// SPDX-License-Identifier: GPL-2.0-only /* * Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved. * Copyright (C) 2004-2006 Red Hat, Inc. All rights reserved. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "gfs2.h" #include "incore.h" #include "bmap.h" #include "aops.h" #include "dir.h" #include "glock.h" #include "glops.h" #include "inode.h" #include "log.h" #include "meta_io.h" #include "quota.h" #include "rgrp.h" #include "trans.h" #include "util.h" /** * gfs2_llseek - seek to a location in a file * @file: the file * @offset: the offset * @whence: Where to seek from (SEEK_SET, SEEK_CUR, or SEEK_END) * * SEEK_END requires the glock for the file because it references the * file's size. * * Returns: The new offset, or errno */ static loff_t gfs2_llseek(struct file *file, loff_t offset, int whence) { struct gfs2_inode *ip = GFS2_I(file->f_mapping->host); struct gfs2_holder i_gh; loff_t error; switch (whence) { case SEEK_END: error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY, &i_gh); if (!error) { error = generic_file_llseek(file, offset, whence); gfs2_glock_dq_uninit(&i_gh); } break; case SEEK_DATA: error = gfs2_seek_data(file, offset); break; case SEEK_HOLE: error = gfs2_seek_hole(file, offset); break; case SEEK_CUR: case SEEK_SET: /* * These don't reference inode->i_size and don't depend on the * block mapping, so we don't need the glock. */ error = generic_file_llseek(file, offset, whence); break; default: error = -EINVAL; } return error; } /** * gfs2_readdir - Iterator for a directory * @file: The directory to read from * @ctx: What to feed directory entries to * * Returns: errno */ static int gfs2_readdir(struct file *file, struct dir_context *ctx) { struct inode *dir = file->f_mapping->host; struct gfs2_inode *dip = GFS2_I(dir); struct gfs2_holder d_gh; int error; error = gfs2_glock_nq_init(dip->i_gl, LM_ST_SHARED, 0, &d_gh); if (error) return error; error = gfs2_dir_read(dir, ctx, &file->f_ra); gfs2_glock_dq_uninit(&d_gh); return error; } /* * struct fsflag_gfs2flag * * The FS_JOURNAL_DATA_FL flag maps to GFS2_DIF_INHERIT_JDATA for directories, * and to GFS2_DIF_JDATA for non-directories. */ static struct { u32 fsflag; u32 gfsflag; } fsflag_gfs2flag[] = { {FS_SYNC_FL, GFS2_DIF_SYNC}, {FS_IMMUTABLE_FL, GFS2_DIF_IMMUTABLE}, {FS_APPEND_FL, GFS2_DIF_APPENDONLY}, {FS_NOATIME_FL, GFS2_DIF_NOATIME}, {FS_INDEX_FL, GFS2_DIF_EXHASH}, {FS_TOPDIR_FL, GFS2_DIF_TOPDIR}, {FS_JOURNAL_DATA_FL, GFS2_DIF_JDATA | GFS2_DIF_INHERIT_JDATA}, }; static inline u32 gfs2_gfsflags_to_fsflags(struct inode *inode, u32 gfsflags) { int i; u32 fsflags = 0; if (S_ISDIR(inode->i_mode)) gfsflags &= ~GFS2_DIF_JDATA; else gfsflags &= ~GFS2_DIF_INHERIT_JDATA; for (i = 0; i < ARRAY_SIZE(fsflag_gfs2flag); i++) if (gfsflags & fsflag_gfs2flag[i].gfsflag) fsflags |= fsflag_gfs2flag[i].fsflag; return fsflags; } int gfs2_fileattr_get(struct dentry *dentry, struct fileattr *fa) { struct inode *inode = d_inode(dentry); struct gfs2_inode *ip = GFS2_I(inode); struct gfs2_holder gh; int error; u32 fsflags; if (d_is_special(dentry)) return -ENOTTY; gfs2_holder_init(ip->i_gl, LM_ST_SHARED, 0, &gh); error = gfs2_glock_nq(&gh); if (error) goto out_uninit; fsflags = gfs2_gfsflags_to_fsflags(inode, ip->i_diskflags); fileattr_fill_flags(fa, fsflags); gfs2_glock_dq(&gh); out_uninit: gfs2_holder_uninit(&gh); return error; } void gfs2_set_inode_flags(struct inode *inode) { struct gfs2_inode *ip = GFS2_I(inode); unsigned int flags = inode->i_flags; flags &= ~(S_SYNC|S_APPEND|S_IMMUTABLE|S_NOATIME|S_DIRSYNC|S_NOSEC); if ((ip->i_eattr == 0) && !is_sxid(inode->i_mode)) flags |= S_NOSEC; if (ip->i_diskflags & GFS2_DIF_IMMUTABLE) flags |= S_IMMUTABLE; if (ip->i_diskflags & GFS2_DIF_APPENDONLY) flags |= S_APPEND; if (ip->i_diskflags & GFS2_DIF_NOATIME) flags |= S_NOATIME; if (ip->i_diskflags & GFS2_DIF_SYNC) flags |= S_SYNC; inode->i_flags = flags; } /* Flags that can be set by user space */ #define GFS2_FLAGS_USER_SET (GFS2_DIF_JDATA| \ GFS2_DIF_IMMUTABLE| \ GFS2_DIF_APPENDONLY| \ GFS2_DIF_NOATIME| \ GFS2_DIF_SYNC| \ GFS2_DIF_TOPDIR| \ GFS2_DIF_INHERIT_JDATA) /** * do_gfs2_set_flags - set flags on an inode * @inode: The inode * @reqflags: The flags to set * @mask: Indicates which flags are valid * @fsflags: The FS_* inode flags passed in * */ static int do_gfs2_set_flags(struct inode *inode, u32 reqflags, u32 mask, const u32 fsflags) { struct gfs2_inode *ip = GFS2_I(inode); struct gfs2_sbd *sdp = GFS2_SB(inode); struct buffer_head *bh; struct gfs2_holder gh; int error; u32 new_flags, flags; error = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &gh); if (error) return error; error = 0; flags = ip->i_diskflags; new_flags = (flags & ~mask) | (reqflags & mask); if ((new_flags ^ flags) == 0) goto out; error = -EPERM; if (IS_IMMUTABLE(inode) && (new_flags & GFS2_DIF_IMMUTABLE)) goto out; if (IS_APPEND(inode) && (new_flags & GFS2_DIF_APPENDONLY)) goto out; if (!IS_IMMUTABLE(inode)) { error = gfs2_permission(&init_user_ns, inode, MAY_WRITE); if (error) goto out; } if ((flags ^ new_flags) & GFS2_DIF_JDATA) { if (new_flags & GFS2_DIF_JDATA) gfs2_log_flush(sdp, ip->i_gl, GFS2_LOG_HEAD_FLUSH_NORMAL | GFS2_LFC_SET_FLAGS); error = filemap_fdatawrite(inode->i_mapping); if (error) goto out; error = filemap_fdatawait(inode->i_mapping); if (error) goto out; if (new_flags & GFS2_DIF_JDATA) gfs2_ordered_del_inode(ip); } error = gfs2_trans_begin(sdp, RES_DINODE, 0); if (error) goto out; error = gfs2_meta_inode_buffer(ip, &bh); if (error) goto out_trans_end; inode->i_ctime = current_time(inode); gfs2_trans_add_meta(ip->i_gl, bh); ip->i_diskflags = new_flags; gfs2_dinode_out(ip, bh->b_data); brelse(bh); gfs2_set_inode_flags(inode); gfs2_set_aops(inode); out_trans_end: gfs2_trans_end(sdp); out: gfs2_glock_dq_uninit(&gh); return error; } int gfs2_fileattr_set(struct user_namespace *mnt_userns, struct dentry *dentry, struct fileattr *fa) { struct inode *inode = d_inode(dentry); u32 fsflags = fa->flags, gfsflags = 0; u32 mask; int i; if (d_is_special(dentry)) return -ENOTTY; if (fileattr_has_fsx(fa)) return -EOPNOTSUPP; for (i = 0; i < ARRAY_SIZE(fsflag_gfs2flag); i++) { if (fsflags & fsflag_gfs2flag[i].fsflag) { fsflags &= ~fsflag_gfs2flag[i].fsflag; gfsflags |= fsflag_gfs2flag[i].gfsflag; } } if (fsflags || gfsflags & ~GFS2_FLAGS_USER_SET) return -EINVAL; mask = GFS2_FLAGS_USER_SET; if (S_ISDIR(inode->i_mode)) { mask &= ~GFS2_DIF_JDATA; } else { /* The GFS2_DIF_TOPDIR flag is only valid for directories. */ if (gfsflags & GFS2_DIF_TOPDIR) return -EINVAL; mask &= ~(GFS2_DIF_TOPDIR | GFS2_DIF_INHERIT_JDATA); } return do_gfs2_set_flags(inode, gfsflags, mask, fsflags); } static int gfs2_getlabel(struct file *filp, char __user *label) { struct inode *inode = file_inode(filp); struct gfs2_sbd *sdp = GFS2_SB(inode); if (copy_to_user(label, sdp->sd_sb.sb_locktable, GFS2_LOCKNAME_LEN)) return -EFAULT; return 0; } static long gfs2_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) { switch(cmd) { case FITRIM: return gfs2_fitrim(filp, (void __user *)arg); case FS_IOC_GETFSLABEL: return gfs2_getlabel(filp, (char __user *)arg); } return -ENOTTY; } #ifdef CONFIG_COMPAT static long gfs2_compat_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) { switch(cmd) { /* Keep this list in sync with gfs2_ioctl */ case FITRIM: case FS_IOC_GETFSLABEL: break; default: return -ENOIOCTLCMD; } return gfs2_ioctl(filp, cmd, (unsigned long)compat_ptr(arg)); } #else #define gfs2_compat_ioctl NULL #endif /** * gfs2_size_hint - Give a hint to the size of a write request * @filep: The struct file * @offset: The file offset of the write * @size: The length of the write * * When we are about to do a write, this function records the total * write size in order to provide a suitable hint to the lower layers * about how many blocks will be required. * */ static void gfs2_size_hint(struct file *filep, loff_t offset, size_t size) { struct inode *inode = file_inode(filep); struct gfs2_sbd *sdp = GFS2_SB(inode); struct gfs2_inode *ip = GFS2_I(inode); size_t blks = (size + sdp->sd_sb.sb_bsize - 1) >> sdp->sd_sb.sb_bsize_shift; int hint = min_t(size_t, INT_MAX, blks); if (hint > atomic_read(&ip->i_sizehint)) atomic_set(&ip->i_sizehint, hint); } /** * gfs2_allocate_page_backing - Allocate blocks for a write fault * @page: The (locked) page to allocate backing for * @length: Size of the allocation * * We try to allocate all the blocks required for the page in one go. This * might fail for various reasons, so we keep trying until all the blocks to * back this page are allocated. If some of the blocks are already allocated, * that is ok too. */ static int gfs2_allocate_page_backing(struct page *page, unsigned int length) { u64 pos = page_offset(page); do { struct iomap iomap = { }; if (gfs2_iomap_alloc(page->mapping->host, pos, length, &iomap)) return -EIO; if (length < iomap.length) iomap.length = length; length -= iomap.length; pos += iomap.length; } while (length > 0); return 0; } /** * gfs2_page_mkwrite - Make a shared, mmap()ed, page writable * @vmf: The virtual memory fault containing the page to become writable * * When the page becomes writable, we need to ensure that we have * blocks allocated on disk to back that page. */ static vm_fault_t gfs2_page_mkwrite(struct vm_fault *vmf) { struct page *page = vmf->page; struct inode *inode = file_inode(vmf->vma->vm_file); struct gfs2_inode *ip = GFS2_I(inode); struct gfs2_sbd *sdp = GFS2_SB(inode); struct gfs2_alloc_parms ap = { .aflags = 0, }; u64 offset = page_offset(page); unsigned int data_blocks, ind_blocks, rblocks; vm_fault_t ret = VM_FAULT_LOCKED; struct gfs2_holder gh; unsigned int length; loff_t size; int err; sb_start_pagefault(inode->i_sb); gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &gh); err = gfs2_glock_nq(&gh); if (err) { ret = block_page_mkwrite_return(err); goto out_uninit; } /* Check page index against inode size */ size = i_size_read(inode); if (offset >= size) { ret = VM_FAULT_SIGBUS; goto out_unlock; } /* Update file times before taking page lock */ file_update_time(vmf->vma->vm_file); /* page is wholly or partially inside EOF */ if (size - offset < PAGE_SIZE) length = size - offset; else length = PAGE_SIZE; gfs2_size_hint(vmf->vma->vm_file, offset, length); set_bit(GLF_DIRTY, &ip->i_gl->gl_flags); set_bit(GIF_SW_PAGED, &ip->i_flags); /* * iomap_writepage / iomap_writepages currently don't support inline * files, so always unstuff here. */ if (!gfs2_is_stuffed(ip) && !gfs2_write_alloc_required(ip, offset, length)) { lock_page(page); if (!PageUptodate(page) || page->mapping != inode->i_mapping) { ret = VM_FAULT_NOPAGE; unlock_page(page); } goto out_unlock; } err = gfs2_rindex_update(sdp); if (err) { ret = block_page_mkwrite_return(err); goto out_unlock; } gfs2_write_calc_reserv(ip, length, &data_blocks, &ind_blocks); ap.target = data_blocks + ind_blocks; err = gfs2_quota_lock_check(ip, &ap); if (err) { ret = block_page_mkwrite_return(err); goto out_unlock; } err = gfs2_inplace_reserve(ip, &ap); if (err) { ret = block_page_mkwrite_return(err); goto out_quota_unlock; } rblocks = RES_DINODE + ind_blocks; if (gfs2_is_jdata(ip)) rblocks += data_blocks ? data_blocks : 1; if (ind_blocks || data_blocks) { rblocks += RES_STATFS + RES_QUOTA; rblocks += gfs2_rg_blocks(ip, data_blocks + ind_blocks); } err = gfs2_trans_begin(sdp, rblocks, 0); if (err) { ret = block_page_mkwrite_return(err); goto out_trans_fail; } /* Unstuff, if required, and allocate backing blocks for page */ if (gfs2_is_stuffed(ip)) { err = gfs2_unstuff_dinode(ip); if (err) { ret = block_page_mkwrite_return(err); goto out_trans_end; } } lock_page(page); /* If truncated, we must retry the operation, we may have raced * with the glock demotion code. */ if (!PageUptodate(page) || page->mapping != inode->i_mapping) { ret = VM_FAULT_NOPAGE; goto out_page_locked; } err = gfs2_allocate_page_backing(page, length); if (err) ret = block_page_mkwrite_return(err); out_page_locked: if (ret != VM_FAULT_LOCKED) unlock_page(page); out_trans_end: gfs2_trans_end(sdp); out_trans_fail: gfs2_inplace_release(ip); out_quota_unlock: gfs2_quota_unlock(ip); out_unlock: gfs2_glock_dq(&gh); out_uninit: gfs2_holder_uninit(&gh); if (ret == VM_FAULT_LOCKED) { set_page_dirty(page); wait_for_stable_page(page); } sb_end_pagefault(inode->i_sb); return ret; } static vm_fault_t gfs2_fault(struct vm_fault *vmf) { struct inode *inode = file_inode(vmf->vma->vm_file); struct gfs2_inode *ip = GFS2_I(inode); struct gfs2_holder gh; vm_fault_t ret; int err; gfs2_holder_init(ip->i_gl, LM_ST_SHARED, 0, &gh); err = gfs2_glock_nq(&gh); if (err) { ret = block_page_mkwrite_return(err); goto out_uninit; } ret = filemap_fault(vmf); gfs2_glock_dq(&gh); out_uninit: gfs2_holder_uninit(&gh); return ret; } static const struct vm_operations_struct gfs2_vm_ops = { .fault = gfs2_fault, .map_pages = filemap_map_pages, .page_mkwrite = gfs2_page_mkwrite, }; /** * gfs2_mmap * @file: The file to map * @vma: The VMA which described the mapping * * There is no need to get a lock here unless we should be updating * atime. We ignore any locking errors since the only consequence is * a missed atime update (which will just be deferred until later). * * Returns: 0 */ static int gfs2_mmap(struct file *file, struct vm_area_struct *vma) { struct gfs2_inode *ip = GFS2_I(file->f_mapping->host); if (!(file->f_flags & O_NOATIME) && !IS_NOATIME(&ip->i_inode)) { struct gfs2_holder i_gh; int error; error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY, &i_gh); if (error) return error; /* grab lock to update inode */ gfs2_glock_dq_uninit(&i_gh); file_accessed(file); } vma->vm_ops = &gfs2_vm_ops; return 0; } /** * gfs2_open_common - This is common to open and atomic_open * @inode: The inode being opened * @file: The file being opened * * This maybe called under a glock or not depending upon how it has * been called. We must always be called under a glock for regular * files, however. For other file types, it does not matter whether * we hold the glock or not. * * Returns: Error code or 0 for success */ int gfs2_open_common(struct inode *inode, struct file *file) { struct gfs2_file *fp; int ret; if (S_ISREG(inode->i_mode)) { ret = generic_file_open(inode, file); if (ret) return ret; } fp = kzalloc(sizeof(struct gfs2_file), GFP_NOFS); if (!fp) return -ENOMEM; mutex_init(&fp->f_fl_mutex); gfs2_assert_warn(GFS2_SB(inode), !file->private_data); file->private_data = fp; if (file->f_mode & FMODE_WRITE) { ret = gfs2_qa_get(GFS2_I(inode)); if (ret) goto fail; } return 0; fail: kfree(file->private_data); file->private_data = NULL; return ret; } /** * gfs2_open - open a file * @inode: the inode to open * @file: the struct file for this opening * * After atomic_open, this function is only used for opening files * which are already cached. We must still get the glock for regular * files to ensure that we have the file size uptodate for the large * file check which is in the common code. That is only an issue for * regular files though. * * Returns: errno */ static int gfs2_open(struct inode *inode, struct file *file) { struct gfs2_inode *ip = GFS2_I(inode); struct gfs2_holder i_gh; int error; bool need_unlock = false; if (S_ISREG(ip->i_inode.i_mode)) { error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY, &i_gh); if (error) return error; need_unlock = true; } error = gfs2_open_common(inode, file); if (need_unlock) gfs2_glock_dq_uninit(&i_gh); return error; } /** * gfs2_release - called to close a struct file * @inode: the inode the struct file belongs to * @file: the struct file being closed * * Returns: errno */ static int gfs2_release(struct inode *inode, struct file *file) { struct gfs2_inode *ip = GFS2_I(inode); kfree(file->private_data); file->private_data = NULL; if (gfs2_rs_active(&ip->i_res)) gfs2_rs_delete(ip, &inode->i_writecount); if (file->f_mode & FMODE_WRITE) gfs2_qa_put(ip); return 0; } /** * gfs2_fsync - sync the dirty data for a file (across the cluster) * @file: the file that points to the dentry * @start: the start position in the file to sync * @end: the end position in the file to sync * @datasync: set if we can ignore timestamp changes * * We split the data flushing here so that we don't wait for the data * until after we've also sent the metadata to disk. Note that for * data=ordered, we will write & wait for the data at the log flush * stage anyway, so this is unlikely to make much of a difference * except in the data=writeback case. * * If the fdatawrite fails due to any reason except -EIO, we will * continue the remainder of the fsync, although we'll still report * the error at the end. This is to match filemap_write_and_wait_range() * behaviour. * * Returns: errno */ static int gfs2_fsync(struct file *file, loff_t start, loff_t end, int datasync) { struct address_space *mapping = file->f_mapping; struct inode *inode = mapping->host; int sync_state = inode->i_state & I_DIRTY; struct gfs2_inode *ip = GFS2_I(inode); int ret = 0, ret1 = 0; if (mapping->nrpages) { ret1 = filemap_fdatawrite_range(mapping, start, end); if (ret1 == -EIO) return ret1; } if (!gfs2_is_jdata(ip)) sync_state &= ~I_DIRTY_PAGES; if (datasync) sync_state &= ~I_DIRTY_SYNC; if (sync_state) { ret = sync_inode_metadata(inode, 1); if (ret) return ret; if (gfs2_is_jdata(ip)) ret = file_write_and_wait(file); if (ret) return ret; gfs2_ail_flush(ip->i_gl, 1); } if (mapping->nrpages) ret = file_fdatawait_range(file, start, end); return ret ? ret : ret1; } static inline bool should_fault_in_pages(ssize_t ret, struct iov_iter *i, size_t *prev_count, size_t *window_size) { char __user *p = i->iov[0].iov_base + i->iov_offset; size_t count = iov_iter_count(i); int pages = 1; if (likely(!count)) return false; if (ret <= 0 && ret != -EFAULT) return false; if (!iter_is_iovec(i)) return false; if (*prev_count != count || !*window_size) { int pages, nr_dirtied; pages = min_t(int, BIO_MAX_VECS, DIV_ROUND_UP(iov_iter_count(i), PAGE_SIZE)); nr_dirtied = max(current->nr_dirtied_pause - current->nr_dirtied, 1); pages = min(pages, nr_dirtied); } *prev_count = count; *window_size = (size_t)PAGE_SIZE * pages - offset_in_page(p); return true; } static ssize_t gfs2_file_direct_read(struct kiocb *iocb, struct iov_iter *to, struct gfs2_holder *gh) { struct file *file = iocb->ki_filp; struct gfs2_inode *ip = GFS2_I(file->f_mapping->host); size_t prev_count = 0, window_size = 0; size_t written = 0; ssize_t ret; /* * In this function, we disable page faults when we're holding the * inode glock while doing I/O. If a page fault occurs, we indicate * that the inode glock may be dropped, fault in the pages manually, * and retry. * * Unlike generic_file_read_iter, for reads, iomap_dio_rw can trigger * physical as well as manual page faults, and we need to disable both * kinds. * * For direct I/O, gfs2 takes the inode glock in deferred mode. This * locking mode is compatible with other deferred holders, so multiple * processes and nodes can do direct I/O to a file at the same time. * There's no guarantee that reads or writes will be atomic. Any * coordination among readers and writers needs to happen externally. */ if (!iov_iter_count(to)) return 0; /* skip atime */ gfs2_holder_init(ip->i_gl, LM_ST_DEFERRED, 0, gh); retry: ret = gfs2_glock_nq(gh); if (ret) goto out_uninit; retry_under_glock: pagefault_disable(); to->nofault = true; ret = iomap_dio_rw(iocb, to, &gfs2_iomap_ops, NULL, IOMAP_DIO_PARTIAL, written); to->nofault = false; pagefault_enable(); if (ret > 0) written = ret; if (should_fault_in_pages(ret, to, &prev_count, &window_size)) { size_t leftover; gfs2_holder_allow_demote(gh); leftover = fault_in_iov_iter_writeable(to, window_size); gfs2_holder_disallow_demote(gh); if (leftover != window_size) { if (!gfs2_holder_queued(gh)) goto retry; goto retry_under_glock; } } if (gfs2_holder_queued(gh)) gfs2_glock_dq(gh); out_uninit: gfs2_holder_uninit(gh); if (ret < 0) return ret; return written; } static ssize_t gfs2_file_direct_write(struct kiocb *iocb, struct iov_iter *from, struct gfs2_holder *gh) { struct file *file = iocb->ki_filp; struct inode *inode = file->f_mapping->host; struct gfs2_inode *ip = GFS2_I(inode); size_t prev_count = 0, window_size = 0; size_t read = 0; ssize_t ret; /* * In this function, we disable page faults when we're holding the * inode glock while doing I/O. If a page fault occurs, we indicate * that the inode glock may be dropped, fault in the pages manually, * and retry. * * For writes, iomap_dio_rw only triggers manual page faults, so we * don't need to disable physical ones. */ /* * Deferred lock, even if its a write, since we do no allocation on * this path. All we need to change is the atime, and this lock mode * ensures that other nodes have flushed their buffered read caches * (i.e. their page cache entries for this inode). We do not, * unfortunately, have the option of only flushing a range like the * VFS does. */ gfs2_holder_init(ip->i_gl, LM_ST_DEFERRED, 0, gh); retry: ret = gfs2_glock_nq(gh); if (ret) goto out_uninit; retry_under_glock: /* Silently fall back to buffered I/O when writing beyond EOF */ if (iocb->ki_pos + iov_iter_count(from) > i_size_read(&ip->i_inode)) goto out; from->nofault = true; ret = iomap_dio_rw(iocb, from, &gfs2_iomap_ops, NULL, IOMAP_DIO_PARTIAL, read); from->nofault = false; if (ret == -ENOTBLK) ret = 0; if (ret > 0) read = ret; if (should_fault_in_pages(ret, from, &prev_count, &window_size)) { size_t leftover; gfs2_holder_allow_demote(gh); leftover = fault_in_iov_iter_readable(from, window_size); gfs2_holder_disallow_demote(gh); if (leftover != window_size) { if (!gfs2_holder_queued(gh)) goto retry; goto retry_under_glock; } } out: if (gfs2_holder_queued(gh)) gfs2_glock_dq(gh); out_uninit: gfs2_holder_uninit(gh); if (ret < 0) return ret; return read; } static ssize_t gfs2_file_read_iter(struct kiocb *iocb, struct iov_iter *to) { struct gfs2_inode *ip; struct gfs2_holder gh; size_t prev_count = 0, window_size = 0; size_t written = 0; ssize_t ret; /* * In this function, we disable page faults when we're holding the * inode glock while doing I/O. If a page fault occurs, we indicate * that the inode glock may be dropped, fault in the pages manually, * and retry. */ if (iocb->ki_flags & IOCB_DIRECT) { ret = gfs2_file_direct_read(iocb, to, &gh); if (likely(ret != -ENOTBLK)) return ret; iocb->ki_flags &= ~IOCB_DIRECT; } iocb->ki_flags |= IOCB_NOIO; ret = generic_file_read_iter(iocb, to); iocb->ki_flags &= ~IOCB_NOIO; if (ret >= 0) { if (!iov_iter_count(to)) return ret; written = ret; } else { if (ret != -EAGAIN) return ret; if (iocb->ki_flags & IOCB_NOWAIT) return ret; } ip = GFS2_I(iocb->ki_filp->f_mapping->host); gfs2_holder_init(ip->i_gl, LM_ST_SHARED, 0, &gh); retry: ret = gfs2_glock_nq(&gh); if (ret) goto out_uninit; retry_under_glock: pagefault_disable(); ret = generic_file_read_iter(iocb, to); pagefault_enable(); if (ret > 0) written += ret; if (should_fault_in_pages(ret, to, &prev_count, &window_size)) { size_t leftover; gfs2_holder_allow_demote(&gh); leftover = fault_in_iov_iter_writeable(to, window_size); gfs2_holder_disallow_demote(&gh); if (leftover != window_size) { if (!gfs2_holder_queued(&gh)) { if (written) goto out_uninit; goto retry; } goto retry_under_glock; } } if (gfs2_holder_queued(&gh)) gfs2_glock_dq(&gh); out_uninit: gfs2_holder_uninit(&gh); return written ? written : ret; } static ssize_t gfs2_file_buffered_write(struct kiocb *iocb, struct iov_iter *from, struct gfs2_holder *gh) { struct file *file = iocb->ki_filp; struct inode *inode = file_inode(file); struct gfs2_inode *ip = GFS2_I(inode); struct gfs2_sbd *sdp = GFS2_SB(inode); struct gfs2_holder *statfs_gh = NULL; size_t prev_count = 0, window_size = 0; size_t read = 0; ssize_t ret; /* * In this function, we disable page faults when we're holding the * inode glock while doing I/O. If a page fault occurs, we indicate * that the inode glock may be dropped, fault in the pages manually, * and retry. */ if (inode == sdp->sd_rindex) { statfs_gh = kmalloc(sizeof(*statfs_gh), GFP_NOFS); if (!statfs_gh) return -ENOMEM; } gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, gh); retry: ret = gfs2_glock_nq(gh); if (ret) goto out_uninit; retry_under_glock: if (inode == sdp->sd_rindex) { struct gfs2_inode *m_ip = GFS2_I(sdp->sd_statfs_inode); ret = gfs2_glock_nq_init(m_ip->i_gl, LM_ST_EXCLUSIVE, GL_NOCACHE, statfs_gh); if (ret) goto out_unlock; } current->backing_dev_info = inode_to_bdi(inode); pagefault_disable(); ret = iomap_file_buffered_write(iocb, from, &gfs2_iomap_ops); pagefault_enable(); current->backing_dev_info = NULL; if (ret > 0) { iocb->ki_pos += ret; read += ret; } if (inode == sdp->sd_rindex) gfs2_glock_dq_uninit(statfs_gh); if (should_fault_in_pages(ret, from, &prev_count, &window_size)) { size_t leftover; gfs2_holder_allow_demote(gh); leftover = fault_in_iov_iter_readable(from, window_size); gfs2_holder_disallow_demote(gh); if (leftover != window_size) { if (!gfs2_holder_queued(gh)) { if (read) goto out_uninit; goto retry; } goto retry_under_glock; } } out_unlock: if (gfs2_holder_queued(gh)) gfs2_glock_dq(gh); out_uninit: gfs2_holder_uninit(gh); if (statfs_gh) kfree(statfs_gh); return read ? read : ret; } /** * gfs2_file_write_iter - Perform a write to a file * @iocb: The io context * @from: The data to write * * We have to do a lock/unlock here to refresh the inode size for * O_APPEND writes, otherwise we can land up writing at the wrong * offset. There is still a race, but provided the app is using its * own file locking, this will make O_APPEND work as expected. * */ static ssize_t gfs2_file_write_iter(struct kiocb *iocb, struct iov_iter *from) { struct file *file = iocb->ki_filp; struct inode *inode = file_inode(file); struct gfs2_inode *ip = GFS2_I(inode); struct gfs2_holder gh; ssize_t ret; gfs2_size_hint(file, iocb->ki_pos, iov_iter_count(from)); if (iocb->ki_flags & IOCB_APPEND) { ret = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, 0, &gh); if (ret) return ret; gfs2_glock_dq_uninit(&gh); } inode_lock(inode); ret = generic_write_checks(iocb, from); if (ret <= 0) goto out_unlock; ret = file_remove_privs(file); if (ret) goto out_unlock; ret = file_update_time(file); if (ret) goto out_unlock; if (iocb->ki_flags & IOCB_DIRECT) { struct address_space *mapping = file->f_mapping; ssize_t buffered, ret2; ret = gfs2_file_direct_write(iocb, from, &gh); if (ret < 0 || !iov_iter_count(from)) goto out_unlock; iocb->ki_flags |= IOCB_DSYNC; buffered = gfs2_file_buffered_write(iocb, from, &gh); if (unlikely(buffered <= 0)) { if (!ret) ret = buffered; goto out_unlock; } /* * We need to ensure that the page cache pages are written to * disk and invalidated to preserve the expected O_DIRECT * semantics. If the writeback or invalidate fails, only report * the direct I/O range as we don't know if the buffered pages * made it to disk. */ ret2 = generic_write_sync(iocb, buffered); invalidate_mapping_pages(mapping, (iocb->ki_pos - buffered) >> PAGE_SHIFT, (iocb->ki_pos - 1) >> PAGE_SHIFT); if (!ret || ret2 > 0) ret += ret2; } else { ret = gfs2_file_buffered_write(iocb, from, &gh); if (likely(ret > 0)) ret = generic_write_sync(iocb, ret); } out_unlock: inode_unlock(inode); return ret; } static int fallocate_chunk(struct inode *inode, loff_t offset, loff_t len, int mode) { struct super_block *sb = inode->i_sb; struct gfs2_inode *ip = GFS2_I(inode); loff_t end = offset + len; struct buffer_head *dibh; int error; error = gfs2_meta_inode_buffer(ip, &dibh); if (unlikely(error)) return error; gfs2_trans_add_meta(ip->i_gl, dibh); if (gfs2_is_stuffed(ip)) { error = gfs2_unstuff_dinode(ip); if (unlikely(error)) goto out; } while (offset < end) { struct iomap iomap = { }; error = gfs2_iomap_alloc(inode, offset, end - offset, &iomap); if (error) goto out; offset = iomap.offset + iomap.length; if (!(iomap.flags & IOMAP_F_NEW)) continue; error = sb_issue_zeroout(sb, iomap.addr >> inode->i_blkbits, iomap.length >> inode->i_blkbits, GFP_NOFS); if (error) { fs_err(GFS2_SB(inode), "Failed to zero data buffers\n"); goto out; } } out: brelse(dibh); return error; } /** * calc_max_reserv() - Reverse of write_calc_reserv. Given a number of * blocks, determine how many bytes can be written. * @ip: The inode in question. * @len: Max cap of bytes. What we return in *len must be <= this. * @data_blocks: Compute and return the number of data blocks needed * @ind_blocks: Compute and return the number of indirect blocks needed * @max_blocks: The total blocks available to work with. * * Returns: void, but @len, @data_blocks and @ind_blocks are filled in. */ static void calc_max_reserv(struct gfs2_inode *ip, loff_t *len, unsigned int *data_blocks, unsigned int *ind_blocks, unsigned int max_blocks) { loff_t max = *len; const struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode); unsigned int tmp, max_data = max_blocks - 3 * (sdp->sd_max_height - 1); for (tmp = max_data; tmp > sdp->sd_diptrs;) { tmp = DIV_ROUND_UP(tmp, sdp->sd_inptrs); max_data -= tmp; } *data_blocks = max_data; *ind_blocks = max_blocks - max_data; *len = ((loff_t)max_data - 3) << sdp->sd_sb.sb_bsize_shift; if (*len > max) { *len = max; gfs2_write_calc_reserv(ip, max, data_blocks, ind_blocks); } } static long __gfs2_fallocate(struct file *file, int mode, loff_t offset, loff_t len) { struct inode *inode = file_inode(file); struct gfs2_sbd *sdp = GFS2_SB(inode); struct gfs2_inode *ip = GFS2_I(inode); struct gfs2_alloc_parms ap = { .aflags = 0, }; unsigned int data_blocks = 0, ind_blocks = 0, rblocks; loff_t bytes, max_bytes, max_blks; int error; const loff_t pos = offset; const loff_t count = len; loff_t bsize_mask = ~((loff_t)sdp->sd_sb.sb_bsize - 1); loff_t next = (offset + len - 1) >> sdp->sd_sb.sb_bsize_shift; loff_t max_chunk_size = UINT_MAX & bsize_mask; next = (next + 1) << sdp->sd_sb.sb_bsize_shift; offset &= bsize_mask; len = next - offset; bytes = sdp->sd_max_rg_data * sdp->sd_sb.sb_bsize / 2; if (!bytes) bytes = UINT_MAX; bytes &= bsize_mask; if (bytes == 0) bytes = sdp->sd_sb.sb_bsize; gfs2_size_hint(file, offset, len); gfs2_write_calc_reserv(ip, PAGE_SIZE, &data_blocks, &ind_blocks); ap.min_target = data_blocks + ind_blocks; while (len > 0) { if (len < bytes) bytes = len; if (!gfs2_write_alloc_required(ip, offset, bytes)) { len -= bytes; offset += bytes; continue; } /* We need to determine how many bytes we can actually * fallocate without exceeding quota or going over the * end of the fs. We start off optimistically by assuming * we can write max_bytes */ max_bytes = (len > max_chunk_size) ? max_chunk_size : len; /* Since max_bytes is most likely a theoretical max, we * calculate a more realistic 'bytes' to serve as a good * starting point for the number of bytes we may be able * to write */ gfs2_write_calc_reserv(ip, bytes, &data_blocks, &ind_blocks); ap.target = data_blocks + ind_blocks; error = gfs2_quota_lock_check(ip, &ap); if (error) return error; /* ap.allowed tells us how many blocks quota will allow * us to write. Check if this reduces max_blks */ max_blks = UINT_MAX; if (ap.allowed) max_blks = ap.allowed; error = gfs2_inplace_reserve(ip, &ap); if (error) goto out_qunlock; /* check if the selected rgrp limits our max_blks further */ if (ip->i_res.rs_reserved < max_blks) max_blks = ip->i_res.rs_reserved; /* Almost done. Calculate bytes that can be written using * max_blks. We also recompute max_bytes, data_blocks and * ind_blocks */ calc_max_reserv(ip, &max_bytes, &data_blocks, &ind_blocks, max_blks); rblocks = RES_DINODE + ind_blocks + RES_STATFS + RES_QUOTA + RES_RG_HDR + gfs2_rg_blocks(ip, data_blocks + ind_blocks); if (gfs2_is_jdata(ip)) rblocks += data_blocks ? data_blocks : 1; error = gfs2_trans_begin(sdp, rblocks, PAGE_SIZE >> inode->i_blkbits); if (error) goto out_trans_fail; error = fallocate_chunk(inode, offset, max_bytes, mode); gfs2_trans_end(sdp); if (error) goto out_trans_fail; len -= max_bytes; offset += max_bytes; gfs2_inplace_release(ip); gfs2_quota_unlock(ip); } if (!(mode & FALLOC_FL_KEEP_SIZE) && (pos + count) > inode->i_size) i_size_write(inode, pos + count); file_update_time(file); mark_inode_dirty(inode); if ((file->f_flags & O_DSYNC) || IS_SYNC(file->f_mapping->host)) return vfs_fsync_range(file, pos, pos + count - 1, (file->f_flags & __O_SYNC) ? 0 : 1); return 0; out_trans_fail: gfs2_inplace_release(ip); out_qunlock: gfs2_quota_unlock(ip); return error; } static long gfs2_fallocate(struct file *file, int mode, loff_t offset, loff_t len) { struct inode *inode = file_inode(file); struct gfs2_sbd *sdp = GFS2_SB(inode); struct gfs2_inode *ip = GFS2_I(inode); struct gfs2_holder gh; int ret; if (mode & ~(FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE)) return -EOPNOTSUPP; /* fallocate is needed by gfs2_grow to reserve space in the rindex */ if (gfs2_is_jdata(ip) && inode != sdp->sd_rindex) return -EOPNOTSUPP; inode_lock(inode); gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &gh); ret = gfs2_glock_nq(&gh); if (ret) goto out_uninit; if (!(mode & FALLOC_FL_KEEP_SIZE) && (offset + len) > inode->i_size) { ret = inode_newsize_ok(inode, offset + len); if (ret) goto out_unlock; } ret = get_write_access(inode); if (ret) goto out_unlock; if (mode & FALLOC_FL_PUNCH_HOLE) { ret = __gfs2_punch_hole(file, offset, len); } else { ret = __gfs2_fallocate(file, mode, offset, len); if (ret) gfs2_rs_deltree(&ip->i_res); } put_write_access(inode); out_unlock: gfs2_glock_dq(&gh); out_uninit: gfs2_holder_uninit(&gh); inode_unlock(inode); return ret; } static ssize_t gfs2_file_splice_write(struct pipe_inode_info *pipe, struct file *out, loff_t *ppos, size_t len, unsigned int flags) { ssize_t ret; gfs2_size_hint(out, *ppos, len); ret = iter_file_splice_write(pipe, out, ppos, len, flags); return ret; } #ifdef CONFIG_GFS2_FS_LOCKING_DLM /** * gfs2_lock - acquire/release a posix lock on a file * @file: the file pointer * @cmd: either modify or retrieve lock state, possibly wait * @fl: type and range of lock * * Returns: errno */ static int gfs2_lock(struct file *file, int cmd, struct file_lock *fl) { struct gfs2_inode *ip = GFS2_I(file->f_mapping->host); struct gfs2_sbd *sdp = GFS2_SB(file->f_mapping->host); struct lm_lockstruct *ls = &sdp->sd_lockstruct; if (!(fl->fl_flags & FL_POSIX)) return -ENOLCK; if (cmd == F_CANCELLK) { /* Hack: */ cmd = F_SETLK; fl->fl_type = F_UNLCK; } if (unlikely(gfs2_withdrawn(sdp))) { if (fl->fl_type == F_UNLCK) locks_lock_file_wait(file, fl); return -EIO; } if (IS_GETLK(cmd)) return dlm_posix_get(ls->ls_dlm, ip->i_no_addr, file, fl); else if (fl->fl_type == F_UNLCK) return dlm_posix_unlock(ls->ls_dlm, ip->i_no_addr, file, fl); else return dlm_posix_lock(ls->ls_dlm, ip->i_no_addr, file, cmd, fl); } static int do_flock(struct file *file, int cmd, struct file_lock *fl) { struct gfs2_file *fp = file->private_data; struct gfs2_holder *fl_gh = &fp->f_fl_gh; struct gfs2_inode *ip = GFS2_I(file_inode(file)); struct gfs2_glock *gl; unsigned int state; u16 flags; int error = 0; int sleeptime; state = (fl->fl_type == F_WRLCK) ? LM_ST_EXCLUSIVE : LM_ST_SHARED; flags = (IS_SETLKW(cmd) ? 0 : LM_FLAG_TRY_1CB) | GL_EXACT; mutex_lock(&fp->f_fl_mutex); if (gfs2_holder_initialized(fl_gh)) { struct file_lock request; if (fl_gh->gh_state == state) goto out; locks_init_lock(&request); request.fl_type = F_UNLCK; request.fl_flags = FL_FLOCK; locks_lock_file_wait(file, &request); gfs2_glock_dq(fl_gh); gfs2_holder_reinit(state, flags, fl_gh); } else { error = gfs2_glock_get(GFS2_SB(&ip->i_inode), ip->i_no_addr, &gfs2_flock_glops, CREATE, &gl); if (error) goto out; gfs2_holder_init(gl, state, flags, fl_gh); gfs2_glock_put(gl); } for (sleeptime = 1; sleeptime <= 4; sleeptime <<= 1) { error = gfs2_glock_nq(fl_gh); if (error != GLR_TRYFAILED) break; fl_gh->gh_flags = LM_FLAG_TRY | GL_EXACT; fl_gh->gh_error = 0; msleep(sleeptime); } if (error) { gfs2_holder_uninit(fl_gh); if (error == GLR_TRYFAILED) error = -EAGAIN; } else { error = locks_lock_file_wait(file, fl); gfs2_assert_warn(GFS2_SB(&ip->i_inode), !error); } out: mutex_unlock(&fp->f_fl_mutex); return error; } static void do_unflock(struct file *file, struct file_lock *fl) { struct gfs2_file *fp = file->private_data; struct gfs2_holder *fl_gh = &fp->f_fl_gh; mutex_lock(&fp->f_fl_mutex); locks_lock_file_wait(file, fl); if (gfs2_holder_initialized(fl_gh)) { gfs2_glock_dq(fl_gh); gfs2_holder_uninit(fl_gh); } mutex_unlock(&fp->f_fl_mutex); } /** * gfs2_flock - acquire/release a flock lock on a file * @file: the file pointer * @cmd: either modify or retrieve lock state, possibly wait * @fl: type and range of lock * * Returns: errno */ static int gfs2_flock(struct file *file, int cmd, struct file_lock *fl) { if (!(fl->fl_flags & FL_FLOCK)) return -ENOLCK; if (fl->fl_type & LOCK_MAND) return -EOPNOTSUPP; if (fl->fl_type == F_UNLCK) { do_unflock(file, fl); return 0; } else { return do_flock(file, cmd, fl); } } const struct file_operations gfs2_file_fops = { .llseek = gfs2_llseek, .read_iter = gfs2_file_read_iter, .write_iter = gfs2_file_write_iter, .iopoll = iomap_dio_iopoll, .unlocked_ioctl = gfs2_ioctl, .compat_ioctl = gfs2_compat_ioctl, .mmap = gfs2_mmap, .open = gfs2_open, .release = gfs2_release, .fsync = gfs2_fsync, .lock = gfs2_lock, .flock = gfs2_flock, .splice_read = generic_file_splice_read, .splice_write = gfs2_file_splice_write, .setlease = simple_nosetlease, .fallocate = gfs2_fallocate, }; const struct file_operations gfs2_dir_fops = { .iterate_shared = gfs2_readdir, .unlocked_ioctl = gfs2_ioctl, .compat_ioctl = gfs2_compat_ioctl, .open = gfs2_open, .release = gfs2_release, .fsync = gfs2_fsync, .lock = gfs2_lock, .flock = gfs2_flock, .llseek = default_llseek, }; #endif /* CONFIG_GFS2_FS_LOCKING_DLM */ const struct file_operations gfs2_file_fops_nolock = { .llseek = gfs2_llseek, .read_iter = gfs2_file_read_iter, .write_iter = gfs2_file_write_iter, .iopoll = iomap_dio_iopoll, .unlocked_ioctl = gfs2_ioctl, .compat_ioctl = gfs2_compat_ioctl, .mmap = gfs2_mmap, .open = gfs2_open, .release = gfs2_release, .fsync = gfs2_fsync, .splice_read = generic_file_splice_read, .splice_write = gfs2_file_splice_write, .setlease = generic_setlease, .fallocate = gfs2_fallocate, }; const struct file_operations gfs2_dir_fops_nolock = { .iterate_shared = gfs2_readdir, .unlocked_ioctl = gfs2_ioctl, .compat_ioctl = gfs2_compat_ioctl, .open = gfs2_open, .release = gfs2_release, .fsync = gfs2_fsync, .llseek = default_llseek, };