From: Mohan Srinivasan Date: Fri, 3 Feb 2017 23:48:03 +0000 (-0800) Subject: ANDROID: Refactor fs readpage/write tracepoints. X-Git-Tag: release-20171130_firefly~4^2~100^2~244 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=db943372859b8acf8b99e258c0f2146238793e12;p=firefly-linux-kernel-4.4.55.git ANDROID: Refactor fs readpage/write tracepoints. Refactor the fs readpage/write tracepoints to move the inode->path lookup outside the tracepoint code, and pass a pointer to the path into the tracepoint code instead. This is necessary because the tracepoint code runs non-preemptible. Thanks to Trilok Soni for catching this in 4.4. Change-Id: I7486c5947918d155a30c61d6b9cd5027cf8fbe15 Signed-off-by: Mohan Srinivasan --- diff --git a/fs/ext4/inline.c b/fs/ext4/inline.c index 84da8fd0ab11..bc7c082b7913 100644 --- a/fs/ext4/inline.c +++ b/fs/ext4/inline.c @@ -503,8 +503,16 @@ int ext4_readpage_inline(struct inode *inode, struct page *page) return -EAGAIN; } - trace_android_fs_dataread_start(inode, page_offset(page), PAGE_SIZE, - current->pid, current->comm); + if (trace_android_fs_dataread_start_enabled()) { + char *path, pathbuf[MAX_TRACE_PATHBUF_LEN]; + + path = android_fstrace_get_pathname(pathbuf, + MAX_TRACE_PATHBUF_LEN, + inode); + trace_android_fs_dataread_start(inode, page_offset(page), + PAGE_SIZE, current->pid, + path, current->comm); + } /* * Current inline data can only exist in the 1st page, diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index 3b8a0b052988..1c733321b03c 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -1017,8 +1017,16 @@ static int ext4_write_begin(struct file *file, struct address_space *mapping, pgoff_t index; unsigned from, to; - trace_android_fs_datawrite_start(inode, pos, len, - current->pid, current->comm); + if (trace_android_fs_datawrite_start_enabled()) { + char *path, pathbuf[MAX_TRACE_PATHBUF_LEN]; + + path = android_fstrace_get_pathname(pathbuf, + MAX_TRACE_PATHBUF_LEN, + inode); + trace_android_fs_datawrite_start(inode, pos, len, + current->pid, path, + current->comm); + } trace_ext4_write_begin(inode, pos, len, flags); /* * Reserve one block more for addition to orphan list in case @@ -2745,8 +2753,16 @@ static int ext4_da_write_begin(struct file *file, struct address_space *mapping, len, flags, pagep, fsdata); } *fsdata = (void *)0; - trace_android_fs_datawrite_start(inode, pos, len, - current->pid, current->comm); + if (trace_android_fs_datawrite_start_enabled()) { + char *path, pathbuf[MAX_TRACE_PATHBUF_LEN]; + + path = android_fstrace_get_pathname(pathbuf, + MAX_TRACE_PATHBUF_LEN, + inode); + trace_android_fs_datawrite_start(inode, pos, len, + current->pid, + path, current->comm); + } trace_ext4_da_write_begin(inode, pos, len, flags); if (ext4_test_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA)) { @@ -3355,16 +3371,27 @@ static ssize_t ext4_direct_IO(struct kiocb *iocb, struct iov_iter *iter, return 0; if (trace_android_fs_dataread_start_enabled() && - (iov_iter_rw(iter) == READ)) + (iov_iter_rw(iter) == READ)) { + char *path, pathbuf[MAX_TRACE_PATHBUF_LEN]; + + path = android_fstrace_get_pathname(pathbuf, + MAX_TRACE_PATHBUF_LEN, + inode); trace_android_fs_dataread_start(inode, offset, count, - current->pid, + current->pid, path, current->comm); + } if (trace_android_fs_datawrite_start_enabled() && - (iov_iter_rw(iter) == WRITE)) + (iov_iter_rw(iter) == WRITE)) { + char *path, pathbuf[MAX_TRACE_PATHBUF_LEN]; + + path = android_fstrace_get_pathname(pathbuf, + MAX_TRACE_PATHBUF_LEN, + inode); trace_android_fs_datawrite_start(inode, offset, count, - current->pid, + current->pid, path, current->comm); - + } trace_ext4_direct_IO_enter(inode, offset, count, iov_iter_rw(iter)); if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) ret = ext4_ext_direct_IO(iocb, iter, offset); diff --git a/fs/ext4/readpage.c b/fs/ext4/readpage.c index 1ce24a6759a0..1c5db9fd9c8f 100644 --- a/fs/ext4/readpage.c +++ b/fs/ext4/readpage.c @@ -152,11 +152,17 @@ ext4_submit_bio_read(struct bio *bio) struct page *first_page = bio->bi_io_vec[0].bv_page; if (first_page != NULL) { + char *path, pathbuf[MAX_TRACE_PATHBUF_LEN]; + + path = android_fstrace_get_pathname(pathbuf, + MAX_TRACE_PATHBUF_LEN, + first_page->mapping->host); trace_android_fs_dataread_start( first_page->mapping->host, page_offset(first_page), bio->bi_iter.bi_size, current->pid, + path, current->comm); } } diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c index e692958d6e78..8936044dee4c 100644 --- a/fs/f2fs/data.c +++ b/fs/f2fs/data.c @@ -1402,8 +1402,16 @@ static int f2fs_write_begin(struct file *file, struct address_space *mapping, struct dnode_of_data dn; int err = 0; - trace_android_fs_datawrite_start(inode, pos, len, - current->pid, current->comm); + if (trace_android_fs_datawrite_start_enabled()) { + char *path, pathbuf[MAX_TRACE_PATHBUF_LEN]; + + path = android_fstrace_get_pathname(pathbuf, + MAX_TRACE_PATHBUF_LEN, + inode); + trace_android_fs_datawrite_start(inode, pos, len, + current->pid, path, + current->comm); + } trace_f2fs_write_begin(inode, pos, len, flags); f2fs_balance_fs(sbi); @@ -1587,15 +1595,27 @@ static ssize_t f2fs_direct_IO(struct kiocb *iocb, struct iov_iter *iter, trace_f2fs_direct_IO_enter(inode, offset, count, iov_iter_rw(iter)); if (trace_android_fs_dataread_start_enabled() && - (iov_iter_rw(iter) == READ)) + (iov_iter_rw(iter) == READ)) { + char *path, pathbuf[MAX_TRACE_PATHBUF_LEN]; + + path = android_fstrace_get_pathname(pathbuf, + MAX_TRACE_PATHBUF_LEN, + inode); trace_android_fs_dataread_start(inode, offset, - count, current->pid, + count, current->pid, path, current->comm); + } if (trace_android_fs_datawrite_start_enabled() && - (iov_iter_rw(iter) == WRITE)) - trace_android_fs_datawrite_start(inode, offset, count, - current->pid, current->comm); + (iov_iter_rw(iter) == WRITE)) { + char *path, pathbuf[MAX_TRACE_PATHBUF_LEN]; + path = android_fstrace_get_pathname(pathbuf, + MAX_TRACE_PATHBUF_LEN, + inode); + trace_android_fs_datawrite_start(inode, offset, count, + current->pid, path, + current->comm); + } if (iov_iter_rw(iter) == WRITE) { __allocate_data_blocks(inode, offset, count); if (unlikely(f2fs_cp_error(F2FS_I_SB(inode)))) { diff --git a/fs/f2fs/inline.c b/fs/f2fs/inline.c index d2c5d69ba0b1..dbb2cc4df603 100644 --- a/fs/f2fs/inline.c +++ b/fs/f2fs/inline.c @@ -85,9 +85,16 @@ int f2fs_read_inline_data(struct inode *inode, struct page *page) { struct page *ipage; - trace_android_fs_dataread_start(inode, page_offset(page), - PAGE_SIZE, current->pid, - current->comm); + if (trace_android_fs_dataread_start_enabled()) { + char *path, pathbuf[MAX_TRACE_PATHBUF_LEN]; + + path = android_fstrace_get_pathname(pathbuf, + MAX_TRACE_PATHBUF_LEN, + inode); + trace_android_fs_dataread_start(inode, page_offset(page), + PAGE_SIZE, current->pid, + path, current->comm); + } ipage = get_node_page(F2FS_I_SB(inode), inode->i_ino); if (IS_ERR(ipage)) { diff --git a/fs/mpage.c b/fs/mpage.c index 5c65d8942692..0fd48fdcc1b1 100644 --- a/fs/mpage.c +++ b/fs/mpage.c @@ -79,11 +79,17 @@ static struct bio *mpage_bio_submit(int rw, struct bio *bio) struct page *first_page = bio->bi_io_vec[0].bv_page; if (first_page != NULL) { + char *path, pathbuf[MAX_TRACE_PATHBUF_LEN]; + + path = android_fstrace_get_pathname(pathbuf, + MAX_TRACE_PATHBUF_LEN, + first_page->mapping->host); trace_android_fs_dataread_start( first_page->mapping->host, page_offset(first_page), bio->bi_iter.bi_size, current->pid, + path, current->comm); } } diff --git a/include/trace/events/android_fs.h b/include/trace/events/android_fs.h index 531da433a7bc..49509533d3fa 100644 --- a/include/trace/events/android_fs.h +++ b/include/trace/events/android_fs.h @@ -9,8 +9,8 @@ DEFINE_EVENT(android_fs_data_start_template, android_fs_dataread_start, TP_PROTO(struct inode *inode, loff_t offset, int bytes, - pid_t pid, char *command), - TP_ARGS(inode, offset, bytes, pid, command)); + pid_t pid, char *pathname, char *command), + TP_ARGS(inode, offset, bytes, pid, pathname, command)); DEFINE_EVENT(android_fs_data_end_template, android_fs_dataread_end, TP_PROTO(struct inode *inode, loff_t offset, int bytes), @@ -18,14 +18,48 @@ DEFINE_EVENT(android_fs_data_end_template, android_fs_dataread_end, DEFINE_EVENT(android_fs_data_start_template, android_fs_datawrite_start, TP_PROTO(struct inode *inode, loff_t offset, int bytes, - pid_t pid, char *command), - TP_ARGS(inode, offset, bytes, pid, command)); + pid_t pid, char *pathname, char *command), + TP_ARGS(inode, offset, bytes, pid, pathname, command)); DEFINE_EVENT(android_fs_data_end_template, android_fs_datawrite_end, TP_PROTO(struct inode *inode, loff_t offset, int bytes), - TP_ARGS(inode, offset, bytes)); + TP_ARGS(inode, offset, bytes)); #endif /* _TRACE_ANDROID_FS_H */ /* This part must be outside protection */ #include + +#ifndef ANDROID_FSTRACE_GET_PATHNAME +#define ANDROID_FSTRACE_GET_PATHNAME + +/* Sizes an on-stack array, so careful if sizing this up ! */ +#define MAX_TRACE_PATHBUF_LEN 256 + +static inline char * +android_fstrace_get_pathname(char *buf, int buflen, struct inode *inode) +{ + char *path; + struct dentry *d; + + /* + * d_obtain_alias() will either iput() if it locates an existing + * dentry or transfer the reference to the new dentry created. + * So get an extra reference here. + */ + ihold(inode); + d = d_obtain_alias(inode); + if (likely(!IS_ERR(d))) { + path = dentry_path_raw(d, buf, buflen); + if (unlikely(IS_ERR(path))) { + strcpy(buf, "ERROR"); + path = buf; + } + dput(d); + } else { + strcpy(buf, "ERROR"); + path = buf; + } + return path; +} +#endif diff --git a/include/trace/events/android_fs_template.h b/include/trace/events/android_fs_template.h index 618988b047c1..4e61ffe7a814 100644 --- a/include/trace/events/android_fs_template.h +++ b/include/trace/events/android_fs_template.h @@ -5,11 +5,10 @@ DECLARE_EVENT_CLASS(android_fs_data_start_template, TP_PROTO(struct inode *inode, loff_t offset, int bytes, - pid_t pid, char *command), - TP_ARGS(inode, offset, bytes, pid, command), + pid_t pid, char *pathname, char *command), + TP_ARGS(inode, offset, bytes, pid, pathname, command), TP_STRUCT__entry( - __array(char, path, MAX_FILTER_STR_VAL); - __field(char *, pathname); + __string(pathbuf, pathname); __field(loff_t, offset); __field(int, bytes); __field(loff_t, i_size); @@ -19,27 +18,7 @@ DECLARE_EVENT_CLASS(android_fs_data_start_template, ), TP_fast_assign( { - struct dentry *d; - - /* - * Grab a reference to the inode here because - * d_obtain_alias() will either drop the inode - * reference if it locates an existing dentry - * or transfer the reference to the new dentry - * created. In our case, the file is still open, - * so the dentry is guaranteed to exist (connected), - * so d_obtain_alias() drops the reference we - * grabbed here. - */ - ihold(inode); - d = d_obtain_alias(inode); - if (!IS_ERR(d)) { - __entry->pathname = dentry_path(d, - __entry->path, - MAX_FILTER_STR_VAL); - dput(d); - } else - __entry->pathname = ERR_PTR(-EINVAL); + __assign_str(pathbuf, pathname); __entry->offset = offset; __entry->bytes = bytes; __entry->i_size = i_size_read(inode); @@ -50,9 +29,8 @@ DECLARE_EVENT_CLASS(android_fs_data_start_template, ), TP_printk("entry_name %s, offset %llu, bytes %d, cmdline %s," " pid %d, i_size %llu, ino %lu", - (IS_ERR(__entry->pathname) ? "ERROR" : __entry->pathname), - __entry->offset, __entry->bytes, __get_str(cmdline), - __entry->pid, __entry->i_size, + __get_str(pathbuf), __entry->offset, __entry->bytes, + __get_str(cmdline), __entry->pid, __entry->i_size, (unsigned long) __entry->ino) );