ * In the xfs_buf_inode_iodone() routine we clear ili_last_fields, since
+ * we know that the information those bits represent is permanently on
+ * disk. As long as the flush completes before the inode is logged
+ * again, then both ili_fields and ili_last_fields will be cleared.
+ */
+ error = 0;
+flush_out:
+ spin_lock(&iip->ili_lock);
+ iip->ili_last_fields = iip->ili_fields;
+ iip->ili_fields = 0;
+ iip->ili_fsync_fields = 0;
+ spin_unlock(&iip->ili_lock);
+
+ /*
+ * Store the current LSN of the inode so that we can tell whether the
+ * item has moved in the AIL from xfs_buf_inode_iodone().
+ */
+ xfs_trans_ail_copy_lsn(mp->m_ail, &iip->ili_flush_lsn,
+ &iip->ili_item.li_lsn);
+
+ /* generate the checksum. */
+ xfs_dinode_calc_crc(mp, dip);
+ return error;
+}
+
+/*
+ * Non-blocking flush of dirty inode metadata into the backing buffer.
+ *
+ * The caller must have a reference to the inode and hold the cluster buffer
+ * locked. The function will walk across all the inodes on the cluster buffer it
+ * can find and lock without blocking, and flush them to the cluster buffer.
+ *
+ * On successful flushing of at least one inode, the caller must write out the
+ * buffer and release it. If no inodes are flushed, -EAGAIN will be returned and
+ * the caller needs to release the buffer. On failure, the filesystem will be
+ * shut down, the buffer will have been unlocked and released, and EFSCORRUPTED
+ * will be returned.
+ */
+int
+xfs_iflush_cluster(
+ struct xfs_buf *bp)
+{
+ struct xfs_mount *mp = bp->b_mount;
+ struct xfs_log_item *lip, *n;
+ struct xfs_inode *ip;
+ struct xfs_inode_log_item *iip;
+ int clcount = 0;
+ int error = 0;
+
+ /*
+ * We must use the safe variant here as on shutdown xfs_iflush_abort()
+ * will remove itself from the list.
+ */
+ list_for_each_entry_safe(lip, n, &bp->b_li_list, li_bio_list) {
+ iip = (struct xfs_inode_log_item *)lip;
+ ip = iip->ili_inode;
+
+ /*
+ * Quick and dirty check to avoid locks if possible.
+ */
+ if (__xfs_iflags_test(ip, XFS_IRECLAIM | XFS_IFLUSHING))
+ continue;
+ if (xfs_ipincount(ip))
+ continue;
+
+ /*
+ * The inode is still attached to the buffer, which means it is
+ * dirty but reclaim might try to grab it. Check carefully for
+ * that, and grab the ilock while still holding the i_flags_lock
+ * to guarantee reclaim will not be able to reclaim this inode
+ * once we drop the i_flags_lock.
+ */
+ spin_lock(&ip->i_flags_lock);
+ ASSERT(!__xfs_iflags_test(ip, XFS_ISTALE));
+ if (__xfs_iflags_test(ip, XFS_IRECLAIM | XFS_IFLUSHING)) {
+ spin_unlock(&ip->i_flags_lock);
+ continue;
+ }
+
+ /*
+ * ILOCK will pin the inode against reclaim and prevent
+ * concurrent transactions modifying the inode while we are
+ * flushing the inode. If we get the lock, set the flushing
+ * state before we drop the i_flags_lock.
+ */
+ if (!xfs_ilock_nowait(ip, XFS_ILOCK_SHARED)) {
+ spin_unlock(&ip->i_flags_lock);
+ continue;
+ }
+ __xfs_iflags_set(ip, XFS_IFLUSHING);
+ spin_unlock(&ip->i_flags_lock);
+
+ /*
+ * Abort flushing this inode if we are shut down because the
+ * inode may not currently be in the AIL. This can occur when
+ * log I/O failure unpins the inode without inserting into the
+ * AIL, leaving a dirty/unpinned inode attached to the buffer
+ * that otherwise looks like it should be flushed.
+ */
+ if (xlog_is_shutdown(mp->m_log)) {
+ xfs_iunpin_wait(ip);
+ xfs_iflush_abort(ip);
+ xfs_iunlock(ip, XFS_ILOCK_SHARED);
+ error = -EIO;
+ continue;
+ }
+
+ /* don't block waiting on a log force to unpin dirty inodes */
+ if (xfs_ipincount(ip)) {
+ xfs_iflags_clear(ip, XFS_IFLUSHING);
+ xfs_iunlock(ip, XFS_ILOCK_SHARED);
+ continue;
+ }
+
+ if (!xfs_inode_clean(ip))
+ error = xfs_iflush(ip, bp);
+ else
+ xfs_iflags_clear(ip, XFS_IFLUSHING);
+ xfs_iunlock(ip, XFS_ILOCK_SHARED);
+ if (error)
+ break;
+ clcount++;
+ }
+
+ if (error) {
+ /*
+ * Shutdown first so we kill the log before we release this
+ * buffer. If it is an INODE_ALLOC buffer and pins the tail
+ * of the log, failing it before the _log_ is shut down can
+ * result in the log tail being moved forward in the journal
+ * on disk because log writes can still be taking place. Hence
+ * unpinning the tail will allow the ICREATE intent to be
+ * removed from the log an recovery will fail with uninitialised
+ * inode cluster buffers.
+ */
+ xfs_force_shutdown(mp, SHUTDOWN_CORRUPT_INCORE);
+ bp->b_flags |= XBF_ASYNC;
+ xfs_buf_ioend_fail(bp);
+ return error;
+ }
+
+ if (!clcount)
+ return -EAGAIN;
+
+ XFS_STATS_INC(mp, xs_icluster_flushcnt);
+ XFS_STATS_ADD(mp, xs_icluster_flushinode, clcount);
+ return 0;
+
+}
+
+/* Release an inode. */
+void
+xfs_irele(
+ struct xfs_inode *ip)
+{
+ trace_xfs_irele(ip, _RET_IP_);
+ iput(VFS_I(ip));
+}
+
+/*
+ * Ensure all commited transactions touching the inode are written to the log.
+ */
+int
+xfs_log_force_inode(
+ struct xfs_inode *ip)
+{
+ xfs_csn_t seq = 0;
+
+ xfs_ilock(ip, XFS_ILOCK_SHARED);
+ if (xfs_ipincount(ip))
+ seq = ip->i_itemp->ili_commit_seq;
+ xfs_iunlock(ip, XFS_ILOCK_SHARED);
+
+ if (!seq)
+ return 0;
+ return xfs_log_force_seq(ip->i_mount, seq, XFS_LOG_SYNC, NULL);
+}
+
+/*
+ * Grab the exclusive iolock for a data copy from src to dest, making sure to
+ * abide vfs locking order (lowest pointer value goes first) and breaking the
+ * layout leases before proceeding. The loop is needed because we cannot call
+ * the blocking break_layout() with the iolocks held, and therefore have to
+ * back out both locks.
+ */
+static int
+xfs_iolock_two_inodes_and_break_layout(
+ struct inode *src,
+ struct inode *dest)
+{
+ int error;
+
+ if (src > dest)
+ swap(src, dest);
+
+retry:
+ /* Wait to break both inodes' layouts before we start locking. */
+ error = break_layout(src, true);
+ if (error)
+ return error;
+ if (src != dest) {
+ error = break_layout(dest, true);
+ if (error)
+ return error;
+ }
+
+ /* Lock one inode and make sure nobody got in and leased it. */
+ inode_lock(src);
+ error = break_layout(src, false);
+ if (error) {
+ inode_unlock(src);
+ if (error == -EWOULDBLOCK)
+ goto retry;
+ return error;
+ }
+
+ if (src == dest)
+ return 0;
+
+ /* Lock the other inode and make sure nobody got in and leased it. */
+ inode_lock_nested(dest, I_MUTEX_NONDIR2);
+ error = break_layout(dest, false);
+ if (error) {
+ inode_unlock(src);
+ inode_unlock(dest);
+ if (error == -EWOULDBLOCK)
+ goto retry;
+ return error;
+ }
+
+ return 0;
+}
+
+static int
+xfs_mmaplock_two_inodes_and_break_dax_layout(
+ struct xfs_inode *ip1,
+ struct xfs_inode *ip2)
+{
+ int error;
+ bool retry;
+ struct page *page;
+
+ if (ip1->i_ino > ip2->i_ino)
+ swap(ip1, ip2);
+
+again:
+ retry = false;
+ /* Lock the first inode */
+ xfs_ilock(ip1, XFS_MMAPLOCK_EXCL);
+ error = xfs_break_dax_layouts(VFS_I(ip1), &retry);
+ if (error || retry) {
+ xfs_iunlock(ip1, XFS_MMAPLOCK_EXCL);
+ if (error == 0 && retry)
+ goto again;
+ return error;
+ }
+
+ if (ip1 == ip2)
+ return 0;
+
+ /* Nested lock the second inode */
+ xfs_ilock(ip2, xfs_lock_inumorder(XFS_MMAPLOCK_EXCL, 1));
+ /*
+ * We cannot use xfs_break_dax_layouts() directly here because it may
+ * need to unlock & lock the XFS_MMAPLOCK_EXCL which is not suitable
+ * for this nested lock case.
+ */
+ page = dax_layout_busy_page(VFS_I(ip2)->i_mapping);
+ if (page && page_ref_count(page) != 1) {
+ xfs_iunlock(ip2, XFS_MMAPLOCK_EXCL);
+ xfs_iunlock(ip1, XFS_MMAPLOCK_EXCL);
+ goto again;
+ }
+
+ return 0;
+}
+
+/*
+ * Lock two inodes so that userspace cannot initiate I/O via file syscalls or
+ * mmap activity.
+ */
+int
+xfs_ilock2_io_mmap(
+ struct xfs_inode *ip1,
+ struct xfs_inode *ip2)
+{
+ int ret;
+
+ ret = xfs_iolock_two_inodes_and_break_layout(VFS_I(ip1), VFS_I(ip2));
+ if (ret)
+ return ret;
+
+ if (IS_DAX(VFS_I(ip1)) && IS_DAX(VFS_I(ip2))) {
+ ret = xfs_mmaplock_two_inodes_and_break_dax_layout(ip1, ip2);
+ if (ret) {
+ inode_unlock(VFS_I(ip2));
+ if (ip1 != ip2)
+ inode_unlock(VFS_I(ip1));
+ return ret;
+ }
+ } else
+ filemap_invalidate_lock_two(VFS_I(ip1)->i_mapping,
+ VFS_I(ip2)->i_mapping);
+
+ return 0;
+}
+
+/* Unlock both inodes to allow IO and mmap activity. */
+void
+xfs_iunlock2_io_mmap(
+ struct xfs_inode *ip1,
+ struct xfs_inode *ip2)
+{
+ if (IS_DAX(VFS_I(ip1)) && IS_DAX(VFS_I(ip2))) {
+ xfs_iunlock(ip2, XFS_MMAPLOCK_EXCL);
+ if (ip1 != ip2)
+ xfs_iunlock(ip1, XFS_MMAPLOCK_EXCL);
+ } else
+ filemap_invalidate_unlock_two(VFS_I(ip1)->i_mapping,
+ VFS_I(ip2)->i_mapping);
+
+ inode_unlock(VFS_I(ip2));
+ if (ip1 != ip2)
+ inode_unlock(VFS_I(ip1));
+}