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Diffstat (limited to '')
| -rw-r--r-- | fs/xfs/xfs_inode.c | 3540 |
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)); +} |