diff options
Diffstat (limited to 'fs/gfs2/file.c')
| -rw-r--r-- | fs/gfs2/file.c | 763 |
1 files changed, 763 insertions, 0 deletions
diff --git a/fs/gfs2/file.c b/fs/gfs2/file.c new file mode 100644 index 000000000000..73318a3ce6f1 --- /dev/null +++ b/fs/gfs2/file.c @@ -0,0 +1,763 @@ +/* + * Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved. + * Copyright (C) 2004-2006 Red Hat, Inc. All rights reserved. + * + * This copyrighted material is made available to anyone wishing to use, + * modify, copy, or redistribute it subject to the terms and conditions + * of the GNU General Public License version 2. + */ + +#include <linux/slab.h> +#include <linux/spinlock.h> +#include <linux/completion.h> +#include <linux/buffer_head.h> +#include <linux/pagemap.h> +#include <linux/uio.h> +#include <linux/blkdev.h> +#include <linux/mm.h> +#include <linux/mount.h> +#include <linux/fs.h> +#include <linux/gfs2_ondisk.h> +#include <linux/ext2_fs.h> +#include <linux/crc32.h> +#include <linux/writeback.h> +#include <asm/uaccess.h> +#include <linux/dlm.h> +#include <linux/dlm_plock.h> + +#include "gfs2.h" +#include "incore.h" +#include "bmap.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" +#include "eaops.h" + +/** + * gfs2_llseek - seek to a location in a file + * @file: the file + * @offset: the offset + * @origin: 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 origin) +{ + struct gfs2_inode *ip = GFS2_I(file->f_mapping->host); + struct gfs2_holder i_gh; + loff_t error; + + if (origin == 2) { + error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY, + &i_gh); + if (!error) { + error = generic_file_llseek_unlocked(file, offset, origin); + gfs2_glock_dq_uninit(&i_gh); + } + } else + error = generic_file_llseek_unlocked(file, offset, origin); + + return error; +} + +/** + * gfs2_readdir - Read directory entries from a directory + * @file: The directory to read from + * @dirent: Buffer for dirents + * @filldir: Function used to do the copying + * + * Returns: errno + */ + +static int gfs2_readdir(struct file *file, void *dirent, filldir_t filldir) +{ + struct inode *dir = file->f_mapping->host; + struct gfs2_inode *dip = GFS2_I(dir); + struct gfs2_holder d_gh; + u64 offset = file->f_pos; + int error; + + gfs2_holder_init(dip->i_gl, LM_ST_SHARED, 0, &d_gh); + error = gfs2_glock_nq(&d_gh); + if (error) { + gfs2_holder_uninit(&d_gh); + return error; + } + + error = gfs2_dir_read(dir, &offset, dirent, filldir); + + gfs2_glock_dq_uninit(&d_gh); + + file->f_pos = offset; + + return error; +} + +/** + * fsflags_cvt + * @table: A table of 32 u32 flags + * @val: a 32 bit value to convert + * + * This function can be used to convert between fsflags values and + * GFS2's own flags values. + * + * Returns: the converted flags + */ +static u32 fsflags_cvt(const u32 *table, u32 val) +{ + u32 res = 0; + while(val) { + if (val & 1) + res |= *table; + table++; + val >>= 1; + } + return res; +} + +static const u32 fsflags_to_gfs2[32] = { + [3] = GFS2_DIF_SYNC, + [4] = GFS2_DIF_IMMUTABLE, + [5] = GFS2_DIF_APPENDONLY, + [7] = GFS2_DIF_NOATIME, + [12] = GFS2_DIF_EXHASH, + [14] = GFS2_DIF_INHERIT_JDATA, +}; + +static const u32 gfs2_to_fsflags[32] = { + [gfs2fl_Sync] = FS_SYNC_FL, + [gfs2fl_Immutable] = FS_IMMUTABLE_FL, + [gfs2fl_AppendOnly] = FS_APPEND_FL, + [gfs2fl_NoAtime] = FS_NOATIME_FL, + [gfs2fl_ExHash] = FS_INDEX_FL, + [gfs2fl_InheritJdata] = FS_JOURNAL_DATA_FL, +}; + +static int gfs2_get_flags(struct file *filp, u32 __user *ptr) +{ + struct inode *inode = filp->f_path.dentry->d_inode; + struct gfs2_inode *ip = GFS2_I(inode); + struct gfs2_holder gh; + int error; + u32 fsflags; + + gfs2_holder_init(ip->i_gl, LM_ST_SHARED, 0, &gh); + error = gfs2_glock_nq(&gh); + if (error) + return error; + + fsflags = fsflags_cvt(gfs2_to_fsflags, ip->i_diskflags); + if (!S_ISDIR(inode->i_mode) && ip->i_diskflags & GFS2_DIF_JDATA) + fsflags |= FS_JOURNAL_DATA_FL; + if (put_user(fsflags, ptr)) + error = -EFAULT; + + gfs2_glock_dq(&gh); + 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); + 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_SYSTEM| \ + GFS2_DIF_INHERIT_JDATA) + +/** + * gfs2_set_flags - set flags on an inode + * @inode: The inode + * @flags: The flags to set + * @mask: Indicates which flags are valid + * + */ +static int do_gfs2_set_flags(struct file *filp, u32 reqflags, u32 mask) +{ + struct inode *inode = filp->f_path.dentry->d_inode; + 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 = mnt_want_write(filp->f_path.mnt); + if (error) + return error; + + error = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &gh); + if (error) + goto out_drop_write; + + flags = ip->i_diskflags; + new_flags = (flags & ~mask) | (reqflags & mask); + if ((new_flags ^ flags) == 0) + goto out; + + error = -EINVAL; + if ((new_flags ^ flags) & ~GFS2_FLAGS_USER_SET) + 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 (((new_flags ^ flags) & GFS2_DIF_IMMUTABLE) && + !capable(CAP_LINUX_IMMUTABLE)) + goto out; + if (!IS_IMMUTABLE(inode)) { + error = gfs2_permission(inode, MAY_WRITE); + if (error) + goto out; + } + if ((flags ^ new_flags) & GFS2_DIF_JDATA) { + if (flags & GFS2_DIF_JDATA) + gfs2_log_flush(sdp, ip->i_gl); + error = filemap_fdatawrite(inode->i_mapping); + if (error) + goto out; + error = filemap_fdatawait(inode->i_mapping); + if (error) + goto out; + } + 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; + gfs2_trans_add_bh(ip->i_gl, bh, 1); + 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); +out_drop_write: + mnt_drop_write(filp->f_path.mnt); + return error; +} + +static int gfs2_set_flags(struct file *filp, u32 __user *ptr) +{ + struct inode *inode = filp->f_path.dentry->d_inode; + u32 fsflags, gfsflags; + if (get_user(fsflags, ptr)) + return -EFAULT; + gfsflags = fsflags_cvt(fsflags_to_gfs2, fsflags); + if (!S_ISDIR(inode->i_mode)) { + if (gfsflags & GFS2_DIF_INHERIT_JDATA) + gfsflags ^= (GFS2_DIF_JDATA | GFS2_DIF_INHERIT_JDATA); + return do_gfs2_set_flags(filp, gfsflags, ~0); + } + return do_gfs2_set_flags(filp, gfsflags, ~GFS2_DIF_JDATA); +} + +static long gfs2_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) +{ + switch(cmd) { + case FS_IOC_GETFLAGS: + return gfs2_get_flags(filp, (u32 __user *)arg); + case FS_IOC_SETFLAGS: + return gfs2_set_flags(filp, (u32 __user *)arg); + } + return -ENOTTY; +} + +/** + * gfs2_allocate_page_backing - Use bmap to allocate blocks + * @page: The (locked) page to allocate backing for + * + * 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, thats ok too. + */ + +static int gfs2_allocate_page_backing(struct page *page) +{ + struct inode *inode = page->mapping->host; + struct buffer_head bh; + unsigned long size = PAGE_CACHE_SIZE; + u64 lblock = page->index << (PAGE_CACHE_SHIFT - inode->i_blkbits); + + do { + bh.b_state = 0; + bh.b_size = size; + gfs2_block_map(inode, lblock, &bh, 1); + if (!buffer_mapped(&bh)) + return -EIO; + size -= bh.b_size; + lblock += (bh.b_size >> inode->i_blkbits); + } while(size > 0); + return 0; +} + +/** + * gfs2_page_mkwrite - Make a shared, mmap()ed, page writable + * @vma: The virtual memory area + * @page: The page which is about to become writable + * + * When the page becomes writable, we need to ensure that we have + * blocks allocated on disk to back that page. + */ + +static int gfs2_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf) +{ + struct page *page = vmf->page; + struct inode *inode = vma->vm_file->f_path.dentry->d_inode; + struct gfs2_inode *ip = GFS2_I(inode); + struct gfs2_sbd *sdp = GFS2_SB(inode); + unsigned long last_index; + u64 pos = page->index << PAGE_CACHE_SHIFT; + unsigned int data_blocks, ind_blocks, rblocks; + int alloc_required = 0; + struct gfs2_holder gh; + struct gfs2_alloc *al; + int ret; + + gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &gh); + ret = gfs2_glock_nq(&gh); + if (ret) + goto out; + + set_bit(GLF_DIRTY, &ip->i_gl->gl_flags); + set_bit(GIF_SW_PAGED, &ip->i_flags); + + ret = gfs2_write_alloc_required(ip, pos, PAGE_CACHE_SIZE, &alloc_required); + if (ret || !alloc_required) + goto out_unlock; + ret = -ENOMEM; + al = gfs2_alloc_get(ip); + if (al == NULL) + goto out_unlock; + + ret = gfs2_quota_lock_check(ip); + if (ret) + goto out_alloc_put; + gfs2_write_calc_reserv(ip, PAGE_CACHE_SIZE, &data_blocks, &ind_blocks); + al->al_requested = data_blocks + ind_blocks; + ret = gfs2_inplace_reserve(ip); + if (ret) + 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; + ret = gfs2_trans_begin(sdp, rblocks, 0); + if (ret) + goto out_trans_fail; + + lock_page(page); + ret = -EINVAL; + last_index = ip->i_inode.i_size >> PAGE_CACHE_SHIFT; + if (page->index > last_index) + goto out_unlock_page; + ret = 0; + if (!PageUptodate(page) || page->mapping != ip->i_inode.i_mapping) + goto out_unlock_page; + if (gfs2_is_stuffed(ip)) { + ret = gfs2_unstuff_dinode(ip, page); + if (ret) + goto out_unlock_page; + } + ret = gfs2_allocate_page_backing(page); + +out_unlock_page: + unlock_page(page); + gfs2_trans_end(sdp); +out_trans_fail: + gfs2_inplace_release(ip); +out_quota_unlock: + gfs2_quota_unlock(ip); +out_alloc_put: + gfs2_alloc_put(ip); +out_unlock: + gfs2_glock_dq(&gh); +out: + gfs2_holder_uninit(&gh); + if (ret == -ENOMEM) + ret = VM_FAULT_OOM; + else if (ret) + ret = VM_FAULT_SIGBUS; + return ret; +} + +static struct vm_operations_struct gfs2_vm_ops = { + .fault = filemap_fault, + .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)) { + struct gfs2_holder i_gh; + int error; + + gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &i_gh); + error = gfs2_glock_nq(&i_gh); + file_accessed(file); + if (error == 0) + gfs2_glock_dq_uninit(&i_gh); + } + vma->vm_ops = &gfs2_vm_ops; + vma->vm_flags |= VM_CAN_NONLINEAR; + + return 0; +} + +/** + * gfs2_open - open a file + * @inode: the inode to open + * @file: the struct file for this opening + * + * Returns: errno + */ + +static int gfs2_open(struct inode *inode, struct file *file) +{ + struct gfs2_inode *ip = GFS2_I(inode); + struct gfs2_holder i_gh; + struct gfs2_file *fp; + int error; + + fp = kzalloc(sizeof(struct gfs2_file), GFP_KERNEL); + if (!fp) + return -ENOMEM; + + mutex_init(&fp->f_fl_mutex); + + gfs2_assert_warn(GFS2_SB(inode), !file->private_data); + file->private_data = fp; + + 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) + goto fail; + + if (!(file->f_flags & O_LARGEFILE) && + ip->i_disksize > MAX_NON_LFS) { + error = -EOVERFLOW; + goto fail_gunlock; + } + + gfs2_glock_dq_uninit(&i_gh); + } + + return 0; + +fail_gunlock: + gfs2_glock_dq_uninit(&i_gh); +fail: + file->private_data = NULL; + kfree(fp); + return error; +} + +/** + * gfs2_close - 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_close(struct inode *inode, struct file *file) +{ + struct gfs2_sbd *sdp = inode->i_sb->s_fs_info; + struct gfs2_file *fp; + + fp = file->private_data; + file->private_data = NULL; + + if (gfs2_assert_warn(sdp, fp)) + return -EIO; + + kfree(fp); + + return 0; +} + +/** + * gfs2_fsync - sync the dirty data for a file (across the cluster) + * @file: the file that points to the dentry (we ignore this) + * @dentry: the dentry that points to the inode to sync + * + * The VFS will flush "normal" data for us. We only need to worry + * about metadata here. For journaled data, we just do a log flush + * as we can't avoid it. Otherwise we can just bale out if datasync + * is set. For stuffed inodes we must flush the log in order to + * ensure that all data is on disk. + * + * The call to write_inode_now() is there to write back metadata and + * the inode itself. It does also try and write the data, but thats + * (hopefully) a no-op due to the VFS having already called filemap_fdatawrite() + * for us. + * + * Returns: errno + */ + +static int gfs2_fsync(struct file *file, struct dentry *dentry, int datasync) +{ + struct inode *inode = dentry->d_inode; + int sync_state = inode->i_state & (I_DIRTY_SYNC|I_DIRTY_DATASYNC); + int ret = 0; + + if (gfs2_is_jdata(GFS2_I(inode))) { + gfs2_log_flush(GFS2_SB(inode), GFS2_I(inode)->i_gl); + return 0; + } + + if (sync_state != 0) { + if (!datasync) + ret = write_inode_now(inode, 0); + + if (gfs2_is_stuffed(GFS2_I(inode))) + gfs2_log_flush(GFS2_SB(inode), GFS2_I(inode)->i_gl); + } + + return ret; +} + +#ifdef CONFIG_GFS2_FS_LOCKING_DLM + +/** + * gfs2_setlease - acquire/release a file lease + * @file: the file pointer + * @arg: lease type + * @fl: file lock + * + * We don't currently have a way to enforce a lease across the whole + * cluster; until we do, disable leases (by just returning -EINVAL), + * unless the administrator has requested purely local locking. + * + * Returns: errno + */ + +static int gfs2_setlease(struct file *file, long arg, struct file_lock **fl) +{ + return -EINVAL; +} + +/** + * 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 (__mandatory_lock(&ip->i_inode)) + return -ENOLCK; + + if (cmd == F_CANCELLK) { + /* Hack: */ + cmd = F_SETLK; + fl->fl_type = F_UNLCK; + } + if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags))) + 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->f_path.dentry->d_inode); + struct gfs2_glock *gl; + unsigned int state; + int flags; + int error = 0; + + state = (fl->fl_type == F_WRLCK) ? LM_ST_EXCLUSIVE : LM_ST_SHARED; + flags = (IS_SETLKW(cmd) ? 0 : LM_FLAG_TRY) | GL_EXACT | GL_NOCACHE; + + mutex_lock(&fp->f_fl_mutex); + + gl = fl_gh->gh_gl; + if (gl) { + if (fl_gh->gh_state == state) + goto out; + flock_lock_file_wait(file, + &(struct file_lock){.fl_type = F_UNLCK}); + gfs2_glock_dq_wait(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); + } + error = gfs2_glock_nq(fl_gh); + if (error) { + gfs2_holder_uninit(fl_gh); + if (error == GLR_TRYFAILED) + error = -EAGAIN; + } else { + error = flock_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); + flock_lock_file_wait(file, fl); + if (fl_gh->gh_gl) + gfs2_glock_dq_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 = do_sync_read, + .aio_read = generic_file_aio_read, + .write = do_sync_write, + .aio_write = generic_file_aio_write, + .unlocked_ioctl = gfs2_ioctl, + .mmap = gfs2_mmap, + .open = gfs2_open, + .release = gfs2_close, + .fsync = gfs2_fsync, + .lock = gfs2_lock, + .flock = gfs2_flock, + .splice_read = generic_file_splice_read, + .splice_write = generic_file_splice_write, + .setlease = gfs2_setlease, +}; + +const struct file_operations gfs2_dir_fops = { + .readdir = gfs2_readdir, + .unlocked_ioctl = gfs2_ioctl, + .open = gfs2_open, + .release = gfs2_close, + .fsync = gfs2_fsync, + .lock = gfs2_lock, + .flock = gfs2_flock, +}; + +#endif /* CONFIG_GFS2_FS_LOCKING_DLM */ + +const struct file_operations gfs2_file_fops_nolock = { + .llseek = gfs2_llseek, + .read = do_sync_read, + .aio_read = generic_file_aio_read, + .write = do_sync_write, + .aio_write = generic_file_aio_write, + .unlocked_ioctl = gfs2_ioctl, + .mmap = gfs2_mmap, + .open = gfs2_open, + .release = gfs2_close, + .fsync = gfs2_fsync, + .splice_read = generic_file_splice_read, + .splice_write = generic_file_splice_write, + .setlease = generic_setlease, +}; + +const struct file_operations gfs2_dir_fops_nolock = { + .readdir = gfs2_readdir, + .unlocked_ioctl = gfs2_ioctl, + .open = gfs2_open, + .release = gfs2_close, + .fsync = gfs2_fsync, +}; + |