cregit-Linux how code gets into the kernel

Release 4.10 fs/gfs2/file.c

Directory: fs/gfs2
 * 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/falloc.h>
#include <linux/swap.h>
#include <linux/crc32.h>
#include <linux/writeback.h>
#include <linux/uaccess.h>
#include <linux/dlm.h>
#include <linux/dlm_plock.h>
#include <linux/delay.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"

 * 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: /* These reference inode->i_size */ case SEEK_DATA: case SEEK_HOLE: 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_CUR: case SEEK_SET: error = generic_file_llseek(file, offset, whence); break; default: error = -EINVAL; } return error; }


david teiglanddavid teigland8771.31%120.00%
steven whitehousesteven whitehouse2923.77%240.00%
andrew mortonandrew morton43.28%120.00%
andi kleenandi kleen21.64%120.00%

/** * 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; }


david teiglanddavid teigland6370.00%114.29%
steven whitehousesteven whitehouse1516.67%457.14%
al viroal viro77.78%114.29%
robert s. petersonrobert s. peterson55.56%114.29%

/** * 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; }


steven whitehousesteven whitehouse46100.00%1100.00%

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, [17] = GFS2_DIF_TOPDIR, }; 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_TopLevel] = FS_TOPDIR_FL, [gfs2fl_InheritJdata] = FS_JOURNAL_DATA_FL, };
static int gfs2_get_flags(struct file *filp, u32 __user *ptr) { struct inode *inode = file_inode(filp); 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) goto out_uninit; 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); out_uninit: gfs2_holder_uninit(&gh); return error; }


steven whitehousesteven whitehouse12994.16%1083.33%
daniel defreezdaniel defreez53.65%18.33%
al viroal viro32.19%18.33%

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; }


steven whitehousesteven whitehouse12099.17%375.00%
benjamin marzinskibenjamin marzinski10.83%125.00%

/* 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_TOPDIR| \ GFS2_DIF_INHERIT_JDATA) /** * do_gfs2_set_flags - set flags on an inode * @filp: file pointer * @reqflags: 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 = file_inode(filp); 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_file(filp); if (error) return error; error = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &gh); if (error) goto out_drop_write; error = -EACCES; if (!inode_owner_or_capable(inode)) goto out; error = 0; 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, NORMAL_FLUSH); 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_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); out_drop_write: mnt_drop_write_file(filp); return error; }


steven whitehousesteven whitehouse38792.58%1266.67%
miklos szeredimiklos szeredi235.50%15.56%
al viroal viro51.20%316.67%
benjamin marzinskibenjamin marzinski20.48%15.56%
serge hallynserge hallyn10.24%15.56%

static int gfs2_set_flags(struct file *filp, u32 __user *ptr) { struct inode *inode = file_inode(filp); u32 fsflags, gfsflags; if (get_user(fsflags, ptr)) return -EFAULT; gfsflags = fsflags_cvt(fsflags_to_gfs2, fsflags); if (!S_ISDIR(inode->i_mode)) { gfsflags &= ~GFS2_DIF_TOPDIR; if (gfsflags & GFS2_DIF_INHERIT_JDATA) gfsflags ^= (GFS2_DIF_JDATA | GFS2_DIF_INHERIT_JDATA); return do_gfs2_set_flags(filp, gfsflags, ~GFS2_DIF_SYSTEM); } return do_gfs2_set_flags(filp, gfsflags, ~(GFS2_DIF_SYSTEM | GFS2_DIF_JDATA)); }


steven whitehousesteven whitehouse10292.73%675.00%
abhijith dasabhijith das54.55%112.50%
al viroal viro32.73%112.50%

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); case FITRIM: return gfs2_fitrim(filp, (void __user *)arg); } return -ENOTTY; }


steven whitehousesteven whitehouse77100.00%5100.00%

/** * 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_res.rs_sizehint)) atomic_set(&ip->i_res.rs_sizehint, hint); }


steven whitehousesteven whitehouse8883.02%125.00%
robert s. petersonrobert s. peterson1514.15%250.00%
al viroal viro32.83%125.00%

/** * 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_SIZE; u64 lblock = page->index << (PAGE_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; }


steven whitehousesteven whitehouse11196.52%133.33%
robert s. petersonrobert s. peterson21.74%133.33%
kirill a. shutemovkirill a. shutemov21.74%133.33%

/** * gfs2_page_mkwrite - Make a shared, mmap()ed, page writable * @vma: The virtual memory area * @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 int gfs2_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf) { struct page *page = vmf->page; struct inode *inode = file_inode(vma->vm_file); struct gfs2_inode *ip = GFS2_I(inode); struct gfs2_sbd *sdp = GFS2_SB(inode); struct gfs2_alloc_parms ap = { .aflags = 0, }; unsigned long last_index; u64 pos = page->index << PAGE_SHIFT; unsigned int data_blocks, ind_blocks, rblocks; struct gfs2_holder gh; loff_t size; int ret; sb_start_pagefault(inode->i_sb); ret = gfs2_rsqa_alloc(ip); if (ret) goto out; gfs2_size_hint(vma->vm_file, pos, PAGE_SIZE); gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &gh); ret = gfs2_glock_nq(&gh); if (ret) goto out_uninit; /* Update file times before taking page lock */ file_update_time(vma->vm_file); set_bit(GLF_DIRTY, &ip->i_gl->gl_flags); set_bit(GIF_SW_PAGED, &ip->i_flags); if (!gfs2_write_alloc_required(ip, pos, PAGE_SIZE)) { lock_page(page); if (!PageUptodate(page) || page->mapping != inode->i_mapping) { ret = -EAGAIN; unlock_page(page); } goto out_unlock; } ret = gfs2_rindex_update(sdp); if (ret) goto out_unlock; gfs2_write_calc_reserv(ip, PAGE_SIZE, &data_blocks, &ind_blocks); = data_blocks + ind_blocks; ret = gfs2_quota_lock_check(ip, &ap); if (ret) goto out_unlock; ret = gfs2_inplace_reserve(ip, &ap); 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; rblocks += gfs2_rg_blocks(ip, data_blocks + ind_blocks); } ret = gfs2_trans_begin(sdp, rblocks, 0); if (ret) goto out_trans_fail; lock_page(page); ret = -EINVAL; size = i_size_read(inode); last_index = (size - 1) >> PAGE_SHIFT; /* Check page index against inode size */ if (size == 0 || (page->index > last_index)) goto out_trans_end; ret = -EAGAIN; /* If truncated, we must retry the operation, we may have raced * with the glock demotion code. */ if (!PageUptodate(page) || page->mapping != inode->i_mapping) goto out_trans_end; /* Unstuff, if required, and allocate backing blocks for page */ ret = 0; if (gfs2_is_stuffed(ip)) ret = gfs2_unstuff_dinode(ip, page); if (ret == 0) ret = gfs2_allocate_page_backing(page); out_trans_end: if (ret) unlock_page(page); 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 == 0) { set_page_dirty(page); wait_for_stable_page(page); } out: sb_end_pagefault(inode->i_sb); return block_page_mkwrite_return(ret); }


steven whitehousesteven whitehouse46483.45%1242.86%
robert s. petersonrobert s. peterson305.40%828.57%
abhijith dasabhijith das173.06%13.57%
nick pigginnick piggin152.70%13.57%
andreas gruenbacherandreas gruenbacher81.44%13.57%
benjamin marzinskibenjamin marzinski81.44%13.57%
jan karajan kara50.90%13.57%
kirill a. shutemovkirill a. shutemov50.90%13.57%
al viroal viro30.54%13.57%
darrick j. wongdarrick j. wong10.18%13.57%

static const struct vm_operations_struct gfs2_vm_ops = { .fault = filemap_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; }


steven whitehousesteven whitehouse9490.38%583.33%
benjamin marzinskibenjamin marzinski109.62%116.67%

/** * 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; return 0; }


steven whitehousesteven whitehouse5856.86%583.33%
david teiglanddavid teigland4443.14%116.67%

/** * 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; }


steven whitehousesteven whitehouse5353.00%266.67%
david teiglanddavid teigland4747.00%133.33%

/** * 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 (!(file->f_mode & FMODE_WRITE)) return 0; gfs2_rsqa_delete(ip, &inode->i_writecount); return 0; }


robert s. petersonrobert s. peterson3045.45%562.50%
david teiglanddavid teigland2639.39%112.50%
steven whitehousesteven whitehouse1015.15%225.00%

/** * 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_ALL; 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 | I_DIRTY_TIME); if (sync_state) { ret = sync_inode_metadata(inode, 1); if (ret) return ret; if (gfs2_is_jdata(ip)) filemap_write_and_wait(mapping); gfs2_ail_flush(ip->i_gl, 1); } if (mapping->nrpages) ret = filemap_fdatawait_range(mapping, start, end); return ret ? ret : ret1; }


steven whitehousesteven whitehouse12465.96%758.33%
david teiglanddavid teigland2111.17%18.33%
josef bacikjosef bacik2111.17%18.33%
benjamin marzinskibenjamin marzinski136.91%18.33%
theodore tsotheodore tso52.66%18.33%
christoph hellwigchristoph hellwig42.13%18.33%

/** * gfs2_file_write_iter - Perform a write to a file * @iocb: The io context * @iov: The data to write * @nr_segs: Number of @iov segments * @pos: The file position * * 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 gfs2_inode *ip = GFS2_I(file_inode(file)); int ret; ret = gfs2_rsqa_alloc(ip); if (ret) return ret; gfs2_size_hint(file, iocb->ki_pos, iov_iter_count(from)); if (iocb->ki_flags & IOCB_APPEND) { struct gfs2_holder gh; ret = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, 0, &gh); if (ret) return ret; gfs2_glock_dq_uninit(&gh); } return generic_file_write_iter(iocb, from); }


steven whitehousesteven whitehouse7461.67%225.00%
robert s. petersonrobert s. peterson2722.50%337.50%
al viroal viro1915.83%337.50%

static int fallocate_chunk(struct inode *inode, loff_t offset, loff_t len, int mode) { struct gfs2_inode *ip = GFS2_I(inode); struct buffer_head *dibh; int error; unsigned int nr_blks; sector_t lblock = offset >> inode->i_blkbits; 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, NULL); if (unlikely(error)) goto out; } while (len) { struct buffer_head bh_map = { .b_state = 0, .b_blocknr = 0 }; bh_map.b_size = len;